An Open letter to major camera manufacturers has been issued on the LL due to the apparent discrepancies of the light loss from certain lenses and manufacturers bumping up the ISO -without the user being aware- to compensate for this loss of speed.
it makes for some interesting reading.
An Open Letter To The Major Camera Manufacturers
My personal thoughts in regards to pentax is that this would become painfully obvious is pentax was doing this behind the scenes ISO push. E.G: If a photographer using a M 50mm f/1.4 lens - with no electronic communication between the lens and body it would be impossible for the sensor's ISO to be increased because the camera has no idea of what aperture is being used. And if said photographer suddenly switched to a DA*55mm f/1.4 and noticed a difference in exposure/noise level then things would be looking fishy. As far as my experience goes I have heard reports of people experiencing differentials in exposure when they take their lenses off the A setting and controlling the aperture manually.For examples sake setting the aperture electronically to f/4 taking an image, and then repeating the process but manually setting the aperture to f/4 yields slightly brighter/darker images on certain lenses. Could this be evidence of this phenomenon?
Last edited by Digitalis; 10-27-2010 at 04:53 PM.