Category » Roger’s Ramblings

Lensrentals.com, 2016

Equipment

A Look at Electromagnetic Focusing

By

If you’re like me you like to know what’s going on inside your camera or lens to some degree. They are tools, and if I want to get the best use out of my tool I need to know it’s strengths and weaknesses. You may not have noticed, especially if you shoot just Canon or […]

Equipment

Mythbusting: Parfocal Photo Zooms

By

About twice a week I get a call from a photo-videographer wanting to know which photo zoom lenses in a certain focal length are parfocal (stays in focus while changing focal lengths). It’s understandable why they would ask; a superb photo zoom is 1/10th the cost of a good video zoom. They get pretty mad […]

Equipment

Optical Quality Assurance

By

  Pinhole images from new, but optically decentered lens. Olaf Optical Testing, 2016   After we published a number of posts about copy-to-copy variation, people were quick to say that this company or that needs to ‘just’ improve quality control. I totally agree but realize most people don’t have a clue what ‘improving quality control’ […]

1024px-lens6b-en

History of Photography

A Clear History of Glass

By

I’ve written about glass, as in lenses, for years now. But I’ve never looked into the history of glass as just a substance, because, well, who cared? When I accidentally did some reading about early glass, though, I was rather amazed at just how important it was. So I thought I’d write about the history […]

Follow on Feedly