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p.1 #9 · Tips for Manual Focusing | |
uplink wrote:
I can't seem to get as sharp as I'd like.
A few quick points:
1: There's nothing inadequate about your focus screen, unless you use a lens with an aperture of less than f/2.5, so don't worry about it.
2: Realize that AF lenses are not well-designed for MF use. The amount of movement in the helical gear is relatively small, giving less precision. Also, the gearing is not well damped, because the AF motor doesn't want to see much resistance. So, don't beat yourself up over this.
It can be done, but realize that true MF lenses are easier to use.
3: You should IMMEDIATELY check you camera to see if it's set-up accurately. Both the mirror-box and the focus screen positions can be adjusted, and they are critical.
I don't know how to do the former (there are screws inside) and probably it's OK if your AF was working accurately. However, the latter is typically not perfect, will absolutely affect MF (but not AF) and can be adjusted by shimming the focus screen.
Go to the alt forum and do a search on this. You will find tons of information. If your focus screen is not at the exact correct distance from the lens, you simply cannot focus correctly with your eye. Manufacturers don't worry about getting this dead-on, as few people these days would care, so we must check & do it ourselves if its off.
BTW: The test is easy (do it in bright light) but the fix is a bit of a PITA.
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