Introduction: Convert Analog Camera to (partially) Digital

By Dr. Tõnis
About: Self-made, well made

Hi all!

Three years ago I found a model in Thingiverse that connected the Raspberry camera with a Canon EF lens. Here is a Link https://www.thingiverse.com/thing:909176

It worked well and I forgot it. Few months ago I found the old project again and thought about redoing it. This time I wanted to use an older manual lens (Canon FD). Nobody has made a proper model for the FD lens and I was already planning to give up.

Luckily, I got an old Canon A1 camera with a FD lens. First, I wasn’t sure how I could use it, but there is actually a very simple way to connect it with an Raspberry camera.

Step 1: What You Need

What do you need:

  1. Canon A1 with a lens
  2. A raspberry Pi (I used a 3+, but other models would work)
  3. A raspberry camera (I used a Chinese clone)
  4. A FFC cable (1.0mm 15pin Type B, the length is not so important, but I used 1.5m)
  5. Some black tape (I recommend a non-reflecting one)
  6. 3d printed distance holder (could be anything with proper thickness, I had 3 mm)
  7. Tripod (optional)

Probably most other analog camera brands would work as well, just the distance between the camera module and the back plate can be different. I managed to modify the camera without cutting/ permanently modifying any part of it. Theoretically, I can remove the added camera module and use the Canon again as normal analog camera.

Step 2: Preparing the Camera

If one opens an analog camera film compartment then it looks usually the same. I used the Canon A1 and it had a special spring system to push the film against the body. One needs to remove it. I don’t have pictures about that process, but it should be self-explanatory.

The light hole is covered with a black “cover cloth” (I don’t know the proper name) and the mirror should be down too. We need to remove these obstacles, as we need free hole to see through the lens. The simplest way is to make a picture and tape the “cover cloth” when it has been moved. You can see from the pictures how I did it and when you play around with the camera one can see how the “cover cloth” and mirror moves. Just adjust the picture time to 10-30 seconds. As long the “cover cloth” is in the open position the mirror stays upwards.

Now comes the most difficult part. Remove the Raspberry camera lens. I would recommend to buy few Chinese copies as it is very probable that the first try doesn’t work. The new v2.1 camera should have a lens that can be easier to adjust. I haven’t tried it.

Connect the cable with the camera and fix the Raspberry Camera on the Canon back plate. I would recommend to place the camera more or less in the middle of the hole. The attached 3 mm thick 3d print file helps to fix the camera sensor with good distance. In the first try I just taped the camera on the back plate, but the sensor distance from lens was wrong and I was not able to focus to the infinity. With the 3 mm distance I was able to focus to infinity. I fixed the raspberry camera by using a black electrical tape. From the pictures one can see how I did it. The Raspberry camera must be fixed properly so that it can't move.

I added extra tape layer on both sides of the cable, as I was afraid that the cover may have sharp edged and it could damage the cable.

Connect the camera with the Raspberry and that’s it.

Attachments

Step 3: Results

I didn’t use a screen with the raspberry, thus I set the camera to a webcam mode so that I was able to test the focusing. Here is a tripod useful because of the large zoom. It’s not very easy to keep it stable just holding everything by hand.

The image/video are made when the camera was at 35 mm position. Next to them I have one made with 200 mm (full frame) and one with a mobile phone.

The resulting images are not the best and I assume that the used electrical tape is the main problem here. It reflects relatively good and I assume that causes the color loss in the bottom left corner. Additionally it can be that some light can come in between the back cover and the body. Eventually I should try to cover everything added with a matte black color (till now, no plan how to do it). The camera lens is already old and I think it’s not in its best condition either. To top all this I noticed that the temperature difference added some distortion. In the added video one can see that the warm air is moving.

Some useful links:

https://randomnerdtutorials.com/video-streaming-wi...

https://learn.adafruit.com/diy-wifi-raspberry-pi-t...

Now I need to wait for a full moon and try to capture that. When I have some time, I should try to improve the color disturbance.