Archives for April 2016

This is a continuation of testing of  the following macro lenses : Sony 90mm f/2.8 FE Macro Leica 100mm f/2.8 Apo Macro-Elmarit-R Zeiss 100mm f/2 Makro-Planar ZF Nikon 105mm f/2.8 Micro-Nikkor G VR The test starts here: Focus shift and LoCA in the Leica-R 100/2.8 Apo Macro The first series of tests is aimed at determining focus shift… [Read More]

I’m going to be testing the following macro lenses over the next couple of weeks: Sony 90mm f/2.8 FE Macro Leica 100mm f/2.8 Apo Macro-Elmarit-R Zeiss 100mm f/2 Makro-Planar ZF Nikon 105mm f/2.8 Micro-Nikkor G VR and, added as the test progresses, the Coastal Optical 60mm f/4 UV-VIS-IR To see all of the posts in this… [Read More]

I’m thinking about doing a report comparing several 100ish mm macro lenses, and I need a protocol to do modulation transfer function (MTF) and longitudinal chromatic aberration (LoCA) testing. I find it much more fun to devise new protocols than perform the old ones, so I jumped at the chance. I can’t use any of… [Read More]

To a first approximation, the modulation transfer function (MTF) curve for a given lens and a given sensor is the product of the MTF curve for the lens alone times the MTF for the sensor alone. But how do you measure the MTF of a sensor with a perfect lens? You don’t. You simulate it…. [Read More]