depth of field on crop and full frame body

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denniskee

Senior Member
come across this site.

http://www.photo.net/learn/optics/dofdigital/

Depth of Field and the Digital Domain
by Bob Atkins

1. For an equivalent field of view, the EOS 10D has at least 1.6x MORE depth of field that a 35mm film camera would have - when the focus distance is significantly less then the hyperfocal distance (but the 35mm format need a lens with 1.6x the focal length to give the same view).

2. Using the same lens on a EOS 10D and a 35mm film body, the 10D image has 1.6x LESS depth of field than the 35mm image would have (but they would be different images of course since the field of view would be different).

3. If you use the same lens on a EOS 10D and a 35mm film body and crop the 35mm image to give the same view as the digital image, the depth of field is IDENTICAL.

4. If you use the same lens on an EOS 10D and a 35mm film body, then shoot from different distances so that the view is the same, the 10D image will have 1.6x MORE DOF then the film image.

5. Close to the hyperfocal distance, the EOS 10D has a much more than 1.6x the DOF of a 35mm film camera. The hyperfocal distance of the EOS 10D is 1.6x less than that of a 35mm film camera.

lastboltnut

Senior Member
I am just talking about point 3. But cropping the pic will change the DOF????? :dunno: Thought a lens will give the same DOF to 10D or SLR, it is not depending on the sensor size.
Only the FOV is depending on sensor size.

I am newbie, just trying to say what I learnt so far, please correct me if I am wrong....thanks!

denniskee said:
come across this site.

http://www.photo.net/learn/optics/dofdigital/

Depth of Field and the Digital Domain
by Bob Atkins

1. For an equivalent field of view, the EOS 10D has at least 1.6x MORE depth of field that a 35mm film camera would have - when the focus distance is significantly less then the hyperfocal distance (but the 35mm format need a lens with 1.6x the focal length to give the same view).

2. Using the same lens on a EOS 10D and a 35mm film body, the 10D image has 1.6x LESS depth of field than the 35mm image would have (but they would be different images of course since the field of view would be different).

3. If you use the same lens on a EOS 10D and a 35mm film body and crop the 35mm image to give the same view as the digital image, the depth of field is IDENTICAL.

4. If you use the same lens on an EOS 10D and a 35mm film body, then shoot from different distances so that the view is the same, the 10D image will have 1.6x MORE DOF then the film image.

5. Close to the hyperfocal distance, the EOS 10D has a much more than 1.6x the DOF of a 35mm film camera. The hyperfocal distance of the EOS 10D is 1.6x less than that of a 35mm film camera.

denniskee

Senior Member
ok, imagin now, so how i cut a very very thin black color rectangle "frame", with external dimension enough to cover slightly more than a 135mm format frame. the inner "rectangle hole" has the dimension the same as eg. 1.6x crop (like the 2 and 3 digit model of dlsr from canon).

imagin i place this infront, just next to the negative / positive inside the slr, and that slr can function as per normal.

this will give exactly same effect as the dslr right?

so what bob atkins is saying is the same as above imagination, except he scan the full frame image, than crop to size.

hope you can understand what i am trying to say.

lastboltnut

Senior Member
Sorry dennis. I think I mis-read point 3, it says the DOF is identical, so correct lah.

But by this theory, then my S3 IS with crop factor of 6 has 6x more DOF loh......correct lah, that's why so difficult to get shallow DOF mah.

Sorry for the confusion.

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