Using teleconverter vs cropping with new mirrorless cameras

[Ivan Rothman]

In 2016, Steve posted a video about whether better to use 1.4X TC or to crop to DX in the Nikon DSLRs.
https://backcountrygallery.com/comparison-test-crop-camera-vs-1-4x-teleconverter-full-frame/
His conclusions were that TC always causes some loss of sharpness and therefore sharper results when cropping than when using DSLR. For example using a 20MP cropped sensor camera was better than using a 20MP full sensor camera with TC.
My impression was that if using an FX sensor camera, if it is 20MP and cropping reduces size to 12 MP, then using TC is better than cropping. But if it is 40+ MP sensor and cropping reduces size to 20MP, then cropping is better than TC.
Now with the new mirrorless cameras, the Z lenses and teleconverters are better than the older F-mount lenses and TCs.
I would love to see some testing (or maybe I'll try doing the testing myself) to see if it is better to use a TC or better to crop to DX. Especially with a high MP camera like the Z9.

 

[bleirer]

I think the old order still holds, as Steve showed it in his excellent demonstrations with all the variables of lens, lens plus TC, and pixel density. It's still "pixels per duck" that counts with the quality of the image projected onto the sensor by the lens or lens plus tc combo being a big factor.

 

[Doug Herr]

"Pixels per Duck" rules. Many stock agencies have minimum un-interpolated pixel dimension requirements or minimum file size requirements. Depending on how much you crop, there will be times when the photo made with a TC will meet that requirement and cropping will not.