Aperture recognition K200D

Can't figure this out. I've looked at the manual, honest.

With the above camera, I have two mirror lens.

1) Tamron SP Adaptall 2 PK mount 500mm f8
2) Chinon T2 PK mount 300mm f 5.6

On AV, the exposure seems OK with the Tamron, but the Chinon seems to need a full two stops exposure adjustment, and even then it's darkish.

So, I can't help but feel I'm missing something. How do I get the Chinon to work please? It doesn't seem a bad lens otherwise.

ok... i haven't got a 200d i have the 100d, but i do have the Tamron lens... on the 100d you had to select that the camera would accept a lens without an automatic aperture (it is in the custom setup screen).

now, the adaptall was in two versions (i believe). one relays the aperture info. could it be that this is happening, so the camera knows it's an f8, but doesn't know what the Chinon is? is the camera set up to take non auto aperture lenses?

sorry i can't be of more help, but i'm sure someone else will be.

Are you using manual mode and pressing the green button to get a light reading? Even if you are, there is an issue (with the K10 anyway) that it will not do a good job of getting the metering right. I suggest you set the thing on a tripod pointing at some flat neutral scene (a grey card if you have one), press the green button for manual metering, take the shot, check the histogram, then dial in some exposure adjustment and try again. After a bit of experimenting you'll know to add or subtract x-amount to the manual reading for that lens. As it had a fixed aperture you won't have the problem of compensating for different f-stops.

Hope this helps. Kris.

The stop-down-metering issue is with the K10D as you say. However, it's only when it is stopped down in Manual mode using the green button or the DOF preview lever. There is no issue with wide-open metering, manual or otherwise, with the K10D.

Some are of the opinion that the K10D underexposes generally by a little more than half a stop. But that has nothing to do with the stop-down metering issue, which manifests itself as a progressively increasing over-exposure with increasing F-number.

Mirror lenses are usually fixed aperture, always effectively wide open, and so I would not expect this particular issue to be relevant.

From what I've read, but cannot verify, this was not, apparently, a problem with the K100D. I haven't read any comments about the K200D in this context.

I tested the exposure problem on my K10 a little while back and found it gets progressively worse as you say until about f/11 then got better again. Not sure what the issue is with the Chinon lens but the fix -- determining a standard EV compensation -- should still help I would have thought?

BTW... does the K20D have the same problem with the M-series lenses?

Best, Kris.