Can't get shallow DOF with A85

[drocpsu]

I've noticed that although I try to, I can never seem to get a shallow depth of field. I've tried small apertures, and the only time it seems to work is on macros (or at least pretty close-up shots), and while zoomed in.

Does anyone know the maximum distance that I can be from my subject and get a shallow DOF? It's really frustrating me.

[JustShootin']

That's one of the major setbacks with the digital compacts. Except with macro or maybe long zoom, shallow DOF just can't be obtained

[drocpsu]

Is your S2 any better with being able to control this?

[JustShootin']

Originally Posted by drocpsu

Is your S2 any better with being able to control this?

No, there seems to be no reasonable way to get a true shallow depth of field. On the S2, using full, or near full zoom will automatically give you a shallow DOF, but this is of no value for normal portraits etc.. As I said, this is my biggest gripe about these cameras. It's got me thinking about an DSLR if for nothing but grandchildren portraits etc. Software programs like Picasi can help by using their soft focus feature, but it's nothing close to as good as just getting it the way you want it right from the camera.

[eccles]

Professional studio portraits are shot with neutral backgrounds so that a shallow depth of field is mostly irrelevant.
I may be wrong, but here's my take on the whole DOF thing:
DOF is a function of lens focal length and aperture, and as far as I can tell, the size of the camera doesn't affect that. Compact cameras have much shorter focal length lenses than SLRs, which is how they can be made compact in the first place, but equally the smaller sensor will show up any out of focus at a proportionately higher degree so it's equivalent focal length that's relevant here. So if you use a DSLR with a portrait lens, say 100mm set to F5 then you should get the same DOF as a compact set to the same equivalent (not actual) focal length and the same aperture. When you see OOF backgrounds to shots of wildlife for instance these are shot with long lenses with near full aperture. Cropping will accentuate this effect. Furthermore, DSLR prime lenses usually have much wider apertures than F5. The Canon EF100mm for instance will open up to F2.
So in short, as JustShootin' says, use a camera that has a long telephoto range and/or wide aperture. The A85 has a short zoom range, and furthermore the aperture goes down as you zoom in, keeping that wide depth of field. S2/S3 models are better in this respect and will still give F3.5 at maximum zoom, but they still won't compete with, say, a DSLR 100mm F2 lens at the equivalent focal length because the aperture on the DSLR can be opened up further.

[Jon]

Sensor size does enter into it as well. DoF will be different if you use the same lens on a 350D or a 5D. The degree of enlargement is the third factor, and getting a given print size from different "negative" (sensor) sizes requires different amounts of magnification.

[JustShootin']

Originally Posted by eccles

Professional studio portraits are shot with neutral backgrounds so that a shallow depth of field is mostly irrelevant.

That's very true. I have spent many 18 hour days working wth those old master's bagkgrounds, and shallow DOF really didn't matter. But now I'm retired and have no intentions of ever stepping foot inside a studio again! So I make portraits mostly outside, and sometimes a shallow depth of field is a must, and that's where the SLR comes in. And right now for me, that's film. But that may be going to change.

[Graystar]

removed

[bishoy]

If we are shooting with the same equivalent focal length and the same aperture number (f-number) then the DOF will be proportional with the size of the sensor. Or in other words (if you want to take out the size of the sensor) the DOF is proportional with the absolute diameter of the aperture opening, which of course is larger for a larger sensor for the same f-number.

Refer to http://en.wikipedia.org/wiki/Depth_of_field

[JustShootin']

Since this thread was started two years ago, almost to the day, and the OP hasn't posted anything since Jan of 2008. betcha he/she's not reading these last two messages!

[Howard Ting]

Originally Posted by JustShootin'

Since this thread was started two years ago, almost to the day, and the OP hasn't posted anything since Jan of 2008. betcha he/she's not reading these last two messages!

probably not. but.

get a dSLR!