pentax screw mount bellows lens

I won a Honeywell Pentax SP500 screw mount camera on ebay, for about $15, and my grandfather told me he had some lenses for it. The only one he could find so far was a 50mm f4 Super Multi Coated Takumar Bellows lens, as I do not have a bellows, or whatever, I was wondering how much this lens might be worth? It's in perfect condition. The lens that came on the camera is an auto mayima 55mm f1.4, but the rear element is rather cloudy.

This lens was never made in K-mount, as far as I can see, but it is very probably optically identical to the ordinary K 1:4 50mm macro, which is a very sharp lens indeed.

If I were you, I would hang onto it and buy a bellows.

G

The K mount bellows lens was the 100mm f4.

Yes, they put the 100mm into K mount, but not the 50mm.

G

Hi,
One point to note which hasn't been mentioned is that the unlike the Macro lenses, the bellows lenses have no focus ring as this is done using the bellow. As such they can only be used with the bellows. Unless you intend to do macro work, I would be tempted to try and swap it for a good standard and/or other Pentax lens either through this site or maybe the Spotmatic forum. You will probably get a beter deal this way than selling/ buying on the Bay. It will save the fees and you are more likely to know what you are getting. I would have to check the relative values but PM me if you are interested.

Kim

first off, my mistake, it is a 100mm f/4, secondly, how much $US would a bellows for my setup cost? I do love macro. And thirdly does anyone have any experience with my 55mm auto mayima/sekor 1:1.4 lens? and is there a way to get the fungus off the rear element?

One way to get rid of fungus in a lens is to leave it out, apeture wide open, on a foil surface, on a really sunny day. This has been known to clear up growths on lenses. I beleive it's the UV component or the sunlight that kills the fungus.

If that doesn't work, then you're looking at a repair bill, unless you feel confident to take the lens apart yourself.

Hi,
This is a good method of clearing the yellowing caused by the radioactive elements in some Takumar lenses but is not much use for fungus!

The fungus will have to be removed but it may have caused irrepairable damage. A byproduct of some fungi is hydro-flouric acid which etches glass nicely. In this case the lens is a goner. If not it may clean. You will have to get at the affected elements to get them clean properly. Very light fungus may come of with a good optical cloth. If this fails some people advocate ponds cream and other a weak bleach mixture.

It is probably worth having a go yourself. The cost of a pro job is likely to be about the same as a replacement and there is no guarantee that it will clean.

Regards
Kim

Screw mount bellows units cost very little on Ebay. I paid about a tenner for mine. The 100mm length is generally more useful than 50mm, so things are looking good for you.

Does this look like your lens:

http://www.bdimitrov.de/kmp/lenses/primes/short-tele/K100f4-Bellows.html

It's the K mount version, but I'm pretty sure yours will be optically identical.

G

nope, fairly different looking. I'd post a picture, but the woman has the digital today.