3D-printing a smartphone holder for taking pictures on a microscope

Taking microscopy pictures with a smartphone is quite common at the teaching lab. Students often use their favorite electronical device for documenting observations and illustrating their journals or their Instagram feed.

Taking pictures directly through the eyepiece of a microscope isn't that difficult, to be honest. However, taking good pictures is somehow a bit tricky. The main issues are often stability and shutter lag (in other words, the delay between pushing the trigger button on the phone and the actual time the picture is taken). Practically talking, one must hold the phone stable at the right position so that the camera lens is aligned with the ocular lens and the right distance from the lens, and long enough so that the picture does not turn out blurry.

Some students are really good at it (see picture to the right), some lose patience quite fast and give up. So how may we help them?

Browsing your favorite shops online, it does not take long before you find smartphone holders for the car, bike, kitchen bench, telescope, or ... microscope. Such small devices cost a couple hundred Norwegian crowns and are usually made of 100% plastic. But then, if it is just plastic, why not 3D-printing it instead of buying it?

Apparently, someone else has had the same question in mind, and come with a 3D model that fits exactly the purpose (picture to the left). This original design was published by martinlessard100 on Thingiverse, and can be found here. All files are free to download. It is made of 7 parts including 3 screws, may be printed all together in a working day and does not cost much more than 30-40 crowns in PLA filament.

Of course we had to try it... and acknowledge that the model is both simple and great. However, this particular design was a bit too narrow for our Leica DM750 microscopes which ocular pieces are approximately 40mm wide. The main part of the smartphone holder thus had to be rescaled using Tinkercad to fit our equipment. A few minor modifications were added, and now, it works nicely at BIO! (NB: you may download the customized version using this link).