There are yellow wildflowers everywhere in my town right now. On Friday evening I decided to run down the street and see if I could make some photos. Getting out of the car, I decided that I was going to put the 50mm prime lens on the camera and try to make what I can with just one focal length. This would either be an exercise is problem solving or in frustration.
Another challenge that I had was watching the background. This spot is close to a busy highway and construction and I wanted to keep all of that out of my photos. To do this, I got down really low and tried to isolate a single flower to put against the other flowers.
This 50mm prime will allow me to get down to f/1.8 aperture to really blur out the background. Though there was too much light to get down to f/1.8, I did manage to get as low as f/2.5. The below photo was shot at 50mm, f/2.5, 1/4000s, ISO100. The focus depth at this aperture and focus distance is so thin that the flower just in front of the subject is completely blurred out as is the background. It certainly does make the subject stand out, but is maybe a bit much.
The focus depth is a function of mainly focus distance and aperture. With a 50mm lens set to f/2.5, the focus depth with a subject distance of 0.25m is less than 1 cm. If I step back to half a meter, the focus depth increases to about 2 cm. And if I go back to 1 meter, I get about 6 cm of focus depth. For the above photo, I was inside half a meter from the flower.
The focus depth will also increase as you stop down the aperture. As an experiment, I shot the following flower four times, reducing the aperture a full stop each time from f/8 to f/2.8. You can see quite a change in the background blur across 4 stops. The photo shot at f/2.8 is probably too much bokeh for me.
There were also quite a few butterflies around, but they wouldn’t let me get too close to them and I was shooting with a prime, or foot-zoom, lens, so the below photo is the best that I got and it’s cropped.
Shooting with only a prime was not incredibly limiting and it did kind get me to focus on a few other aspects of shooting, so a fun exercise.