Digital Camera Lens Revelation
Did you know that digital cameras see only 67% of the image that a film camera lens will see? With many camera manufacturers, lenses are interchangeable with their digital and film cameras. But if you use one of these lenses on a digital, it will see only 67% of what that same lens would photograph on a film camera. This little nugget of information has totally changed my thoughts about what lenses I want to buy with my next camera. I’m sure this is old news to those fully entrenched in the digital world, but as the blog says, I Speak Film.
After so many years working as a cinematographer and camera assistant, I know what a 100mm shot will look like or a 35mm or 10mm or 200mm. I know this without even thinking about it. With my Pentax film SLR, I know what my 135mm portrait lens will do to an image or my 50mm. But digital is different. Now, all bets are off and I will have to start thinking of those millimeters in a whole new way. I just read that to figure out the focal length of a lens for digital, you need to divide multiply it by 1.5. Mmm, right. I’ll get working on that.
Responses and Conversations
Yes, the APS-C sized sensor on most digital SLRs can take some getting used to. You just have to think of it as a new format. It’s not 35mm (in most cases). So while that 135mm is still a 135mm, it behaves differently on the new tool.
Just to clarify something, you have to multiple, not divide, by 1.5 to get the effective focal length. The good news is that, at least for me, multiplying is easier than dividing! This is great on the long end, where a 200mm now acts like a 300mm. But terribly frustrating on the wide end. I love 24mm, but on my D70, it acts like 36mm. You can get wider, but those super wides aren’t cheap.
The other thing to watch for, is that not all camera manufactures have the same size sensor. Nikon is fully entrenched with the 1.5 multiplication factor size. However, Canon has cameras with sensor multiplication factors of 1.6, 1.3, and 1.0 (”full frame”, but is expensive).
Comment by John Koontz on February 2nd, 2006 at 9:50 am
Thank you for the math clarification! That could have gotten ugly!
Comment by Stephanie Simpson on February 2nd, 2006 at 10:00 am