In praise of good glass
My adapter arrived from Hong Kong. After a minute's experimentation (some documentation--ANY documentation--would have been nice!) I attached it to my 70's vintage, 58mm f1.4 lens. Then, being careful about the aperture-control pin that sticks out the back of the lens, I affixed it to the camera, found a workable exposure in manual mode, and took this:
Then for comparison, I put the kit lens back on and shot essentially the same photo with it:
The extra light from the old lens makes a big difference for this shot, which was indoors, hand-held, in natural light (and not that much natural light because it's a scorcher and I have the drapes drawn). The lens was wide-open, which gave an f-stop of around 4.3.
That light-admitting ability comes at a price, though: it's a fixed-focus lens, for starters, and even so it weighs half again as much as the zoom. The new lens presumably has a small servo to perform the autofocus, as well as the zoom mechanism...but the housing is mostly plastic, and there's clearly some air in there. (For any number of reasons, digital SLR lenses have a form factor which is similar to 35mm lenses.) The extra weight of the old lens comes from an all-metal housing, and more glass: the optics in the lens for the 35mm camera are about 72% larger in diameter, as seen below.
(To those of you who will say "it looks like the difference is a lot larger: yes, it looks that way to me too. But I got out my calipers, held my breath, and very carefully measured: .725" for the digital lens vs 1.25" for the 35mm lens.)
More fun later.
Posted at 04:59PM Jul 10, 2008 by AceOfSpuds in Photography |