The camera in question also does Aperture Priority, and you can limit how far the program modes will stop down by setting the aperture to other than minimum.
-Adam John Francis wrote: > It will suffer from running out of metering range, though, just > as the Pentax green button stop-down metering workaround does. > > Nor is it quite as easy to predict what it will do. It sounds as > though the camera picks an aperture setting it wants to use, moves > the stop down actuator to the position that would produce the chosen > aperture with an "A" lens mounted, and then does a quick stop-down > metering step to adjust the shutter speed based on the actual > aperture (which, on a K/M lens, will not match the chosen aperture). > > I guess it's OK as an alternative to full program mode; most of > the time people wouldn't care too much if the program got shifted > slightly (I'd expect less than half a stop difference most of the > time). But I would get annoyed trying to use this as a substitute > for either aperture priority or shutter priority (unless the camera > adjusted aperture based on the stop down metering, not the shutter > speed); when I choose a shutter speed or an aperture value I want > the camera to do exactly what I ask, not some approximation to it. > > > On Sun, Oct 22, 2006 at 09:31:25PM -0400, Adam Maas wrote: >> Ah, but it is open aperture. The second metering after stop-down is >> merely for confirmation that the aperture was selected correctly. >> >> -Adam >> >> >> J. C. O'Connell wrote: >>> Its not open aperture either which is a big >>> Difference too and wont even work at all >>> In low light with smaller fstops ( meter sensitivity >>> is sucked away by stop down method at small stops. ) >>> jco >>> >>> -----Original Message----- >>> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of >>> Adam Maas >>> Sent: Sunday, October 22, 2006 8:37 PM >>> To: Pentax-Discuss Mail List >>> Subject: Re: Some observations on lens mount capability. >>> >>> If the aperture is set to minimum, you get Programed AE. It follows the >>> program line. And you only get an extremely short delay to teh firing of >>> >>> the shutter (Which is exactly the same delay you get with any camera >>> using pe-flash based TTL flash, like all P-TTL pentax bodies). >>> >>> So yes, this is Programmed AE. It's just not as elegant as pentax's >>> solution. >>> >>> -Adam >>> >>> >>> J. C. O'Connell wrote: >>>> I do not understand what you have posted. >>>> How can the camera set the aperture when >>>> Its turned by hand? If you just leave >>>> The fstop at minimum all the time you >>>> Are not really getting true program operation >>>> If the fstops are approximate, metering is stopped down, and you >>>> Don't get instant exposure when you fire >>>> The shutter LIKE PENTAX DOES. They may be >>>> Calling that programmed AE but its not >>>> The same as pentaxes programmed AE which is much better >>>> And without those degradations. We are talking >>>> About two different modes here with the same name >>>> Which is bad. Blame that on Chinon if they >>>> Call it the same as pentax's programmed mode. >>>> jco >>>> >>>> -----Original Message----- >>>> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf >>> Of >>>> Adam Maas >>>> Sent: Sunday, October 22, 2006 5:19 PM >>>> To: Pentax-Discuss Mail List >>>> Subject: Re: Some observations on lens mount capability. >>>> >>>> Funny, but my Chinon CP-6 does programmed exposure (with two seperate >>>> selectable program lines) with K/M lenses. >>>> >>>> It does this by selecting the desired aperture, attempting to set it, >>>> then remetering to confirm. >>>> >>>> The Nikon FA does the same thing with AI and Ai converted lenses in >>>> Program and Shutter priority modes. AI lenses are functionaly >>> identical >>>> to K/M lenses apart from their ability to mechnically communicate >>>> maximum aperture (the FA is one of two bodies which takes full >>> advantage >>>> of that to allow matrix metering). >>>> >>>> So reality proves you wrong. >>>> >>>> -Adam >>>> >>>> >>>> J. C. O'Connell wrote: >>>>> K/M lenses cannot support programmed >>>>> Exposure modes because in programmed >>>>> Exposrue modes the camera choosed the >>>>> Fstop and the shutter speed based on >>>>> Light condtions. K/M lenses cannot >>>>> Have their fstops set by the body because >>>>> They lack the consistant linear stop >>>>> Down levers ( even non-linear compensation >>>>> Wont work because the lensse are inconsistant >>>>> If you try to stop them down by partially >>>>> Actuating the stop down lever). >>>>> >>>>> IF it were possible pentax wouldn't have >>>>> Bothered with A series lenses. >>>>> jco >>>>> >>>>> -----Original Message----- >>>>> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf >>>> Of >>>>> Adam Maas >>>>> Sent: Sunday, October 22, 2006 4:23 PM >>>>> To: Pentax-Discuss Mail List >>>>> Subject: Some observations on lens mount capability. >>>>> >>>>> I've been thinking about exactly what K/M lenses are capable of, and >>> a >>>>> few asides. >>>>> >>>>> First off, you can do at least Program mode with K/M lenses. In fact >>> I >>>>> own a camera that offers this with K lenses(Chinon CP-6 Dual Program) >>>>> and another that does this with the functionally identical Nikon AI >>>>> lenses (Nikon FA). Shutter Priority is also possible if you are >>>> willing >>>>> to override shutter speed selection in some cases (the Nikon FA does >>>>> this with AI and earlier lenses) in both cases the camera double >>>> checks >>>>> the metering after stopping the lens down, the FA will override >>>> shutter >>>>> speed selection by up to a stop in either direction to compensate for >>>>> non-linear apertures, this only occurs at small apertures though. An >>>>> interesting capability of the CP-6 is you can limit the smallest >>>>> aperture the camera will select in program mode with the aperture >>>> ring, >>>>> the FA requires aperture to be set to minimum to work in P and S >>>> modes. >>>>> So Pentax has never chosen to take full advantage of the automation >>>> that >>>>> is technically possible with K/M lenses, even if they weren't >>> designed >>>>> with this in mind. >>>>> >>>>> Nikon has never produced an AF body that fully couples with AI-S >>>> lenses, >>>>> the F4 is the only one to fully couple with AI lenses. In fact Nikon >>>>> only ever made one camera that takes full advantage of the AI-S >>> mount, >>>>> the FA. And Nikon is the only other maker with reasonable backwards >>>>> compatibility with its SLR mount, but it hasn't fully supported it's >>>> MF >>>>> mount since 1989 (when the FA was discontinued). >>>>> >>>>> -Adam >>>>> >>> >> >> -- >> 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
