I was hoping for a discussion of how the tri-bahtinov mask is used to check collimation, and better still how to use the diffracted image to achieve collimation.
Tri-Bahtinov works for collimation because the pattern goes visibly off-Center if the scope is not collimated correctly. Where as the other masks this is not the case (it’s still off but the difference visually is harder to gauge).
You mentioned focusing on Jupiter. I have read elsewhere that you should focus on a star being the source of light and not on a planet being the reflection of light. Is that correct?
If you want to focus on a planet you’ll want to use a Hart Mask (basically 2 or 3 circles in the mask) for best results. These masks are for stars but can be used for planets if you are in a pinch.
Refractors generally don’t need collimation (so they are fixed) where as reflectors and CAT with mirrors do. If the scope is not collimated then the prongs won't be perfectly aligned, there will be a skewed segment which indicats which side needs to be adjusted to bring into alignement. NOTE: You needed to align the tri-bat mask to be in-line with your adjustment screws (3 screws) so you minimize turning 2 screws at once trying to recolimate.
The sound appears to be out of sync on this video. I tried it in another browser and I tried it on my phone and all show the same out of sync. Is this the case with anyone else? 0 Great subject but hard to follow along with the sound out of sync.
Thanks for the feedback, I did try to "trim" the video in UA-cam Studio and it appears the audio was trimed but the video was not... I'm investigating but I may have to re-upload the video if I can't find a fix.
The mask goes on the front of your telescope (or lens) and helps with focus on stats by creating diffraction spikes that you visually align to ensure Critical focus.
Hello, thank you very much for the 3 descriptions. I've a Schmidt-Cassegrain 11" and a tri-bahtinov mask. The collimation is nearly ok. I've just the vertical frame not perfect but the other two are good. How can I know witch bob's knob I have to move to correct that and to obtain a good collimation ?? Thanks in advance for your help.
Hi Dominique, basically you should be adjusting the bob-knob in the direction of the collimation error. It’s important you align your tribathinov mask such that it is in-line with the knobs so you are having to guess which to turn to correct the optics.
@@EmberSkyMedia ah okay, 'cause i'll try to use the github.com/cytan299/tribahtinov/releases and when i enter 0 in the inner radius the program crashe ibb.co/c32js3z
@@RaphaelBeguin Hmmm... when I use the webpage application I can put in "0" and it kicks out a mask design. svg2.mbsrv.net/astro/Tri-Bahtinov.html However given the tri-bahtinov mask design nature, you can enter 0.1, 0.5, 1" depending on your overall size as there is a center that is always going to be there, even at zero.
#FreeFocusingMask Tri-Bahtinov for an Orion ED80 Keep up the good work on the videos. I didn't know about the other two mask styles. A video on guide styles might be good. (off axis, guide scope, etc)
Thank you for entering the Giveaway Contest and the suggestion about guiding styles, that is actually a very good concept and I’ll happily make a video about the differences between off-axis, on-axis, guidescope, etc guiding for you this month.
So you've won by default (only entry on this video) please let me know a social media profile (twitter?) that I can send you a DM and arrange to make you that focusing mask.
I was hoping for a discussion of how the tri-bahtinov mask is used to check collimation, and better still how to use the diffracted image to achieve collimation.
Tri-Bahtinov works for collimation because the pattern goes visibly off-Center if the scope is not collimated correctly. Where as the other masks this is not the case (it’s still off but the difference visually is harder to gauge).
Great review. Thanks
Glad you enjoyed it!
You mentioned focusing on Jupiter. I have read elsewhere that you should focus on a star being the source of light and not on a planet being the reflection of light. Is that correct?
If you want to focus on a planet you’ll want to use a Hart Mask (basically 2 or 3 circles in the mask) for best results. These masks are for stars but can be used for planets if you are in a pinch.
@@EmberSkyMedia Thanks, I bought the Bahtinov mask. Look forward to trying it out.
Gotcha, but how do i now if scope is collimated or not when using tribahtinov? Great video btw
Refractors generally don’t need collimation (so they are fixed) where as reflectors and CAT with mirrors do.
If the scope is not collimated then the prongs won't be perfectly aligned, there will be a skewed segment which indicats which side needs to be adjusted to bring into alignement.
NOTE: You needed to align the tri-bat mask to be in-line with your adjustment screws (3 screws) so you minimize turning 2 screws at once trying to recolimate.
@@EmberSkyMedia yeah, understood now! That's why i asked you, cuz i have a Newt. Thanks a lot tho :)
@@lepetitbaigneur9073 Good luck! Just remember small adjustments = big results. A quarter/half turn is all that is generally needed.
Have you tried a Duncan Mask for SCT Collimation? If so what did you think about it??
I have not, I'll have to look into it and get back to you!
A flour sifter for $1.50 also works great
I guess you could also use it to do that as well… or a filter on a drain pipe.
I’m looking for something with less dense screening like a floor drain cover but at 6”.
The sound appears to be out of sync on this video. I tried it in another browser and I tried it on my phone and all show the same out of sync. Is this the case with anyone else?
0 Great subject but hard to follow along with the sound out of sync.
Thanks for the feedback, I did try to "trim" the video in UA-cam Studio and it appears the audio was trimed but the video was not... I'm investigating but I may have to re-upload the video if I can't find a fix.
What is its purpose?
The mask goes on the front of your telescope (or lens) and helps with focus on stats by creating diffraction spikes that you visually align to ensure Critical focus.
Hello, thank you very much for the 3 descriptions.
I've a Schmidt-Cassegrain 11" and a tri-bahtinov mask.
The collimation is nearly ok. I've just the vertical frame not perfect but the other two are good.
How can I know witch bob's knob I have to move to correct that and to obtain a good collimation ??
Thanks in advance for your help.
Hi Dominique, basically you should be adjusting the bob-knob in the direction of the collimation error. It’s important you align your tribathinov mask such that it is in-line with the knobs so you are having to guess which to turn to correct the optics.
@@EmberSkyMedia thank you very much, I will try !
Hi, another instructive video, thank you for explaining differences, those tools are great! how did you generate yourself the carey mask ?
I got the design from George Carey's Website and then scaled it to match my telescope.
www.geoastro.co.uk/careymask.htm
@@EmberSkyMedia ah okay, 'cause i'll try to use the github.com/cytan299/tribahtinov/releases and when i enter 0 in the inner radius the program crashe ibb.co/c32js3z
@@RaphaelBeguin Hmmm... when I use the webpage application I can put in "0" and it kicks out a mask design. svg2.mbsrv.net/astro/Tri-Bahtinov.html
However given the tri-bahtinov mask design nature, you can enter 0.1, 0.5, 1" depending on your overall size as there is a center that is always going to be there, even at zero.
@@EmberSkyMedia ah ookay maybe it's dependent to the application conception, anyway thanks for your help!
Anyway there are the same idea (light interference) as in Bahtinov mask, nothing new. 🤷🏻♂️
Different patterns to give different results for different purposes.
#FreeFocusingMask Tri-Bahtinov for an Orion ED80
Keep up the good work on the videos. I didn't know about the other two mask styles. A video on guide styles might be good. (off axis, guide scope, etc)
Thank you for entering the Giveaway Contest and the suggestion about guiding styles, that is actually a very good concept and I’ll happily make a video about the differences between off-axis, on-axis, guidescope, etc guiding for you this month.
So you've won by default (only entry on this video) please let me know a social media profile (twitter?) that I can send you a DM and arrange to make you that focusing mask.
@@EmberSkyMedia Do you use CloudyNights.com at all? I'm texcoco on there