Porst 135mm f/2.8

General
Long time ago I had written a general article about 135mm f/2.8 lenses (search the site to see if you can find it!), where I had mentioned that's it quite difficult to find a bad one. It's true, but it's also hard to find an exceptional one (unless you have money for the Nikkor 135mm f/2 DC). It's all a mater of compromises. Today, I'll give you a review of a pretty darn good compromise: the Porst 135mm f/2.8

Pros/Cons
+ superb value, you get plenty of performance for very little money (I got mine for $35, you can also find them cheaper)
+ excellent resolution in the center, very good in the corners. Stopped-down to f/5.6 it's superb all-around
+ small and light (by comparison)

- pretty visible chromatic aberrations - BUT modern digital cameras correct them automatically.
- M42 mount issues (you lose infinity focus)
- manual focus, remember. Not for moving subjects

No complaints at all about Image Quality

Intended Users
Great for:

• those needing a super-cheap but capable 135mm f/2.8 lens
• portraits (for subjects who can stay still)
• mirrorless - highly adaptable, thanks to the m42 mount

Not for:

• moving subjects. Manual focus
• non-digital cameras. The chromatic aberration is excessive.
• if you can afford to pay another $150 or so, the Nikkor AI-S 135mm f/2.8 is obviously better.

Final Verdict
In absolute terms, this is nothing special. It does the job fine, still. However, if we consider how cheap this lens is, it's a real bargain, particularly because of its...digital love. By that I mean a) it's easy to adapt to all kinds of cameras, thanks to the M42 mount (although, in Nikon you either lose infinity focus or you have to put yet another glass behind it - an adaptor with infinity focus adjustment); and b) optically, its only serious flaw is chromatic aberration, which is automatically corrected by modern digital Nikons (you can do it on Photoshop, too, if you're working on the .nef file). All-in-all, I can recommend this lens - at least for a while, it will do the job just fine.