Anyone use the Pentax 200mm 2.8 ?

[Hoges]

There isn't a huge amount of lenses available for the Pentax compared to Canon and Nikon, but I've read some reasonably good things about the 200mm 2.8 Pentax lens....except for some purple fringing in high contrast areas. I can't find any astro photos done with this lens. Anyone?

Recently bought the inexpensive Pentax 35mm 2.4 which is a lovely little lens during the day, but a completely different story at night where nearly every star has a nice red circle around it. Wouldn't like to blow a grand on a telephoto lens and have it do the same thing at night.

[Nico13]

Hi John,
I also have heard lots of good things about the 200mm but all pertaining to daylight.
I am a Pentax user and have a number of primes but unfortunately they all seem to suffer some aberration to some extent and also some internal reflections on brighter objects at night, some acceptable some not.
I have a rather nice first quality Sigma 24-60 that is great in daylight but suffer the internal reflections terribly at night.
Have you asked on the Pentax forums to see if anyone is doing astro with the 200? Worth a look there I would say.

[gregbradley]

Which Pentax 200 2.8? I think there may be a few.

The 6x7 seems to do well. I have a 165 2.8 6 x 7 which is sharp wide open and no false colour.

Marc on this site has posted numerous Pentax 200mm astro shots. Perhaps look for one of them to get the exact 200mm model he used. I am not sure now if it was the 6 7 version or another one.

Greg.

[multiweb]

I have used a SMC Pentax M 200mm F/4 (http://www.pentaxforums.com/lensreviews/SMC-Pentax-M-200mm-F4-Lens.html) with a 2" Baader fringe killer filter and a UV/IR cut, Baader also. It did help with the fringing. LMC here (https://onedrive.live.com/?cid=6930D3AD12D5044C&id=6930D3AD12D5044C%211086&v=3). I also used it to do some narrowband (https://onedrive.live.com/?cid=6930D3AD12D5044C&id=6930D3AD12D5044C%211268&v=3)and that works great. They're nice and inexpensive prime lenses.

[Hoges]

Cheers guys. The lens I was thinking of is the PENTAX DA* SMC 200MM F2.8 ED (IF) SDM which is their latest incarnation of the lens - I think the DA's are not for the full frame sensor but could be wrong there.

Thanks for the link to the LMC pic - nice, bit of fringing but I'm probably not going to get away without some fringing in the price bracket I can afford. I've got the Sigma 70-300 (supposedly APO) that will stay at f4.5 at 200mm - I'll give that a whirl in the next week and see how it goes. No noticeable CA in the daytime shots - it's real impressive for a little over $200.

[gregbradley]

The Pentax 6x7 165mm F2.8 is very cheap and no fringing.

http://www.pbase.com/gregbradley/image/137896676

Greg.