There is an opinion that the hot spots that you sometimes see when lenses not intended for use in the infrared are used there is the result of lens flare. In other words, the light that causes the hot spot is not light from parts of the scene close to the center of the image,… [Read More]

In yesterday’s post, there were some indications of hotspotting with the Zeiss ZF.2 35mm lens. I did a test for that today. In visible light, when I look for non-uniformity in field illumination, I use an Expodisc. I was worried that that technique might induce some artifact that I don’t understand. The sky was overcast… [Read More]

There aren’t a lot of people doing infrared photography, probably because, to do it right, you have to have a camera modified, and that’s a big step if you just want to get your feet wet. For that reason, this post won’t be useful to many people. However, because there aren’t a lot of people… [Read More]

This is a continuation of the real-world test of four 35mm lenses on the Sony alpha 7 Mark II: Sony/Zeiss (Zony) 35mm f/2.8 Zeiss 35mm f/2 Biogon M-mount Zeiss 35mm f/2 DIstagon F-mount Nikon 35mm f/2 Nikkor-D This post will look at the upper right at f/8. f/2 is here f/2.8 is here. f/4 is here…. [Read More]

This is a continuation of the real-world test of four 35mm lenses on the Sony alpha 7 Mark II: Sony/Zeiss (Zony) 35mm f/2.8 Zeiss 35mm f/2 Biogon M-mount Zeiss 35mm f/2 DIstagon F-mount Nikon 35mm f/2 Nikkor-D This post will look at the center and upper right at f/5.6 The center, at 2:1: Virtually the same…. [Read More]