Roadtest - Rubinar 500mm

[rmuhlack (Richard)]

First real field test of my newly acquired Rubinar 500mm f8 mirror lens.

Brolgas at the Town Common Conservation Park in Townsville

[bojan]

Have you tried it on stars yet?
I would be interesting to see how it performs, as I have this lens for quite some time, and my specimen needs glass relax mod
(http://www.harpoint-observatory.com/...ussentonne.pdf)
http://www.strickling.net/russentonne.htm

(http://www.iceinspace.com.au/forum/s...ad.php?t=37039)

[rmuhlack (Richard)]

I did a quick test last month, but found it a challenge to focus precisely. Nevertheless i did get a couple of rough test shots before it clouded in that evening.

Wasn't sure if the odd star shapes at the bottom of the image is due to the lens, or my modded DSLR which could have some residual sensor tilt from the modification process. i have another unmodded 400D which I am planning to use to confirm this.

This is a 30sec exposure (full frame reduced by 50%, top @ 100%, centre @ 100%, bottom @ 100%)

[bojan]

Originally Posted by rmuhlack

... if the odd star shapes at the bottom of the image is due to the lens, or my modded DSLR which could have some residual sensor tilt from the modification process. i have another unmodded 400D which I am planning to use to confirm this...

Thanks for posting those test shots..
Looks like sensor is not parallel with lens focal plane (mod could be the reason if sensor was not put back in place properly).
Otherwise, it seems it performs better than my specimen.