"Oh Well" Department Prior to doing anything, I made a few exposures of a standardized test target with the K10D to check the histogram in both CW Averaging and Evaluative Metering modes. (Forgot to do Spot mode ... I hardly use it very much and expected it would be the same...)
I pulled the custom Katz Eye screen from the DS and fitted it into the K10D. Making the same exposures in both modes, the K10D now underexposed by -0.7 EV. Refitting the K10D's original screen restored its normal exposure accuracy. This means that for some reason, the Katz Eye screen is delivering +0.7 EV more light to the metering sensor, on average. (I did the same test in the *ist DS once again and found zero meter calibration change from stock screen to custom Katz Eye.) Then I called Rachel Katz and talked with her about what I'd discovered. There are several possibilities causing this difference, most likely are - the position of the metering sensor(s) have changed slightly relative to the screen, or - the tuning of the stock screen's scatter vs the rest of the viewfinder optical system has shifted in the K10D. So the long and the short of it is that at present this particular screen can be used with the K10D but it will require, on average, a +0.7 EV compensation setting. A possibility that Rachel mentioned was that the OptiBrite screen treatment they offer might tune the screen scatter to deliver brighter a image to the eye while decreasing the amount of light the sensor gets, netting a more accurate meter reading. She said she'd stay in touch if she learned anything more regards the K10D and their screen treatments. Godfrey On Jan 15, 2007, at 7:59 AM, Godfrey DiGiorgi wrote: > I had Katz Eye Optics customize a screen: > > - no focusing aids (split image prisms, etc) > - standard matte surface (no OptiBrite treatment) > - add the horizontal/vertical and 8x10 crop lines > > The result is a screen with a clean, unobstructed view and excellent > manual focusing surface. > > http://homepage.mac.com/godders/custom-focus-screen-DS.jpg > > It cost the same as a Katz Eye standard screen with the crop lines > added, about $140. It's been in one of my *ist DS bodies since I got > it, it's the best focusing screen I've had in a DSLR to date. I think > I'll test it in the K10D today to see if it causes any metering > errors, and put a standard screen back into the DS since that body is > going to Ebay... -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
