RF extender experiences with RF 100-500 1.4x vs 2.0? Locked

frostybe3r wrote:

Franz Kerschbaum wrote:

This time everything you wrote is correct! Good to see some progess! (By the way: I am frequently in such situations you describe. Thats why I dont sell my EF Superteles before the RFs become available) At the same time I know of many situations where a lens like the RF100-500 also with an Rf1,4x has its application. And all this is based on simple optics.

What gets me is the 'just increase ISO, it'll be fine, cameras can handle it' argument. The R5/6 maybe alright with high ISO but they're not that good.

You're thinking in an inferior, photographically-indirect paradigm.

I am not academically clever here, even though I did graduate from college with a 4.0 and two A+ grades. I am as practical and down-to-earth as a rock tossed at a window. It is the idea that f-numbers, ISOs, and exposures dictate "image quality" that is theoretical, academic, and practically flawed.

ISO does not dictate underlying analog subject quality. Underlying analog subject quality is dictated by the quality of subject illumination, subject size, subject distance, entrance pupil size (and any aberrations), and shutter speed, as well as pixels-on-subject (when you capture it in a sensor). If the subject doesn't fit in the sensor's frame, then you have to change something, but as long as it fits (and the context in the rectangle around it that you want), then these parameters are the ones that matter most.

ISOs, exposures, and f-numbers do not appear in the final images in any absolute sense. Sure, if you stop down, and change nothing else, subject noise goes up with the f-ratio and the ISO, and DOF increases relative to subject depth, but that's only because you haven't increased subject size on the sensor. If the f-ratio goes up due to an equal increase in magnification from a TC, then these things do not fundamentally change; you just have better sampling, for the most part.