Lens classes

[alanswan]

There are 5 main classes of lens for Pentax DSLRs: DA, D FA, FA, FA J and F.
Just wondering what each of this class mean?
I would assume that lens from the same class would share certain similar properties.
But I have no idea what.

[stk]

If i'm not wrong.. DA lenses are for use with digital bodies with APS-C size sensors.. not to be used with film bodies.

Not clear about the rest cos I'm a pentax newbie, but just to share a URL listing of the lenses that can be used with *ist bodies which i find useful..

http://www.dcviews.com/lenses/Pentax-comp-lenses.htm

[fengwei]

Originally Posted by alanswan There are 5 main classes of lens for Pentax DSLRs: DA, D FA, FA, FA J and F. Just wondering what each of this class mean? I would assume that lens from the same class would share certain similar properties. But I have no idea what.

Well, actually there are K, M, A lenses too, if not counting the M42 screw mount lenses You can get more knowledge about Pentax K mount history here:

http://www.bdimitrov.de/kmp/technolo...ary/index.html

Summery about the history of Pentax K Mount (mostly copied from somewhere else):
1.K mount: original K-mount, released in 1976. Strictly mechanical connection. (K and M lenses).
2. KA mount: released in 1981-82. Electronic aperture control and information about widest aperture is transmitted to the camera. Allows for program mode and shutter priority. (A lenses).
3. KAF mount: released in 1987, autofocus mount with distance information and other parameters send to the camera. (F lenses).
4. KAF2 mount: released in 1991, as KAF but with additional information send to the camera, as MTF information (every individual lens is measured and the information about lens performance at different apertures are stored in the lens internal ROM). (FA, FAJ, DFA, DA lenses).


And difference between these lenses (my own summery):
1. Basically K/M lenese are the same while M lenses are smaller/lighter than K versions
2. A lenses are similar to M lenses with additional exposure info (extra pins on the mount side)
3. F lenses have (first generation) auto focusing and everything else that A lenses have
4. FA lenses is similar to F lenses but have second generation auto focusing .
5. FAJ lensese are cheaper version FA lenses with plastic mount and less of aperture ring (to reduce cost) - which can only be fully used on modern bodies (film and digital) because the lack of aperture ring. while all FA lenses have metal mount and aperture rings.
6. DFA lenses are similar to FA lenses with digitally enhanced design and coating.
7. DA lenses are similar to DFA lenses but with no aperture ring, and mostly are designed for APS-C sensor. They can still be used on modern film bodies but mostly you'd see dark corners (vignetting). But the DA40/2.8 Limited lens has been approved to be able to use on a film body without any problem.

Our dSLR cameras can use all these lenses, including M42 screw mount lenses with the help of M42 to K adaptor That's one of the good things about Pentax.

That's all what I can remember. Someone can addup or correct me if I missed anything here

Cheers!