Pentax Glass

darin3200 · Oct 25, 2005

I'm looking at buying a wide-angle lens that is either M42 screw or K mount. There is a pentax that I really like. Anyone have expierence with these lenses or have any insights?

Thanks

photobug · Oct 25, 2005

For what camera? Film or digital? Makes a difference on how wide "wide" is.

Also may make a difference whether an m42 mount will work with your body.

Need a little input to properly answer your question.

jstuedle · Oct 25, 2005

If is a M42 mount I would imagine it's for a film camera. Pentax made some very fine glass back in the day. If my memory serves, the Takumar 28mm was an outstanding wide angle available in either M42 or K mounts.

darin3200 · Oct 25, 2005

photobug: Film camera, 28 or 35mm, I plan to get a k to m42 mount converter. I was just wondering if pentax made good lenses.

jstuedle: Yeah, I'm looking at a Takumar 28mm or a Chinon 28mm. Thanks for the input

selmerdave · Oct 26, 2005

The 28/3.5 lenses are generally considered to be superior to the larger aperature (2.8, 2) ones. I think generally the "K" would be the most desireable in K-mount, while for M42 mount the SMC Takumar would be considered best, they're essentially the same lens in a slightly different package. "M" is also supposed to be very good, I think (it's considered) slightly better than the "A". I haven't really heard that any of the M42's are bad, but that's just from reading online. From experience all I have used is the K 28/3.5 and it is excellent to be sure.

While I'm sure it's possible descriptions I've read of using the converters didn't sound to pretty, I would be very sure of what you're getting into before going that route. ie. to remove a lens you have to first unscrew the lens, and then use some sort of a pen or a tool to remove the adaptor. Maybe it's easier going the other way, I don't know.

Dave

usayit · Oct 26, 2005

I have a collection of pentax cameras and I really haven't found any Takumars that I did not like. All are very fine glass. Unfortunately, I don't have too much experience with either the 28 or 35mm lenses. The only glass that might have a slight complaint from me is the 50mm f1.4. Although they were considered one of the finest pieces in that time period, the coating wasn't stable and over the years they developed a yellow hue. Despite the yellow hue, I still shoot lots of B&W film with it and it produces nice results.

If you find a good source ( other than ebay ) for takumars, please post. I'm always in the market.

some links for your reading
http://www.bdimitrov.de/kmp/
http://www.aohc.it/indexe.htm

usayit · Oct 26, 2005

curious... which Kmount camera do you have?

darin3200 · Oct 26, 2005

Thanks for the responses!
Usayit: Praktica B200

selmerdave · Oct 26, 2005

usayit, I presume you know the trick about leaving the lens in sunlight for a week or so to get rid of the yellow hue, I don't think it has anything to do with degradation of the coating.

Dave

photobug · Oct 26, 2005

Not much to add to that. There is a mod you can make to the m42-to-K mount adapter so it will come off with the lens.

The disadvantage of using m42 mount lenses is it's totally manual. Stop down metering etc.

jstuedle- m42 works just fine on the Pentax digital bodies. I've got a Pentacon (medium format) 300mm lens with m42 threads that works perfectly well on my *istD with an adapter.

Some examples:
http://bimjo.com/bimjoriginal/pics/forums3/gull01.jpg
http://bimjo.com/bimjoriginal/pics/forums3/gull02.jpg
http://bimjo.com/bimjoriginal/pics/forums3/gull03.jpg
http://bimjo.com/bimjoriginal/pics/forums3/gull04.jpg

jstuedle · Oct 26, 2005

I stand corrected. Forgot about the adapters.

darin3200 · Oct 26, 2005

photobug: It turns out that the B200 has a "B" bayonet, not "K". However, if I can't find those lenses a M42 converter will work fine. I had a 50mm pentacon on my first camera and I always had manually do everything. I must be getting lazy

usayit · Oct 26, 2005

selmerdave said:
usayit, I presume you know the trick about leaving the lens in sunlight for a week or so to get rid of the yellow hue, I don't think it has anything to do with degradation of the coating.

Dave

Yes, I know that trick. I've tried it a while back and had very limited results. My guess is that I did not leave it out in the sunlight long enough. Some report tha it can take 3 weeks. BTW... the same trick is used by people to try and get rid of fungus too.

The yellowing is from trace amounts of radioactive materials in the coating of the glass. The ultraviolet light is suppose to help reverse the effects.

http://medfmt.8k.com/mf/radioactive.html

and here's one fellows solution:

http://www.hermes.net.au/bayling/repair.html << definitely doesn't work