PO Box 1505
Fresno, TX 77455-1505
ph: 281-778-1486
nchappel
JULY 2013 NEWSLETTER
This newsletter discusses depth of field for bird photography. It will be the first of two on the topic so be sure to read next month's as well to get the full story. It features images from recent workshops.
Harris's Hawk photographed March 2013 at Santa Clara Ranch, Texas. Canon 5D Mark III, 500F4 lens, 1/1250 at F5.6, iso 800, Gitzo tripod with Wimberley head. This shot was taken from the excellent raptor blind at Santa Clara. You will notice I stopped down 1 stop from wide open on this shot which is my default setting for bird photography (2/3 of 1 stop or 1 stop even). What that means for beginners is that if your lens is wide open at F4, 1 stop down from wide open is F5.6. If for example your lens or lens with teleconverter was wide open at F5.6, then F8 would be wide open and 2/3 of a stop down from wide open would be F7.1. When I say default setting that just means my beginning setting before adjusting for any other factors, if I get on a bird and need to fire off a shot quickly that is what it is set to. I will adjust that for whatever the particular situation of the shot is.
There are a few reasons why about 1 stop down from wide open is my preferred setting. First I find that if the bird is fairly large in the frame and I have focused on the head or the shoulder that I am going to get most of the bird in focus that way. If I shot it wide open and focused on the head I might not get most of the bird's body in focus. Worse yet, if I missed the focus on the head or didn't have time to get the focus on the head, then if I focused on the body the bird's head might not be sharp and the image would be a throw away. Well then why not stop down even more to 2 stops? With stopping down 2 stops, for the Harris's Hawk shot above, the aperture would be at F8. Two things happen which are not generally desirable when you stop down that much. First you bring the background more in to focus. In this image it's nicely muted with just a bit of texture but if I had stopped down to F8 it would compete with the bird more. Secondly you lose shutter speed, my shutter speed would have dropped from 1/1250 to 1/640. This bird was moving and I might not have stopped the action, the extra shutter speed helps with sharpness as well.
Long-tailed Jaeger photographed June 2013, Nome, Alaska. Canon 5D Mark III, 500F4 lens, 1.4x tc III, 1/2500 at F8, iso 800, handheld. Here's another example of a shot taken exactly 1 stop down from wide open, this time with a teleconverter on the lens. All of these images have been cropped just slightly. This bird's long tail probably wouldn't have been in focus if I had shot this closer to wide open and if I had stopped down even more I would have lost shutter speed which is more valuable when you are doing flight photography. Another reason for stopping down 2/3 of a stop to 1 stop is that many lenses are sharpest if they are stopped down a bit. With my Canon 500mmF4 I especially find this to be the case when I am using a teleconverter with it. I find that all of the Sigma lenses I have used need to be stopped down this way to get sharp results. I can get very sharp images wide open with just the 500F4 without a teleconverter.
Rock Ptarmigan photographed June 2013 in Nome, Alaska. Canon 5D Mark III, 500F4 lens, 1.4x III tc, 1/500 at F7.1, iso 800, handheld. Both the Willow and the Rock Ptarmigans were my favorite birds from our recent Nome workshop. A big thanks to Ken Archer who did a great job leading the workshop and scouting the area the week before we came. On this shot I stopped down 2/3 of a stop and the bird is sharp from head to almost the tip of it's tail. This is an image where I like the background of rocks covered with tundra vegetation a lot, but if I had stopped down much more it would have become too busy. If I had stopped down less more of the body would have been out of focus as the tail is starting to be here. Next we are going to look at a few images where the depth of field wasn't quite right.
Bald Eagles photographed May 2013 at Hood Canal, WA. Canon 5D Mark III, 500F4 lens, 1.4x III teleconverter, 1/1600 at F8, iso 800. Here's an example of a shot that I took 1 stop down from wide open that missed the mark. Even though these eagles were quite a way out, I needed more depth of field to get all 3 sharp. The bird on the left is sharpest, the middle bird is not very sharp and the bird on the right is in between. While I think it's a good image, it could have been a great image if I had stopped down to about F10 or so. This would have made the background a little busy but overall it would have improved the image quite a bit. Most people generally underestimate the amount of depth of field you need to get multiple birds sharp.
Bald Eagle photographed June 2012 at Hood Canal, WA. Canon 7D, 500F4 lens at 1/1000 F7.1, iso 500, handheld. This was taken with the 500 without a teleconverter so wide open I would have been at F4, one stop down at F5.6. As you can see I actually took the shot at F7.1. Often when I am photographing eagles out at Hood Canal I am closer to 2 stops down from wide open because I am always trying to capture interaction between 2 eagles or between an eagle and a heron. In this case it was only one eagle and because I stopped down that much the background has come into focus more and competes with the bird. At F5 or F5.6 the background would have been much smoother. Some people will like that the background has more texture, so it's partially a matter of taste of course.
Crested Caracara photographed March 2013 at Santa Clara Ranch, Texas. Canon 5D Mark III, 500F4 lens, 1/6400 at F5, iso 500, Gitzo tripod, Wimberley head. Here's an example of where I should have stopped down more. With this good sized bird at fairly close range I didn't have enough depth of field to get the wings sharp when it spread it's wings even though I was 2/3 of a stop down from wide open. I certainly had plenty of light available to work with. I think there are a lot of instructors out there telling people it's best to shoot wide open most of the time, mostly to try and get that nice, smooth background. But I don't think in general it's very good advice, as I have explained here shooting about 1 stop down from wide open will generally give you better results. My workshop participants often ask about this, having been exposed to the idea that it's best to shoot wide open. After my explanations and some time trying it in the field, most agree that their images are usually better when stopped down a bit compared to wide open. Next month I will show images with a greater variation in depth stop and the reasons I used a different aperture.
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PO Box 1505
Fresno, TX 77455-1505
ph: 281-778-1486
nchappel