By Roger (22 January 2015)
Have you ever been in this situation? You are being pressed by a crowd at an event; the window light is a little iffy; you open the lens wide; up the ISO a skosch; and slow down the shutter speed a tick. You know you're near your limit, with that heavy 70-200 lens on the camera. But, hey you know what you're doing, right? You take the shot, and it works! Yeah, there is a little bit of motion blur, on her right hand, but it is acceptable in this scenario.
Man, you think, I've got this down. I'm in manual mode, making adjustments on the fly. But, since I have my lens open to f2.8, and I hate to move the ISO higher, I have only one control available to adjust if I need more light – my shutter speed. Then, another subject
comes into the room, further from the window light, and you adjust down one stop to 1/25 of a second to compensate. You twist your body to get the shot, so you're not as steady as you should be, either. Click goes the shutter. Have you ever been in this situation? Um, me neither. (Cough, cough) Well, maybe once. ;-)
What happens to your photo, when you push too far in those situations, is motion blur that isn't acceptable. You may not be able to see it in this photo, so let's zoom in a bit.
It's a portrait, so look at the eyes. Trouble. Look at the brim of his hat; the strands of hair in beard. Ouch! There is definitely motion blur present. I used too slow a shutter speed for the 70-200, and the photo is a good copy of the look on my face. Except, his mouth is closed, and mine is using words that would get me a bite of soap 45 years ago. I know better than to push this far. Before you hit the DELETE key on this photo, give Photoshop a chance to save you.
Let me be the first to warn you that this particular tool, nestled under the Filter menu, won't always fix your problem. It can also give you some strange artifacting, even when it does work. However, I only got two photos of this man, and the second shot is beyond repair. So, with second shot deleted, I jumped into Photoshop to try to salvage my mistake. Under Filter, Sharpen, you'll find the Shake Reduction tool. It opens a window, with a couple of controls on the right.
When the tool opens, it will draw a Blur Estimation Region (gotta love the engineer's use of the language, huh?) and make it's first attempt to fix your problem. You can add another BER, but I have never found this effective. I always check the Artifact Suppression box, at the top of the menu. The software does a pretty good job, so I rarely move the sliders much. You'll need to try them a little to see if they favorably impact your photo. I click the Preview box (top of menu) on and off to see the difference. If you're lucky, this is the new zoom.
I've used no other tricks or tools on this example. The feather, hat brim, and eyes are much better. It still isn't as good as if I had used the proper settings, but this photo can be used, especially if the subject doesn't want a 20x30.
There aren't any weird artifacts on this photo. The two I've seen most frequently are haloing around high contrast areas (like the edge around his coat and hat in this photo) or a “crunchiness” in the finer details. The crunchiness looks like you've grossly over-sharpened that part of the photo.
The key move is to use appropriate settings for the situation. A good rule of thumb is to keep your shutter speed as high, or higher, than your lens' longest focal length. My 70-200 was being used at 1/25 – rather far from 1/200. In addition, whenever possible, leave yourself room to move all your settings to get the correct exposure. At f2.8, I had no room to move there. My shutter speed was already too slow. I should have changed my ISO to keep my shutter speed higher. But, when you need some help, give the Shake Reduction tool a try, as a last resort. It worked for me on this photo.