You know, If you think about the geometery invloved, it would seem that if the shutter speed is correct for a middle aperture like F8, wider apertures like f2.8 would be underexposed and smaller apertures like f22 would be overexposed. Seems like a good design would be right on the money at F8 in order to minimize the error at smaller or larger apertures. How big are these errors is fstops is the question??? I've never tried to measure it. What confuses the issue is the accuracy of the fstop aperture setting too, this is never perfect and varies from lens to lens. Good thing exposure latitude is wide enuff in most films to mask the "problem". JCO
> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of Shel Belinkoff > Sent: Sunday, April 07, 2002 11:06 PM > To: [EMAIL PROTECTED] > Subject: Re: RE: Leaf Shutters > > > According to the Kodak Professional Photoguide, as well as > numerous sources on the 'net, including mailing lists that feature > cameras with leaf shutters, high shutter speeds used in conjunction > with smaller apertures produce slower effective shutter speeds, > producing more exposure than the indicated shutter speed/f-stop > combination. This is caused, according to Kodak, "by the geometry > of the lens-shutter-diaphragm assembly combined with inertia of > moving parts, and is not a manufacturing defect." > > "J. C. O'Connell" <[EMAIL PROTECTED]> wrote: > > >I havent noticed this with mine ( 90mm SMCT LS for 6X7 ) but I > >seriously doubt that Pentax would "design-in" an exposure error > >on what are professional products. > --- > Shel Belinkoff - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
