Collimation Aid for SCT's

[VinnyV84]

Hey Robin,

Just a thought - How about some type of collimation aid / tool for SCT's? Something similar to Metaguide or perhaps even far simpler like ability to display size adjustable rings on a defocused star to help determine center and if collimation is off? I already pay for the pro version of sharpcap but would gladly pay if this was considered an add-on or extension, no doubt many others would as well!

[Borodog]

Seconded. :O)

[Menno555]

It already has it ... sort of
I always use the Circle Reticule for that. There is no active indication of how good or bad the collimation is, but you can adjust the circles radius (drag with right mouse button pressed) to divide it fitting the de-focused star.
See this screenshot. The red lines are better visible in SharpCap itself.

Menno

circle.jpg (218.67 KiB) Viewed 954 times

[admin]

Hi,

there's certainly scope for something like this, although as Menno points out there are options that help already. Actually Mike (@Borodog) has been tinkering with using the planetary live stacking to enhance the image of the star during collimation - see his thread here : https://www.cloudynights.com/topic/9119 ... ry13281003

I have to admit that my SCT (Celestron 8") doesn't get much use these days - I have 3 scopes on my mount most of the time to allow a quick change to any sort of imaging (70mm f/5 refractor for deep sky, Vixen ED81S + quark for solar, 6" Classical Cass for planetary/lunar). The SCT is too big/heavy to be part of that setup, so it sits in a box most of the time...

cheers,

Robin

[VinnyV84]

It already has it ... sort of
I always use the Circle Reticule for that. There is no active indication of how good or bad the collimation is, but you can adjust the circles radius (drag with right mouse button pressed) to divide it fitting the de-focused star.
See this screenshot. The red lines are better visible in SharpCap itself.

Menno

circle.jpg

Thanks Menno, but does the 1 ring help? Wouldn’t multiple circle reticules be needed to see if the shape / spacing between them is even?

[Menno555]

The Circle Reticule has multiple rings in it.
The first screenshot is the ring when activated. The second one I made smaller with dragging the mouse with the right mouse button pressed.
Just don't make the de-focused star too bright and the circles show with good contrast than.

Menno

ring1.jpg (185.5 KiB) Viewed 867 times

ring2.jpg (106.41 KiB) Viewed 867 times

[Borodog]

A defocused "donut" will get you to rough collimation. It won't get you to the accuracy required for planetary imaging.

I developed an idea for turning the planetary live stacking method into a full blown dedicated tool for collimation that should hopefully be easier to use than Metaguide. I've talked with Robin about it, but I know he is busy with many feature requests, so I'm going to wait a while before pestering him about it again. :O)

[VinnyV84]

Wow that would be great! Thanks Mike looking forward to it!

[Borodog]

Hey now. I didn't promise anything. This is Robin's show and he has a million things to do. So don't get your hopes up. :O)

It would be awesome though. ;O)

[VinnyV84]

lol ha - I will keep expectations low but hopes high!