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Old Feb 13, 2004, 5:21 AM   #1
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Default Autofocus problems - do we need it?

When I browse these forums there seem to be lots of folk with focus problems on most makes of digicam. Given the large depth of field available even at full aperture with these very short focal length lenses, I'd like to see four manual 'zone focusing' buttons (head & shoulders, group, tree, mountain) as on cheap 35mm kiddies' cameras of the olden days, and the abandonment of autofocus for everything except macro modes. I note that my Casio QV-5700 gives its focus distance in the EXIF file as 1.5, 2,5, 5,10, or 20m, so it's probably doing a zone focus whether I like it or not. I'm confident I can guess these distances by eye better than the camera can measure.

No-one replied when I floated this idea a few weeks ago. I think autofocus is one of the occasional giant leaps backwards in photography, but it's unfortunately combined with the great digital leap forwards. What do you all think?
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Old Feb 13, 2004, 7:39 AM   #2
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Alan

I don't know if other cameras do this but at least in the Minolta D7, D7i, D7Hi, A1... A2, the camera kind of do this already: ie on manual focus you can preset the manual focus ring to fix distances in meter which showed up in their EVF...

Another mode is its flex-focus where you can move a cursor anywhere in the viewfinfer and only the area hightlighted by the cursor will be in focus (I believe Canon P/S has this mode too!) 8)
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Old Feb 13, 2004, 9:32 AM   #3
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Alan, I think if people learned how to take pictures on a completely manual camera (manual exposure, manual focus -- no batteries necessary) that they would become a much better photographer. While autofocus and autoexposure have some significant advantages, especially in the areas of capturing moving subjects or scenes that require a quick shutter release, those same features can be a hindrance to learning. But, I guess it's a lot easier on people to find blame on the camera for being underexposed or out of focus. :roll:

I don't quite agree with your abandonment of autofocus for macro. I would think macro is one of the areas where autofocus would be the least desired. I always manual focus macro shots.
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Old Feb 13, 2004, 10:25 AM   #4
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I donít see where it has to be an either/or. I think Konica designed that into the Minolta G500 as an alternative to manual focus and not to replace automatic focus. And a zone focus system isnít going to work for a 10X or 12X lens unless you have so many zones you defeat the purpose of the system. I do like the Konica zone focus application as a manual backup on a limited telephoto camera.

I donít think manual focus is such a wonderful learning tool. Maybe using the depth of field to blur a background a little more, but that doesnít work that well with little CCDs anyway. Anything that stands in the way of lighting and composition is a hindrance rather than help in learning to take good photographs. If they came up with a camera that never made a focus mistake it would be an excellent learning tool IMO because you arenít getting lost in the equipment but the photography.

My first camera was a SLR with everything manual and no built-in light meter of any kind. I got pretty good at estimating light but it is not a skill I have had much use for since I got my SRT101 with a real match needle. I donít think learning to estimate my light or manually focus or any other pre-modern feature was anything but a hindrance to my learning to recognize a photographic opportunity and frame it with appropriate lighting from the right place.
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Old Feb 13, 2004, 5:14 PM   #5
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Manufacturers et Al: I just want a digital readout of the distance the AF has focussed to, which I can also use in manual focus mode. Nice to bracket the changing DOF to track with zoom as well.

That's what you used to get when you looked down at the lens barrel and rotated it on your Voigtlander! so why does AF have to be so blind? I could understand if it always worked, but it doesn't. There are a few irrecoverable (in PS) errors taking pics. You've crashed and burned if it's out of focus, and I can't easily see that on an lcd whilst post view mag is often so slow to work.

I agree with AlanT, when I'm playing with my S414, I can see a distance setting on the lcd and get from 2M to infinity at f3.5 wide angle, and I can sure estimate that. However bring on the zoom and of course the DOF shrinks very fast and focus auto or manual again becomes an issue. VOX
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Old Feb 13, 2004, 5:45 PM   #6
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Vox

I'm glad you bring the zoom issue up:
Most AF cameras have varifocal in their zoom, ie the focus point varies as one zoom-in and out. So if you change the zoom position after you've zoom-in to focus, the picture is out of focus again!

If you get your hand on a Minolta D's or A series try it on manual focus... the focus motor actually is servoed to the zoom (it focus tracks the zoom) even if you don't touch the focusing ring!
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Old Feb 13, 2004, 6:03 PM   #7
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Quote:
Originally Posted by voxmagna
Manufacturers et Al: I just want a digital readout of the distance the AF has focussed to, which I can also use in manual focus mode. Nice to bracket the changing DOF to track with zoom as well.
VOX
Hear hear!..My FZ10 doesnít even give the focus distance in manual.

I wouldnít find much use for it in a camera with a rangefinder type optical finder as I usually donít use the LCD. But it would be great for manual focus. You can guess pretty closely. And it would be nice in the EVF of a relatively unsophisticated camera like the FZ10 in auto to cross check it isnít focused on the wrong thing.

The Minolta D7/A1 series has an indicator in the EVF to show you exactly what the camera is focused on and I suppose other more sophisticated cameras do that as well. It also shows the focus distance in the viewfinder in manual. But you are just trusting to faith with the FZ10 unless you switch to manual and use the zoom feature to check the actual focus.

I think maybe they figure that too much information is confusing, but I would sure like a readout of the focus distance with all cameras in manual as well as auto.
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Old Feb 13, 2004, 6:49 PM   #8
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.......The Minolta D7/A1 series has an indicator in the EVF to show you exactly what the camera is focused on and I suppose other more sophisticated cameras do that as well.......

The later Canon A series do this, it works where there is a significant vertical object or a person, but if you've got less distinct or graduated things like roads/grass/trees, I can never relate the distance or focus point to the green box in the EVF. The less sophistocated cameras just have a green led! Who knows what it thinks is correct AF. I'm always annoyed when most cameras give an AF warning, they seem to default to macro distances. I'm sure there'd be less lost pics if focus was set closer to infinity or is it hyperfocal distance at the working aperture?

Reflecting on Alan T's first post, perhaps the 'near' 'medium' and 'far' concept would work, although having seen how DOF shrinks when you use zoom, these modes would only work, in say full or near wide angle. VOX
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