View Full Version : Test of the K10D exposure issue with M lenses


danag42
03-20-2007, 01:07 PM
After hearing that the exposure errors with the K10D might have to do with the grip, I tested it with an ole 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 also tested with the grip removed. I tested with the grip on and attached. It doesn't seem to make much of a difference.

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.






--
http://www.gartenphotography.com/images/sillly.gif

''We have met the enemy, and he is us!' - Walt Kelley

danag42
03-24-2007, 06:08 PM
I've now tested the M 20mm f/4 and the K 45-125mm f/4 lenses. Results were similar, which means that using the lenses you could, if you want, open half a stop at f/4 and perhaps open half a stop at f/22 to f/32

I think all the nonsense about the K10D not working with manual lenses is just fluff. If you use manual lenses, you're used to adjusting the lens to the specific camera's meter, and this is no different.

If you can't deal with it, buy an A or later lens. That still lets you use lenses that go back to the 1970's.

This is with the Katz Eye screen. Obviously, I have a large number of manual focus lenses. In fact, I never used an autofocus camera until I got a digital (Olympus E-20)

Jim Perkins
09-08-2007, 01:00 PM
I want to purchase a K10 and take different types of photos ranging from sports to nature, infrared to weddings. My father is a retired photographer who used a Pentax 645 as his primary medium format camera. I know the quaility of his camera and lenses is excellent and I was wondering if using those lenses with an adapter on a K10 would work as well as they did on the 645? Any thoughts?

Didache
09-08-2007, 10:50 PM
Oddly enough, I read somewhere that DSLRs (not just Pentax) tended to be set to underexpose very slightly (in their default configurations). The rationale is that it is easier to correct that than to recover blown highlights. I don't know if that is generally true, but both my DSLRs do tend to the underexposure (not much, maybe 1/3 stop)

Mike

jgredline
09-16-2007, 02:03 PM
Hi
I can't see the images. :idea: