WIlliam Maroldo
07-18-2008, 08:06 PM
I need help! I am having somewhat of a dispute over at another bird photography forum, and I desperately need to hear your opinions, whether it is on my side or not. I've been wrong before, and I could be again, but in this case I'm having great difficulty in understanding the other side of the argument.. This is something that I need the opinions of experts and I consider many members here to be in that category, and even if they are not quite experts yet, if they keep hanging around BFN long enough they will be..
So here is the dispute. It concerns Aperture Priority vs Shutter Speed Priority in taking photographs of birds in flight. My opinion is that Shutter Speed priority is preferred. My reasoning is that because too low a shutter speed will cause a blurred image, the camera must be set up to always shoot a high enough shutter speed. The actually shutter speed required is based on a number a variables, like distance to subject, speed and direction the subject is traveling, etc. In any case, the photographers first job would be to determine the speed necessary to avoid blurring from either camera shake of motion of the subject. . Correct exposure would be achieved by allowing the camera to set the aperture, and using the appropriate ISO. To me, at least, in Aperture Priority there is always a risk that a shutter speed will be too slow, the result would be a blurred image. In birds in flight, especially at a distance, there is no real advantage in a greater depth of field. The whole bird can be in focus at wide aperture. Closer in, depth of field is more important, but how many BIF images are close-ups? Now a group of birds in flight can be shot at a wide aperture if there are in relatively the same focal plane, however this would be helped by a wider aperture.
In SS priority the risk is that the aperture was incorrect, most likely resulting in an underexposed image, or the aperture was insufficient to create a desired depth f field. Now, it is my contention that a blurred image is far worse than an underexposed image, not to say either is great. A blurred image is not salvageable. An under-exposed image might be saved, and since brightening an underexposed image introduces noise, it is possible to use noise reduction software. So what if I need a greater aperture to get greater depth of field, to include a number of birds in flight in an image? I would increase the ISO, and a smaller aperture would result(and of course more noise with the higher ISO). In any case, by using a shutter speed of 1/1600 and SS priority, and using an ISO appropriate for the ambient light conditions I have been fairly successful in BIF images. I could be completely wrong about all of this. I would like to hear how other far more accomplished photographers than I deal with these issues. ~onlybill
So here is the dispute. It concerns Aperture Priority vs Shutter Speed Priority in taking photographs of birds in flight. My opinion is that Shutter Speed priority is preferred. My reasoning is that because too low a shutter speed will cause a blurred image, the camera must be set up to always shoot a high enough shutter speed. The actually shutter speed required is based on a number a variables, like distance to subject, speed and direction the subject is traveling, etc. In any case, the photographers first job would be to determine the speed necessary to avoid blurring from either camera shake of motion of the subject. . Correct exposure would be achieved by allowing the camera to set the aperture, and using the appropriate ISO. To me, at least, in Aperture Priority there is always a risk that a shutter speed will be too slow, the result would be a blurred image. In birds in flight, especially at a distance, there is no real advantage in a greater depth of field. The whole bird can be in focus at wide aperture. Closer in, depth of field is more important, but how many BIF images are close-ups? Now a group of birds in flight can be shot at a wide aperture if there are in relatively the same focal plane, however this would be helped by a wider aperture.
In SS priority the risk is that the aperture was incorrect, most likely resulting in an underexposed image, or the aperture was insufficient to create a desired depth f field. Now, it is my contention that a blurred image is far worse than an underexposed image, not to say either is great. A blurred image is not salvageable. An under-exposed image might be saved, and since brightening an underexposed image introduces noise, it is possible to use noise reduction software. So what if I need a greater aperture to get greater depth of field, to include a number of birds in flight in an image? I would increase the ISO, and a smaller aperture would result(and of course more noise with the higher ISO). In any case, by using a shutter speed of 1/1600 and SS priority, and using an ISO appropriate for the ambient light conditions I have been fairly successful in BIF images. I could be completely wrong about all of this. I would like to hear how other far more accomplished photographers than I deal with these issues. ~onlybill