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-   -   Depth of Field (https://forums.steves-digicams.com/general-discussion-11/depth-field-56003/)

jpdigi May 19, 2005 11:18 AM

I have been researching a few cameras over the past couple of months. I've narrowed it down to the KM A200, Olympus 8080, Canon Pro1, and the Panasonic FZ20. I currently own an old Canon Rebel and like to take artistic shots with shallow DOF. Are any of these cameras better than the other in this respect? Are there any other fixed lens cameras I should be looking at? The shallow DOF is fairly important to me, I just need to figure out how much I will be loosing with a non-SLR. I am not really up to speed on what the limitations of these camera's are compared to a SLR. Any information you can give will be helpful and much appreciated. Thank you.

Jacob

JimC May 19, 2005 11:29 AM

Jacob:

It can be quite hard to get a shallow depth of field with a non-DSLR model for larger subjects. This is because the tiny sensors used innon-DSLR models can also use a much shorter focal length lens (and Depth of Field is based on the Actual versus 35mm equivalent focal length, distance to subject, and aperture).

You can get an idea ofhow this works using this Depth of Field Calculator (select a camera model, make sure to use the actual versus 35mm equivalent focal lengths of the lenses). Also, keep in mind that you'll need to be further away from the subject each time you use a longer focal length, so that tends to cancel out the benefit of using more zoom in many conditions). Remember, the subject occupies a dramatically larger percentage of the frame with a non-DSLR model for any given actual focal length.

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

I'd stick to a DSLR (Canon Digital Rebel, Rebel XT, Nikon D70, etc.)if a shallow depth of field is important to you. Else,plan on using an editor to simulate a shallow depth of field by blurring the background using gaussian blur, etc., unless you are framingtight (head shots, etc.) and/or have lots of distance between your subject and the background.

Even with a DSLR (unless you buy a full frame model like the Kodak DCS Pro/x Canon EOS-1DS, etc.), you'll have greater depth of field than you're used to.

But,a DSLR would be dramatically better than a non-DSLR for this purpose (they have MUCH larger sensors compared to the non-DSLR models, and only use a 1.5 - 1.6x crop factor (a.k.a., Focal Length Multiplier) with their lenses on most entry level models, when compared to a 35mm SLR.


jpdigi May 19, 2005 12:48 PM

Thanks for the comments, very helpful. I will continue my research, I'm sure I will have more questions. I've actually been reading "Understanding Exposure", which was recommended by someone on this site, and is a valuable source of information on the technical side of photography.

Thanks again.

ukwoody May 20, 2005 6:09 AM

can i suggest asking the same question on the Pansonic forum on here. We've got a couple of very knowledge experienced guys that can undoutably show you some shots taken with various DOF.

Hope this helps, Woody



geriatric May 27, 2005 7:12 AM

Focal length of the lens is the main criteria for DOF. DSLR`s are not that much different to SLR`s

peripatetic May 28, 2005 3:29 PM

geriatric wrote:
Quote:

Focal length of the lens is the main criteria for DOF. DSLR`s are not that much different to SLR`s
"not that much different" is rather subjective.

There are 4 variables in the DOF equation: distance, focal length, aperture & sensor size.

If you keep the distance to subject, focal length and aperture constant the difference in DOF is exactly that of the focal length multiplier. The DOF on the smaller sensor is greater by the amount of the focal length multiplier.

So comparing a Canon film SLR to the Canon 20D/XT the DOF is 1.6 times greater on the DSLR. Nikon film v Nikon digital the difference would be 1.5 times.

Check out Jim's link and play with the values:

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



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