Grabbing my camera and playing around with aperture settings is one of my favorite things to do after a long day at the office. Especially my office. I have no heating or air conditioning. There are always bug and rodent problems, sometimes even carnivores ramble through my workplace. No roof means I am at the mercy of the weather. Don't believe me? Here is proof.
The aperture setting on your camera controls the depth of field, also known as the plane of focus. In any photograph, only one point (a certain distance from your camera) is in perfect focus. The rest of the photo resides in circles of confusion. I love that term. What that means is everything else is out of focus. But that amount of unfocusness (is that a word?) varies depending on your camera's aperture setting. The smaller the F stop, meaning the higher the number, brings the level of "acceptable sharpness" into play. Ansel Adams, and to some extent Edward Weston, were members of the F/64 club. They would set the aperture to F/64 on their big view cameras and everything from just in front of the camera to infinity would be acceptably sharp.
But that is not where I am going with this photo tip. I am going the opposite direction. Call it bokeh, baby. Shooting with your lens wide open, (smallest F/ number) reduces the depth of field to inches or less.
Imagine if I had taken this photo at F/16 instead of F/3.5. Well, you will have to imagine because I didn't. The result would have been almost everything in focus and the flower would have blended into the background with almost no separation at all.
Bokeh also comes into play when shooting wide open. There is much debate about good bokeh and bad bokeh but it boils down to whether you can see the lens blades or not. Creamy bokeh will have nice round circles while nasty bokeh will show the blades.
Mine is in the middle for this lens as seen below.
You can see some edges but hey, so what? The point to all of these tips is step away from auto mode and take some neat photographs.
Here are two photos showing the dramatic difference in depth of field while shooting wide open.
I think those two would look good on the wall next to each other. That's what I am talking about. Photos that would look boring in auto mode can become interesting by setting your camera's aperture to wide open and just walking around the campground.
Here are two more.
The last one was taken at Ocean Beach State Park in Washington in May 2012. You can tell by the water drops. There was some rain during that trip...
So don't be a slave to the auto setting on your camera. Play with your aperture.
Regards, Park Ranger