Monday, November 26, 2007
The Digital Lens Revisited
In a world of marketing buzzwords like 'optimized' and 'designed for digital,' what's really going on behind all the hype?
There are other medium- and large-format lenses that have this capability, but this isn't true across the board. Paul Cousins, large-format lens specialist of Schneider Optics, says, “If you compare our Digitar lenses to a large-format film lens that projects onto a 4x5-inch piece of film, to get that same image quality on a digital sensor that's 36x48mm—about one-third the size—the resolution has to be much higher, which is certainly the case with our Digitar lenses. Some film lenses have high enough resolving power for today's high-megapixel digital backs, but not all of them.
“The problem that the lens designers face is, as the resolving power gets greater and greater, the image circle gets smaller and smaller. So they have to make a compromise somewhere. They have to have a lens that has enough resolution for a digital chip, but also has enough image circle to cover these digital backs. That's where the balance lies.”
Cousins says different lenses have different-sized image circles, so you always need to verify if a particular lens will match your requirements.
At the end of the day—beyond all the technical details of why and how—it's about quality. What are the best lenses for your camera, either the one you own or the one you rent when you go in the studio or out on location? What will get you the best possible images when you snap the shutter? No amount of editing will ever make up for lack of quality at the moment of capture.
Lenses designed for digital capture have many advantages over analog lenses, to be sure. Not in every case—there are exceptions, as we mentioned. But there are some good reasons why everyone is making them now and why you should consider using them if you haven't already.
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