Yesterday I wrote about sharpness testing, with emphasis on lighting the target. I’ve been thinking about the target itself. I’ve been using a set of targets of my own design. Here’s a very tight crop of one: They are characterized by a lot of fairly wide bandwidth high-frequency energy that is uniform across the frame,… [Read More]

The a7R is not compatible with the Nikon 24mm f/3.5 ED PC-E Nikkor with any adapter that I’ve tried. The “E” in the name stands for electronic diaphragm, and I know of no adapter that supports it. If there aren’t any adapters that support the lens, that’s too bad, because the PC Nikkors seem otherwise… [Read More]

When I last discussed sharpness testing, it was in the context of shutter slap.  Before, I’d been working on generalized sharpness testing, in which many sharpness-damaging effects — camera motion, diffraction, lens quality, flatness of field, adapter alignment, etc. — were given the opportunity to create the final result. While I’d like to be able… [Read More]

Lens hoods are like coat hangers; they multiply when left in isolation. Actually, there’s a reason for that big pile of lens hoods in your camera cabinet: it’s not obvious which ones go on which lenses. A new lens comes with a lens hood, but you don’t always use it with the hood. When you… [Read More]