It's odd that you would see this pattern when using Takumars (presumably M42 screw mount?) stopped down in Av mode. The camera body knows nothing at all of the lens opening in those cases and should be responding to the light as if the lens were wide open. At least in the green-button stop-down mode case, the body has stopped the lens down from wide open to working aperture so there's something going on there that could account for it.
Some folks have told me that replacing the focusing screen with a Pentax *ist DS focusing screen solved the problem. I might give that a try when I get a moment. I tried switching my custom Katz Eye screen from the DS into the K10D but found consistent underexposure with FA/DA lenses so that wasn't useful to me, but perhaps the Pentax DS screen will act differently. Godfrey On Apr 30, 2007, at 2:31 PM, Bob Rapp wrote: > Thanks Godfrey, > The "lens based aperture" is exactly what my experience is when > using K > and M lenses. Also, in Av mode, the same pattern is present when using > Takumars stopped down. > > Cheers, > Bob > ----- Original Message ----- > From: "Godfrey DiGiorgi" <[EMAIL PROTECTED]> > To: "Pentax-Discuss Mail List" <[email protected]> > Sent: Tuesday, May 01, 2007 7:06 AM > Subject: Re: Firmware 1.10 > > >> Not really. I did a quick test and found that green button semi- >> automatic exposure mode still overexposes. Perhaps not quite as much, >> but I don't have enough data to assert that. This is on a single pass >> through all the metering patters with Av, green button stopdown mode, >> then standard manual mode with the lens locked on the A setting: >> >> http://homepage.mac.com/godders/PentaxK10D_1.20fw_metertest.jpg >> >> You can see that the CW and Spot settings on stop-down mode tend to >> go to overexposure, but it's fairly predictable. >> >> G >> >> >> On Apr 29, 2007, at 9:11 PM, Bob Rapp wrote: >> >>> Anything new with regards to exposure errors when using K and M >>> lenses in >>> manual using the green button? >>> >>> Bob >>> ----- Original Message ----- >>> From: "Godfrey DiGiorgi" <[EMAIL PROTECTED]> >>> To: "Pentax-Discuss Mail List" <[email protected]> >>> Sent: Monday, April 30, 2007 1:13 PM >>> Subject: Re: Firmware 1.10 >>> >>> >>> Remember that the K10D's 1.10 update incited second curtain sync and >>> possibly wireless remote flash issues. >>> >>> I have v1.20 installed now. Some folks on DPReview have reported >>> reduced noise with it. >> >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net

