K10D Stop down metering exposure problem

Sorry, but that's so untue in both cases. Using lenses and the seriousness or otherwise of the images has nothing whatsoever to do with the method of capture.

Would you say shooting black and white film was for serious photographers but shooting colour was for snapshots?

Professional photographers will use whatever is appropriate to their purpose. The result is what counts, not what you use.

With respect, John, a professional has to make every shot count. For that reason alone, RAW is well worth using because it acts as a great insurance policy against inaccurate exposure.

Whilst YOU may be able to guarantee perfect exposure with every shot, busy professionals don't necessarily have the time to take accurate readings with hand-held exposure meters. They often have to shoot first and ask questions afterwards. RAW gives them much greater latitude than JPEG.

Then there's the question of the need to tweak the image a bit for reasons other than wrong exposure. The possibilities are much greater in RAW because you have much more information to work with.

So I think Arthur is right in saying that RAW is for professionals. Serious amateurs with a leisurely approach to static subjects may allow themselves the luxury of shooting JPEG, but that's what it is - a luxury.

And finally, once you've got a handle on Silkypix or one of the other converters, processing RAW doesn't really take very much time - arguably less time than trying to disguise even slightly ill-exposed JPEGs.

G

I've never seen anyone do a demonstration on 'RAW' and I haven't got anything on this computer to do it yet although there is a mention of the'Silkypix' on the K10D camera box it doesn't come with it and I e-mailed Pentax if I COULD use Windows ME edition with the software and today they replied " Computer says 'NO'". ( Anyone out there 'Little Britain' fans?)

Unfortunately, it is not that straightforward as the metering problem is so variable. I accept that there have to be restrictions but it would be good to understand what exectly they are -and to have been clear on this BEFORE I bought the camera. If I could guarantee that I always got an accurate exposure using just DOF preview at just one aperture setting then I could compensate for this, but the problem seems to vary with the light intensity. In low light, I seem to get an underexposure above f8 with accurate exposure in the f4-f8 range. This morning, I am getting an over exposure in the range f2.8 - f8.

If Pentax were clear on these "restrictions" and exposure problems and explained that TTL metering does not work reliably with M and K series lenses, then those of us to whom this is important could have taken an informed decision: Basically we either chose a 6MP Pentax Digital or accept that we carry a light-meter/make adjustments in our heads.

The situation is far from clear:

i) Is this a problem with all K10D cameras? (If not, then an exchange should be offered)

ii) If it is a problem with then all, can it be resolved by a future firmware fix? (in which case we might decide to hang on) or is it a hardware fix? (in which case we might just as well get a refund and either buy a 6MP model or wait for a revised K10D)

iii) If it can't be resolved, are Pentax committed to addressing the issue on a future camera, or have they accepted that this is as far as compatability goes? (If so, again, we can make an informed decision.)

Pentax Europe, although helpful on the phone, are clearly very vague as to the exact nature of the problem and the type of exposure errors that may occur. I am left with the feeling that they have released a beta version of the camera which has an unresolved issue - the question is, how are they going to resolve it if at all?

As far as new lenses go - I accept that they are the future, and will invest in them as I already have. It would be nice to be able to use some of the older superb optics on a compatible DSLR - but maybe we will have to accept that the K10 is not actually compatible......contrary to what we were told.

Hi, I'm new around here. Sorry to jump in, but I'm a bit confused.

First, my camera is a K100D, not a K10D, and second I'm definitely not a professional photographer. For the last 20-odd years I've been using an MEF (which incidentally came with a KA 1.7 lens - probably they'd stopped making the AF lens by the time I bought it).

I have mainly M and KA lenses, and I haven't had any problem with either of them, once I found out you can't use old polarizing filters.

Now, with the M series lenses I can use them three ways,

a) aperture priority. which gets set regardless of what you set the dial to except manual, where as said they stay wide open but you get the right exposure within that limit

b) manual using the AE-Lock which gives an 'instant' exposure setting locked until the meter times out. This will expose correctly providing nothing moves (and will correctly close the aperture when the shutter is fired)

c) manual using the DOF on optical. zero in on the right exposure using the EV display, aperture is closed normally when you press the shutter. This produces right exposure within normal level - by which I mean errors I get are the normal sort of error I can easily commit on the old MEF. Plus, you can check round different parts of the area of the picture to check highs and lows, i.e the difference to b) is the metering is dynamic rather than a single snapshot.

Now, is there something that I am missing, or is it simply that all this works on the K100D and not on the K10D - in which case I'm pretty glad I didn't wait until I could afford the K10!

Regards

Pete

Hi Pete

No - you are not missing anything. It seems that this problem is unique to the K10D - hence my whinge!

K10D users essentially have the same 3 choices that you do, but it would appear that only (a) (Aperture wide open) works correctly. Stopped down metering using the "green button" (similar to AE lock) or manual DOF metering is not reliable and throws up some wild results.
It seems (from the various posts on this site and others) as though this issue varies between individual cameras and different light intensities.

In short though - your K100D appears to function a lot better on this point....want to swap?

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.

I wouldn't go that far.

Despite the annoyances with M series lenses, and A-lenses in non-A mode, I still don't regret buying the 10.

My photographic mojo had completely evaporated after the shutter lag with my digital compact (Sony DSC T3) drove me nuts, but it's back now with the '10 and I have enough A- and later lenses to keep me at it.

It would be fab if Pentax waved a magic wand and fixed the stop-down performance with a firmware update - or indeed if it could be shown unequivocally that some bodies have the problem and some don't.

I'd still like to see some rigorous test results from those claiming that their '10 has no problems with stop-down metering.

It can't be hard, surely - slap an A lens on the front, and take a series of shots with the camera in manual and the lens in A, and then the same series with the camera in manual and the lens not in A - but use stop-down metering to pick the exposure.

If a) the exposures are the same in each series (or nearly) and b) the exposures follow the law of reciprocity as the F-number changes (because they surely do with the lens set to A), then I'll be straight down to Jessops asking for an exchange.

um, no I don't think I'll swap.

But it's saved me second guessing my decision to go for the K100D - which was really all I could afford anyway. I just wasn't sure that I was understanding the correct way of using it - there's a lot to learn.

Regards

Pete

Chris,

I've been reading this thread with interest, I haven't actually tried any of this out as the only M lenses I have are 50mm which are attached to old MF bodies that I learnt on. As I've got the same focal length in AF there's no need to use the older lenses on the K10D...

Is one way of testing things to get a couple of K10D owners together and try out the tests in unison, same lighting, same lenses, same settings - if all of the bodies show the same exposure values then at least you know it's a set problem and not specific to just your K10D body?

Will

It would be interesting but not conclusive, since it would be hard to ensure that the two cameras were looking at exactly the same thing. As has been observed by others, the camera only needs to point at a slightly different part of a heterogeneous scene for the exposure to vary quite a bit.

If the scene was a big grey card, of course...

But I still think that the comparison we're looking for is between A mode and non-A (ie aperture ring) mode on the same (A-series) lens, on the same camera. Consistency across bodies is desirable, but it's a different issue.

The camera stays in manual for both, and the exposures should be the same at corresponding apertures, set for A-mode and non-A respectively at the camera and the lens.

Another interesting phenomenon that I have just noticed:

When using DOF (Optical) preview in Hyper Manual, the EV meter in the viewfinder is 1-2 stops different from the meter on the top LCD. Invariably ONE of them is showing correctly...but it seems to vary as to which one. This happens when using DA AND M series lenses.

Using the green button tends to select one of these two at full aperture and the wrong one at fully stopped down

Am I doing something really stupid? Or is this just weird?

Are you covering up the viewfinder when looking at the top LCD?

Thanks Chris - I was covering it with my hand - but will re-run the test over the weekend using the little plastic cover just to be sure. Am returning the camera for an exchange on Monday anway...will be interesting to see if the next one has the same DOF exposure problem.

Sorry if I was teaching my granny to suck eggs...

But I'll be very interested to hear if the new one is better or the same.