The is the sixth in a series of posts about the Voigtlander 65 mm f/2 Apo-Lanthar macro lens. The series starts here. I screwed up the last landscape comparison that I tried to do between the Apo-Lanthar and the F-mount 55 mm f/1.4 Zeiss Otus, so I redid the test this morning. The scene with… [Read More]
Archives for September 2017
A personal look at metameric failure
I recently had cataract surgery; two weeks ago on my left eye, and yesterday on my right. So for two weeks, I got to walk around comparing the colors with the treated versus those with the untreated eye. Cataracts are known to block short wavelengths to a greater extent than long ones, so I expected… [Read More]
65/2 Apo-Lanthar 1:2 field flatness
The is the fifth in a series of posts about the Voigtlander 65 mm f/2 Apo-Lanthar macro lens. The series starts here. We proved here that the Apo-Lanthar has a flat field for distant subjects. I received a request to look at field flatness at 1:2. It’s taken me several days to develop an alignment… [Read More]
Detectability of visual signals below the noise, part 2
A few days ago, I made this post about the visual detectability of information with a signal to noise ratio (SNR) of less than one. If you don’t remember it you should at least go back and skim it, or this post won’t make much sense to you. It occurs to me that the normalization… [Read More]
65/2 Apo-Lanthar, 55/1.8 Zony
The is the fourth in a series of posts about the Voigtlander 65 mm f/2 Apo-Lanthar macro lens. The series starts here. I got a request to test the Apo-Lanthar against the Sony/Zeiss (Zony) 55mm f/1.8 Sonnar at macro distances, using extension tubes on the Sony/Zeiss lens. I’m still working out a good visual test… [Read More]