You can only use the lens in two modes. AV in which case the camera never stops the lens down to marked aperture but always exposes wide open, this does continuously set the correct shutter speed, (this is alright for "available darkness" shooting. M mode where you set the aperture and meter using the "green button". With the Ds this is accomplished with pressing the AE button, which stops down the lens to shooting aperture then sets the shutter speed for you, or holding the Off/On/DOF switch in the DOF position which stops the lens down while leaving the meter on. You can then adjust the aperture and shutter speed to zero the meter. You then take photos until the light changes enough to merit taking another meter reading. It's a lot easier than it sounds either way. The biggest disadvantage, aside from making an exposure a bit more complicated is that you may run out of the EV range of the meter. Something you have to remain aware of.
Glen Berry wrote: > Hi, > > I have a Pentax DS, and I'm thinking of buying a used manual focus 28mm > lens for it. I already have a 50mm f2.0 manual focus lens and I like the > image quality and fast maximum aperture quite a lot. > > My 50mm f2.0 lens has an "A" setting on the aperture ring. I leave the > lens set on this, and adjust aperture on the camera body. I like it just > fine that way. > > However, I've noticed that some of the used 28mm lenses I've seen have > an "A" setting on their aperture rings and some don't. What would be the > disadvantage, for a DS user, to not having the "A" setting on the > aperture ring? I assume that shutter-priority and program-mode auto > exposure would be out of the question. Is there anything else I should > know about? Would I have to use "stop-down" metering with such an lens? > > thanks, > Glen > > -- Entropy Seminar: The results of a five yeer studee ntu the sekend lw uf thurmodynamiks aand itz inevibl fxt hon shewb rt nslpn raq liot. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
