Sharp Detail or Beautiful Blur?
Sometimes you want all the details sharp and revealing. Other times you want the background to be beautifully blurred, or everything blurred. What you get depends on your aperture, shutter speed, ISO, and the focal length of your lens.
By changing the aperture (the f/stop), you can let less light into the camera or more light. As I discuss in a separate post, changing the aperture also changes the depth of field. At high f/stops like f/32 or f/22, more is in focus. At low f/stops like f/1.4 or f/2.8 or even f/4, less is in focus. Click here to read my post about aperture settings and depth of field.
Focal lengths of lenses vary from as short as 10mm to as long as 1,200mm. 18mm is considered a wide focal length because it captures a wide angle of view. 200mm and longer focal lengths are called long focal lengths or telephotos because they mimic binoculars or telescopes, showing only a very narrow picture.
Excellent depth of field, getting everything sharp and detailed is possible at short focal lengths but can be impossible at long focal lengths, no matter how high an f/stop is used.
If you have looked through a pair of binoculars or a telescope — instruments with long focal lengths — you have seen how one thing will be in focus but the rest is blurred. So, if you want a sharp, detailed image, you may want to avoid long focal lengths unless everything in the frame is the same distance away from the camera.
With a short or medium focal length, great detail is possible if:
- The shutter speed is fast enough to stop any motion blur including camera shake,
- The aperture is high enough to give good depth of field,
- and the ISO is low enough to minimize noise.
Beyond that, experiment with various f/stops and, if you are using a zoom lens, experiment with various focal lengths. You may find that one f/stop is sharper than others, or one focal length is sharper than others using a zoom lens.
Austin, Texas, Easter afternoon 2022, ISO 800, 1/1000 sec, f16, 50mm prime lens. Most of the original image is shown here.
Pixel-for-pixel detail of previous image — Austin, Texas, Easter afternoon 2022, ISO 800, 1/1000 sec, f16, 50mm prime lens.
Short focal-length (wide-angle) lenses capture big scenes and make spaces appear more open. At the same time, everything is easily held in focus.
Short focal-length (wide angle) lenses capture big scenes and make spaces appear more open. At the same time, everything is easily held in focus.
A lens with a short focal length can make a small room appear much larger than it really is.
Long focal-length (telephoto) lenses have less depth of focus. Backgrounds are easily blurred.
Long focal-length (telephoto) lenses have less depth of focus. Backgrounds are easily blurred. With the background blurred, the subject looks more in focus and more detailed.