focus problems

[46100ROYALSCOT]

I seem to have focusing problems with my camera which is an Olympus E450 DSLR. It's the type where you hold down the shutter button halfway while the camera auto focuses. On bright days there seems to be no problem but if at all dull then the picture of say a moving train I am trying to take as passed by without me getting a shot. I normally leave the settings in "auto" mode. should I select a manual mode and if so which do you recommend. Thanks to you all in advance of your replies.

 

[HugePilchard]

I don't know your camera, but on any other DSLR I've used, the mode dial just controls how exposure and aperture are set, and has nothing to do with the focus settings.

There will probably be a switch either on the lens, or near where the lens mounts to the camera that'll let you choose between automatic and manual focus (usually written as AF and MF). Try setting that to manual, and see how you get on focussing by hand. If you always take the photo at the same sort of distance, then you may be able to get away with focussing once, and leaving it.

 

[46100ROYALSCOT]

there is a switch for auto and manual, I do on occasion try manual focus but not havingvery good eyesight i usually end up with shots still out of focus. Thanks for your helpful advice.
John

 

[c259]

I'm not too sure what the problem seems to be. Do you mean when your taking the photo the picture is blurred?

I'd take a guess that as your pressing the shutter button as the train is passing, the shutter speed is not high enough to make the subject look still on the image. To determine this properly you'd have to post one of your photos as an example.

If this is the problem, you should try using Shutter Speed Priority. Most bridge and DSLR cameras have this option and is mostly accessable using the dial on the top of the camera. You'd probably have to play about with the shutter speed to get the image as you want it. Try starting at 1/1000.

Hope this helps!

 

[46100ROYALSCOT]

I'm not too sure what the problem seems to be. Do you mean when your taking the photo the picture is blurred?

I'd take a guess that as your pressing the shutter button as the train is passing, the shutter speed is not high enough to make the subject look still on the image. To determine this properly you'd have to post one of your photos as an example.

If this is the problem, you should try using Shutter Speed Priority. Most bridge and DSLR cameras have this option and is mostly accessable using the dial on the top of the camera. You'd probably have to play about with the shutter speed to get the image as you want it. Try starting at 1/1000.

Hope this helps!

thanks for your reply. I am aware of shutter speed / aperture priority and I do often use 1/1000 speed, the problem seems to be that when I attempt to focus on a fast moving train you can hear the auto focus motor "hunting" for correct focus and quite often before the auto focus has focused correctly its to late as loco is in totally wrong position, I don't think its a camera fault just my lack of ability I was hoping for tips that might help me overcome this little problem.

 

[mumrar]

With the speed trains can move at it is far better to pre-focus your shot to be prepared. A lot of people forget because of zoom lenses, it's far better to take one nicely framed shot, than a sequence of shots where you're zooming out and refocussing all the while.

 

[TGV]

Can I also suggest checking your AF mode. I'm a Canon user so the terms may not be the same but the theory is. On my cameras there is "One Shot" which means the camera will focus on the half press and stay there no matter where I move it. There are 2 other modes but the useful one is AI Servo where the lens constantly refocuses to what's behind the selected AF point as long as you are holding the half press of the shutter button. So if you track the train under that AF point while holding the half press, when you decide to take the shot, it should be in focus. If you are using the One Shot method, if the train has moved even 20ft between the half press and shutter release you will have, depending on aperture selected and hence depth of field set, some of it out of focus. Or do as someone else suggested, focus on a static object, say the track or a tree where you want the photo to be taken, switch the AF off and wait for the train to pass that point and fire. Good luck and post some results.

 

[Peter Mugridge]

One other possibility: check that there is no "play" in the lens.