The Art of Compromise
|Guitarist Michael Raitzyk|
Bright Light Situations. Suppose you want to get that nice, silky effect on a waterfall on a bright, sunny day mid-afternoon. The sun is shining directly on the the falls, and it looks so pretty you have to get the picture. Here's the problem. On a bright, sunny day, there's so much light that can be impossible to make your ISO slow enough and your aperture small enough to get your shutter speed in the 2-3 sec. range. If, on top of that you want a narrow depth of field (large aperture), well, you may as well ask for the moon.
This situation forces a compromise--the best solution is to return in the early morning hours before the sun shines on the falls. But if that's not an option, you can use a filter, called a Neutral Density (ND) filter. ND filters are simply neutral grey filters that cut down on the amount of light entering the lens. I have them in three strengths: -1, -2 and -5 stops. So if your proper exposure is 1/100sec at f/16 and ISO 100 and you add a -5 stop ND filter, your proper exposure will become 1/3 sec at f/16 and ISO 100. I used this technique to get the photograph of rapids below.
|Rapids in Patapsco State Park, McKeldin Area|
This situation also forces a compromise. You could opt for a shallow depth of field and shoot the scene at f/2.8 or f/4. You could also decide to pan your camera while shooting--that is, you can follow the deer with your camera as you shoot, hoping that the deer will be sharp--this will give you "motion blur" in the deer's surroundings. There's another trick I sometimes use (and it sometimes works). I intentionally underexpose the image to get a fast shutterspeed and then try to increase the exposure with software. If you're shooting RAW, you can sometimes get 1-2 stops this way. You will have a grainier image this way, but it's better than not getting the shot. I used this technique to get the photo of the Carolina Wren below. It's not ideal, but I wanted the bird.
This is the art of compromise. In dim light, you often cannot have wide depth of field and a fast shutter speed. In bright light, you often cannot have a narrow depth of field and a slow shutter speed. You must compromise what you want less to get what you want most. So you must know what you want most, what to give up to get it, and how to compensate for what you gave up with filters, software, and anything else you can pull out of your bag of tricks.
Scott, thanks for a great article! I had never thought of the other problem: Wanting to leave the shutter open when there's TOO MUCH light. I learn something every day from this site.ReplyDelete
Hey, thank you for the idea to write it. That was fun.ReplyDelete