focusing question

[PhotoGirl]

hi everyone,
I have a question about focusing. when taking a picture through something like a fence, window screen etc. how do you make sure the camera focuses on the person behind those things rather than on the screen or fence itself? thanks.

[another view]

Get as close to a screen or chainlink fence as possible (like 1/2" away). This should work fine with autofocus because since it's so close it'll be hard to see. Use the widest aperture (smallest f-number) you can get away with so the depth of field is smaller (putting the screen or fence farther outside of the DOF). You'll still be able to see it a little bit, but sometimes there is no other option.

[PhotoGirl]

thanks for your reply, another view.

[livin4lax09]

it helps if you can paint whatever you are focusing through black. the trick is commonly used for baseball photos through the fence, because its less likely to cloud the photo and less likely to attract the AF than a white/bright silver fence.

[PhotoGirl]

that is very interesting; I didn't know that!
thanks livin4lax09.

[SmartWombat]

Like these ... taken through the safety fence in the rain at Le Mans
Sometimes even using the maximum f/5.6 of my lens, I was too far away from the fence to make it disappear completely.
The top one (2 1/2 cars) I was closer to the fence than the third one (the AUDI), but still not close enough to make it completely go away.

But if you get really close it works.
The last one, the Torro Rosso car, I had the lens almost touching the fence and at f/5.6 you can't see it.


If your subject is moving, you can also use a slow shutter speed and pan with the car (in my case) so that the car appears sharp and everything else is blurred ... and that means the fence !
That's how I got the photo of the Audi in the evening with the barrier (and a fan's head) blurred.

But when you do that, be prepared for about 1 in 10 to work, and the other 90 out of 100 to be in the trash bin.

[PhotoGirl]

thanks SmartWombat for your reply and your photos, they really helped show me what you meant.

[another view]

Great examples, Paul. Audi TDI - how cool is that?!

[SmartWombat]

So cool it beat the Peugeot TDI at le Mans.

[K815Robert]

Hi,
I recently purchased a 1200-90mm telescope that can be fitted to the camera. I am obcessed with taking long distance photos. The problem I have is that I focous on a subject ie the moon I focused throu the camera. THE RESULT IS NOT A CLEAR PICTURE ON THE CAMERA SCREEN. I am carefull while pressing the button and use delay. My camera is the olympus E-330. What am doing wrong.

[another view]

Robert, this question would be a good thread on its own.

I'm assuming that you're using a tripod since you mention using delay (self timer?). You're dealing with a really long focal length and any movement will be magnified. Is your tripod sturdy/heavy duty? Try lowering it closer to the ground - since the legs are shorter they may flex a little less. Do not use the center column. Make sure the tripod is on sturdy ground (not a wooden deck, sand beach). Shutter speeds of about 1/8 to 1/30 can be the most problematic, but ISO 100 at 1/125 and f11 should get you pretty close to proper exposure for the full moon anyway.