G'day Alistair,
Quote:
Originally Posted by alistairsam
are you able to post a video showing the guide star at various intervals starting from 10ms? you might have to use a screen recording software. plenty of freeware around.
at 10ms, the guide star dances all over the place in my system, and just like your results, found the best results to be between 300 and 500ms with an AO as we stop chasing seeing. I'm looking at improving this with an NIR filter http://www.edmundoptics.com.au/optic...s-filters/1918 as mine's a newt and the CC has a 93mm backfocus.
would be ideal if we could use the ONAG's on newts with an AO, wonder if anyone's done that.
finally, you mentioned backfocus for the camera is 62 and guide cam is 90mm. why is that? physical design of the ONAG?
have you see the focal reducer for the guide camera for the ONAG that allows you to use an FR on the main cam?
http://www.innovationsforesight.com/...odshow&ref=AFR |
I can do that, I have nVidia ShadowPlay installed which should allow for desktop recording. You have to be careful how you interpret the results though -- even in NIR, stars which are further towards the horizon from the zenith will still be subject to some atmospheric distortion. It would definitely help with imaging a target like Pleiades from the southern latitudes.
A comparison of stars at various angles would be useful, but people just need to remember that the results are going to vary wildly based on their locations and the local conditions on a particular night. On Tuesday night the seeing in Melbourne was pretty good -- maybe 8 out of 10? Pointing near zenith, the ONAG cleaned up any effects of seeing completely and guide camera image was rock solid.
Guide camera backfocus is 90mm because it's further away from the imaging camera (by an amount equal to the length of the ONAG body) and doesn't benefit from the 45 degree AOI of the dichroic mirror.
I'm familiar with the AFR but I'm not able to connect my existing FR to the ONAG imaging port, it's male M42 on one end and 2" female thread on the other (Orion x0.85). Waiting on a Televue RFL-4087 to replace it.