Focusing Question

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azuresauron

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John
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Hi Guys,

Im looking for advice when trying to capture more than one subject in focus. I have recently been taking pictures of birds, and inspite of trying higher f numbers to increase the depth of field, can still only rarely get the second subject in focus.

Can anyone please advise me how to focus on multiple targets, say a Pair of birds, 10 inches apart and slightly behind one another. Do I focus on a point between them for example?

Its driving me crackers.

Thanks in Advance.
 
What camera & lens are you using? How far away are they and what settings are you on?

Heather
 
Im still getting to grips with the Canon 7d and Tamron 70-300 VC lens. I know I can set the canon to pick its own focus points from a choice of 19, but that often results in the camera focusing on a blade of grass for example.

Im shooting anywhere from 5ft to 100ft plus. Sometimes you have a split second to capture the moment, and dont have time to change camera settings on the hoof, so to speak.

The two images below may show you what I mean, each is almost as I wanted, but one bird is out of focus. The second shot is almost what I wanted.

http://farm8.staticflickr.com/7275/7682838716_9beae6aaeb_o.jpg

http://farm9.staticflickr.com/8028/7682838250_1a8c0ffcd8_o.jpg
 
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Hi John
First make sure you know were the center of the dof is in relation to your chosen point of focus. You may have to use micro adjust to get it in the right place. Then you can start to use the apature settings to give you enough dof to include both objects. Useing manual selection of focus point.
 
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I would aim at one or the other of the birds, at least that way you stand a better chance of getting one of them in focus rather than neither of them (obviously this will depend on the DoF which will vary due to a number of factors mentioned above).

I'm not sure which "point" you would have to aim at between them?
 
On the first picture how far away were you as you/we need to know this to get a reasonable estimate on DOF, I see you were using f7.1 at 1/50 at 154mm ISO 100, I don't know if your 70-300 has IS but that shutter speed is too low for objects which can move at any moment so that's not going to be helping any. You need to bump your ISO to get a decent shutter speed, if you don't have IS then you need at least 1/250 which is also going to help (but not eliminate) any movement in the birds themselves.
 
It appears that you are zoomed in very close to the subject. Understanding the dof in relations to the zoom will help you understand why a subjest so close to each other can be out of the dof range resulting in an out of focus shot. It might be helpful for you to set up some targets and test the dof at different zoom levels. Leave the camera on a tripod to eliminate any outside factors of movement. I did this with multiple objects within one area and hooked my laptop to my camera so that I could get a good view of the test shots. It helped me understand what was going on.
 
When you have the shot set up just hit the DOF preview button and you will see what part of the photo will be in focus and adjust the aperture to get the correct DOF and alter the other settings (shutter speed and ISO) accordingly. The DOF button is just under the lens release on the 7D IIRC, it's on the opposite side on my 5D3 and it's very easy to use.
 
modchild said:
When you have the shot set up just hit the DOF preview button and you will see what part of the photo will be in focus and adjust the aperture to get the correct DOF and alter the other settings (shutter speed and ISO) accordingly. The DOF button is just under the lens release on the 7D IIRC, it's on the opposite side on my 5D3 and it's very easy to use.
Click to expand...

I tried that many times and it is so hard to really see what is going on. This may work for some in the field but imo I don't think it is a good tool to use for learning dof because for learning it you really need to see a clear view and even be able to zoom in to see slight differences of focus.

I do see how it could be helpful in something like portrait work (I don't do).:shrug:
 
Thanks everyone for the great advice. All the exif data is attached to my shots, im fairly close for most of the bird shots. I will continue shooting them and test different appertures. I tend to shoot in apperture mode, maybe time to learn manual.

I appreciate all the help.

John
 
Looks like you've been practicing recently John, looking good there buddy. A lot better DOF and some real good colouring there.
 
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