Old lenses! worth to buy an adapter?

[A7man]

Well I found about three old lenses I think they were used for a pentax.

The first one is this one: a Sigma YS 100mm f=2.8 Macro Lens



The next is a a super-takmur XXmm? f=3.5



the third one is: a Tamron 35mm-135mm f=3.5-4.2




I've already googled all three. But I was wondering what you guys think about those. Lenses to keep and by an adapter for my canon 500D? Or do I get a better lens for the same price as the adapter(s)?

hope for some constructive feedback, thanks already!

raphy

[OsmosisStudios]

Meh, I wouldnt bother.

[spazoid1965]

The only one that seems worth the price of the adapter would be the Sigma YS 100mm f2.8 Macro.

[Aegea]

I think the Takumar has a pretty good reputation for a lens of its age (it's a 35mm, BTW). If I could find a cheap adaptor I think I'd be inclined to try it.

[inkista]

I agree: of the three, the Macro is the most likely to be worthwhile (particularly since focus to infinity is not what you buy a macro lens for), but YS is one of those weird mounts like Adaptall. I have no idea how it works or how you'd adapt it directly, since the Canon adapter for YS would have been for FD mount, not EOS. If it really already does fit on K-mount or M42, then a simple K-mount or M42 to EOS adapter ring should work, but... stacked adapters. Not my thing.

The Takumar would probably be the easiest and best adaption, but since it's an f/3.5 lens, it may or may not be worth the effort. The samples I've seen from one, while very nice, were not particularly stunning. You know me--I prefer adapting Oly OM, Contax Zeiss, & Leica-R and I like my glass fast.

Adapting a lens is kind of a PITA, shooting wise, and whether it's worth it or not really does depend on the individual lens and how much you'll use it. When you adapt a manual-focus lens, you can only shoot in M or Av modes, you don't have autofocus, you get half-empty EXIF, and you don't have aperture control from the camera body. This last has a side-effect most folks don't realize, which is that you won't get wide-open metering. With an EOS lens, the aperture is held wide open while you compose and meter the scene, and it's only stopped down to your aperture setting before the shot is taken. With a manual focus lens, if you stop down the lens, you'll see it grow darker in the viewfinder, which makes it harder to focus/compose. Canon dSLRs can, however, perform stop-down metering in this situation, so you at least retain accurate metering.

Personally, I usually only find it's worthwhile to use an adapted manual-focus lens if the lens is really nice or ultra cheap. Preferably both (e.g., Contax Zeiss 50/1.7). Also, you do want to keep in mind that only six mounts are easily adapted to Canon EOS with simple rings: M42 (Pentax screwmount), Pentax K, Olympus OM, Nikon F, Contax/Yashica, and Leica-R. Canon FD/FL or Minolta MD/MC are right out unless you like performing lens-mount surgery and have your own machine shop. Also, forget any and all rangefinder glass.