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Crude Real time Newtonian Collimation Feature

Posted: Sun Sep 13, 2020 7:22 pm
by calypsob
I would like to suggest a new collimation tool which would be very quick and intuitive. I believe the current collimation tool is nice for fine tuning collimation after say a meridian flip, but for crude rapid adjustment we need something more simple especially for fast reflector optics.

What I am suggesting would require its own tool menu with some simple features.
It would involve the user making collimation adjustments in realtime live view while watching the laptop screen and adjusting the primary and the secondary after say taking a Newtonian on a long car ride to a dark site and doing a basic laser collimation.

- First you would need a custom ROI display or some way to sample all 4 corners of the frame in realtime, if the user could adjust the size of the squares, that would be great. In a high gain live view feed it would be easy to point the scope at a field of stars in the area intended to image and make adjustments. Some cameras may not be sensitive enough to produce a starfield shooting 1 fps or faster, this would be the ideal framerate to make fast real time adjustments to collimation.

-Next we would need a way to invert the image so that the stars are black and the background is white. We would also need a way to adjust the contrast so we would just be looking at bright star profiles.

This is a crude tool with no measuring, it would be strictly visual and in real time. Poor seeing may prevent this type of tool from working in real time.
But, I want to also suggest a way to mitigate in poor seeing. This would be done by allowing the user to stack 3-10 frames from the 1fps or faster readout. The user would then still have the option to visually adjust collimation, albeit much more cumbersome than making real time adjustments.

Once this procedure is complete you could jump over to the collimation tool that already exists and measure how precise the collimation is.

Re: Crude Real time Newtonian Collimation Feature

Posted: Mon Sep 14, 2020 8:35 pm
by admin

I have to admit that I can't quite work out how you would tell from the steps that you've described whether the collimation is good or not :(

As I've mentioned in another post this evening, I've pretty much given up on using telescopes that require collimation, so I haven't really been thinking much about the ins and outs of collimation techniques recently.

Cheers, Robin

Re: Crude Real time Newtonian Collimation Feature

Posted: Sat Oct 10, 2020 10:19 pm
by calypsob
Being able to sample the four corners of the sensor in a video feed would allow you to see if there is sensor tilt and also fine tune the primary in a newtonian. I have a RASA on the way, being able to have a split realtime video feed of its corners would make collimation adjustments easy, especially when the baader FCCT is released.

This link shows an example of how Pixinisght abbberation inspector can split an image to show the center and edges of the frame http://little-piney-observatory.blogspo ... e-dew.html

I am essentially proposing this to be an option in realtime so adjustments can be made immediately, rather than taking and image and downloading then having the program do this.

Re: Crude Real time Newtonian Collimation Feature

Posted: Sun Oct 11, 2020 2:23 am
by chongo228
I’ve used the collimation tool to try and set back focus and solve a tilt issue on a refractor. I was waiting until I’d used the tool a few more times to post a feature suggestion but the four corners and center ROI like the PI tool was on the list.

Re: Crude Real time Newtonian Collimation Feature

Posted: Fri Oct 23, 2020 2:28 pm
by calypsob
It would be a fantastic tool. I just got a rasa and if there is tilt, at least one corner will have a donut hole star. Havving realtime views of all 4 corners would make adjusting tilt a breeze.

Re: Crude Real time Newtonian Collimation Feature

Posted: Fri Oct 23, 2020 8:43 pm
by admin
So would a view where you see just the four corners of the image, but enlarged to fill the screen cover this ground completely?

If there is a consensus on that then I'll jot this down in my long list of interesting ideas for consideration in the future.

Cheers, Robin

Re: Crude Real time Newtonian Collimation Feature

Posted: Tue Oct 27, 2020 8:51 pm
by deneb
I think that collimating is not such a good tool.
but to adjust the tilt yes.
I give it a +1