View Full Version : Camera Shake vs. Out Of Focus


Marv
01-21-2006, 06:04 PM
How can I tell the difference between mild camera movement and slightly out of focus? I have been getting some less than sharp photos with my D70, particularly with a longer lens. Thanks.

JSPhoto
01-21-2006, 06:33 PM
Use a tripod or monopod. Or, if you don't have access to them see if when your pressing the shutter button if your moving the camera as you push the shutter button. Happens more than people realize, and is usually due to improper positioning while shooting or too much pressure on the shutter button.

If that dosn't work set the camera on a table or something and shoot a few and see if they are still blurred, if so, it's possibly an AF or lens problem.

JS

opus
01-21-2006, 08:06 PM
I think the difference, visually, would be that out-of-focus would just be soft, whereas camera shake would have some direction to the blur. For instance, the first example is camera shake. The second example you can tell the focal point is off just a hair, making the main subject a tad soft:

Franglais
01-22-2006, 03:25 AM
How can I tell the difference between mild camera movement and slightly out of focus? I have been getting some less than sharp photos with my D70, particularly with a longer lens. Thanks.

With mild camera movement the whole image is blurred.

With slight out of focus the chances are that something is in focus, but it's not what you intended. Look closely at the image, particularly things slightly in front and behind what you thought you were focussing on and see if they are sharp. If you're using a lens that has an effective maximum aperture of f6.3 (or worse) at the longest focal length then be aware that the camera's autofocus is only guaranteed to work up to maximum aperture f5.6.

The third possibility is that your lens is not as sharp at long focal lengths as it is at short focal lengths. This is a common feature of non-pro lenses.

Charles

JSPhoto
01-22-2006, 10:30 AM
There is one other common focus issue, one I ran into several years ago, and that is a loose barrel. A loose barrel is fairly obvious, and simple to determine, if the barrel moves at all from side to side it's loose. If thats the case you have to send the lens in to get it fixed.

JS

Marv
01-22-2006, 01:36 PM
Thanks, friends, for your helpful comments. From reading your responses, I think my problem is focus at longer focal lengths. I appreciate it.

-- Marvin

OldSchool
01-23-2006, 04:56 AM
Hi Marvin,

When I first got my D70, I too felt my images were soft. I have since upped my shutter some, and now don't have this issue.

One reason why is the 1.5 crop factor. If you used to shoot a film SLR, the rule of them was (when handheld) to shoot at no less than 1/focal length. So if you were at 50mm, you tried to keep the shutter ~1/60.

However with your D70, the rule should be 1/[(focal length)*1.5]. So, if you are shooting at 50mm, then 1(50*1.5) = 1/75 ~ 1/100.

Also regarding the comment about a lose barrel above, all the 18-70 lenses that came with the D70 wiggle at the tip. This is not a problem.

BR,
Tim