On Sun, Feb 11, 2007 at 10:32:37AM -0800, Godfrey DiGiorgi wrote: > > That said, if you use *only* older lenses with the green button stop- > down metering, you *might* find that exposure accuracy improves. Some > have reported that fitting a DS screen solved this K10D problem ... > It might be that the exposure system recal they did for the other > modes is not applied to the stop-down metering mode erroneously. > > Godfrey
>From what I read on dpreview that isn't the case - in fact metering is quite likely to be *worse* with old lenses on the K10D, no matter what screen is in the camera. The extra viewfinder brightness in the K10D comes with a cost; a very non-linear change in illumination on the metering photocells with aperture. The K10D is programmed to automatically compensate for this, but to do so it needs to know the metering aperture. With older lenses it doesn't know this, so presumably it uses some fixed default value. If this doesn't match the actual aperture being used then there's going to be a metering error. Some user reports suggest that the problem is most noticeable with fast lenses being used wide open. If that is the case then errors from stop-down metering presumably become reasonably linear at small apertures. Fitting a DS screen will change the size of the fixed part of the error, but will do nothing to help with the way the error varies with aperture. I'd suggest sticking to spot metering when using the green button. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
