Maximum diameter or optical resolution possible with a PST modded telescope?

[etatsolarchat]

So someone said that using a PST etalon modded telescope there was no point going beyond 5 or 6in I believe because any larger would get you nothing due to the size of the etalon. Is that right?

Speaking of maximum resolutions, I would guess at some point more pixels in your camera will do nothing for you when imaging, does anyone know what those limits are or how to calculate?

[Merlin66]

The size of the suns disk is roughly 1/100 the focal length. In a PST mod the etalon must be placed -200mm inside prime focus and the recommended focal ratio is f10.
This means the size of the solar disk at the etalon will be (200/10 +fl/100)
The etalon is just 20mm diameter, so longer focal lengths will lead to more vignetting and light losses.
Re cameras - to me it comes down to plate scale (arc sec/ pixel) and there should be enough "total" pixels to record the size of the image you want.
Craig Stark's CCDCalc is a great starting point for these calculations.
http://www.newastro.com/book_new/camera_app.php

[peter drew]

Very happy with my 6" F10 PST mod. Definitely better than my smaller ones under most conditions.

[etatsolarchat]

I think anything beyond 6in is pointless, so you did good..


I understand the pixel dimension to size of image etc, but what I'm saying is with say a Solarmax 60 telescope and under normal air conditions, I think there is some limit to amount of resolution you can get, thus a camera beyond X? pixels is pointless..

[Merlin66]

I'm not sure I understand the second part of your question...

I think there is some limit to amount of resolution you can get, thus a camera beyond X? pixels is pointless..

The resolution you obtain will be a result of the seeing conditions, the optical resolution of the objective you use and effective sampling with the camera CCD pixels.
When you say "beyond X pixels" what do you mean? The number of pixels in the CCD array? the size of the pixel?
Help me.