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forum for AF100
Is there another forum for the AF100? This forum seems a bit quiet. I feel that the cow might have more editor types than dp types.
I used the AF100 for the first time last week, with Canon L-series lenses. I’ve notice that the focus slips as I move through the zoom range (24-70). In other words, in the camcorder world, I would zoom in to get critical focus, then I was free to move about zooming in and zooming out and changing composition often throughout an interview. But with this camera, I noticed that the image would soften a bit as I backed out. Is this a back focus issue? Is this inherent to photo lenses? (I’ve noticed this on my DSLR’s sometimes too).
This is one more reason NOT to use DSLRs as your “can do anything” camera.
-Trevor Ward
Red Eye Film Co.
http://www.redeyefilmco.com
Orlando, FL -
10 Replies
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Canon lenses have a very crítical focus. One mm and your are soft. 🙁
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That’s not exactly an accurate statement. First, the canon brand isn’t necessarily different than other brands. Second, depth of field (and apparent focus) is dependent upon aperture. Third, I’m not talking about how critical focus is. I’m talking about a back focus effect.
-Trevor Ward
Red Eye Film Co.
http://www.redeyefilmco.com
Orlando, FL -
Hi Trevor – video and cinema lenses are what is called “parfocal”. In other words, they maintain focus throughout the zoom range. This is sometimes accepted as an excuse for the high cost of cinema lenses, but shouldn’t be. Heck, the 12:1 zoom on my 1970s Chinon Super 8 camera held focus throughout the zoom range.
Until recently, still camera lenses have not needed to maintain focus throughout the zoom range. Still photographers don’t need parfocal lenses and are accustomed to refocusing between shots. As a result, standard DSLR zooms, with a few exceptions, are “varifocal”.
Since the advent of the video capable DSLR/DSLT/DSLM camera (and large sensor interchangeable lens camcorder such as the AF100), some manufacturers are making parfocal zooms for still camera mounts – but they are hard to find.
As far as AF100 forum discussion goes, I recommend dvxuser and dvinfo. There are still very active AF100 communities on both boards.
Cheers,
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Thanks Bill. Good explanation.
-Trevor Ward
Red Eye Film Co.
http://www.redeyefilmco.com
Orlando, FL -
Since I realized that what I said earlier was kind of dumb I seek for an explanation, 🙂
But I guess the one they allready give is the proper one but they also told me that when a lens is damage or not a very good one that could happen because the things inside it also move.
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the Panasonic Lumix G 12-35 lens is parfocal if you’re looking for one. It also is f2.8 and works with the af100 auto controls.
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When I first got the AF-100 I used older Nikon manual lenses and they worked very well. Canon EF mount has issues unless you use an electronic adapter to control aperture. I recomned staying with Nikon and native lenses. The Panasonic Lumix MFT lenses are very good and work with all the controls of the camera. With the new 12-35 and 35-100 you pretty much are covered and both are 2.8, OIS and parfocal. Add the 7-14 and call it a day. I use the GH2 camera as well so having native lenses for both are a plus.
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Thanks. This is a good discussion. I needed to re-learn cinema-style shooting/focusing. Most DSLR (and HDcamcorders) provides a magnification facilty to do critical focusing. That’s the way to do it.
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I’m certainly glad you mentioned this. I am using Canon zooms on my AF100 and I just assumed they were parfocal. I just got my AF100 and so I hadn’t figured this out yet. My Sony FX1000s have no problem with this because they are traditional video cameras.
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