Back in the days of film and darkrooms I used to lug around an SLR camera. I never really called photography a hobby, so I gave it away when digital point-and-shoot cameras came out. These days I can usually take all the pictures I want with my smartphone.
The only thing I miss about SLR cameras is the ability to take photos with shallow depth of field, the ones where the background or foreground is blurred. You need a macro or zoom lens to do that, and smartphones don't have them. My Samsung S5 camera has a feature called Selective Focus that tries to achieve the effect using multiple shots and software tricks, but it's very finicky. I can also reproduce the effect by processing the digital image with an app, but it takes a lot of work for the result not to look fake. The other option is fit my phone with a Sony QX lens, but that costs as much as a professional camera.
Some time ago I was told that it was possible to use zoom lenses on a smartphone by putting a telescope eyepiece between them. This week I finally got the chance to test the idea when I found a used nonworking DSLR lens for $10. As I try to demonstrate in this project, for the fraction of the price of a point-and-shoot you can vastly improve the power of your smartphone camera and rescue a fully functioning but obsolete piece of precision technology from destruction.
Comments and tips from the more knowledgeable will be appreciated!
- Zoom lens with rear cover. The one I found was a Canon EFS 18-55. The rear cover is where the eyepiece will attach to.
- "Telescope Camera Lens." It's really just cheap zoom lens for smartphones. The quotation marks are there because that's what it's called on ebay. I bought one a long time ago because I thought it might be useful, but it was a waste of $9. This project gives me a chance to get something out of it.
Mine came with a case specifically for my Samsung S5. Its eyepiece attaches to the phone case using mounting slots. This was a big plus, because I didn't have to figure out how to connect the two together.
- Plastic tube with inner diameter exactly equal to the barrel of the cheap zoom lens. The fit should be tight. This part is actually optional but is useful if the barrel is too short, and it creates another way to get focus by letting you adjust the distance between zoom lens and the eyepiece. You will then be able to use the full range of focal lengths of the zoom lens.
I found the perfect tube in my pile of random junk. I believe it's the tube that dispensed those clear plastic bags in the vegetable aisle of the supermarket. I have a habit of picking up trash like this all the time, and this time it paid off.
Update: I finally found the perfect Android app to use with the lens. The app is called Open Camera, which has a mode that rotates the image on the camera viewfinder, correcting the rotated image seen through the lens.