I am giving a serious thought to this lens cos I am looking for a wide angle for architecture (and landscapes). My first intention is using it with a film camera (PZ1 or K1000) but I would like to know if somebody used it also in a K100D/K10d. This would be my first m42 lens so I would really appreciate any comment/tip about potential mettering problems, etc. Any information on sharpness will be also wellcome

Thanks in advance.

[carpents]

I believe that Jens Rösner did a comparison including the Flek 20/4 but unfortunately his site seems to be down ATM. (It should be at http://www.jr-worldwi.de/.)

I'm not sure if Jens used the 20/4 or 20/2.8 - and if I remember correctly the 20/4 is regarded to be better overall than its faster sibling.

As for using M42 lenses (specifically on the K10D), I've had much more consistent metering using a focus screen (LL-60) from the *ist series. I had a post a long time ago about the metering with manual lenses, and users with newer K10Ds seemed to report a different exposure line than mine, so I would simply check your camera when you get it. Just shoot a white or grey wall, stopping down from wide open to see if the exposure stays consistent. If you decide to go with a different focus screen, I have not noticed any problems with using A lenses with the new screen, so it is a win-win for me.

Another word of caution for M42 lenses, which won't be much of a problem for the Flek 20/4, is difficulty in focusing wide aperture lenses.

Lastly, since M42 lenses are cheap and good, it can get addicting!

(PS - I haven't found any great Pentax ultra-wides except the Fisheye lenses. So if I really wanted a 20mm, it would probably be a Zeiss.)

I believe that Jens Rösner did a comparison including the Flek 20/4 but unfortunately his site seems to be down ATM. (It should be at Jens Roesner - Photography - Art & Technic.)

I'm not sure if Jens used the 20/4 or 20/2.8 - and if I remember correctly the 20/4 is regarded to be better overall than its faster sibling.

As for using M42 lenses (specifically on the K10D), I've had much more consistent metering using a focus screen (LL-60) from the *ist series. I had a post a long time ago about the metering with manual lenses, and users with newer K10Ds seemed to report a different exposure line than mine, so I would simply check your camera when you get it. Just shoot a white or grey wall, stopping down from wide open to see if the exposure stays consistent. If you decide to go with a different focus screen, I have not noticed any problems with using A lenses with the new screen, so it is a win-win for me.

Another word of caution for M42 lenses, which won't be much of a problem for the Flek 20/4, is difficulty in focusing wide aperture lenses.

Lastly, since M42 lenses are cheap and good, it can get addicting!

(PS - I haven't found any great Pentax ultra-wides except the Fisheye lenses. So if I really wanted a 20mm, it would probably be a Zeiss.)

Thank you very much for the info.

I have a pentax k100d and I dont know how easy will be to change the focussing screen (I think that it is easier in the K10d). I love to manual focus but I am finding it very difficult to do in the K100d (specially considering that I am spoiled with the K1000 viewfinder). I am seriously considering to adapt a split screen or something similar but I dont know how traumatic will it be.

About the addiction to the m42s, I would dare to say that I am easy prey for them. They are cheap, high quality and beautiful. But one of the things that I like the most of them is that they are easy to adapt to other systems.