Despite the negative reviews, I purchased a Opteka 500mm mirror lens and a 2x teleconverter awhile ago. Last week I was finally able to go to the beach and take some test shots. Per the title, My final set up was a manual focus 1000mm lens @ f 12.6 on a Sony a7ii. The IBIS in the Sony is what allowed me to handhold the lens and at 1000mm, I think thats amazing.
I was shooting at 1/1600. Because its a mirror lens, the aperture was fixed at 12.6 ( 6.3 + 2x tele ) and the ISO was 800 to 1250. This trip I was more interested in the reach of the lens and next time out I will try to figure out the sweet spot for the settings.
I was pleased with the results. However, the contrast and sharpness of this lens is horrible and it took a lot of adjustments in Lightroom.
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