Hi James, thanks for taking the time to make these videos. As a total newbie just starting out in this hobby your videos are very educational for myself and many others I'm sure. I have the zwo OAG that I purchased in early spring along with the asi120mm mini and .7 reducer for my 127 MAK. and canon camera. I was able to get both cameras focused on terrestrial objects but was lost when it came to the software needed to bring everything together for astrophotography. I have since gone with the asiair, zwo183mc pro and wo z73 at 430mm FL and 200mm guide scope. The asiair app has really helped in simplifying things to the point where I'm not pulling my hair out, ( I'm 57 and need to keep what I've got). Now I'm able to PA, Go-To, Plate solve and capture images without too much of a problem. I may have to revisit that OAG sometime in the future.
Hey Gary, thanks for watching! I know the feeling-I’m always trying solve one problem or another. I guess that’s what makes this a good hobby: it’s a continuous mental grind. And occasionally I even end up with a picture that doesn’t suck.
Thanks James for taking the time to make and share this. I am new to this, just got the redcat this week after only having done Milky Way photos until now. Many thanks, it is very informative!
I'm using my (heavy) SCT right now. So looking forward to getting back to the RedCat! Looks damn cool too...not that matters (Ha! I may have bought it because it looked cool). After looking at the universe through a soda straw (SCT), the wide angle of the RedCat has really opened my eyes. Enjoy!
James, I had the same AMP glow issues with the ASI-1600MM Pro. In my case the problem was with the dark frames, which I believe it's the same for you. Light sneaked inside the camera, most probably through the focuser or filter wheel. So I had to rebuild the dark library, but this time I made sure no light was "contaminating" the dark frames. I've put the camera facing down in my fridge! :) and it worked - cold and dark, it makes sense. AMP glow is completely removed in calibration process. Also, when you take darks, make sure you use the same USB cable and in the same USB port on your laptop or other machine. Noise created when data is transferred from your camera can be different. Red Cat and your results looks good, keep up the good work!
Great comments, Andrei! I suspect you're correct. I use the same cables and same USB port. I take the darks outside with the lens cap on and a cover over the scope--still, light can sneak in. I'll try rebuilding the darks in a totally dark room and see if that helps---I need room in the fridge for beer though! Gotta have priorities.
James, good review. You can use Sharp Cap software for real-time viewing with 1600 for focusing with small stars. You can also switch from Stellarium to SGP for framing.
That’s a good question. Once upon a time, I thought it was “silly” and “lazy” to have an electronic focuser on a telescope. Boy, was I wrong! I noticed my images were losing focus during the night. Now, I have 3 autofocusers on 4 scopes. The Redcat is the one that doesn’t have an auto focuser on it. Mostly because I don’t trust autofocusers that are compatible with the helical focuser (I have no experience with autofocusers for this scope, just skeptical). I will say that I “get by” without a focuser, but I do go outside and adjust focus once during a night. I think my conclusion that the Redcat holds focus well came before I realized that the Bahtinov focus should be assessed in 1:1 image mode. I’d say, If you trust autofocusers for this helical focuser and you don’t mind spending the money, go ahead and install a focuser. If you’re squeamish about it for $$ or mechanical reasons, you can get by without one. Sorry, I gave you a long answer to a good short question!
Did you make those Imaging Target graphs (altitude/month/observation times) yourself based on other data or is there a site that you pulled it from? That's a great way to plan your targets. Thanks for the video. Much appreciated.
Thanks for watching, David! I made those graphs from some work I did. There’s a long-winded video (of course) in my list called “Finding Observable DSOs With A Complex Horizon” that show’s where they came from. I do find them useful for imaging session planning purposes.
Hey Nathan. At the time of that video, I had not yet realized that you need to be in 1:1 pixel mode when using the Bahtinov aid which does magnify the image to the proper scale. The magnifier tool does not work when overlaid on the Bahtinov tool (I don't think it does). In any event, I should have been using the 1:1 mode while focusing. Thanks for watching!
Absolutely. What I haven't done is put the Bahtinov Aid over the magnifier tool window--will have to try that. I get weird Bahtinov Aid scores when I use the ROI region. Thanks for watching!
Looks great! I just picked up a Redcat this week. I have a question. Does this need the standard 55mm's of backfocus spacing? My cameras are the ZWO ASI294 and the 183MC Pro. I normally use a FF/reducer on my other refractors and have to use 55-56mm's of spacing for backfocus. Thanks!
I love the RedCat. Yes, 55 mm is the distance back from the M48 thread on the RedCat. You won't need your field flattener of course, so you should have: RedCat -> 16.5 mm -> 21 mm -> 11 mm -> Camera (6.5mm) = 55 mm Enjoy! And thanks for watching!
Hey Wyatt. That makes no sense to me. First, the shorter the focal length (the larger the image scale), the less sensitive your system is to guiding error. So a 250 mm scope (my Redcat 51) is far less sensitive to guiding error than a 2500 mm scope (my C9.25). Second, OAGs are awesome because they allow you to have a guide camera image scale that is very close to the imaging camera image scale because they share the same scope (they typically have different pixel sizes). PHD2 guiding algorithm sends guide commands to correct for a fraction of the guide camera pixel width (which is a fraction of the imaging camera pixel width since they share the same scope). Now, I suppose you could pair a 400 mm guide scope with a 250 mm imaging scope, but this seems silly to me because you're already correcting for deviations at a fraction of the imaging pixel size with the OAG--is a half of the fraction better? You'll never see it. The down-side of the OAG is:1. Finding a guide star when paired with a high-focal length imaging scope (C9.25 vs Redcat)--you're only seeing a tiny portion of the sky.2. When imaging through filters and you may make focus adjustments for different filters (blue vs red or o3 vs Ha), your guide star will tend to be out of focus a little because you're adjusting focus for the imaging camera and the focus for the guide star was set for the luminance filter (probably). Fortunately, guide camera focus is not as critical as imaging camera focus and PHD2 folks claim that a little out-of-focus helps the guide algorithm identify the center of the guide start.Sorry for the long-winded response! Thanks for watching.
Yep. It's great. At that focal length, I never worry about a star being in the field of view like I do with my C9.25. Plus, no cumbersome guidescope to get in the way. Best of both worlds, in my view. Thanks for watching!
Hi James, thanks for taking the time to make these videos. As a total newbie just starting out in this hobby your videos are very educational for myself and many others I'm sure.
I have the zwo OAG that I purchased in early spring along with the asi120mm mini and .7 reducer for my 127 MAK. and canon camera. I was able to get both cameras focused on terrestrial objects but was lost when it came to the software needed to bring everything together for astrophotography.
I have since gone with the asiair, zwo183mc pro and wo z73 at 430mm FL and 200mm guide scope. The asiair app has really helped in simplifying things to the point where I'm not pulling my hair out, ( I'm 57 and need to keep what I've got). Now I'm able to PA, Go-To, Plate solve and capture images without too much of a problem. I may have to revisit that OAG sometime in the future.
Hey Gary, thanks for watching! I know the feeling-I’m always trying solve one problem or another. I guess that’s what makes this a good hobby: it’s a continuous mental grind. And occasionally I even end up with a picture that doesn’t suck.
Thanks James for taking the time to make and share this. I am new to this, just got the redcat this week after only having done Milky Way photos until now. Many thanks, it is very informative!
I'm using my (heavy) SCT right now. So looking forward to getting back to the RedCat! Looks damn cool too...not that matters (Ha! I may have bought it because it looked cool). After looking at the universe through a soda straw (SCT), the wide angle of the RedCat has really opened my eyes. Enjoy!
I have similar equipment and just bought a bunch of stuff I see you're using that is clearly better than my setup. Thanks for the helpful videos.
Thanks for watching, Wyatt! I love the Redcat--great little scope.
James, I had the same AMP glow issues with the ASI-1600MM Pro. In my case the problem was with the dark frames, which I believe it's the same for you. Light sneaked inside the camera, most probably through the focuser or filter wheel. So I had to rebuild the dark library, but this time I made sure no light was "contaminating" the dark frames. I've put the camera facing down in my fridge! :) and it worked - cold and dark, it makes sense. AMP glow is completely removed in calibration process. Also, when you take darks, make sure you use the same USB cable and in the same USB port on your laptop or other machine. Noise created when data is transferred from your camera can be different. Red Cat and your results looks good, keep up the good work!
Great comments, Andrei! I suspect you're correct. I use the same cables and same USB port. I take the darks outside with the lens cap on and a cover over the scope--still, light can sneak in. I'll try rebuilding the darks in a totally dark room and see if that helps---I need room in the fridge for beer though! Gotta have priorities.
James Lamb I also have better results at calibration stage with the Optimize option unchecked
James, good review. You can use Sharp Cap software for real-time viewing with 1600 for focusing with small stars. You can also switch from Stellarium to SGP for framing.
Thanks Ray. I agree, Sharpcap is a great alternative. One day I imagine I’ll “grow up” and get SGP. All the cool kids use it.
Thanks for the review. Do you think this scope needs an EAF? Since it’s holding the focus pretty well.
That’s a good question. Once upon a time, I thought it was “silly” and “lazy” to have an electronic focuser on a telescope. Boy, was I wrong! I noticed my images were losing focus during the night. Now, I have 3 autofocusers on 4 scopes. The Redcat is the one that doesn’t have an auto focuser on it. Mostly because I don’t trust autofocusers that are compatible with the helical focuser (I have no experience with autofocusers for this scope, just skeptical). I will say that I “get by” without a focuser, but I do go outside and adjust focus once during a night. I think my conclusion that the Redcat holds focus well came before I realized that the Bahtinov focus should be assessed in 1:1 image mode. I’d say, If you trust autofocusers for this helical focuser and you don’t mind spending the money, go ahead and install a focuser. If you’re squeamish about it for $$ or mechanical reasons, you can get by without one. Sorry, I gave you a long answer to a good short question!
Did you make those Imaging Target graphs (altitude/month/observation times) yourself based on other data or is there a site that you pulled it from? That's a great way to plan your targets. Thanks for the video. Much appreciated.
Thanks for watching, David! I made those graphs from some work I did. There’s a long-winded video (of course) in my list called “Finding Observable DSOs With A Complex Horizon” that show’s where they came from. I do find them useful for imaging session planning purposes.
I'm sure you figured this out by now but APT has a magnifier feature under tools.
Hey Nathan. At the time of that video, I had not yet realized that you need to be in 1:1 pixel mode when using the Bahtinov aid which does magnify the image to the proper scale. The magnifier tool does not work when overlaid on the Bahtinov tool (I don't think it does). In any event, I should have been using the 1:1 mode while focusing. Thanks for watching!
APT has a magnifier tool where you can zoom in 3 - 10x
Absolutely. What I haven't done is put the Bahtinov Aid over the magnifier tool window--will have to try that. I get weird Bahtinov Aid scores when I use the ROI region. Thanks for watching!
Looks great! I just picked up a Redcat this week. I have a question. Does this need the standard 55mm's of backfocus spacing? My cameras are the ZWO ASI294 and the 183MC Pro. I normally use a FF/reducer on my other refractors and have to use 55-56mm's of spacing for backfocus. Thanks!
I love the RedCat. Yes, 55 mm is the distance back from the M48 thread on the RedCat. You won't need your field flattener of course, so you should have:
RedCat -> 16.5 mm -> 21 mm -> 11 mm -> Camera (6.5mm) = 55 mm
Enjoy! And thanks for watching!
@@Aero19612 Thanks James! Cant wait to try it out.
Great review. Thanks.
Thanks for watching, Gollond!
Some comments floating around that using an OAG with an aperture this size could negatively impact guiding. Any truth to this from your experience?
Hey Wyatt. That makes no sense to me. First, the shorter the focal length (the larger the image scale), the less sensitive your system is to guiding error. So a 250 mm scope (my Redcat 51) is far less sensitive to guiding error than a 2500 mm scope (my C9.25). Second, OAGs are awesome because they allow you to have a guide camera image scale that is very close to the imaging camera image scale because they share the same scope (they typically have different pixel sizes). PHD2 guiding algorithm sends guide commands to correct for a fraction of the guide camera pixel width (which is a fraction of the imaging camera pixel width since they share the same scope). Now, I suppose you could pair a 400 mm guide scope with a 250 mm imaging scope, but this seems silly to me because you're already correcting for deviations at a fraction of the imaging pixel size with the OAG--is a half of the fraction better? You'll never see it. The down-side of the OAG is:1. Finding a guide star when paired with a high-focal length imaging scope (C9.25 vs Redcat)--you're only seeing a tiny portion of the sky.2. When imaging through filters and you may make focus adjustments for different filters (blue vs red or o3 vs Ha), your guide star will tend to be out of focus a little because you're adjusting focus for the imaging camera and the focus for the guide star was set for the luminance filter (probably). Fortunately, guide camera focus is not as critical as imaging camera focus and PHD2 folks claim that a little out-of-focus helps the guide algorithm identify the center of the guide start.Sorry for the long-winded response! Thanks for watching.
@@Aero19612 fantastic, thorough answer. Appreciate it.
OAG is working well with redcat?
Yep. It's great. At that focal length, I never worry about a star being in the field of view like I do with my C9.25. Plus, no cumbersome guidescope to get in the way. Best of both worlds, in my view. Thanks for watching!
What filter wheel are you using? Thanks!
Hey Andrea. It's the 8-position ZWO filter wheel. Seems to work very well-I haven't had any issues with it. Thanks for watching!
@@Aero19612 Thank you!!😊
Dam. I was first!