Go Back   Steve's Digicams Forums > Digital Cameras (Point and Shoot) > Canon

Reply
 
Thread Tools Search this Thread
Old Oct 11, 2004, 5:40 PM   #1
Junior Member
 
Join Date: Mar 2004
Posts: 6
Default

I have a canon a70 and I'm having a bad time trying to get some dof in portrait photos. I want to have the subject focused, and the background blurred. I' m trying it with F2.8, full telephoto, and I don't get good results.

If I do manual focusing I can get what I'm looking for, but, is not any other option? is very HARD and tedious to manual focus with the A70 controls.


Thanks.
Apoc is offline   Reply With Quote
Sponsored Links
Old Oct 11, 2004, 6:21 PM   #2
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Your best bet is to use software to blur the background.

The reason you have more Depth of Field with a non-DSLR camera is because of the actual focal length of the lens. The sensor on a camera like the A70 issmall, requiring a very small image circle. As a result, the lens can have a much shorter focal length, to get any given 35mmequivalentfocal length.

The Lens on the A70 is only 5.4-16.2mm (to give it a 35mm equivalent focal range of35-105mm). As a result, your subject occupies a much larger percentage of the frame at any given actual focal length, compared to a 35mm camera at the same distance to subject.

So, for any given 35mm Equivalent Focal Length, you'll have dramatically more Depth of Field compared to a camera with less of a "crop factor". This is because Depth of Field is computed by the actual versus 35mm equivalent focal length, distance to subject and aperture.

The Depth of Field you can get depends on your subject, the percentage of the frame you need it to occupy, and the distance to the background that you want your subject to stand out from. There's not a lot you can do to get less depth of field for blurring backgrounds with your camera (or with other non-DSLR models). Evenusing max zoom won't really help with a larger subject. Since each time you double the amount of zoom used, you need to take the photo from twice as far away.

Load this Depth of Field Calculator and select a camera model. Then, plug in the *actual* focal length of the lens, focus distance and aperture to calculate Depth of Field. For your model, that's 5.4 to 16.2mm.

http://dfleming.ameranet.com/dofjs.html

Your best bet is to try and use software to simulate a shallow depth of field. You may want to check in theEditors forum to get some tips. Here is one method of doing it:

http://www.stevesforums.com/forums/v...mp;forum_id=31
JimC is offline   Reply With Quote
Old Oct 12, 2004, 10:44 AM   #3
Junior Member
 
Join Date: Mar 2004
Posts: 6
Default

JimC wrote:
Quote:
Your best bet is to use software to blur the background.

The reason you have more Depth of Field with a non-DSLR camera is because of the actual focal length of the lens. The sensor on a camera like the A70 issmall, requiring a very small image circle. As a result, the lens can have a much shorter focal length, to get any given 35mmequivalentfocal length.

As a result, your subject occupies a much larger percentage of the frame at any 35mm equivalent focal length, too. The Lens on the A70 is only 5.4-16.2mm (to give it a 35mm equivalent focal range of35-105mm).

So, for any given 35mm Equivalent Focal Length, you'll have dramatically more Depth of Field compared to a camera with less of a "crop factor". This is because Depth of Field is computed by the actual versus 35mm equivalent focal length, distance to subject and aperture.

The Depth of Field you can get depends on your subject, the percentage of the frame you need it to occupy, and the distance to the background that you want your subject to stand out from. There's not a lot you can do to get less depth of field for blurring backgrounds with your camera (or with other non-DSLR models). Evenusing max zoom won't really help with a larger subject. Since each time you double the amount of zoom used, you need to take the photo from twice as far away.

Load this Depth of Field Calculator and select a camera model. Then, plug in the *actual* focal length of the lens, focus distance and aperture to calculate Depth of Field. For your model, that's 5.4 to 16.2mm.

http://dfleming.ameranet.com/dofjs.html

Your best bet is to try and use software to simulate a shallow depth of field. You may want to check in theEditors forum to get some tips. Here is one method of doing it:

http://www.stevesforums.com/forums/v...mp;forum_id=31

Thanks, I will try it.
Apoc is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 6:23 AM.