400mm Focusing

[britt777]

Can anyone tell me if it is at all possible when using a super telephoto lens to get things in front or behind the subject in focus. I tried shooting the attached photo with a f/stop as small as f/16 and could not get the bird in front in focus. Is there any tips or suggestions anyone may have?

Thanks Brittany

[rwolfert]

I have the same camera. Try using the center point focus only on the subject, depressing the shutter button only half-way to activate AF on the subject you want to be sharp. Then, while maintaining hold on the shutter release button, move to frame the image the way you want. It should hold the focus until you take the picture.

Of course, there's always manual focusing.

Rich

[tommykjensen]

Do you mean you want the closest bird in focus or both birds in focus.


If the last then You are probably too close to get a deep enough DOF. How far away where you?

If the subject where 10 meters away the DOF is only 36 centimeters, 18 cm in front of the focuspoint and 19 cm behind. Have a look at this DOF calculator.

http://www.dofmaster.com/dofjs.html

[britt777]

I was using manual focus. I dont know how to use DOF calculator. I guess that answers ? though. I wanted both birds in focus and this won't happen with a telphoto lens

[tommykjensen]

On the page I link you select 20D as the camera, Select 400 mm, Select f/16, then enter the distance to the subject and it will show you how deep the DOF is. How har away were the birds?

You should be able to get both birds in focus at the same time if the distance to them are so long that the DOF covers the distance between the 2 birds.

[S Taylor]

Do you remember how close you were when you shot it? I think what Tommy covered in his post is likely the cause, regarding your distance and the related depth of field.

WT

[britt777]

I was about 25ft. thank you for the calculator

[tommykjensen]

That means at f/16 you only had 0.34 feet in front of the focus point that would be in focus.

[britt777]

when calculating the focal distance do I take 400mm x1.6x1.4=896? or just400mmx1.4=560? 560 I would assume since when putting 20d in it already calculated the 1.6 crop factor. Yes?

[tommykjensen]

Yes the calculator already takes the crop factor into account so you should enter 560 mm. Ahh you also had the extender on.

Use the actual focal length of the lens for depth of field calculations. The calculator will automatically adjust for any "focal length multiplier" or "field of view crop" for the selected camera.

[Mr. Clean]

Still a great pic...I see what you're saying about wanting them both in focus. That would have made a great pic even better I think. You would have had to get close for that though. Your 70-200 would've been the deal to get that shot with.

[GyRob]

try selective sharpning on the gull around 185 at 2 :)
Rob.

[johnstoy]

Here is a link to yesterday's shoot from the Birds section...
The EXIF is intact...the shot is from approx 15 to 20 feet away.
The focus worked out for the entire body of the bird...I don't think it would have encompassed much more.

"A Beautiful Pair of Wild Mourning Doves-w/400mm 5.6L"

http://www.photography-on-the.net/forum/showthread.php?t=276580

[DavidEB]

part of it is focusing about halfway between the two birds. then you get depth of field in front and behind the focus point helping you. in the photo you've got, half the depth-of-field is wasted behind the pelican.


nice shot

[Big Hands]

Check into the A-DEP feature of the 20D.

Regards,
Jeff