Lenses and Optics

Field Curvature and Stopping Down

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Ignorance more frequently begets confidence than does knowledge. Charles Darwin What I know that I don’t know doesn’t cause me much trouble. I don’t know the formulas for 7th order optical aberrations for example. I don’t know enough math to calculate those formulas even if I did memorize them. But I’ve got shelves of books […]

Other

The Itsy Bitsy Spider

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We spend a lot of time here at Lensrentals getting dust out of lenses. Dust doesn’t affect an image, except in very rare circumstances, but people want their rental lenses to look nice and clean inside and out, and our inspectors check the inside of every lens with spotlights and send any dusty ones over to the […]

Lenses and Optics

Just the Lenses: Canon and Nikon Mount 35mm f/1.4s

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As I discussed in the last post, it’s impossible to accurately compare lenses from different mounts using any form of computerized target analysis testing (methods like DxO or Imatest). Target analysis tests an entire system (camera and lens). That’s a very practical thing, of course, but it has some limitations. Directly comparing the lenses on […]

Lenses and Optics

Just The Lenses: Canon vs Nikon Zooms at 70mm

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It’s impossible to accurately compare lenses from different mounts using any form of Computerized Target Analysis testing (methods like DxO or Imatest). Target analysis tests an entire system (camera and lens). People try to, of course, but it’s not accurate since you always have the added variables of camera sensor, microlenses, in-camera image processing, etc. […]

Lenses and Optics

Some M-Mount Field Curvatures

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I haven’t posted very much lately. We’ve had some new equipment installed and we’ve been doing a LOT of testing as we develop our new database of lenses on the optical bench. As the database fills out I’ll be posting more than ever, just because a lot of this stuff is just fun. Today’s post […]

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