Well explained. Thanks! This is such a tedious task for me and this helps a lot. I liked your description of how the clock wise and counterclockwise turns on the knobs moves the center of the donut. 👍
Thanks for the comment! I have not tried an artificial star, though I have seen videos of folks doing so. One of the tricky aspects of the SCT is the tendency of the mirror to shift and flop when slewing to your target. So, when I collimate, I try to do it after the slew. Cheers!
Thank you for the comment! I don't have a Hyperstar setup - yet... I may try it out with my C8 and if I do, I will most certainly cover collimation. Thanks again!
Gracias, Jose. Creo que si, puedo hacer uno para el telescopio Meade ACF de 14". dna.oneill@streamingrelativity.com y podemos discutir los detalles. Saludos!
Do you only see defraction rings on a censor (i don't see any)? My little 6sct is solid at 8mm. Off-putting to do visually thankfully ive been lucky with my secondary and position. It definitely needs a fine tune though. Well my primary on the other hand.. TIL
Thanks for the comment. I generally do my collimation with a sensor, but it can be done through the eye-piece as well. The diffraction rings are always present, but seeing will affect appearance. Love the little SCTs - super portable, good bang for the buck... Cheers!
Your kit for combination is awesome idea. I have a celestron 9.25 I know you didn't State my scope in your video but I was wondering if you make them for the 925 Thanks cuz I'd like to get one
Thanks for the question - I have not tried a Tri-bathinov mask yet - though I am familiar with its design and function. I have been using MetaGuide for my "in-focus" fine collimation for sessions where it is most important. I do plan to laser cut one and experiment with it - perhaps sooner rather than later. Cheers!
Hi, Brian. In my closing I provide my email address if you are interested in the EasyCollimation Kit. All you need to do is shoot me an email at: dna.oneill@streamingrelativity.com and specify which model SCT you have - for example Celestron C8 XLT or Celestron 9.25 Edge. I will calculate the cost to ship based on your email address and shoot over a Paypal invoice for the shipped kit. This kit has gotten such a great response from the channel - thanks for your interest and thanks for your comment!-David
I was collimating in the "before focus" state. I did not make that clear and should have. And really I should have indicated that it is good practice to collimate in both the "before" and "past focus" positions. But lets pause and think more carefully about what happens when we move from inside to outside focus. The image on the sensor will flip both horizontally and vertically - including the shadow cast by any mask. So, and therefore your collimation screw adjustments will be the same - which makes perfect sense. In the end, the mirrors must be aligned. Thank you for posting that comment and picking up on that detail. I will make a point to mention this on my next video... Cheers!
The direction of the screw adjustments will will always have the same impact on the optical path. Clockwise pulls on the secondary mirror and pushes the image away from the screw. Counterclockwise pushes the secondary mirror and pulls the image towards the screw. This relationship holds true regardless of whether you're inside or outside focus.
I have seen them, tried to order one from Farpoint - never arrived. My biggest challenge has always been keeping track of the screws I'm adjusting, and direction I'm working, in dark awkward positioning. This may be an age related thing!!! Thanks for the comment!
I heard Farpoint closed. You can make one, there are online generators. We had one made with a laser cutter for our club’s 14” Edge. We align it with the screws, always goes on the scope the same way.
@@AstroDNAObservatory Nice video. 👏🏽👏🏽👏🏽 When you get around to trying a Tri Bahtinov mask, be sure to also use it in combination with Chris’ Bahtinov Collimator application. Soon to also become a N.I.N.A. plugin….
Thanks for the ask. When imaging a low magnitude (bright) star, especially with high exposure times, everything in the image train will contribute to the diffraction pattern - even the micro lenses of the CMOS sensor. If we lower the exposure, an airy disk will emerge - provided seeing allows. Cheers and thank you!
Understood and fair observation. I don't know if there was a frame where the secondary shadow was perfectly centered in this video. When I was making the video, I did rough collimation and intentionally left it short of ideal so I could then test the MetaGuide software to see how it would behave when collimating an focused star in poor seeing. I do mention that later in the video, but perhaps I should have added an annotation when I presented the example of good collimation. Interestingly enough, the author of MetaGuide makes a case that a centered secondary shadow may not always represent optimized collimation. The star centroid, as calculated with high-frame rate stacking, in relation to coma would be best - and that is very situational I think! Thank you for watching and sharing your comment! Best.
Actually, you can use the mask with MetaGuide - for rough collimation where MG is simply displaying a doughnut and you are making gross adjustments - HOWEVER, you probably won't be able to take advantage of the Red Dot guiding and centroid calculations. I think the mask will present interference. I'm new to MG so I am still learning more about how it works, but my initial impression is that it is quite sensitive (not necessarily a bad thing) and I am inclined to employ it as a final step in my "fine" collimation workflow. Something I would do when kicking off a planetary imaging session. Dialing MG in with my super small pixel OSC planetary camera took a bit and I am not convinced I got it right yet, but I am hopeful! Frank is one of the good ones out there and as a software developer, I appreciate all the work he's put into the tool. Cheers!
LOL! I rescued this dome from a prior home about 80 miles south of me. It was abandoned and in very bad shape. Reviving it took a lot of love and, well creative enhancements. One of those enhancements is an L-bracket that has to be loosely positioned on top of a limit switch inorder for the actuator arm to trigger it in the fully retracted position. This hack ensures my upper shutter can close at the end of a session. As I was fiddling with my hand over the C11, my arm brushed against it and it fell out of position. I actually cut the sound out of the video. But this is a perfect example of the frustrating stuff that happens - and distracts you - from the task at hand, collimation! Nice pickup on the UFO. Love it! Cheers.
Real simple. Set the scope on a table and look STRAIGHT through the front of the scope from about ten feet away. Make sure your eye is exactly level with the OTA in all directions. Adjust screws until everything is concentric. Done! Leave the diagonal out of it!
If only it were that simple... In principle, yes you want the mirrors to align, in practice this would be impossible by eye. But I suppose in really severe cases of misalignment, or during the construction phase of a DIY scope, your approach is a rational starting point! I would however adjust expectations relative to the actual results. All good, thank you for the comment!
Well explained. Thanks! This is such a tedious task for me and this helps a lot. I liked your description of how the clock wise and counterclockwise turns on the knobs moves the center of the donut. 👍
Thank you! The key to many of these procedures is to understand and appreciate the fundamentals!
I hung a Christmas tree silver bulb in a tree on a sunny day as an artificial star. Much easier to adjust in the daytime.
Timely technique! Thanks for the comment!
Great video! Thanks for sharing the knowledge 🙏 Have you done this with an artificial 🌟??
Thanks for the comment! I have not tried an artificial star, though I have seen videos of folks doing so. One of the tricky aspects of the SCT is the tendency of the mirror to shift and flop when slewing to your target. So, when I collimate, I try to do it after the slew. Cheers!
Great Video and some good tips! Do you plan to do a collimation video for a Hyperstar setup? You've got a new subscriber. Clear Skies!
Thank you for the comment! I don't have a Hyperstar setup - yet... I may try it out with my C8 and if I do, I will most certainly cover collimation. Thanks again!
Buen trabajo, seria posible para en MeadeLX200 acf de 14 pulgadas. Gracias
Gracias, Jose. Creo que si, puedo hacer uno para el telescopio Meade ACF de 14". dna.oneill@streamingrelativity.com y podemos discutir los detalles. Saludos!
How can I get the collimation kit? I have a Celestron 1100 Edge HD?
@WilliamHurley-z7d - Hi, William. Just shoot me an email at dna.oneill@streamingrelativity.com and I'll coordinate with you. Cheers!
Do you only see defraction rings on a censor (i don't see any)? My little 6sct is solid at 8mm. Off-putting to do visually thankfully ive been lucky with my secondary and position. It definitely needs a fine tune though. Well my primary on the other hand.. TIL
Thanks for the comment. I generally do my collimation with a sensor, but it can be done through the eye-piece as well. The diffraction rings are always present, but seeing will affect appearance. Love the little SCTs - super portable, good bang for the buck... Cheers!
Your kit for combination is awesome idea. I have a celestron 9.25 I know you didn't State my scope in your video but I was wondering if you make them for the 925 Thanks cuz I'd like to get one
Absolutely can make you one - shoot me an email and I will take it from there. Thank you for commenting!
dna.oneill@streamingrelativity.com
Have you tried your colimation tool with a tri-bathinov mask?
Thanks for the question - I have not tried a Tri-bathinov mask yet - though I am familiar with its design and function. I have been using MetaGuide for my "in-focus" fine collimation for sessions where it is most important. I do plan to laser cut one and experiment with it - perhaps sooner rather than later. Cheers!
Did I miss the link to the easycollimationkit?
Hi, Brian. In my closing I provide my email address if you are interested in the EasyCollimation Kit. All you need to do is shoot me an email at: dna.oneill@streamingrelativity.com and specify which model SCT you have - for example Celestron C8 XLT or Celestron 9.25 Edge. I will calculate the cost to ship based on your email address and shoot over a Paypal invoice for the shipped kit. This kit has gotten such a great response from the channel - thanks for your interest and thanks for your comment!-David
Doesnt whether you tighten or loosen a screw depend on if you are before the focus point or past it?
I was collimating in the "before focus" state. I did not make that clear and should have. And really I should have indicated that it is good practice to collimate in both the "before" and "past focus" positions. But lets pause and think more carefully about what happens when we move from inside to outside focus. The image on the sensor will flip both horizontally and vertically - including the shadow cast by any mask. So, and therefore your collimation screw adjustments will be the same - which makes perfect sense. In the end, the mirrors must be aligned. Thank you for posting that comment and picking up on that detail. I will make a point to mention this on my next video... Cheers!
The direction of the screw adjustments will will always have the same impact on the optical path. Clockwise pulls on the secondary mirror and pushes the image away from the screw. Counterclockwise pushes the secondary mirror and pulls the image towards the screw. This relationship holds true regardless of whether you're inside or outside focus.
Have you ever tried a tri-bahtinov mask?
I have seen them, tried to order one from Farpoint - never arrived. My biggest challenge has always been keeping track of the screws I'm adjusting, and direction I'm working, in dark awkward positioning. This may be an age related thing!!! Thanks for the comment!
I heard Farpoint closed. You can make one, there are online generators. We had one made with a laser cutter for our club’s 14” Edge. We align it with the screws, always goes on the scope the same way.
I think you are right about Farpoint. Will check out the templates for the laser cutter as well. Cheers!
@@AstroDNAObservatory
Nice video. 👏🏽👏🏽👏🏽
When you get around to trying a Tri Bahtinov mask, be sure to also use it in combination with Chris’ Bahtinov Collimator application. Soon to also become a N.I.N.A. plugin….
I bought a Celestron C6-A XLT and I can not see any stars. I do see many little comets.
That is definitively a problem! Perhaps the corrector plate or the secondary mirror housing was disturbed in shipping?
@3:57 Why do you have diffraction spikes on your SCT?
Thanks for the ask. When imaging a low magnitude (bright) star, especially with high exposure times, everything in the image train will contribute to the diffraction pattern - even the micro lenses of the CMOS sensor. If we lower the exposure, an airy disk will emerge - provided seeing allows. Cheers and thank you!
@@AstroDNAObservatory Ah, that makes sense. Thanks for the explanation.
Nice video but at 3:33 the secondary shadow is not centered.
Understood and fair observation. I don't know if there was a frame where the secondary shadow was perfectly centered in this video. When I was making the video, I did rough collimation and intentionally left it short of ideal so I could then test the MetaGuide software to see how it would behave when collimating an focused star in poor seeing. I do mention that later in the video, but perhaps I should have added an annotation when I presented the example of good collimation. Interestingly enough, the author of MetaGuide makes a case that a centered secondary shadow may not always represent optimized collimation. The star centroid, as calculated with high-frame rate stacking, in relation to coma would be best - and that is very situational I think! Thank you for watching and sharing your comment! Best.
@@AstroDNAObservatory Still nice vid. I use Metaguide for my C9.25 collimation. I assume that you remove the collimation guide while using Metaguide.
Actually, you can use the mask with MetaGuide - for rough collimation where MG is simply displaying a doughnut and you are making gross adjustments - HOWEVER, you probably won't be able to take advantage of the Red Dot guiding and centroid calculations. I think the mask will present interference. I'm new to MG so I am still learning more about how it works, but my initial impression is that it is quite sensitive (not necessarily a bad thing) and I am inclined to employ it as a final step in my "fine" collimation workflow. Something I would do when kicking off a planetary imaging session. Dialing MG in with my super small pixel OSC planetary camera took a bit and I am not convinced I got it right yet, but I am hopeful! Frank is one of the good ones out there and as a software developer, I appreciate all the work he's put into the tool. Cheers!
Caught a UFO at 10:15?
LOL! I rescued this dome from a prior home about 80 miles south of me. It was abandoned and in very bad shape. Reviving it took a lot of love and, well creative enhancements. One of those enhancements is an L-bracket that has to be loosely positioned on top of a limit switch inorder for the actuator arm to trigger it in the fully retracted position. This hack ensures my upper shutter can close at the end of a session. As I was fiddling with my hand over the C11, my arm brushed against it and it fell out of position. I actually cut the sound out of the video. But this is a perfect example of the frustrating stuff that happens - and distracts you - from the task at hand, collimation! Nice pickup on the UFO. Love it! Cheers.
Real simple. Set the scope on a table and look STRAIGHT through the front of the scope from about ten feet away. Make sure your eye is exactly level with the OTA in all directions. Adjust screws until everything is concentric. Done! Leave the diagonal out of it!
This is not accurate at all. Eye is "exactly" level with the OTA in all directions - you can't even do that accurately.
If only it were that simple... In principle, yes you want the mirrors to align, in practice this would be impossible by eye. But I suppose in really severe cases of misalignment, or during the construction phase of a DIY scope, your approach is a rational starting point! I would however adjust expectations relative to the actual results. All good, thank you for the comment!