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Old Jun 28, 2007, 11:24 AM   #11
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Here is another but they all look about the same
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Old Jun 28, 2007, 2:02 PM   #12
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nboerner wrote:
Well I tried changing several settings. It did help the exposure but to me they still seem blurry. I half pressed the shutter button with the box right on my sons face. Please let me know if you find them blurry too, maybe it is just my monitor but it surely does not seem as crisp as when I zoom in on pics from my other cameras.
That first photo is very good.

I see you used a -0.3 setting with Exposure Compensation using Center Weighted Metering that time. That worked out nicely, especially considering that the harsh lighting from the window was the only light source.

A flash was not used with that image. For a non-stationary subject, shutter speeds were on the slow side (1/60 second at ISO 200 and f/2.8 ).

The default exposure algorithms don't know that you're shooting a non-stationary subject, and they are only concerned with trying to keep shutter speeds above 1/focal length "rule of thumb" (which is based on about what you'd need to prevent blur from camera shake).

For example, if shooting at a 35mm equivalent of 50mm, try to keep the shutter speeds at 1/50 second or faster (1/focal length in mm if you're using a focal length that is equivalent to 50mm on a 35mm camera). That's great for most people to prevent blur from camera shake, but not necessarily fast enough to prevent blur from subject movement.

So, it didn't use a flash.

That's tough lighting for any camera, since you've got a lot of ambient light coming in through the window.

You could force flash on and it would probably increase the shutter speed or stop down the aperture (smaller aperture/higher fstop number), to block out some of the ambient light to help out.

When flash is the dominant light source, the flash itself has the ability to freeze action, provided you don't have enough ambient light to expose the subject.

That's because a flash burst is very fast (usually from around 1/1000 second to around 1/20,000 second). So, your subject is only exposed properly during the short flash burst (freezing the action, regardless of shutter speed, provided flash is the dominant light source). The problem comes in when ambient light is contributing too much to an exposure. Then, you have to worry about blur from subject movement, and 1/60 second isn't fast enough.

A flash wasn't used at all in that first image. It was still a good shot, especially considering that all ambient light from the window was the light source.

The 1/3 stop -EV setting for Exposure Compensation (-0.3 EV) helped out, and the only hot spots I see are on the top of the shoulders. These areas are shown as black on white in this image.

That's about as good as you can expect to get unless you want to tweak the photo later, since the overall exposure looked like it worked out just about right.

This is zoomed in to 200%, and the black spots are the only areas overexposed (I've got this editor set to show me black on white for overexposed areas). That's pretty good for that lighting, and it's surpringly sharp considering the conditions with no flash used with a shutter speed that slow (ambient light only exposure at 1/60 second of a non-stationary subject).

As for the difference in sharpness, that's only because Canon is using a relatively conservative approach to sharpening in some of their newer models.

I like that approach, since it helps to give you more latitude for sharpening later. Sharpening is mostly an optical illusion (most algorithms work by increasing contrast at edge transitions), and the more "real" detail a manufacturer leaves by default, the better from my perspective. There are too many cameras now that have sharpening, contrast, and saturation bumped up too much, limiting your ability to squeeze the best out of a photo later.

Here's an example of using USM (Unsharp Mask) to make the image look sharper. I'm zoomed in just a touch (133%) for this one and have this editor set so that you can see the before (left) and after (right) . Many image editors can do this kind of thing for you (sharpen).

This is a more sophisticated algorithm.

In both the above USM and this Refocus type algorithm, I'm keeping the values very conservative (I don't like anything to look any sharper than this, since it can start to look artificial, as the photos from many cameras do now).

Here is one of your originals:

Here is the same photo lightly sharpened using the algorithms in my last screen shot above:

Try playing with the camera settings for sharpness if you want them to be sharpened more straight from the camera.

I personally prefer a more conservative approach (as your SD750 uses). You retain more "real" detail without too much sharpening being performed by the camera, and that really shows up in prints (you can't see that kind of thing using monitors set to 96dpi resolution, versus a print with a *much* higher number of pixels per inch).

As for the second image, you missed the focus.

Look at the area of the couch closer to the camera and the area of the couch further from the camera.

Despite the distance and perspective differences, the number of pixels occupied by the closest cushion and the cushion that's closest to your son are not *that* different. Yet, the closer cushion is much sharper.

You focused on something closer than your son.

Flash was used for the second image. The highlights in the windows are a bit blown (as you'd expect with sun shining in). Considering the conditions, that's not too bad at all. A faster shutter speed was being used for that one. So, motion blur was probably not part of the equation. So, the only major issue I see with your last photo was focus point (the camera appeared to be using a focus point closer to the camera compared to your son, for the photo of him on the far end of the couch).

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Old Jun 28, 2007, 5:29 PM   #13
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Thanks for such in depth help. I will keep playing with it and see if I can do better with the focus. I truly appreciate the time you took to help me out. I am having a baby soon and I need to make sure ther camera my husband uses at the birth is up to the job, a once in a lifetime photo opportunity.
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Old Jun 29, 2007, 8:31 AM   #14
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Wow, nice results in sharpening. Are you just cranking up the sharpening or doing other settings as well? I have photoshop, but I don't really know what to use other than the Sharpen tool. If overused it get's noisy.
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Old Jun 29, 2007, 9:29 AM   #15
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All I did was a light sharpening using the "refocus" algorithm in digiKam (an open source photo management application for Linux). digiKam is included in a number of Linux distros. I'm running it under Sidux 2007-2 (a free Linux distribution based on Debian Sid). You can read more about Sidux here:


You can see more of digiKam's features here:


This particular sharpening algorithm does have some parameters to keep noise under control duing the sharpening process. But, that's not really necessary in many cases, depending on the ISO settings you used and your exposure. It's got similar features to this plugin for the Gimp, and there is a section discussing how it differs from other algorithms on this page:


I personally prefer a relatively light touch to sharpening. You could make them look much sharper if desired with a bit of tweaking. I just used some default settings for demonstration.

Depending on the version of Photoshop you have, you will find multiple types of sharpening at your disposal, including USM (Unsharp Mask) and "Smart Sharpen" (just don't overdo it as the defaults can make a photo look way too sharp).

The USM option you'll find in many editors (including Photoshop) works fine for most images. See the sharpening screen print I made using USM. I didn't bother trying to tweak any of the parameters (that's just the defaults I use for web images). Note that an amount setting of 1.1 in my example, is equivalent to 110% in many other editors.

You'll find lots of tutorials on the web for how to use USM and what the parameters can do. Just use google to search for Unsharp Mask:


But, almost any type of sharpening could improve the photos. Even using the ordinary sharpen option (versus unsharp mask) can improve them significantly. You can also use more than one type of sharpening on the same image.

Here is a search for sharpening photoshop how to


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