Comparison of RF 1200mm f/8 L and EF 600mm f/4 L II with 2X III

JohnMoyer wrote:

KevinRA wrote:

JohnMoyer wrote:

An even lower budget path to long focal length.

Since I was stuck at home, I experimented with stacked teleconverters. Hand held, auto focus, F number of 18 when wide open would be 16, motion blur, diffraction blur, very slow AF, DPP digital lens optimizer, focus limiter switch set to full range. With this combination if there is low contrast then AF will bang back and forth between near and far.

Monarch Butterfly (Danaus plexippus) on Zinnia in Norman, Oklahoma, United States on October 5, 2022. Focal Length 1120.0 mm, EF100-400mm f/4.5-5.6L IS II USM +1.4x III + Kenko TELEPLUS HD C-AF 2X DGX

A lovely butterfly.

I do wonder here though if you are gaining anything by stacking the TC's with this combo - e.g. the re the depth of field and sharpness hit.

Thanks.

In this case you are correct that I did not gain anything except isolation of the subject from nearby surroundings. There is much less contrast with the stacked teleconverters and increasing depth of field increases diffraction blur. There is motion blur because the bug was moving and the wind was moving the flower.

It was an experiment. It demonstrates that at some time in the future when I cannot get close enough this will work. Usually 560mm or 800mm is enough. And it costs less money than some other solutions to the same problem.

for me, using my canon 100400 mk2 and a TC 1.4 III has been enough to deal with images like this and birding. i do have the canon 600 f4 mk2 but it is a monster to handhold without a tripod.

the other and better option for me is using my canon 300 f2.8 II and TC 2.0 III, which gives me an instant 600 f5.6 with high IQ focal length. 300 mk2 is a pretty light lens for me that doesn't tire me out carrying it all day. YMMV.