--> Skip to main content


Showing posts from July, 2019

What's That Little Red Dot on my Lens?

If you look closely at many old lenses you'll see a red dot. No- your lens wasn't made in India and that is NOT a bindi, nor is it a manufacturing defect. The red dot is the adjustment for focusing with Infrared film. The red dot will be found on many lenses from the film era. If your lens does have this feature it will be found on the hyperfocal DOF scale, slightly to the left of the center line. So if you were using infrared sensitive film, you'd focus normally, then move the focusing measure to match the red dot. Humans and normal film cannot see infrared light, so we can't focus correctly. Now you know!

Metabones Speed Booster: Lens Profiles

Recently I unearthed my (original version?) Metabones Speed Booster. For those not familiar, this adapter is a revolutionary idea that takes full frame lenses and reduces the magnification and image circle to match smaller sensor sizes. They also have the added benefit of increasing the effective aperture. In my case I'm taking Canon EF mount lenses and using them on my Sony e-mount mirrorless cameras. So one amazing feature of digital photography is the ability of software to correct lens defects. In fact profiles either built in or custom made exist for many lenses that correct for geometric distortion (pincushion or barrel distortion), chromatic aberration and vignetting. I rely on those corrections now. And it occurred to me, how do profiles work when using the "Speed Booster"? There's glass in there, clearly there's going to be some different defects than the primary lens on its own. Does the profile for the primary lens apply at all when using the "

Capture One and an Infrared Converted Camera - Some Settings

Recently I added a Infra-Red converted camera to my stable of digital cameras. There's been a surprisingly steep learning curve. The camera was an amateur conversion - some guy on Ebay did his own conversion by simply (I'm sure it's not that simple really) removing the IR filter. As I am using Sony mirrorless cameras, I thought it'd be cool to have a tiny little IR body to play around with. In this case it's a Sony a5000. Without any filter in front of the lens, this camera creates unremarkable results. In fact, image quality suffers without much notable difference in the visible image. However, if you put a filter on the lens that limits visible light and lets IR pass through the results can be very dramagic. There are some ways to make for interesting color images, but thus far my favorite use of this technique is black and white. I'm fairly new to Capture One and try avoid Adobe products when I can. So I thought I'd share some of the conversion tech