## **Getting into it** Recently, I got curious about what the world looks like under a microscope lens, closer than what normal lenses can capture. While researching how to adapt microscopic lenses for cameras, I realized that many people had already done this with digital setups. Instead of repeating the same path, I wanted to try something different. My Zenit EM film camera turned out to be the most compatible tool for this. The Zenit uses an **M42 mount**, while most microscopes use **RMS mounts**. I thought the problem was solved by simply finding a 3D model of an RMS-to-M42 adapter. But as I quickly learned, things were not that simple. ## **Learning about microscope lenses** Microscope lenses are not like regular camera lenses. They generally fall into two categories: - **Finite lenses** These are designed to project an image at a fixed distance inside the microscope body. They require a very specific distance between the lens and the camera sensor (or film plane) to focus correctly. If that distance is wrong, the image turns out blurry no matter what. - **Infinite lenses** These project light in parallel rays, meaning they need an extra optical element (called a tube lens) to focus the image properly. Without that, the image never forms correctly. At first, I thought magnification (4x, 10x, 40x) was the main thing to worry about, but actually the optical design matters even more. ## **Building the setup** Buying proper microscope objectives online (Amazon, eBay) was expensive, so I found a cheap second-hand microscope on Leboncoin (like French eBay) and harvested its lenses. I then 3D-printed a few adapters to attach the lenses to the Zenit. After a few failed trials, I got the **10x lens** working with the correct distance. That gave me my first working setup. Later, I realized I could have done this more cleverly: instead of mounting the lens directly to the camera, I should have 3D-printed an adapter for the microscope’s eyepiece. That way, the optical path would stay closer to how microscopes are designed. That’s the next step I’ll be testing in the coming weeks. ## **DIY slides and lighting** To prepare samples, I went to the nearest park, picked small grass flowers and leaves, and sandwiched them between glass sheets inside a tiny photo frame. This became my oversized DIY slide. To hold it in place, I 3D-printed a small table-shaped stand. Normally microscope slides are lit from below, but for some reason I didn’t do that—I used a regular light in front instead, without doing enough research. Here’s the setup: > [!figure] ![[MPH-07.jpeg]] ## **Shooting** Microscope lenses are extremely sensitive—just the smallest vibration throws everything out of focus. With the Zenit, I had to use the **self-timer** to avoid shaking the camera when pressing the shutter. Later, I tried a digital camera just to preview results faster, and that’s when I really noticed how much patience this process requires. Here’s one of the first trial images: ![[MPH-01.jpg]] ![[MPH-04.jpg]] ![[MPH-05.jpg]] ![[MPH-03.jpg]] ![[MPH-06.jpg]] ## **First results & next steps** The outcome wasn’t “pretty” in the traditional sense. The image has heavy grain, uneven light, and strange colors. This was just the first attempt. Next, I’ll test with an eyepiece adapter and try backlighting the slides properly. I’m also curious to see how different magnifications will behave on film compared to digital.