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

Franz Kerschbaum wrote:

From my tests the 1,4x still helps a lot on the r5 to get mre detail on piuxel level but the 2x is not gaining extra detail over the 1,4x... for the r6 both are very helpful.

You are probably talking about blatant, contrasted details with possible marginal shutter speed, but the quality of sampling is still better with the R5 and a 2x, giving a better source file in general for any target resampling that needs to be done.  I used a 2xII with my 90D, which has almost double the pixel density of the R5.

I lean towards better sampling, weighed against any possible loss of AF speed or accuracy, which seems to be less with the R5 than my DSLRs, with TCs.  I have been noting also, as someone else mentioned in this thread, that teleconversion can turn a dot into an eye, helping the animal eye AF.

IMO, loss of AF or too narrow an angle of view for the expected range of sudden opportunities are the only two major reasons for not using a TC when you'd otherwise be cropping.  Perhaps bokeh (shape) might be inferior in some cases with a TC, which could be important if the quality of blur is important to a photo.  This is one area where pixel density may be preferable to teleconversion.

Concerns such as increased noise and less sharpness, etc, are usually bogus concerns informed by irrational pixel-level assessments, made in ignorance of the scale of subject size during 100% pixel view inspection.

TCs often get blamed for the real problem with captures: you can't get close enough, (including atmospheric effects at longer distances) or don't have a longer lens with an actual larger aperture.  A TC is not like "getting closer" with the same lens; it is like better sampling of the subject; a second-rate alternative to higher pixel density.  If you hold a TC to the standard of a "closer" illusion, it will fail you to some degree, some of the time.

Take the MTF charts given here - they are only directly relevant if you step back 1.4x and 2x as far from the subject, which is not a realistic representation of real world use of TCs.  Most people put on a TC because the subject is too small in the frame, comprised of too few pixels, without backing away.  Even if you do back away, large pixels make the loss effectively less than the charts would suggest, since these are analog MTF charts, and the pixel count causes an MTF factor of its own, which is often a more significant limit than the MTF of the lens.