Hallo Freunde,
My long-awaited extension rings from JJC have arrived! To determine the maximum magnification, I screwed all rings together between my Canon EOS 90D and the Canon EF-S 60mm f/2.8 Macro USM and simply made a direct comparison.
Ok, I'm sure there are some of you who can calculate this with a formula, but I got nowhere with it.
Here is a direct comparison:
Without extension rings, the set 2mm from the caliper (at minimum close-up limit) corresponds to ~632px. With the extension rings I end up with ~1563px!
Converted to the installed APC sensor with a width of 22.5mm and a pixel resolution of 6960px, this also fits approximately (2mm / 22.5mm) * 6960px = 619px).
So this corresponds to a maximum magnification of almost 2.5:1 compared to 1:1 from the normal macro lens!
Qualitatively, I can't find any problems with the rings (at least in the first tests). They snap tightly and cleanly into place and transmit the electrical signals from the lens without any problems.
Longer / heavier lenses are certainly still to be used with caution, because the lever becomes enormously long!
Apart from that, you should also definitely plan for the loss of light! With the maximum equipment, the extension rings cost me a whole 8 f-stops! In the example pictures, that was a difference of 3.2s to 20s! So freehand without flash will be difficult!
Here is another picture from today, which I took (unfortunately in stormy weather) in nearby forest.
Translated with www.DeepL.com/Translator (free version)
Unfortunately it's a little blurred during stacking, but quiet ok for a small 2-3mm slime mold!
In the sense...
"No light is no solution"
Die Wirkung ist schon genial. Gratulier! Ich habe die von KOOKA 12/20/36 mm und bin ebenfalls sehr zufrieden damit. Sie sind im freien sehr praktisch und wesentlich einfacher zu bedienen als ein Umkehrring! LG René