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03/09/2007 03:02:55 PM · #1 |
I've never done macro photography until a few days ago, so I'm still new to it. I purchased a Canon 100mm F/2.8 on eBay used and I'm having a lot of trouble getting it focused. It has a B+W UV-Haze filter on it. For shots of people and things that are about ten feet away from me, the shots always turn out blurry. I try doing an autofocus but it just blurs it more and more and then after a long time eventually gets it right. Manual focusing is really tough too and it generally always turns out blurry. Now with close up shots, it takes forever to focus. When I actually do focus it, instead of just an area being focused, there is the focused object, and then a whole line across the picture that is focused. Here is an example of what I'm talking about:
//img340.imageshack.us/img340/4702/img0537tx9.jpg
Is this something normal? Do professionals just edit the area with blur? I did buy this used on eBay, should I ask for a refund?
Message edited by author 2007-03-09 15:03:34. |
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03/09/2007 03:07:22 PM · #2 |
It looks like you obtained sharp focus, but with very limited DOF. try stopping down to get more area in focus, but a 100mm lens isn't going to give you huge DOF and once your past about f16 you are going to get alot of difraction softness.
As far as AF with a macro, I'd just ignore it and use manual all the time. |
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03/09/2007 03:36:25 PM · #3 |
A couple of things.
If you don't want really shallow depth of field, don't shoot it at f2.8. Try starting around f8 and working up. The 'line with blur' that you are describing is what happens when you have a very open aperture, close to the subject - that's just the optical properties of lenses.
This is what that 100 2.8 looks like at f2.8, as close as possible to a subject
Second, there is a focus range limiter switch on that lens, you can basically lock out the close focusing, which speeds the focus up for most normal subjects. The switch is on the lens, beside the AutoFocus/Manual focus selection
If you want even more depth of field for macro shots, use a tripod, use a remote release or the 10 second timer on your camera, and stop down as far as you want. While you do get some overall softening beyond f16, you still get a whole lot more sharp focus beyond that point.
Message edited by author 2007-03-09 15:51:34. |
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03/09/2007 03:37:23 PM · #4 |
Try popping the filters off, the less glass for autofocus to look through, the better. If everything in the shot is blurry, then it is not a focus problem, but camera shake. If there is something in focus, but not your main subject then it is a focus problem. If it is camera shake, shoot at 1/60th of a second or faster for handheld shots, or use a tripod. To fix a focus problem you might consider achieving greater Depth of Field (DOF) by using higher ISO, higher F-stops (8, 16, 22), slower shutter speeds, and putting more distance between camera and subject. Also remember when choosing what to focus on that 1/3 of your DOF will fall in front of your focal point, the last 2/3 will fall behind.
Try using the lens when the camera is set to scenic (mountain) mode...if you still have the focus lines, it might be the lens.
Hope this helps...we just discussed DOF last night in class. |
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