The focus ring on my Canon EF 50mm f/1.8 II is very small, and with the added addition to the lens hood that I use, it can sometimes be a struggle to actually find the ring to focus quick enough. I was thinking about how I could improve this focus ring without spending any money, when I thought about one of those rubber wristbands which you buy from different charities. The wristband has a perfect diameter for fitting around the focus ring, and almost triples the surface area to focus with. For a quick modification which didn't cost me a penny, I am very happy with how this turned out and will definitely be keeping it on my 50mm lenses focus ring for future use.
The image to the right shows the wristband on my lens. When you focus on the 50mm lens the front element moves in and out depending on what way you focus. I did think that the lens hood which also moves in and out would get stuck when it got to the wristband, however the movement of the front element stops perfectly at the wristband.
I would definitely recommend doing this quick modification on your EF 50mm f/1.8 II prime lens if you have problems focusing. Currently on eBay the rubber wristbands start from only 99p, click here to view them now, you can even get 'Joseph Kony' ones for a little more.. Most people have these wristbands from when they were a craze a few years ago, you will probably find one laying around like I did. Another solution for lenses with bigger focus rings, such as my EF-S 18-135mm zoom is 'Dave Knops' silicone jar opener follow focus, click here to view his YouTube video on it.
Click here to view the $45 lens/ focus shifter campaign on Kickstarter.