My first pots on FM!

Alt noob here. I am going to get a SMC Takumar 50mm f1.8 lens sometime this week. However it does not come with the caps for this lens. Photodiox seems to sell a lot of lens caps on ebay. I can get the eos adapter for this lens and the lens caps together.

I have tried to find out the size of the caps so I can get one from ebay or somewhere. But I haven't been able to find out what size this lens takes. Can anyone please point out if you've used one?

TIA
Ram

I didn't know there was a 50/1.8 Takumar. I know there was an M42 55/1.8 (which would have 49mm caps/threads) and a K-mount 50/1.7 (which also have 49mm threads).

Chances are, you need 49mm caps.

Edit: there was a K-mount 55/1.8 that has 52mm threads.
See if you can find your lens here:
http://www.bdimitrov.de/kmp/lenses/primes/normal/index.html

oops, it is the 55/1.8 that I was talking about. typo Its an F mount lens.

Thanks for the link!

Hi Ram. Welcome to FM.

I'm still not exactly sure which lens you're talking about. If it's a SMC Takumar, then you want the AOHC. If it's F mount, then you could try Roland Vink.

AOHC Asahi Optical Historical Club: http://www.aohc.it/indexe.htm
Roland Vink http://www.photosynthesis.co.nz/nikon/specs.html

jcolwell,
thanks!

This is the lens that I'll be getting - link
It says its a Pentax screw mount. I suppose I screwed up the description in my previous post.

You're welcome. It should be a fine lens, and you got it for a fine price.

You were led astray by assuming that the seller knew what he was talking about. It would have been much more clear for you (and us) if he had said it's designed for the "Pentax Spotmatic F" camera, not "Pentax F". The "F mount" is for Nikon, and "Pentax F" is a much more recent autofocus system, that's way newer than SMC Takumar lenses.

Since it's one of the most recent SMC Takumars, it'll have an Auto/Manual switch (or 'selector') for aperture control, and it will have diaphragm coupling lever. You can see these things on the AOHC "Mount and Operation of Takumar Lenses" page, http://www.aohc.it/tak00e.htm, near the bottom, in the SMC Takumar mount sketch. You can also see these features in the photos for current eBay item 160366370764, if you know what to look for, of course.

This means that you should get a M42 to EOS adapter that does not have a rim - as shown on the attached photo: adapter on L has no rim (threads go all the way through); adapter on R has a rim. The rim is required for an older lens without Auto/Man switch. With your newer version of the Takumar, you set the Auto/Man switch to Man, and the aperture always opens & closes as you rotate the aperture ring. If you put this lens on an adapter with a rim (and screw it down tight, as you should), then the diaphragm coupling lever grinds against the rim, which is not good for anybody.

Anyway, welcome to an alternative universe.

jcolwell wrote:
You're welcome. It should be a fine lens, and you got it for a fine price.

You were led astray by assuming that the seller knew what he was talking about. It would have been much more clear for you (and us) if he had said it's designed for the "Pentax Spotmatic F" camera, not "Pentax F". The "F mount" is for Nikon, and "Pentax F" is a much more recent autofocus system, that's way newer than SMC Takumar lenses.

Since it's one of the most recent SMC Takumars, it'll have an Auto/Manual switch (or 'selector') for aperture control, and it will have diaphragm coupling lever. You can see these things on the AOHC "Mount and Operation of Takumar Lenses" page, http://www.aohc.it/tak00e.htm, near the bottom, in the SMC Takumar mount sketch. You can also see these features in the photos for current eBay item 160366370764, if you know what to look for, of course.

This means that you should get a M42 to EOS adapter that does not have a rim - as shown on the attached photo: adapter on L has no rim (threads go all the way through); adapter on R has a rim. The rim is required for an older lens without Auto/Man switch. With your newer version of the Takumar, you set the Auto/Man switch to Man, and the aperture always opens & closes as you rotate the aperture ring. If you put this lens on an adapter with a rim (and screw it down tight, as you should), then the diaphragm coupling lever grinds against the rim, which is not good for anybody.

thanks a ton for the wonderful explanation! I'll now scout for the m42 to EOS adapter without the rim.

Anyway, welcome to an alternative universe.