As far as I know, all the 50mm f/1.4 lenses are the same optical design. The difference is in the controls and electronics, but they are all considered one of the finest lenses ever made!

I've been using the 77 for headshots and an old A 50mm f/1.4 for wider portraits. In the studio, I like the primes for their superior quality and predictability.

In the field, the 16-45 gets a lot of use, and soon the 45-125 will be replaced with the 50-135. I come from a time when zooms were generally not trusted for commercial work, and I guess I still have that attitude.

I do have to admit that the 12-24 is the lens that finally convinced me that a zoom could perform on a par with a prime. I was skeptical at first, but that lens has really convinced me that I can use zooms for paid work without fear!

FWIW, I tested an M 20mm f/4 lens today. Results were fairly consistent. It did tend to underexpose, but at all apertures.

One thing I couldn't do is dial in exposure compensation in M mode. That's a bit odd, but there are ways around it (take a reading, open half a stop).

I'll go over the results in more detail later.

As stated in my test, if you turn off the grip (no need to remove it), you can obtain acceptable results with at least one M series lens. More to be tested later.

If you aren't interested in shooting RAW, then you shouldn't be playing with older M and K lenses. jpeg is for snapshots, RAW is for serious photography.

I'm sure I'll get flamed for this opinion, however that's my experience. I have over 35 years' experience in professional photography, and I think I might have learned a thing or two over the years.

After hearing that the exposure errors with the K10D might have to do with the grip, I tested it with an old M 200/4 lens with and with and without the grip.

It seems the grip doesn't make much of a difference. With this particular lens, it was:

f/4 good. slightly dark (histogram towards left
f/5.6 - f/16 good, histogram in middle.
f/22-f/32 slight overexposure but mostly highlights. Recoverable in RAW.

I tried with the grip turned off but still attached to the camera. I tested without the grip. Some of the more extreme shots at f/22 or f/32 were perhaps slightly less overexposed, but fully recoverable in Adobe Camera RAW.

I tested with and without the shake reduction. Did not seem to make much of a difference.
It was an ordinary street scene in a city, not extreme dynamic range. With the lens wide open, the exposures were always withing range, but leaned towards the left. The default in ACR was a touch dark, easy enough to fix.

f/5.6 to f/16 the histogram was more spread out (?!?!) but the photos were well exposed.

Only at the two smallest apertures, f/22 and f/32, were there any blown highlights. And those scenes were recoverable in Camera RAW.
Oddly, the first exposure of each series (after turning the camera on and off) was completely blown out. I had to press the green button a second time, and after that it continued to work fine. Strange.

This was a test with one lens, on a tripod. So now you know you can probably shoot with the M 200/4 lens in RAW (I used DNG) and get good results.

Perhaps later in the week I'll test some other old M lenses.

This is the scene I tested:

http://www.gartenphotography.com/private/test/test_image.jpg

Here's the flag at 100%, no sharpening applied:

http://www.gartenphotography.com/private/test/flag.jpg


Here's a corner at 100%., again no sharpening:

http://www.gartenphotography.com/private/test/corner.jpg

Obviously, this is a pretty decent lens. I'm glad it works as well as it does with the K10D.

Yes, that's the first thing I did after installing the new firmware. Better, but still off. Very disappointing!!

I performed some careful tests with a K 45-125. The results were very inconsistent once you start stopping down the lens.

I also tried with an M 50/1.4,with similar results.

If it's particular to some camera bodies, then it's a defect and the cameras should be exchanged.

I've tried the green button, the DOF preview and metering from that, and various other tricks. The K10D just doesn't like stop-down metering.

I can use match-needle type metering or plain manual if an A lens is set to A, but somehow stopping down doesn't quite work.

I works with the D, and I see no reason it shouldn't work on the K10D. I've used two different focusing screens, same result.

I don't particularly want to buy new 200mm and 45-125 range zooms~

My Sekonic L-358 seems to take care of the problem just fine!

DNG and TIFF were both developed by Adobe (in fact DNG is based on the TIFF code). Since everyone seems to accept TIFF like it was a public format (which it practically is), I suspect that DNG will become the standard RAW format.