I believe the article is written using an overly hysterical tone. This isn't news. It has long been known that the metering in many digital cameras takes the maximum aperture of the lens into account. In the case of Pentax it was discussed when the K-10 was a fairly new body (I believe Ned Bunnell even confirmed that the K-10 metering behaved that way).
The is generally believed to be why metering errors are more visible with old, fast lenses used wide open (often reported for the 50mm/f1.2); as the charts show, the effect is only really noticeable at an aperture wider than f/2.0. I suspect that, in fact, the compensation for this effect is done by changing the measured Ev, and using whatever auto-exposure the camera is set up to provide. Most often this will result in a slight change to shutter speed (in Av mode), aperture (in Tv mode), or both (in Program mode). Presumably the camera has been set up in an auto- mode so that it can take care of the exposure adjustment; it seems unreasonable to complain if this also compensates for the known characteristics of the sensor. The only time this wouldn't happen would be if the camera was being used in manual exposure mode. But if you follow the oft-given advice, and check exposure using the histogram at the start of a shoot, you'll get that right too. On Wed, Nov 03, 2010 at 11:38:42AM -0400, Steven Desjardins wrote: > The best thing would be to admit the correct and allow the shooter to > turn it on or off with a custom function. Why change the iso anyway? > why not just change the Tv? > > On Wed, Nov 3, 2010 at 11:30 AM, CheekyGeek <cheekyg...@gmail.com> wrote: > > On Wed, Nov 3, 2010 at 10:15 AM, Steven Desjardins <drd1...@gmail.com> > > wrote: > >> The funny thing would be if they > >> didn't correct there would no evidence of it in this data but rather > >> in inconsistent exposure results between lenses. > > > > I guess I should have prefaced my comments as coming from one who > > really likes to use old legacy glass on my K-x (and before that > > K200D). Frankly, I'm not a DA buyer, so their current offerings are > > irrelevant to me. I'm interested in m42 Takumars and SMC K-mounts, and > > (to a far lesser degree) F and FA lenses designed for full-frame 35mm. > > And if you hang around in those circles that is EXACTLY what you hear > > about from some people. I've just never paid attention to the CAMERA > > BODIES that the complainers were using before. > > > > I'd really love to hear the Pentax Position on these issues. I think > > that most users would rather have the camera cheat the ISO in favor of > > proper exposure with a given lens, rather than force the photographer > > to keep track of the myriad exposure characteristics of each lens > > (which would change depending on the aperture you were using them > > with). > > > > Darren Addy > > Kearney, Nebraska > > > > > > > > > > -- > > Nothing is sure, except Death and Pentaxes. > > > > -- > > PDML Pentax-Discuss Mail List > > PDML@pdml.net > > http://pdml.net/mailman/listinfo/pdml_pdml.net > > to UNSUBSCRIBE from the PDML, please visit the link directly above and > > follow the directions. > > > > > > -- > Steve Desjardins > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
