Wide Field - M20/M8

JohnH · #1 23-07-2006, 12:57 AM

Took this with my new toy - a Pentax 55mm f1.8 lens (cost $40) on my Canon20d, I am happy!

10x30s shots unguided, stacked and Digital developpment in IP.

tornado33 · #2 23-07-2006, 01:09 AM

Very nice. No sign of coma there.
How do you attach the Pentax lens onto the Canon camera, an adaptor or does the lens come with a Canon EOS mount?
Thanks
Scott

TidaLpHasE · #3 23-07-2006, 07:13 AM

I really like this pic, the rich color is awsome, and focus is spot on, well done.

What f/ value did you have the lens set at? i assume it wasn't at f/1.8, as i think you would get bad coma in a 30 second exposure.

Awsome image

Lester · #4 23-07-2006, 07:34 AM

Hi John,

very nice, dark lanes everywhere.

JohnH · #5 23-07-2006, 10:50 AM

I did try at f1.8 and the coma was not good (you would have to crop the outer 25%) so I went down to f4 in the end to get a good result but I could have lived with f2.8 and a little cropping - this lens is much sharper than the supplied Canon 18-55 zoom , yes it needs an adapter - mine cost $13.50 on ebay. The adapter had to be insulated to stop it confusing the 20d electronics and then you work in M or appature priority (metering mode). Of course you have to set the lens to manual also. None of this is an issue for astro work. Next up - a Zeiss 135 f3.5 on its way for the uk for $80...

Thanks to Itchy for the idea!