Friday, May 18, 2007

Look sharp, be sharp

I frequently find myself wishing my photos were sharper. Now, I don't mean to make too much of sharpness. I know that focus and sharpness are not quite the same thing. I know that composition and exposure (and an interesting subject) are more important for the kind of photography I do than sharpness. Still, I've been wondering lately if I could get my shots to be sharper.

The answer seems to be yes, I can.

Not sure whether you can tell, given the way that Picasa Web Albums displays the photos, but this portrait of one of Catherine's team mates seems to be pretty sharp. Zoom in on it. Unfortunately, in Picasa Web Albums, you can't really zoom to 100% as far as I can tell. At 100% in Lightroom or Picasa, it looks as sharp as it does when its shrunk to show the whole picture in a small window. Looks pretty good even zoomed to 200%. At 100% every freckle on her face seems perfectly distinct. Noteworthy points: This photo was taken outdoors in pretty decent light, ISO 100. I used my Pentax FA 50mm (prime) f/1.4 lens, but at f/2.8, not the max aperture, in other words. The max aperture in many lenses is said to have a tendency to be soft. I was using a tripod, too, but I think that is likely to have had the least impact on the photo. With a shutter speed of 1/250 sec, I think this picture would have looked just the same if I'd shot it handheld - except that perhaps I would not have cut off the bottoms of her toes.

flowers on the porch
This photo of flowers on our porch also seems acceptably sharp. Noteworthy points: It was taken with my Tamron 28-75 lens at 38mm, in other words, not at the extreme end of the zoom, which the experts say usually tends to be soft. The shot was taken at ISO 100, which is as low as my Pentax K10D goes. Finally, the aperture here is f/11, allowing for reasonably decent depth of focus, even though the camera was only about two feet away from the flowers. I think these three facts (focal length in the "sweet spot" of the lens, the low ISO, and the moderately small aperture) are the key factors here in the photo's sharpness. Those three, and the K10D's built-in shake reduction. I was after all shooting at 1/30 second, handheld.

Now the preceding two photos were taken at ISO 100, which I'm beginning to think has something to do with sharpness, and not just with noise reduction. But this group shot was taken at ISO 400, and it too is reasonably sharp. But this one is interesting. At f/2.2, it has pretty shallow depth of field, and you can see that the focus is NOT so sharp in the face of the girl who is on the top of the pile. She is a little further BACK from the face of the coach that I was focusing on. Here again, I was using the Pentax FA 50mm f/1.4 lens. This is the lens I have been using lately for volleyball action, because of the big aperture. I did think to position the group here so that we were getting the benefit of the little bit of daylight coming in through the clerestory high up near the top of the north wall of the gym.

I should add that all of these photos were sharpened a little in Lightroom, but that seems to be absolutely necessary for all photos when you shoot Raw, as there is no in-camera sharpening whatever. But I didn't sharpen them very much, and in my opinion, Lightroom's sharpening never converts a soft-focus photo into one that is tack sharp.

Now, the trick is to take photos this sharp more often. Be nice to be able to shoot outdoors in good light all the time.

About Me

I am an event photographer living in Dallas, Texas.