Tried to get some comparison photos using my 400-800mm G and 100-400mm f/4.5 GM with the Sony 2X TC. I did not realize that the first comparison I had the zoom off from 400mm, and no that was not due to lens creep, just did not get it over to 400mm. The second comparison I had both images at an effective 800mm.
One thing to note is that the 100-400mm does have a lot closer focusing capability. That can make a difference in a case like this where I was photographing dragonflies.
My take on these are that they are very close, with a slight edge going to the 400-800mm. As usual, copy variation may play a role in results. I will say that I have never been super happy with the results from my 2X, with the exception of when I had it on my 300mm. But even then it was a step down from the bare 300mm and the 300mm with 1.4X.
I added 100% crops of the last two images. Processing was in Lightroom Classic with denoise and highlight and shadow corrections. Same settings for both lenses.
Jul 15, 2026 at 12:19 PM
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