I am making a tri-bahtinov mask , I am wondering if the mask has to sit on the retainer rign or can it hand over the front of the scope like the regular bahtinov mask does
A Tri-Bahtinov mask has 3 sections. The cardboad mask isolates 2 of the 3 sections to assist in deteerming which of the 3 collimation screws will be adjusted. you can display the section where the spikes are not even and adjust the associated screw to widen or narrow the collimation spikes for that section.
@@Zealor365 No cardboard is need, just place your hand next to one of the collimation screws to see if the shadow of your hand corresponds to the set of spikes you want to adjust.
Thanks for the explanation, and the cardboard cover design (I was wondering how to make one). I have been using a Bahtinov mask on my C9.25 but I got a Tri Bahtinov a few months ago and I haven't tried it out yet. I'm going to give it a try with your method.
I feel I’ve wasted too much time over the decades in attempting collimation using the traditional method given in the manuals of my vintage C5 and C8. Do I need camera-to-computer live output of the scope’s image in order to use the TB Mask and cardboard overlay to attempt this collimation for optimal visual use? I guess you use super-imposition of the diffraction spikes over the colored calibration dots-but I just need accurate collimation for visual observing? I’m also trying use of an artificial star placed at a reasonable distance. Collimation is the biggest time consumer in this hobby-but Thank You for this info & demonstration :-)
I used the top of a liquor box for the template and used a razor knife to cut the cardboard. This is a custom cutout so I don't think it is for sale anywhere.
Thanks for sharing... very interesting approach!.. If you don't mind, I'd appreciate if you could clarify the following doubt: When you line up the cardboard mask with one of the collimation screws, you keep working that screw until the three spikes are equidistant and then move to the next section?
A Tri-Bahtinov mask has 3 sections. The cardboad mask isolates 2 of the 3 sections to assist in deteerming which of the 3 collimation screws will be adjusted. you can display the section where the spikes are not even and adjust the associated screw to widen or narrow the collimation spikes for that section.
Very interesting concept! Thanks for sharing. Which screw do I need to turn? If I move the purple dot of the cardboard, so that it matches the red dot on the mask, do I turn the screw of the secondary that is matching the red spot, if Collimation is a bit off?
The dots of different color represent the different "Triads" of the scope itself. When you move the template around in a circle, you will see some spikes which are not evenly separated, and the collimation screw which is exposed will be the one to loosen or tighten to evenly space the spikes.
It’s impossible to have them all tightened up. The secondary mirror will not be aligned. The whole point of the three screw method is to tighten and loosen to get the mirror perfectly perpendicular to the axis.
The secondary mirror is held in place and balanced to the frame with a small rubber "O" ring. The 3 collimation screws are used to either compress OR relax the pressure on the "O" ring until the secondary mirror is aligned with the primary mirror.
Worthless...You didn't show how to collimate. Can any one show a simple way to collimate a SCT without trying to sound scientific or complicated. I don't use a computer and software to look through my LX200.
