Archives for 2015

When you change shutter modes on the Sony alpha 7II, you may affect the bit depth. Because of the raw compression algorithm on this and all the other alpha 7 cameras, which is not defeatable, I need to go into a little detail about just what bit depth I’m talking about. The raw compression scheme… [Read More]

A couple of days ago, I tested the MTF vs f-stop of the 28mm f/1.4 Nikkor-D mounted on a IR-modified Sony alpha 7. At the time, there was some discussion as to why the lens delivered the best IR-only results at f/2.8. Jack Hogan speculated that it might be something with the adapter. I checked and… [Read More]

A reader asked if I’d test the in-body image stabilization (IBIS) on the Sony alpha 7II with a shortish lens, to bookend the testing I’ve done previously with a 180mm Apo-Telyt and the Zony 55mm FE. I picked the Leica 28mm f/2.8 Elmarit-R, which has shown strong sharpness in previous testing. You won’t find the… [Read More]

I tested the 28mm f/1.4 Nikkor-D on the Lifepixel-modified Sony alpha 7. The Lifepixel filter I chose was the Super Color one, which passes some visible light. That makes the job of focusing more difficult for the lens, since it needs to simultaneously bring visible and infrared light to the same focus point. The Coastal… [Read More]

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]