Need some Help on a few photo's

[Todd Caswell]

I recently upgraded from a rebel to a D50, same lens I had befor but new, 70-200 F/4. Problem is I don't feel I'm getting the sharpness in the photo's that I expected I would. I got the combo late fall and took it to manitoba on a hunting trip and was happy with it,shooting dogs and waterfowl. I haven't had alot of opportunity to use it on birds untill recently. One thing that did happen is the Camera was dropped, with a different lens on it a few weeks ago, didn't appeer to have any noticable damage to either. Any chance something could have happened inside?

Maybe my shutter speeds are a little slow, on the out of focus ones?

Here are some examples from today.

F6.3 1/200 iso320 200mm AP

This one I'm sure I was focusing on the eye but the legs are more in focus than the head?

F7.1 1/200 iso 320 AP

F/4 1/250 ISO 500 200mm

F/4 1/250 ISO 500 200mm

I would consider this one to be acceptable

F5.6 1/640 ISO 500 200mm

[Dbl]

Todd,

First off is it a D50 or a 50D? I am going to assume you are talking about a 50D for now. A couple of things. The drop may well have knocked something out of whack, you can run a series of focus tests to help verify that. If you do a search for a focus test 50D you will find some simple solutions to do that as well as how to do a micro adjustment. That is one of the options your camera has to help with front focus and back focus on various lenses on your particular camera body.

Lets assume you camera is fine. You very likely are having some issues with a combination of slow shutter speeds and hand holding techniques as you suspected. Let me explain why. The last shot happens to be your sharpest (as you noted) this is the one that was taken at the highest shutter speed, 1/640s. This is fairly telling, your other shots are at 1/200s or 1/250s shutter speeds. You shot all of those at 200mm so if you follow the old rule of using a shutter speed equal to the length of the lens you are using you are on the bottom end of acceptable shutter speeds at 1/250s. You do have a 1.6 crop factor on that camera so that brings your actual focal length up to 280mm.

The other problem is the low contrast on the subjects. Auto focus needs contrast on the subject to work properly, lights and dark lines to allow it to focus. When you have grey birds against bark, these are tough conditions for cameras. Make sure your are using single point focus and it is on a contrasting area of the bird. That will give your camera the best chance to focus properly.

My suggestion would be try some shots using a tripod to check sharpness. If you are going to hand hold up your ISO on these cloudy shots and get your shutter speed up above 1/500s, higher if you can. Your camera will shoot just fine at 1600 or 3200 ISO so get those shutter speeds in the 1/1000s range and check your shots. As you refine your shooting technique through practice you can lower your shutter speeds down where you are now. Good technique will allow you to shoot at fairly low shutter speeds but don't try that until you get some more practice under your belt.

Hope that helps a bit, Merry Christmas!

[Todd Caswell]

Thanks for the reply it is a 50D. Looks like it may be more operator error and not the camera. These were just shot on a tripod.

AF point was center of the beer can, seems the fishes mouth is a bit out of focus

The fishes mouth is a bit out of focus on this one as well, AF point was in the center of the fish

[MN Shutterbug]

The first picture was shot at an aperture of f4, which will leave a pretty narrow depth of field, especially when you are fairly close to the subject. That being said, it makes sense for the center of the can to be sharp and not the fishes mouth, due to the slight difference in distance from the lens.

The second shot was shot at a smaller aperture, but like on your bird pics, there isn't a lot of contrast. Good light and contrast are so important for sharp focus.

Here is an online depth of field calculator, which will help you understand this factor. Click here.

[MARINERMAGNUM]

Try a focus test on a more "matte" finish item. Sometimes a reflective or shiny surface can mess with AF also.

[ShawnZ]

I agree with everything that these knowledgeable individuals have pointed out so far. In addition, with the lighting conditions that you had, think about using a flash unit next time for some fill and pop on the images. Also, if you are really close to the birds, as it appears that you were in these images, and you have better light than this, try adjusting your f-stops to like (f8 to f10) and see if you like what you see. And lastly, in low light like this, well actually in most light, I enjoy practicing the age old technique of manual focus.