Jack Hogan suggested that some of the unusual results for the Nikon 28mm f/1.4, and possibly the Leice 28mm Elmarit-R, might be due to focus shift, since I did all my focusing at f/2.8. Here’s a test with the Nikon lens. I did one 96-shot series (16 shots each at 6 f-stops) focusing as before…. [Read More]
3 28mm lenses on the Sony a7II
The Coastal Optical 60mm is a great lens for infrared, but it’s too long for a lot of landscape use. I’m shooting handheld around the house, and I don’t like to do double-row stitches that way. So I’m looking for something wider. 28mm is a nice focal length for landscape. It’s probably the most versatile… [Read More]
Nikon D810 EFCS with 135mm f/2 Apo Sonnar
A week or so ago, a reader asked if I could try to find out if there’s any vibration difference between a heavy carbon fiber tripod with the skinny legs extended first, or the fat legs extended first. I was doubtful that there would be any difference, and first tried to find out if there… [Read More]
COASTAL OPTICAL 60MM F/4 light falloff
I think this is my last test on the Coastal Optical 60mm f/4 UV-VIS-IR Apo Macro lens. It’s a simple visual demonstration of light falloff. The camera is a Sony a7 modified for IR by LifePixel, using the Super Color sensor stack filter. I put an Expodisc on the lens and aimed it at a… [Read More]
Coastal Optical 60mm f/4 MTF in IR
I redid the testing of the previous post with an R72 filter in front of the lens. This filter blocks visible light, passing IR with a nominal corner wavelength of 720 nm. For the record, here’s the test protocol. I mounted the Coastal Optical 60mm f/4 UV-Vis-IR Apo Macro lens (hereafter called the CO 60) to… [Read More]
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