The *ist D does NOT measure light with open apeture (It can, though). I stops down when the green button is pressed (if Firmware 1.1 is installed) and meter the light at working aperure - and if "F stop other than A" is "ON".
Most modern camears measure with open aperture, calculating the right exposure when releassed. I believe this is done bey the aperture simulator, invented by Topcon many years ago (late sixties perhaps) and later copied by most other manufactureres - like Pentax and others. Older cameras - like the Pentax Spotmatic series, had to be stoped down in order to measure the light, just like the *ist D with a K or M lens mounted. It's kind of sad to see, that Pentax took such a huge step backwards, IMO. Jens Bladt mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt -----Oprindelig meddelelse----- Fra: John Francis [mailto:[EMAIL PROTECTED] Sendt: 16. november 2004 07:12 Til: [EMAIL PROTECTED] Emne: Re: Using pre-A lenses on *istDS (was:*ist-DS english manual) Andy Chang mused: > > Thank you James for the info. > I had a quick look and read the part most important to me several times > (Page 179 of the manual, Page 181 on the PDF doc). > Correct me if I'm wrong... > 1. Does it mean that the DS will only meter at wide open with the old > lens? Yes - just like the *ist-D > 2. If I want to get metering at different aperture, I need to connect > the lens to an Extension Tube K? Yes - just like the *ist-D > 3. Or if I want, I have to go full manual, then use DOF to get the right > exposure... Yes - just like the *ist-D On the *ist-D, in manual exposure mode, pushing "the green button" makes a one-time setting of shutter speed, performing a stopped-down metering step. There is supposedly a similar capability in the *ist-Ds (although as there is no "green button", it's done by something else - the AE-L button, IIRC). I'm not surprised to find no mention of this capability in the manual; it was almost certainly added as an afterthought (just like the *ist-D :-) after the manual was written. > If all of the above are true, I'm going to buy istD.... not DS.... That won't help you :-) > Or I have to buy more AF lenses.... > Argggggggggggggggghhhh > > Andy Welcome to the wonderful world of enablement! You don't need AF lenses, though - just lenses with an "A" setting. That's basically every lens Pentax has made in more than twenty years.
