Topaz AI & teleconverters

[MikeWPM]

I am evaluating the x1.4 vs x2 teleconverters on my A7iv with a 70-200 GM ii lens. My goal is to reach a nominal 800mm for the occasional capture, of wild life or other distant objects, while traveling light.

Getting mixed results on the x2 as others have reported but I saw a significant improvement in image quality in the x2 & x1.4 by using Topaz AI, sharpening, reducing noise and up-scaling by x2. The resulting (particularly the now uncompressed DNG) files are big but the images are greatly improved and can be cropped giving good results and reach.

For example:

x2 : 200mm x 2= 400mm, upscale by x2=800mm.

x1.4: 200 x 1.4 =280, upscale x2= 560 mm, I still have 33M pixels to crop and reach 800mm.

Given the already established performance of x1.4 Vs x2, (low light, focus IQ), is it generally better to have more pixels of the x2 or the better IQ of the x1.4 prior to processing in Topaz or similar software?

The x1.4 IQ appeared marginally better despite the Topaz processing introducing (manageable) artifacts at times but overall, both are very good and that is my quandary; which one should I send back?

 

[Uncle Kevriano]

I personally think that the light loss on a 2x is too much, even on a fast lens, unless you always have good light. Given the resolution you have to crop with the 1.4 is plenty. I will also add, less affected by atmospherics.