thanks to all who replied. today I used some force and now it seems to work better.
the short version: looks like the aperture lever is/was bent such that somehow the camera releasing it for stopping down did not have effect. slightly re-bending it did have positive effect, and the over-exposure problem seems to be gone, but I guess having it looked at it by pentax to get it really fixed wouldn't be a bad idea -- aperture lever doesn't look extremely well. current shape of aperture lever, after applying a little force: http://www.cs.utwente.nl/~belinfan/lens/ (handheld k10d + panagor auto macro converter (K) + FA*28-70/2.8; kitchen halogen lighting - best I could do on short notice) the long version: I tried exercising the aperture level, as suggested. made some more test shots; no effect. actually, looked like the more stopping down I wanted, the larger the over-exposure. I looked a bit better at the lens. actually, the aperture level seems bent away from the lens, i.e. it is not fully parallel with the bigger thing next to it, but it is sticking out a bit away from the lens, so where it is furthest away from the lens flange it also most far away from the lens. I actually was aware of this, but had not paid to much attention (but what do I know of how the lever should actually look on this particular lens.) new hypothesis: maybe the aperture lever somehow gets stuck inside the body and doesn't get released, even when the body does attempt to stop down the lens. I took some looks at the lens while doing the K10D preview with sufficient long time, to see if diafragma closes at all, and bingo, looks like the lens isn't stopped down at all. hypothesis seems more and more likely. I tried something nasty: I tried to bent the aperture lever back a bit. once again do the preview thing. now the diafragma does close. more test shots, quick test series using the hyper-program shift to stop down a bit more in every exposure. they are not entirely evenly lit, but the over-exposure seems to be gone. exposure might be explained by small shift of the camera, I guess (even though you wouldn't want that). I did not try the same preview experiment with Z1 before re-bending; I did try after, the dof-preview shows stopping down. now that I had the Z1 next to the k10d I also noticed the smaller 'mirror house' of k10d - and I noticed a small scratch in the k10d black matte paint in the mirror housing, on the part that is parallel with the sensor at the opposite side of the aperture lever notch in the body, where the straight vertical line of the mirror-housing box is shifted sideways one mili-meter or so. the scratch is about 1 cm long, semi-circular, and really looks like made by something sticking out from a lens that was turned in an attempt to mount it. there are also minor 'scrape signs' just under the bottom opening for the lens flange (near the contacts) since the free space in the lens mount is now smaller than with the non-digital camera's I've been using so far, I'm really starting to wonder if I tried to put on the lens some 180 degrees off and then somehow bent the aperture lever on the lens. I know I'm not especially careful when changing lenses; usually it 'just works'. Regards, Axel. > So your apoerture is hanging.IT's not stopping down properly befor the shiot > is released. Exesize it 100-200 times. I use an old plastic film canister > container for this. It will take you less than 5 minutes. > Regards > > Jens Bladt > > -----Oprindelig meddelelse----- > Fra: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] vegne af Axel > Belinfante > Sendt: 5. juni 2007 21:07 > Til: pdml@pdml.net > Emne: K10d FA*80-200 f/2.8 consistent overexposure unless fully open? > > > I just subscribed to the list, essentially to ask the question below. > > I recently got myself a K10d. When I use the kit 18-55 mm > and a FA*28-70 f/2.8 everything seems to work fine. > > However, with my FA*80-200 f/2.8 (aperture ring set to A) > I seem to get consistent overexposure (2 stops or so?), > _except_ when using it fully open (at 2.8) using the > hyper-program shifting or by using Av mode at 2.8. > > It almost makes me feel there is something wrong with > the way the camera tries to set aperture on the lens > (which would explain why it works fine at 2.8: > then it doesn't have to do anything so it works). > Would that be a valid explanation? > > Setting aperture using the ring on the lens, and > then using lcd-preview gives me correct (not overexposed) > preview shots. > > I have not been using the lens so much recently; in the > somewhat longer past I've been using it on a Z1 shooting > slides (last serious usage about a year ago, at the coast) > and I don't recall this kind of consistent overexposure. > I should probably just do some test shots with the Z1 > but haven't found the time. > > Sending the stuff in to pentax service, or even better, > visiting them, would have been another option except > that the dutch pentax service told me they send these > kind of things to pentax europe in Hamburg > (which doesn't really matter, except that if the dutch > pentax service in Breda would still have existed I would > just have visited them there and explained the issue) > and except for the wrong-time-of-the-year problem > (I've been told that due to holiday season it might > take weeks until I would get it back :-( > > > > Don't know if this is the right forum for these kind of questions; > I have seen there are multiple pentax forums out there, but don't > know how they differ. Any thoughts? > > Minor suggestion: inclusion of (pointer to) PDML mini-faq > on the mailing list web page (and/or in list welcome message) > could be useful, if only to be able to appreciate the acronyms. > > > Thanks, > Axel. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
