Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: Gregory on August 04, 2007, 08:06:06 am
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I use the Canon 350D with a 70-300 DO lense, and occasionally don't get the sharpness that I would like in the images. there is a slight blur. I handhold the camera but even when extremely steady with IS active and a shutter speed of 1/100 or more, the blur can still appear.
both the 350D and the 70-300 DO are very light. a friend suggested that the 350D was too light, and that the mirror movement was causing a slight vibration in the camera leading to the slight blur (at least when shooting at 300mm x 1.6).
what do others think? is this a plausible cause of the occasional blur in my pictures?
(hopefully, it won't happen with the Mark III that I have on order. the Mark III is much heavier!)
regards,
Gregory
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I use the Canon 350D with a 70-300 DO lense, and occasionally don't get the sharpness that I would like in the images. there is a slight blur. I handhold the camera but even when extremely steady with IS active and a shutter speed of 1/100 or more, the blur can still appear.
both the 350D and the 70-300 DO are very light. a friend suggested that the 350D was too light, and that the mirror movement was causing a slight vibration in the camera leading to the slight blur (at least when shooting at 300mm x 1.6).
what do others think? is this a plausible cause of the occasional blur in my pictures?
(hopefully, it won't happen with the Mark III that I have on order. the Mark III is much heavier!)
regards,
Gregory
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The 70-300 IS DO has the latest generation/algorithm for image stabilisation which includes compensation for mirror slap - so it is unlikely to be the cause of your softness.
The lens in question can appear slightly soft at certain focal lengths/apertures. Your shutter speed will need to be above 1/500th of a second to minimise the effect of blur at 300mm focal length 1/100th is too slow (shutter speed > reciprocal of effective focal length). Suggest you also make sure that you have a good handhold technique (keep arms in to your side and squeeze slowly) a lot of people twist the camera when firing the shutter. Also, suggest you get a mono/tri-pod to stabilise your camera if you are still getting blur in the images.
If you can't get sharp images with the 350D you will not get any sharper images with the 1DIII.
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Your shutter speed will need to be above 1/500th of a second to minimise the effect of blur at 300mm focal length 1/100th is too slow (shutter speed > reciprocal of effective focal length).
thank you for the reply.
without IS, the reciprocal rule would normally apply. with IS, I should be able to get vibration-free images with shutter speeds up to 3 stops down, at least according to the marketing material; i.e., 1/500 --> 1/60. right?
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The reciprocal rule, as you call it, is nothing but a guideline or rule of thumb for the minimum shutter speed where one might reasonably expect to get reasonably sharp images with good technique. IOW, go below that guideline, or don't use very good technique, and you can expect your images to be blurred. Beyond that, blurred is a relative characteristic. If you're looking for critical sharpness that holds up at 100% views on your monitor, 1/focal length is not where you want to live. Add to that the fact that IS adding three stops is also a guideline that's usually qualified with terms like "up to," and you're out on the bleeding edge of what can reasonably be expected.
In any event, mirror slap is highly unlikely to be a factor when handholding. It's a factor when you've eliminated everything else — i.e., you're on a very good tripod, in windless and vibration-free conditions, using a remote release.
A heavier camera might help on the margin, but it can cut the other way when fatigue sets in. Look instead to higher shutter speeds and better handholding technique — good stance, holding the camera correctly with elbows tucked in and braced against your body, squeezing the shutter gently as you exhale, etc.
Nill
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www.toulme.net (http://www.toulme.net)
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I agree that mirror slap is unliely to be the issue here. In my experience, a slightly heavier (and it's all relative) camera can dampen the effect of handshake especially if you can rest your elbow on a solid surface. But as Nill says, fatigue becomes an issue if you are shooting free of any support.
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I use the Canon 350D with a 70-300 DO lense, and occasionally don't get the sharpness that I would like in the images. there is a slight blur. I handhold the camera but even when extremely steady with IS active and a shutter speed of 1/100 or more, the blur can still appear.
both the 350D and the 70-300 DO are very light. a friend suggested that the 350D was too light, and that the mirror movement was causing a slight vibration in the camera leading to the slight blur (at least when shooting at 300mm x 1.6).
what do others think? is this a plausible cause of the occasional blur in my pictures?
(hopefully, it won't happen with the Mark III that I have on order. the Mark III is much heavier!)
regards,
Gregory
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If you really think it's the weight, you can just get a piece of lead, drill a hole through it, and mount it on your tripod mount. Or get an extra battery pack. But I think the other posters are more likely to be right.
-Lars
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A battery grip makes the 350D much more stable and substantial. Using a nice heavy lens also makes a world of difference.
To check if you have a problem with the camera, mount it on a tripod and take a picture using mlu. If the image is still a little soft then it's the camera. My 350D developed a close focus problem a while back.
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My 350D developed a close focus problem a while back.
please explain. what is a 'close focus' problem?
I've also heard references to a 'back focus plane' problem. I'm not sure what that is either.
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please explain. what is a 'close focus' problem?
I've also heard references to a 'back focus plane' problem. I'm not sure what that is either.
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Basically any telephoto shot or wide aperture shot came out looking soft. The camera wasn't focussing where it was pointed. Apparently it's not an uncommon problem and they can recalibrate the focus quite easily.