Thank you so much for putting this information on RUclips. I have recently purchased this camera, OSC, as an addition to my ASI 2600MM, which has gone back to China for a repair, because of the infamous, "oil streaks" over the sensor. I decided to purchase a OSC camera, just to be a bit lazy and use it until my 2600MM is returned. I have really struggled with this camera, my 2600MM, with LRGB and HSO imaging was far easier in comaprison. The points I have taken from you are: NO bias frames. More than 3 seconds exposure,. And I have used your workflow diagrams. WHAT A TRANSFORMATION!!! Thank you so much, and I hope lots more people will see this, as I am sure they will have exprienced these issues. I now agree with you that this is indeed a great camera. Keith Dutton - England UK 😁
As someone who has owned the 294MM Pro for a few years now, I'm well acquainted with the rather finicky nature of the beast. The research thread you mentioned from CN - I did all the work for the 294MM Pro, where John (jdupton) did it for the 294MC. What we discovered was the responses were extremely similar between both the IMX294 and IMX492 sensors. I have done all manner of experimentation, trying to find the best method for calibrating data from this camera. I've used dedicated flat panels (the FlatMaster from Pegasus), high CRI video lights from Elgato, Aputure and others, CFL fixtures, incandescent bulbs, halogen bulbs, LED bulbs. I've also used multiple different diffusion materials from professional backdrops to tee shirts. Here's a summary of what has worked best for me: 1. ALWAYS match your flats to your lights in terms of gain, offset, temperature and binning. Many people will tell you it doesn't matter. It might not on other sensors. It does with the 294 series. 2. Take long exposures. If you look closely at the research John and I did, you might conclude that you can take flats less than 1 second. In fact, John even mentions that it's possible as long as you're extremely careful to exactly match everything. I avoid it altogether and take exposures of at least 3 seconds. More typically, I'm taking 5 second flats for broadband and upwards of 30-90 second flats for narrowband. 3. I use indirect lighting. Through all of my tests of different lights and diffusion materials, I found the best flats come from when I bounce light off of my garage walls (painted a flat white), rather than pointing the scope directly to the light source. This is true with both my GT81 and my EdgeHD. 4. Light source matters. You mention this as well. You simply cannot use your iPad as the light source for flats. Use a well-balanced light. 5. Certain gains are problematic. This one took me by surprise, but the research done by Dr Robin Glover (SharpCap) is rather convincing. The 294 series sensor seems to misbehave right around gain 0 and also right around gain 120, where the camera kicks into HCG mode (for the ASI versions... I'm not sure equivalent in QHY/Altair/etc) in the default mode (i.e. bin2, 11MP mode). In my particular case, in the default (bin2 mode), I cannot shoot my lights at gain 0 or gain 120. Instead, I must shoot at gain 8 or gain 137. Using the unlocked (bin1, 46MP) mode, the issue goes away at any gain 12 and higher because the camera is always in HCG mode. Your mileage will vary, so it would be smart to run tests using SharpCap to figure out values that work for you and your particular camera. To James' (DSO Imager) point in his comment, I also mostly suffered with the green filter. In fact, I purchased multiple brands of filters trying to solve it: Astrodon, Chroma, ZWO, Antlia. Using the above process, my calibration issues have gone away.
yup its def about attention to detail with the 294 - and yes the 294MM suffers similarly and you can tame it using the same process and approach - then it behaves :) Gains ... yes I regularly see people using gain 0 with these cameras and then suffering from banding / noise in them. I've not come across the gain 120 issue TBH but its certainly worth noting and def do some tests and QA checks of darks and flats! good feedback and info ! thanks Simon
Hey Jonny, i have taken notes from your research, since i own a 294mm myself. Could you explain what you mean with a well balanced light? What is a well balanced light for an example?
@@Backcorner_Astronomy by well balanced, I mean one that has relatively equal signal strength in R, G and B. An iPad is a poor choice as a light source for flats. I've got an Elgato Key Light Air (bought it a few years ago for streaming) that works pretty well. I've got some portable lights by Aputure that I use. I've got a FlatMaster 150 by Pegasus that I use with my GT81. I haven't tried a Spike-a Flat, but quite a few people swear by them. What I've found that works the best is to use indirect lighting. I light my garage wall pretty evenly with the Key Light and the portable Aputure lights. I then stretch a white cotton tee shirt over the scope and point it to the evenly lit wall. While it shouldn't matter (math), I tend to keep my ADU around 25K.
@@JonnyBravo0311 Very interesting. I have looked at the flatmaster 250 because i have a 8” newt. But it is extremely expensive. At the moment i use a tracing pad that has 3 brightness’s. But the flats are not very consistent. Maybe it’s worth to shell out the cash to buy a flat panel. I do have to use it directly on to the scope because i don’t have a room with white walls. Aaaah the never ending money pit 😉
@@Backcorner_Astronomy I looked at the 250 as well for nearly the same reason: I've got an 8" EdgeHD. I also balked at the asking price. Out of curiosity, what gain do you typically use? Take a look at Robin Glover's post about flats with the 294MC over on the SharpCap forums. He made a very interesting discovery about how the sensor behaves. It was point 5 in my initial comment. I ended up changing the gains at which I shoot from 0 and 120 in the "default" (i.e. 11MP) mode to 8 and 137. If you do end up buying the FM250, I'd love to know how it works out for you.
Excellent presentation! I can't understand why you have only a few hundred subscribers. I'm a 294MC pro owner and very much appreciated the well presented steps to achieve good results with the camera. My experience with the 294MC Pro in combination with a ZWO Duo Band filter has been OK but I always wondered why my flats always ended up with a blue cast on one side and a red one on the other. Correcting an uneven cast in the stacked image in post processing surely reduced the dynamic range of my images from the start. I will be pointing this video out in my circle and hope to see many more videos from you.
Hi Bernard - thank you for your kind comments ... well we are still building our channel and still adding content - we only have been running for a few months but you can be sure we will keep aiming to help users with these kind of issues and creating this kind of content for you. Thank you and we appreciate the feedback - it helps after spending time putting these together :) rgds Simon
I've owned the 294MC Pro for about 6 months, and over time I've learned all these tips. It can definitely produce beautiful images if used properly. One of the technical reasons not to use bias frames is that this camera sensor gets inconsistent results at VERY short exposure lengths. I've had much success taking longer exposure flats along with dark flats. My only challenge during that time is normally I take flats in the morning and making sure there are no light leaks for the dark flats can be a challenge. Having said that it's a wonderful camera and sensor.
Hi there. I have been using the ASI294MC Pro for a long time and still am. It is indeed a wonderful camera and I am very happy with it. I too experienced 'issues' with using the L-eXtreme/eNhance filters, but shooting flats indeed is a necessity. I use a very cheap drawing pad for it which is dimmable in three levels. This is usually good enough especially when I dim it further down by wrapping the A4-sized drawing pad in a white t-shirt. Reason for me doing that is the seemingly ridiculous pricing on flat panels. I am sure there are good explanations for that (such as the balance of the colors as you mention).
Just regarding the work done by J D Upton that is referenced here as the reason for shooting flats of 3 seconds or longer, J D Upton himself provided some further clarification to that on Cloudy Nights in April 2021 on a forum post entitled "ASI294MC Pro flats". Commenting on the common recommendation for 2-3 second flats on this camera, he said " You can blame me for that recommendation. So long as you are careful about matching a set of Flat-Dark frames to your Flat frames, then you will not have trouble. You can shoot at less than 3 seconds exposure. It is best to not use Bias frames in general to calibrate the Flats with this camera. (The exception is very short Flat Frames. If you can shoot Flats at less than about 1/4 second exposure, you can calibrate the Flat with a (real / zero duration) Bias. Otherwise use Flat-Dark frames matching the Flats to calibrate your Flats.)"
thanks - the 294 is a great series and it won't take much to tame ... buying the flat panel is totally the best advice I can give - they make life so much easier plus with the use of dark frame calibration to remove amp glow means you can nail it easy with nothing else than a bit of knowledge :) DO let me know how you get on!
I had the same problem with my sii frames until I posted a new topic in astrobin and someone stated that I have something wrong with my flat. I tried to increase the exposure time from 2sec to 4.5 at %50 ADU and it works good now. thank you for the video I wish I knew that before
Thanks Simon! I use a 294 mc pro. When taking my flats I set a ($300!!) German-made light panel on top of my dew shield while pointing the scope straight up. (My 294mc is attached to my Hyperstar at the front of the scope.) I set the 294 exposure to 3 seconds and keep my gain the same as my lights. BUT when I take the flats even at a very low light setting, I get histograms that are off the chart. So in order to get the ADU down to around 28k I place 3 light-filter papers underneath my panel. (I have not been cooling the camera so I'll start doing that now based on your rec.) I use PI to calibrate and process my subs and use a 3 sec master dark flat to calibrate my flats. Yet, somehow, I'm still getting gradients, dust bunnies, etc. I use DBE to get as much out as I can but I'm still not happy with the results. Folks online say it's all in my flats, some even suggesting going to a low 0.25 seconds to shoot the flats. I also look at the histograms of the flats before placing them in PI to ensure they are in the correct ADU zone. Do you have any other suggestions? I've had a few folks suggest not using the filter paper. Maybe the filter you refer to in this video would be better? Thanks Again
Great video! Glad it justifies my use of a dimmable flat panel, no bias frames, use of dark flats and cooling for all frames with the 294 MC pro. I like the camera though when using it with an Optolong Extreme I do sometimes have to work hard on gradient issues in post processing. I would like to see a video on how to clean filters and the 294 sensor. This channel is one of the most helpful on view, with clear practical advice. Many thanks!
That sounds like a fabulous idea - cleaning filters and sensors - we can do that!! Will def do that for you. the 294 is a great camera still love mine! And thanks for the feedback thats what we aim for - practical advice and honest ones too ! :)
Good choice! The panel was my key to success to be honest! Once I used a panel I never encountered issues calibrating any camera - in fact a local had issues with his QHY camera too and we narrowed it down to his flats and using my flat panel for flats nailed it first time!
I find that my 294mc pro behaves very nicely under a dark sky (Bortle 1\2) but seems 'noisy' at Bortle 4/5. I have been taking short exposure flats of less than one second with an el panel I made up but I'll try darkening the panel with paper or something to get the exposures longer. It's good to see these explanations without drama, just some clear information to try out to see if it solves the problem. Many thanks for the video.
Nice. I'm waiting to give my new 294MM-Pro the first lights and I was already following these tips with my 1600MM-Pro so that will not change the game for me. 👍
awesome - I'm just waiting for some better weather - sick of cloud / rain this spring and now into summer :( still get loads of support tickets for these cameras so was a very long overdue video prompted by these !
Any news on this yet? “We have been made aware that Spike A Flat has been discontinued since this video was produced - we are looking at suitable alternative.”
I just got the Svbony version of the 294, the SV405CC, and I spent the last few hours trying to get the calibration sorted. I was thrown off by Siril, and their article _"Enough with dark flats"_ and the fact that the Siril program seems to insist on you using bias files instead. So I went through a lot of trial and error trying to use bias files, and the results kept ending up worse than using no calibration files at all. But after using your method here, and dumping the bias files, I finally got a good result without any of those weird shadows at the sides, and my master-flat finally removed the few dust spots that are somewhere in my rig. It was also a kind of a eureka moment when I realised that I had to calibrate the flats using the "dark" checkbox instead of the "bias" checkbox when calibrating in Siril.. which became blatantly obvious as soon as I thought about it! I think I'm on the right track now, thanks!
@@TeamAstroworkz AndyofAstro Did a vid on the SV405CC, The issue may not be what you think. There is an issue when the sensor flips to HCG mode. The first few gain steps have issues. Dr Robin Glover mentioned this in a post on Cloudy Nights, I think they flip to HCG at gain 120. But you need to be over 150 ish to not have the issue. You can get test to get the exact value
Late in coming but thank you Simon for another informative video. QQ: What do you use to create your Master files? Would DeepSky Stacker (DSS) work for the Dark, DarkFlats, and Flat frames running each group separately?
Thanks Simon for this video . I have this camera, never knew not to use bias frames .also I'm going to invest into a flat panel with a dimmer switch. I'm Currently using the white t shirt method. Reading all the comments is also helpful. Your channel is way under subscribed. Top content , very professional . Thanks again Simon.
Glad it was helpful! well we are pretty new it takes time to build a base but we will get there! People sharing videos and showing others the content will grow us slowly - and thanks for the feedback thats very much appreciated! Wer are also trying to find more cost effective panels .... I had no idea the Spike A Flat had gotten so expensive .. no idea why ... thats another mission we are on... to find a good cheaper option!
Hi Simon, It looks like I have a lot to learn, I have only just purchased the ZWO ASI294MC Pro color (S/H) for my Saxon 127. I did quite a lot of research on this camera and found it would match up with the Saxon okay. The only problem is that I cant see through the clouds to get any photos yet. I will be putting this video in my Astro video file for future reference. Great video content just what a newbee wants, and a good lot of hints in the comments as well. Cheers Robert Aust'
Thank you for this great video. I’ve only had the 294 and luckily have been following your advice, producing great images. Any chance you could explain how to creat master darks, etc. I’ve never grasped the concept and process of creating masters.
yes - they are just very short darks - so capture them the same was as normal darks - ie with the camera off the scope or on the scope and well covered so no light can get to the sensor, have it cooled and running as normal, then capture darks the same length as your flats. The process guide I uploaded will show you how to use them to calibrate the flats and use them in your processing software but sounds like we need a longer video on calibration frames :)
How about ASI294MC and ASI AIR Plus in EAA? I see there are some options in the app but haven’t an idea of how to use them. I just bought a light panel. Does all the calibration happen in the ASI Air+ at the time of the EAA?
Very useful video. I've been running a 294mm with my edge for some time.. but do occasionally run into problems with flat frames.. specifically with the green filter.. and some times the blue.. the issue looks like a faint reflection coming off the central obstruction (using with an 8" Edge). I'm certain the issue is with the flats because I can see this artifact in the master flat. I've been doing sky flats this whole time. Looks like I'll need to bite the bullet and invest in a light panel. Do you have a suggested alternative to the Spike A? Something that's smaller and less expensive? Thanks and CS!
Tyler and I are going to do a review of other flat panels on the market - the issue for the Edge 8 will be size ... but Deepsky Dad, Baader, Artesky, Primaluce etc all sell them
I've always struggled with my images from my 294MC Pro, so thank you for this video. Also, what about the ASI 2600MC Pro? Should I use this method on that camera too, or is it better to do the standard flats, darks, and bias frames with that camera?
Fantastic video, Simon. Is it necessary to have flats or darks taken using the same filter used to take the lights or should I be removing the filter I’m used from the holder before taking my darks and flats? I realize the back focus needs to remain identical , however. Again, great tutorial.
the darks of course wont matter as they as are darks, but the flats should match those lights using the same filters, as thats what you are trying to calibrate. Glad you enjoyed the video :) Yell out it you have any more questions :)
normally gain 120 is a good spot offset is default 30 but you can safely use the automatic settings in the ascom drivers vs using the expert mode - if using an ASIAR there is no ability to change the offset
Love the information, format and execution of your videos. You can see the effort that was put into it. Please keep these going. I have been running a 294mc pro for over a year with good success using 5sec flats at the same temp as my lights and darks, while also using dark flats. My only difference is I was using bias and running my flats at 30k-32k ADU (ASIair histogram). My next image I will process with 28k ADU and no bias and see what happens. I’m in the process of upgrading my OSC filters from my Baader Moon/SkyGlow & ZWO Duo. You say Optolong coatings have compatibility issues with the coatings on the 294. What Broadband and Dual/Tri-Band filters work well with the 294 under Bortle 5-6 Skies?
thanks for the great feedback - it takes a LOT of work to create these so thanks it makes the effort worthwhile :) its not vendor specific TBH - just the interaction of the sensor and these narrowband filters - I have an Antlia ALP-T does exact the same :) - for broadband the L-Pro seems the goto one - Tyler uses them - I live in Bortle 2-3 so no need for them but he seems to get good results - The ALP-T is a nice one so far - look out for our ALP-T vs L-Ultimate shoot out coming soon :)
it can be hit and miss Ben - some people don't have issues others terrible problems using them ... these tips here are generally give reliable results to most which is why they exist :) I still get people emailing me with issues though so its also down to technique and skill too and also what software too sometimes ... you need to be able to manipulate calibration files easily
@@TeamAstroworkz I am happy to report that sky flats work quite well. A friend of mine who had the flats issue said I got lucky and must have a good camera. :)
Interesting video thank you. I use an Altair Astro 294c, so assume this still relates to me as well? I use an artist A4 light panel bought from Amazon to get my flats and go for 2 sec eposures, would you recommend increasing this to 3 seconds? I have stacked in APP but do get colour gradients in my master flat but have now bought PixInsight so will try in there too. Can you please tell me what the settings are that you refer to in PI?
Hi Julian - yes likely it will relate to the Altair Astro 294 as well as the sensors are all the same. You can try slightly longer flats if you can dim the panel or use some good paper inbetween it and the scope - In pixisight ... you want to be doing manual calibration .... so following the guide ....when you come to image calibrate its going to ask what dark etc you want to calibrate with so you choose the master you created in the first steps and then make sure you calibrate only - untick the box that says optimisation - I will add some settings into a guide and add the in the description over the holidays so people can see the steps
@@TeamAstroworkz I am new to PixInsight so I would love to hear how you would calibrate your flats for greatest effect. I do have the ASI294 but have been using my ASI533 more frequently partly due to flats.
I'll try nail this in the next few days - we were trying to avoid turning the channel into a pixinsight page but I can do a downloadable guide for the key settings and process as an accompaniment guide to the video :)
As a follow up, I just tried to increase my flats to 3 seconds and now see horizontal banding across them, so I tried 2.5 secs where the banding disappeared. So will cap at 2.5s.
Great video, Simon. If my panel is out of balance, can I use my capture software - SharpCap - to adjust them so they are in balance and proceed from there ? And I suspect you disagree with Robin Glover that flats should be monochrome - at least for the ASI294.
unfortunately not - its really about the raw light source - changing the adjustments in Sharpcap really is just changing them for display not the captured data - and no, I don't debayer my flats, they stay as they come off the camera.
@@TeamAstroworkz Too bad. What about adjusting the color balance on my iPad so rgb channels align when viewed in SharpCap ? With my light panel (amazon purchase 0.1x the cost of your magic box) blue is much lower than R/G .
What software do you use to do the following. I don’t understand the next four steps. 1. Integrate Flat Darks to create Master Flat Dark Frame Flat Dark Frames 2. Calibrate Flats with Master Flat Dark 3. Integrate calibrated Flats to create Master Flat Frame 4. Integrate Dark frames to create Master Dark Frame I’m learning to use ASIAir Plus V2.1.1. Do I need to make process changes there? I was thinking of buying an ASI294 MC Pro but this video has put me off until I can get beyond the basics of page one of your chart. Thanks
I had to look at what a definition of a Bias frame was and my understanding is you cover the lens, set the camera to its shortest exposure and shoot 20-50 images. The Dark Flats in this video are same as Bias but you use the same exposure as the 3 to 5 second Flats but remove the light panel and cover the lens for 20-50 images. So is the real key the pre processing to create individual Masters to the stacking program whether it’s PixInSight, Deep Star Stacker, Siril etc? It won’t work if your program like Siril which wants four folders named lights, darks, flats, bias to run through its preprocessing script? Even if the Flat and Dark Flat frames conform to the 294 guidelines. Are all these calibration problems with both versions of the 294; 294MC Pro and 294MM Pro? Thanks.
You're stating that the light source for the flats should be as neutral as possible, with R G and B channels peaks aligned in the histogram. But how would you achieve that when you're shooting your flats with filters which affect the color balance ? For instance, I know that my 294MC + L-Pro filter tends to produce blueish pictures, so even with a neutral light source, the blue channel will always be higher, is that a problem ? Should the light source be pushed towards red to counter the blue tint ?
So I only use Deep Sky Stacker. Am I able to just load dark flats and flats to create a master? Do I just lie and claim the flats are lights (as it won't stack without adding lights). I don't think I can stack without registering, and sense there are no stars in a light flat, how could I even make a flat master in DSS?
Hi Simon great video. I have the 294mc running with the L-extreme filter. I have a Gerd Neumann flat panel. When I look at the histogram I get two peaks about half way at around adu 30000 and a third peak, much smaller in size by at about adu 8000. This doesn't seem very well balanced. Not sure if this is a problem, reports suggest that the GN flat panel is very good. Your feedback would be appreciated. PS I am no expert at this hobby. Thanks Alec
Its not a combination that you look to do ... take all your short length darks and integrate them into a single master file don't apply any enhancement or optimisation to them .... then calibrate your flats using the master dark file - then once you have all the flats calibrated by that dark - then integrate them into a master or you can just use the individual files - the idea is to calibrate the flats using those darks so you remove any thermal effects like amp glow etc so you get left with nice clean flats . It sounds harder than it actually is :) just remember you still do long exposure darks to match your lights too ... when it comes to calibration of your final image then you have the calibrated flats from above, the light frames containing your target image and the darks that match that exposure length. Download the little process flow chart in the description ... it will help visualise it
any of the modern BSI sensors so 533 2600 etc behave better - in all of the ZWO cameras the 2600 is my absolute recommended - it behaves very well is an excellent performer - but the 533 is good if on a budget and if you can accept the square format sensor
@@TeamAstroworkz yes but unfortunately 294 fits better to my telescope (1000mm/200mm). I use some formula and with 294 I have 0.96 and with 533 and 2600 - 0.78 angular size in pixels minutes.
thats sad ... I guess Tyler and I need to get on a mission to find a decent cheap replacement ... they were not cheap but mine have certainly been great performers
Thank you so much for putting this information on RUclips.
I have recently purchased this camera, OSC, as an addition to my ASI 2600MM, which has gone back to China for a repair, because of the infamous, "oil streaks" over the sensor.
I decided to purchase a OSC camera, just to be a bit lazy and use it until my 2600MM is returned.
I have really struggled with this camera, my 2600MM, with LRGB and HSO imaging was far easier in comaprison.
The points I have taken from you are:
NO bias frames.
More than 3 seconds exposure,.
And I have used your workflow diagrams.
WHAT A TRANSFORMATION!!!
Thank you so much, and I hope lots more people will see this, as I am sure they will have exprienced these issues.
I now agree with you that this is indeed a great camera.
Keith Dutton - England UK
😁
it just needs a bit of care - soooo glad the video helped and the workflow helped feedback is much appreeciated!
@@TeamAstroworkz Wondering if you have an updated recommendation for a flat panel?
As someone who has owned the 294MM Pro for a few years now, I'm well acquainted with the rather finicky nature of the beast. The research thread you mentioned from CN - I did all the work for the 294MM Pro, where John (jdupton) did it for the 294MC. What we discovered was the responses were extremely similar between both the IMX294 and IMX492 sensors.
I have done all manner of experimentation, trying to find the best method for calibrating data from this camera. I've used dedicated flat panels (the FlatMaster from Pegasus), high CRI video lights from Elgato, Aputure and others, CFL fixtures, incandescent bulbs, halogen bulbs, LED bulbs. I've also used multiple different diffusion materials from professional backdrops to tee shirts.
Here's a summary of what has worked best for me:
1. ALWAYS match your flats to your lights in terms of gain, offset, temperature and binning. Many people will tell you it doesn't matter. It might not on other sensors. It does with the 294 series.
2. Take long exposures. If you look closely at the research John and I did, you might conclude that you can take flats less than 1 second. In fact, John even mentions that it's possible as long as you're extremely careful to exactly match everything. I avoid it altogether and take exposures of at least 3 seconds. More typically, I'm taking 5 second flats for broadband and upwards of 30-90 second flats for narrowband.
3. I use indirect lighting. Through all of my tests of different lights and diffusion materials, I found the best flats come from when I bounce light off of my garage walls (painted a flat white), rather than pointing the scope directly to the light source. This is true with both my GT81 and my EdgeHD.
4. Light source matters. You mention this as well. You simply cannot use your iPad as the light source for flats. Use a well-balanced light.
5. Certain gains are problematic. This one took me by surprise, but the research done by Dr Robin Glover (SharpCap) is rather convincing. The 294 series sensor seems to misbehave right around gain 0 and also right around gain 120, where the camera kicks into HCG mode (for the ASI versions... I'm not sure equivalent in QHY/Altair/etc) in the default mode (i.e. bin2, 11MP mode). In my particular case, in the default (bin2 mode), I cannot shoot my lights at gain 0 or gain 120. Instead, I must shoot at gain 8 or gain 137. Using the unlocked (bin1, 46MP) mode, the issue goes away at any gain 12 and higher because the camera is always in HCG mode. Your mileage will vary, so it would be smart to run tests using SharpCap to figure out values that work for you and your particular camera.
To James' (DSO Imager) point in his comment, I also mostly suffered with the green filter. In fact, I purchased multiple brands of filters trying to solve it: Astrodon, Chroma, ZWO, Antlia. Using the above process, my calibration issues have gone away.
yup its def about attention to detail with the 294 - and yes the 294MM suffers similarly and you can tame it using the same process and approach - then it behaves :) Gains ... yes I regularly see people using gain 0 with these cameras and then suffering from banding / noise in them. I've not come across the gain 120 issue TBH but its certainly worth noting and def do some tests and QA checks of darks and flats! good feedback and info ! thanks Simon
Hey Jonny, i have taken notes from your research, since i own a 294mm myself. Could you explain what you mean with a well balanced light? What is a well balanced light for an example?
@@Backcorner_Astronomy by well balanced, I mean one that has relatively equal signal strength in R, G and B. An iPad is a poor choice as a light source for flats. I've got an Elgato Key Light Air (bought it a few years ago for streaming) that works pretty well. I've got some portable lights by Aputure that I use. I've got a FlatMaster 150 by Pegasus that I use with my GT81. I haven't tried a Spike-a Flat, but quite a few people swear by them.
What I've found that works the best is to use indirect lighting. I light my garage wall pretty evenly with the Key Light and the portable Aputure lights. I then stretch a white cotton tee shirt over the scope and point it to the evenly lit wall. While it shouldn't matter (math), I tend to keep my ADU around 25K.
@@JonnyBravo0311 Very interesting. I have looked at the flatmaster 250 because i have a 8” newt. But it is extremely expensive. At the moment i use a tracing pad that has 3 brightness’s. But the flats are not very consistent. Maybe it’s worth to shell out the cash to buy a flat panel. I do have to use it directly on to the scope because i don’t have a room with white walls. Aaaah the never ending money pit 😉
@@Backcorner_Astronomy I looked at the 250 as well for nearly the same reason: I've got an 8" EdgeHD. I also balked at the asking price. Out of curiosity, what gain do you typically use? Take a look at Robin Glover's post about flats with the 294MC over on the SharpCap forums. He made a very interesting discovery about how the sensor behaves. It was point 5 in my initial comment. I ended up changing the gains at which I shoot from 0 and 120 in the "default" (i.e. 11MP) mode to 8 and 137.
If you do end up buying the FM250, I'd love to know how it works out for you.
Excellent presentation! I can't understand why you have only a few hundred subscribers. I'm a 294MC pro owner and very much appreciated the well presented steps to achieve good results with the camera. My experience with the 294MC Pro in combination with a ZWO Duo Band filter has been OK but I always wondered why my flats always ended up with a blue cast on one side and a red one on the other. Correcting an uneven cast in the stacked image in post processing surely reduced the dynamic range of my images from the start.
I will be pointing this video out in my circle and hope to see many more videos from you.
Hi Bernard - thank you for your kind comments ... well we are still building our channel and still adding content - we only have been running for a few months but you can be sure we will keep aiming to help users with these kind of issues and creating this kind of content for you. Thank you and we appreciate the feedback - it helps after spending time putting these together :) rgds Simon
I've owned the 294MC Pro for about 6 months, and over time I've learned all these tips. It can definitely produce beautiful images if used properly. One of the technical reasons not to use bias frames is that this camera sensor gets inconsistent results at VERY short exposure lengths. I've had much success taking longer exposure flats along with dark flats. My only challenge during that time is normally I take flats in the morning and making sure there are no light leaks for the dark flats can be a challenge. Having said that it's a wonderful camera and sensor.
this was a complex one to do ... hope it was worth it!! lots to take it and include in a short video :) have fun! rgds Simon
The spike field flatteners are no longer available. What other suggestions might you have for a panel?
Hi there. I have been using the ASI294MC Pro for a long time and still am. It is indeed a wonderful camera and I am very happy with it. I too experienced 'issues' with using the L-eXtreme/eNhance filters, but shooting flats indeed is a necessity. I use a very cheap drawing pad for it which is dimmable in three levels. This is usually good enough especially when I dim it further down by wrapping the A4-sized drawing pad in a white t-shirt. Reason for me doing that is the seemingly ridiculous pricing on flat panels. I am sure there are good explanations for that (such as the balance of the colors as you mention).
actually Tyler and I are on a mission now to do a review of the flat panels on the market - sounds like another video topic!
I use the same technique for the flats, 2 or 3 sheets of paper and medium setting in the drawing pad to get 6-8 sec flats with 32K ADU.
Just regarding the work done by J D Upton that is referenced here as the reason for shooting flats of 3 seconds or longer, J D Upton himself provided some further clarification to that on Cloudy Nights in April 2021 on a forum post entitled "ASI294MC Pro flats". Commenting on the common recommendation for 2-3 second flats on this camera, he said " You can blame me for that recommendation. So long as you are careful about matching a set of Flat-Dark frames to your Flat frames, then you will not have trouble. You can shoot at less than 3 seconds exposure. It is best to not use Bias frames in general to calibrate the Flats with this camera. (The exception is very short Flat Frames. If you can shoot Flats at less than about 1/4 second exposure, you can calibrate the Flat with a (real / zero duration) Bias. Otherwise use Flat-Dark frames matching the Flats to calibrate your Flats.)"
Spot on! Nice to see all of this points so well articulated.
Thanks Simon great video! As an ASI294 owner I will be giving this advice a go. I have struggled with inconsistent flats at times.
thanks - the 294 is a great series and it won't take much to tame ... buying the flat panel is totally the best advice I can give - they make life so much easier plus with the use of dark frame calibration to remove amp glow means you can nail it easy with nothing else than a bit of knowledge :) DO let me know how you get on!
Great, helpful video, Simon! Thank you very much. Clear Skies! 👍🙂🌌💫🔭
Glad it was helpful! That's why we are doing these :)
I had the same problem with my sii frames until I posted a new topic in astrobin and someone stated that I have something wrong with my flat. I tried to increase the exposure time from 2sec to 4.5 at %50 ADU and it works good now.
thank you for the video I wish I knew that before
its amazing how much interest this video has had - great you found out how to fix it too!
Thanks Simon!
I use a 294 mc pro. When taking my flats I set a ($300!!) German-made light panel on top of my dew shield while pointing the scope straight up. (My 294mc is attached to my Hyperstar at the front of the scope.) I set the 294 exposure to 3 seconds and keep my gain the same as my lights. BUT when I take the flats even at a very low light setting, I get histograms that are off the chart. So in order to get the ADU down to around 28k I place 3 light-filter papers underneath my panel. (I have not been cooling the camera so I'll start doing that now based on your rec.) I use PI to calibrate and process my subs and use a 3 sec master dark flat to calibrate my flats. Yet, somehow, I'm still getting gradients, dust bunnies, etc. I use DBE to get as much out as I can but I'm still not happy with the results. Folks online say it's all in my flats, some even suggesting going to a low 0.25 seconds to shoot the flats. I also look at the histograms of the flats before placing them in PI to ensure they are in the correct ADU zone. Do you have any other suggestions? I've had a few folks suggest not using the filter paper. Maybe the filter you refer to in this video would be better?
Thanks Again
Great video! Glad it justifies my use of a dimmable flat panel, no bias frames, use of dark flats and cooling for all frames with the 294 MC pro. I like the camera though when using it with an Optolong Extreme I do sometimes have to work hard on gradient issues in post processing. I would like to see a video on how to clean filters and the 294 sensor. This channel is one of the most helpful on view, with clear practical advice. Many thanks!
That sounds like a fabulous idea - cleaning filters and sensors - we can do that!! Will def do that for you. the 294 is a great camera still love mine! And thanks for the feedback thats what we aim for - practical advice and honest ones too ! :)
Ditto, would love to see a video on cleaning filters and sensor.
Thank you. Just waiting for a light panel for my c11 and 294mm to come in stock
Good choice! The panel was my key to success to be honest! Once I used a panel I never encountered issues calibrating any camera - in fact a local had issues with his QHY camera too and we narrowed it down to his flats and using my flat panel for flats nailed it first time!
I find that my 294mc pro behaves very nicely under a dark sky (Bortle 1\2) but seems 'noisy' at Bortle 4/5. I have been taking short exposure flats of less than one second with an el panel I made up but I'll try darkening the panel with paper or something to get the exposures longer. It's good to see these explanations without drama, just some clear information to try out to see if it solves the problem. Many thanks for the video.
Amazing video, thank you so much for sharing with the community.
Our pleasure!
Nice. I'm waiting to give my new 294MM-Pro the first lights and I was already following these tips with my 1600MM-Pro so that will not change the game for me. 👍
awesome - I'm just waiting for some better weather - sick of cloud / rain this spring and now into summer :( still get loads of support tickets for these cameras so was a very long overdue video prompted by these !
Any news on this yet? “We have been made aware that Spike A Flat has been discontinued since this video was produced - we are looking at suitable alternative.”
Nicely done!
thank you kindly!
I just got the Svbony version of the 294, the SV405CC, and I spent the last few hours trying to get the calibration sorted.
I was thrown off by Siril, and their article _"Enough with dark flats"_ and the fact that the Siril program seems to insist on you using bias files instead. So I went through a lot of trial and error trying to use bias files, and the results kept ending up worse than using no calibration files at all.
But after using your method here, and dumping the bias files, I finally got a good result without any of those weird shadows at the sides, and my master-flat finally removed the few dust spots that are somewhere in my rig.
It was also a kind of a eureka moment when I realised that I had to calibrate the flats using the "dark" checkbox instead of the "bias" checkbox when calibrating in Siril.. which became blatantly obvious as soon as I thought about it!
I think I'm on the right track now, thanks!
thats awesome! great to hear!
@@TeamAstroworkz AndyofAstro Did a vid on the SV405CC, The issue may not be what you think. There is an issue when the sensor flips to HCG mode. The first few gain steps have issues. Dr Robin Glover mentioned this in a post on Cloudy Nights, I think they flip to HCG at gain 120. But you need to be over 150 ish to not have the issue. You can get test to get the exact value
Late in coming but thank you Simon for another informative video. QQ: What do you use to create your Master files? Would DeepSky Stacker (DSS) work for the Dark, DarkFlats, and Flat frames running each group separately?
Very informative! Thank you for the great video.
This is great. Thank you
Thanks Simon for this video . I have this camera, never knew not to use bias frames .also I'm going to invest into a flat panel with a dimmer switch. I'm Currently using the white t shirt method. Reading all the comments is also helpful. Your channel is way under subscribed. Top content , very professional . Thanks again Simon.
Glad it was helpful! well we are pretty new it takes time to build a base but we will get there! People sharing videos and showing others the content will grow us slowly - and thanks for the feedback thats very much appreciated! Wer are also trying to find more cost effective panels .... I had no idea the Spike A Flat had gotten so expensive .. no idea why ... thats another mission we are on... to find a good cheaper option!
Hi Simon, It looks like I have a lot to learn, I have only just purchased the ZWO ASI294MC Pro color (S/H) for my Saxon 127. I did quite a lot of research on this camera and found it would match up with the Saxon okay. The only problem is that I cant see through the clouds to get any photos yet. I will be putting this video in my Astro video file for future reference.
Great video content just what a newbee wants, and a good lot of hints in the comments as well. Cheers Robert Aust'
thanks Robert - lots more coming for newbies and intermediate astronomers too :)
The flat panel you mention is no longer available. Wish I had watched this sooner. Any recommended substitutes? Thanks
We are looking into different alternatives for light panels. We will be making a video on them soon.
@@TeamAstroworkz In that case, I will postpone any purchases until you share the video.
ellumiglow
Thank you for this great video. I’ve only had the 294 and luckily have been following your advice, producing great images. Any chance you could explain how to creat master darks, etc. I’ve never grasped the concept and process of creating masters.
yes - they are just very short darks - so capture them the same was as normal darks - ie with the camera off the scope or on the scope and well covered so no light can get to the sensor, have it cooled and running as normal, then capture darks the same length as your flats. The process guide I uploaded will show you how to use them to calibrate the flats and use them in your processing software but sounds like we need a longer video on calibration frames :)
How about ASI294MC and ASI AIR Plus in EAA? I see there are some options in the app but haven’t an idea of how to use them. I just bought a light panel. Does all the calibration happen in the ASI Air+ at the time of the EAA?
Great tips, and yes, I have been doing this since day one with my ASI294MM Pro and never any issues :D
Great - its def the way to a stress free processing!
@@TeamAstroworkz I also use a Flat Master 150 mounted to the wall in my observatory.
Very useful video. I've been running a 294mm with my edge for some time.. but do occasionally run into problems with flat frames.. specifically with the green filter.. and some times the blue.. the issue looks like a faint reflection coming off the central obstruction (using with an 8" Edge). I'm certain the issue is with the flats because I can see this artifact in the master flat. I've been doing sky flats this whole time. Looks like I'll need to bite the bullet and invest in a light panel. Do you have a suggested alternative to the Spike A? Something that's smaller and less expensive? Thanks and CS!
Tyler and I are going to do a review of other flat panels on the market - the issue for the Edge 8 will be size ... but Deepsky Dad, Baader, Artesky, Primaluce etc all sell them
I've always struggled with my images from my 294MC Pro, so thank you for this video. Also, what about the ASI 2600MC Pro? Should I use this method on that camera too, or is it better to do the standard flats, darks, and bias frames with that camera?
you can use bias with the 2600 ok - its well behaved :) no issues using either process on that one so if you prefer the quicker bias method go for it
Fantastic video, Simon. Is it necessary to have flats or darks taken using the same filter used to take the lights or should I be removing the filter I’m used from the holder before taking my darks and flats? I realize the back focus needs to remain identical , however. Again, great tutorial.
the darks of course wont matter as they as are darks, but the flats should match those lights using the same filters, as thats what you are trying to calibrate. Glad you enjoyed the video :) Yell out it you have any more questions :)
in your opinion, what gain and offset should be used for this camera? say for general DSO imaging.
normally gain 120 is a good spot offset is default 30 but you can safely use the automatic settings in the ascom drivers vs using the expert mode - if using an ASIAR there is no ability to change the offset
Love the information, format and execution of your videos. You can see the effort that was put into it. Please keep these going.
I have been running a 294mc pro for over a year with good success using 5sec flats at the same temp as my lights and darks, while also using dark flats. My only difference is I was using bias and running my flats at 30k-32k ADU (ASIair histogram). My next image I will process with 28k ADU and no bias and see what happens.
I’m in the process of upgrading my OSC filters from my Baader Moon/SkyGlow & ZWO Duo. You say Optolong coatings have compatibility issues with the coatings on the 294. What Broadband and Dual/Tri-Band filters work well with the 294 under Bortle 5-6 Skies?
thanks for the great feedback - it takes a LOT of work to create these so thanks it makes the effort worthwhile :) its not vendor specific TBH - just the interaction of the sensor and these narrowband filters - I have an Antlia ALP-T does exact the same :) - for broadband the L-Pro seems the goto one - Tyler uses them - I live in Bortle 2-3 so no need for them but he seems to get good results - The ALP-T is a nice one so far - look out for our ALP-T vs L-Ultimate shoot out coming soon :)
How do you calibrate the flats with the master dark flat? Do you stack each flat individually with the master dark?
As a new owner of the 294mm should be interesting to see how the process of taking sky flats goes with this camera. I know you advised against it lol
it can be hit and miss Ben - some people don't have issues others terrible problems using them ... these tips here are generally give reliable results to most which is why they exist :) I still get people emailing me with issues though so its also down to technique and skill too and also what software too sometimes ... you need to be able to manipulate calibration files easily
@@TeamAstroworkz I am happy to report that sky flats work quite well. A friend of mine who had the flats issue said I got lucky and must have a good camera. :)
Interesting video thank you. I use an Altair Astro 294c, so assume this still relates to me as well? I use an artist A4 light panel bought from Amazon to get my flats and go for 2 sec eposures, would you recommend increasing this to 3 seconds?
I have stacked in APP but do get colour gradients in my master flat but have now bought PixInsight so will try in there too. Can you please tell me what the settings are that you refer to in PI?
Hi Julian - yes likely it will relate to the Altair Astro 294 as well as the sensors are all the same. You can try slightly longer flats if you can dim the panel or use some good paper inbetween it and the scope - In pixisight ... you want to be doing manual calibration .... so following the guide ....when you come to image calibrate its going to ask what dark etc you want to calibrate with so you choose the master you created in the first steps and then make sure you calibrate only - untick the box that says optimisation - I will add some settings into a guide and add the in the description over the holidays so people can see the steps
@@TeamAstroworkz fabulous thanks. I have only used the WBPP in PI to stack my images which seems automated and fairly easy for PI.
@@TeamAstroworkz I am new to PixInsight so I would love to hear how you would calibrate your flats for greatest effect. I do have the ASI294 but have been using my ASI533 more frequently partly due to flats.
I'll try nail this in the next few days - we were trying to avoid turning the channel into a pixinsight page but I can do a downloadable guide for the key settings and process as an accompaniment guide to the video :)
As a follow up, I just tried to increase my flats to 3 seconds and now see horizontal banding across them, so I tried 2.5 secs where the banding disappeared. So will cap at 2.5s.
Great video, Simon. If my panel is out of balance, can I use my capture software - SharpCap - to adjust them so they are in balance and proceed from there ? And I suspect you disagree with Robin Glover that flats should be monochrome - at least for the ASI294.
unfortunately not - its really about the raw light source - changing the adjustments in Sharpcap really is just changing them for display not the captured data - and no, I don't debayer my flats, they stay as they come off the camera.
@@TeamAstroworkz Too bad. What about adjusting the color balance on my iPad so rgb channels align when viewed in SharpCap ? With my light panel (amazon purchase 0.1x the cost of your magic box) blue is much lower than R/G .
Is there somewhere we can see your astrophotography online? Thanks,
I lost of lot of my stuff in the astrobin crash a while ago but some you can find on AAPOD2 and here photos.app.goo.gl/ZJbYEbZVxyFZetcw8
What software do you use to do the following. I don’t understand the next four steps.
1. Integrate Flat Darks to create Master Flat Dark Frame
Flat Dark Frames
2. Calibrate Flats with
Master Flat Dark
3. Integrate calibrated Flats to create Master Flat Frame
4. Integrate Dark frames to create Master Dark Frame
I’m learning to use ASIAir Plus V2.1.1. Do I need to make process changes there?
I was thinking of buying an ASI294 MC Pro but this video has put me off until I can get beyond the basics of page one of your chart.
Thanks
I had to look at what a definition of a Bias frame was and my understanding is you cover the lens, set the camera to its shortest exposure and shoot 20-50 images. The Dark Flats in this video are same as Bias but you use the same exposure as the 3 to 5 second Flats but remove the light panel and cover the lens for 20-50 images. So is the real key the pre processing to create individual Masters to the stacking program whether it’s PixInSight, Deep Star Stacker, Siril etc? It won’t work if your program like Siril which wants four folders named lights, darks, flats, bias to run through its preprocessing script? Even if the Flat and Dark Flat frames conform to the 294 guidelines. Are all these calibration problems with both versions of the 294; 294MC Pro and 294MM Pro? Thanks.
You're stating that the light source for the flats should be as neutral as possible, with R G and B channels peaks aligned in the histogram. But how would you achieve that when you're shooting your flats with filters which affect the color balance ? For instance, I know that my 294MC + L-Pro filter tends to produce blueish pictures, so even with a neutral light source, the blue channel will always be higher, is that a problem ? Should the light source be pushed towards red to counter the blue tint ?
Can u recommend a good light panel, as the one u list is going out of business and has none left. Thanks
ohh really ? OK sounds like I need to do some digging then - thats news thanks for that !
So I only use Deep Sky Stacker. Am I able to just load dark flats and flats to create a master? Do I just lie and claim the flats are lights (as it won't stack without adding lights). I don't think I can stack without registering, and sense there are no stars in a light flat, how could I even make a flat master in DSS?
Hi Simon great video. I have the 294mc running with the L-extreme filter. I have a Gerd Neumann flat panel. When I look at the histogram I get two peaks about half way at around adu 30000 and a third peak, much smaller in size by at about adu 8000. This doesn't seem very well balanced. Not sure if this is a problem, reports suggest that the GN flat panel is very good. Your feedback would be appreciated. PS I am no expert at this hobby. Thanks Alec
I'm wondering how to take darkflats using a RASA8 scope. Lol. Regards amigo !
Ive seen some use a dew shield then balance the flat panel on top of that :)
I don’t understand how you combine the darks with the flats.I have the dark and flats made but don’t understand the process of combining them.
Its not a combination that you look to do ... take all your short length darks and integrate them into a single master file don't apply any enhancement or optimisation to them .... then calibrate your flats using the master dark file - then once you have all the flats calibrated by that dark - then integrate them into a master or you can just use the individual files - the idea is to calibrate the flats using those darks so you remove any thermal effects like amp glow etc so you get left with nice clean flats . It sounds harder than it actually is :) just remember you still do long exposure darks to match your lights too ... when it comes to calibration of your final image then you have the calibrated flats from above, the light frames containing your target image and the darks that match that exposure length. Download the little process flow chart in the description ... it will help visualise it
and what camera will be better than 294? 533? but what else with similar sensor params?
any of the modern BSI sensors so 533 2600 etc behave better - in all of the ZWO cameras the 2600 is my absolute recommended - it behaves very well is an excellent performer - but the 533 is good if on a budget and if you can accept the square format sensor
@@TeamAstroworkz yes but unfortunately 294 fits better to my telescope (1000mm/200mm). I use some formula and with 294 I have 0.96 and with 533 and 2600 - 0.78 angular size in pixels minutes.
@@TeamAstroworkz I have fount QHY294M Pro with IMX294 and BSI but it doesn't work with ASI AIR...
Didn’t know I owned a controversial camera. I should pair it with my Radian 61 - then all the chicks will know what a rebel I am😂
reading some of the posts you would be LOL :)
"When buying your first flat panel, make sure it has good color balance..." HOW ARE WE SUPPOSED TO DO THAT?
I would ask the vendor for sample spectrum or ask around online what people are using - I agree its not easy
Just seeing this video and the spike a flat Fielder is all sold out as the company is closing its doors.
thats sad ... I guess Tyler and I need to get on a mission to find a decent cheap replacement ... they were not cheap but mine have certainly been great performers