That seems to be a lot of difference betweeen the 2 lenses.

when I did the same type of comparison with the 31 ltd, the differences were much more subtle.

Maybe you could try again in better shooting conditions.

BTW, Malo, whats that new avatar of yours??? scary stuff, and I already miss the competition winning self portrait!

Why is it just not plausible that the lighting conditions are too bright for that lens?

I was getting 1/5000 on f4, (ISO100) by simply spot-metering the very over-cast sky over London, just now. I can safely say that a bright sunlit sky is going to be various stops brighter than that, and I would therefore need to stop the lens down to have the right exposure.

If I shoot with the 50-135 (@100mm) on f4, in the same situation, I get 1/3200. And compared to the scene described in the previous post, I get between 1/640 and 1/500 where the M lens was 1/1000.

Ohh Absolutely CHris!

All the 3 K10's i've had gave me consistently overexposed exposures exactly the same as yours. You're absolutely correct.

I have been doing all my shooting with the K-7 recently, and YEs the metering is greatly improved even with manual lenses. (Mine is the M100 f4)

By using the green button to meter at each exposure these are the results. (Same lighting conditions as you... )
Note - although the lens shows 7 f-stops on the barrel, there are indeed 10. I therefore don't know what exact apertures are in between the stated ones.
f-stop
4 1/1000
5.6 1/400
8 1/250
11 1/100
16 1/50
22 1/30
I then get 1/20 and 1/15 (somewhere over the aperture range there was an f-stop not mentionned)
f32 1/8

Just to make sure, all on K-7, the shots are PERFECTLY metered and the results absolutely consistent.

(another reason to buy the new toy Chris? )

Chris and Mannesty you're both right, and YES, i was wrong, and talking out of my ass...

My mistake is an honest one though, as I usually use the M100 macro in Manual mode, and always get a correct exposure by pressing the green button, or just by arranging the shutter speed myself (Which i'm quite used to doing). When I wrote the post I had just been shooting a few macros in Av with the same lens, and indeed, it was metering perfectly - but only wide open. Same subject in the same light lead me to think it was automatically metering, whilst it obviously wasn't. THerefore my mistake SORRY!!!


The meter does work in manual mode though, and this is where the problem still hasn't been solved: There might be physical (:twisted limitations to the lens' performance in bright light. In the end, any lens will need to be stopped down whilst shooting in those conditions. WHat I also wrote was that the two lenses are different, and unless there is a problem with the 135, its very possible that there are few stops difference between the 2.

Question is, how overexposed is your shot?
And also, does the problem appear in any other condition but bright sunlight?

CHeers

there is no physics involved.

the lenses are manual, but the camera has automated metering modes or non automated metering modes.

If you put a manual lens on a camera, set to Av mode, the camera will automatically read the aperture value (aperture ring allowed in Custom menu) and give an appropriate exposure.

I have manual lenses, and they work brilliantly this way.

NOW; once you establish that the camera can't automatically meter the lens, you should try (as mentionned before) to put the camera in Manual mode, and set the aperture (on the lens aperture ring) and the time on the camera.

If the results are still overexposed in a normal lighting condition, then the lens is faulty.
If though, you expose for the bright sky, it might simply be that the wide aperture is too bright for the maximum shutter speed of 1/4000.

Different lenses will have different properties and characteristics, it is therefore not necessarily true that if one lens behaves one way, another should as well.

there might just be a fault in the camera/lens connection.

If you are shooting in Av, change to M, and try all manual settings.

If this doesn't work, then the camera simply doesn't read the aperture setting on the lens. Or the lens is broken?

Just thoughts

I use a pentax microfiber cloth, but mainly a Kenair air duster for the small places I can't reach with my finger...

I use the compressed air also for dust on lenses, and it works a treat.

Caution needs to be used when (if) you want to clean the inside of the camera, because the cold air can freeze the sensor; therefore only use on mirror, or the top part of it, and never on the sensor...

Thats me in a very contemplative mood...


Matt how old are you???

oh my god!

I am the "Academie Pentaxaise" !!!!!!!!

ahahahahahaahahahah

THanks for that George



Mike, you should get a K7, I have been so incredibly surprised by the performance, I actually stopped lusting after the D700!

The second photo is definitely a better composition than the first one you posted

Daniel's suggestion of shooting earlier in the evening is priceless. I have shot around the area in the past, and the hour before sundown until darkness is definitely much better...

This is one of mine ... (show off.. )

[IMG]http://i517.photobucket.com/albums/u332/nathanever82/TowerBridge4.jpg[/IMG]