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Old Aug 31, 2006, 7:52 PM   #1
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I'm coming from a film slr and trying to produce similar results with depth of field in my new digital camera (the S3 IS). No matter what I try I get everything in focus.I think it's more than the camera can handle but would like feedback from anyone who has tried the same orknows this cameras ability, or inability as the case may be.

Thank you
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Old Aug 31, 2006, 8:41 PM   #2
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I answer this question periodically. So, I'm just copying an answer from another recent thread to here:

Get closer, frame tighter.

As a result of a very tiny sensor compared to 35mm film, the lens on most non-DSLR digital cameras can have a much shorter actual focal length, to get any given 35mmequivalentfocal length (i.e, the same angle of view as you'd have with the lens on a 35mm camera)..

Look at the front of your lens and you'll probably see the actual focal length printed (along with it's aperture ratings for the wide angle and full telephoto zoom positions).

So, 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 with most digicams, and you'll have much more Depth of Field compared to a camera with a larger sensor (or film).. This isbecause Depth of Field is computed by the actual versus 35mm equivalent focal length,focus distance,and aperture.

Your ability to blur the background for any given aperture depends on your subject size, the percentage of the frame you need it to occupy (which you can use focal length or the distance to your subject to change), and the distance to the background that you want your subject to stand out from. Of course, using the largest available aperture (represented by the smallest f/stop number) helps - but this is usually not enough to achieve the desired results for larger subjects with most non-DSLR models (i.e., your people photos).

Your best bet is to frame as tightly as possible (fill the frame by getting in closer or using more zoom). In other words, go for a tight head and shoulders, versus a full length shot. You'll want to use the camera's largest available aperture (smallest f/stop number), and put as much distance as possible between the subject and background.

You could also try focusing in front of the subject (so that your subject is barely in the area of acceptable sharpness).

Load this Depth of Field Calculator and selectyour camera model. Then, plug in the *actual* focal length of the lens, focus distance and aperture to calculate Depth of Field. Keep in mind that "acceptable sharpness" is not the same thing as "acceptable blur" though.

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

Of course, keep in mind that when you use more optical zoom, you'll need to be further away from your subject for it to occupy the same percentage of the frame (hence, cancelling out thebenefits of longer focal lengths in some shooting conditions where you'd want less Depth of Field, especially since the largest available aperture requires the wide angle lens position with most compact digital cameras).

Although the perspective changes (more compressed background from shooting further away) can give the illusion of a shallower depth of field, since blur in out of focus areas will be more obvious (even if the real depth of field isn't changing, since you need to take the photo from further away if you use more zoom for the same framing).

So, for many scenarios, unless you can budget for a DSLR model (which have much larger sensors compared to non-DSLR digital cameras), your best bet is to try and use software to simulate a shallow depth of field for larger subjects. You may want to check in theEditors forum to get some tips. Here is a thread with a couple of different methods mentioned:

http://www.stevesforums.com/forums/view_topic.php?id=29694&forum_id=31

Sbooting small, subjects from close distances is one thing. Trying to blur the background with larger subjects is something else entirely (since you need to be further away to get them fitted in the frame, increasing depth of field).

That's one of the appeals of a DSLR (the ability to control Depth of Field for helping your subjects stand out from distracting backgrounds). The sensors are just too small for that in non-DSLR models (unless your shooting smaller subjects).

A non-DSLR model with much greater depth of field like your camera can be a good thing, too.

You may want more depth of field versus less, and with a DSLR model, you'd need to stop down the aperture (smaller aperture represented by higher f/stop numbers) to get it (often requiring much higher ISO speeds or slower shutter speeds to achieve what you can get with a non-DSLR model shooting at wide open apertures.

There are pros and cons to both types of systems.

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Old Aug 31, 2006, 10:03 PM   #3
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Thank you for your reply it is a tremendous help in both understanding why this is a real problem and inlearningadditional techniques to see if I can accomplish what I hope to do with my particular camera. I'm still wondering has anyone with a S3 IS had any specific luck with depth of field shots and if so any tips they wish to share?


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Old Aug 31, 2006, 10:28 PM   #4
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Well... About the best you'll come up with is to shoot in Av (Aperture Priority) mode, opening up the Aperture all the way (smallest f/stop number), zooming in as much as possible (use longer focal lengths), and framing as tightly as possible (go for a head shot versus a full length shot).

That will get you the shallowest Depth of Field you can get with this model, along with a perspective from shooting from further away (so that you'll have the illusion of a shalower depth of field from a more compressed background.

About the only other thing you could do would be trying to focus a bit in front of your subject, so that they're barely in the area of acceptable sharpness.

If someone has any specific tips for how to accomplish this in a better way with your camera, then that could possibly help.


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Old Sep 15, 2006, 10:08 PM   #5
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I read your post and entered one of my own on Canon Digital forums.

I also have a Canon S# IS, here is the url to my post:

http://photography-on-the.net/forum/...d.php?t=216336

I am going to play around with it, but it looks like I will be using manual mode with a low f/stop. The f/stop is adjusted by using the up/down arrow in Manual mode. The left/right arrow adjusts the shutter speed.
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Old Sep 16, 2006, 8:11 AM   #6
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Thank you for your reply.

I'm still very new to this but this is what I've learned sofar. With depth of field I find you have to get in really tight to get anything that looks good. One trouble we have is our F stopautomatically adjusts toa higher settingwhen we use zoom, and you have to use zoom so F3.5 may be your best and only choice.

Here's what I do. Look through the lens not the monitor. (WYSIWYG) If you're in one place like in the stands viewing a game use your manual focus otherwise use the AF lock. Get in as tight as you reasonably can (you may need a separate lens like a fish eye that someone else may know about) and judging by your volley ball game picture (by the way great shot) focus a few feet in front of your subject. (You're going to need that extra distance to help the camera) I knowplayers are constantly moving but do the best you can. You will have to play around with this to find your best settings and definitely make some compromises but I think you can do it. You'll see the picture in the lens before you take it which makes it easier to judge your settings.

I do the same thing only in reverse if I want to blur the foreground. Using this camera for DOF athigh focal lengths is so much easier. I'm told an SLRisfarbetter for all of this butthey can't take the video the S3IS can take. I'm looking to upgrade in the not to distant future but this is a great all around camera and definitely a keeper.

Best ofluck


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Old Sep 17, 2006, 8:31 AM   #7
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what JimC said is exactly right. Even though your lens says it is f/2.8 it's actual 35mm equivilent is about f/11, so getting a shallow depth of field is pretty hard to do. On the other side of the coin though when you do want that shot with everything in focus you can probably get to around a f/64 equilvilent which is pretty huge.
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