I recently acquired a lot of microfilm (550 rolls). I would like to digitize it to preserve it as it is local history books and documents. I am wondering what would be a good camera to use? I am thinking along the line of a Raspberry Pi camera. I know I would need a macro lens and possibly extension tubes. I have experience with Arduinos but not much with the Raspberry Pi. I priced microfilm scanners and they are out of my price range. I have a microfilm carrier and I can use and backlight the film. I do have access to a microfilm reader that can print on paper but I don’t believe it could be connected to a computer. Any ideas and/or suggestions would be very helpful.
What film format do microfilms use?
This information is essential for the design of the optical system.
Logically, in your case, the use of a frame-by-frame scanning system is mandatory. You’d also need to know how the microfilms are advanced in the transport device you mentioned.
@denvcr if these reels are 16mm, mounting the HQ camera at 90 degrees would give you ~375 pixels per mm edge-to-edge
If these are 35mm, depending on the content, you may need more resolution on the camera.
The scanner I built uses the HQ, and is sprocketless, and can easily handle 16mm microfilm rolls (actually was designed with 16mm Develocorder in mind).
The microfilm is 16mm and 35mm non-perforated black and white. I would be modifying the transport so that I can advance it forward and backward using switches frame by frame.
Within the current range of Raspberry Pi cameras, in my opinion, the most suitable camera for your purposes would be the Raspberry Pi HQ.
This camera’s sensor measures 6.287 x 4.712 mm.
The sensor has an area approximately one-quarter of the 16 mm frame, so we’re not talking about macro photography. However, due to the short focusing distances, an extension tube will be essential.
The lack of perforations in the film makes it difficult to detect the correct frame position when capturing the image; for this reason, my DSuper8 software, published in other posts on this forum, is not suitable for your purposes.
Good luck with your project.
Would there be any other camera that would be good to use? I know some of the film is newspaper and some are books. What I mean is other than one for the Raspberry Pi such as a USB camera or other type.
I have not used it yet, but there are some affordable cameras using 1/2” Sony IMX586 (~$150 in Amazon). Another challenge is to find a less than can perform at that resolution for the intended 16mm or 35mm width.
EDIT: it is unclear if lens of the camera linked is removable.
I thought I’d give a brief update. Firstly, thanks to all who responded. I greatly appreciate it. Secondly, I purchased the camera @PM490 mentioned. I haven’t received it yet and when I try it, I will respond with the findings.
I received the camera. It seems pretty good for the 16mm microfilm but with the 35mm I can’t get a sharp image especially for the newspapers. It has a narrow field of view when close up. For distance, it looks great. Also, the lens is not removable. I have access to a microfilm reader that I want to experiment with. I am thinking about trying to take a picture of the image that’s displayed on the reader almost like a document camera. I will keep experimenting though as I don’t give up easily.
Typically, capturing a good-quality image becomes more difficult the smaller the subject.
I find it strange that you get good images from 16mm microfilm, yet with 35mm, the images aren’t sharp enough. In my opinion, it should be the opposite.
The 16mm format requires a closer zoom than the 35mm format. As we zoom in, the depth of field decreases.
Was the 35mm microfilm perfectly flat?
Just out of curiosity, what software do you use with this camera to capture the images?
Good luck with your project. I hope you manage to resolve the difficulties.
The 35mm film was perfectly flat. The 35mm film was a newspaper from 1889 and the text is small. The text was unreadable in the image. The 16mm was a book from 1925 which was very legible, however the text was a little larger. I was using the Camera which came with Windows 11 set to 48MP. The camera does not do RAW which I was hoping it would.
That is, according to your comment, the image displayed on the microfilm reader is illegible. If this is the case, it is due to poor image quality from the original itself, which can never be improved even with the best optics.
To achieve good digital captures, it is essential to start from originals of the highest possible quality.
Using the raw format is beneficial when trying to improve aspects of an image such as brightness, contrast, color saturation, enhancements in shadows or highlights, etc. In your case, with black and white text images, in my opinion, you would not achieve great improvements, and, furthermore, the raw file sizes are usually very large.
Thank you for confirming that the lens is not removable (which I suspected).
The issue of 35mm content readability may be related to multiple issues, including optical resolution of the setup, focusing, and perhaps even image compression (especially if focusing is an issue).
Based on the results you had, maybe is best -if you can- send back the IMX586, and look for other better documented alternatives at similar cost.
I do not have the know-how to figure out how to change an autofocus module into a macro with very high-resolution requirements.
A raw alternative…
Sorry I did not mention this option initially, based on your reference that you were not familiar with raspberry pi, thought the USB option would be simpler.
Another alternative is the Arducam Hawkeye module, it is an integrated autofocus lens and sensor module (focus range is 8cm to infinity). It connects to and require a raspberry pi, and it will allow you to capture 64MP in raw. Arducam modules have very decent documentation.
The built-in lens will not be able to capture something that small (16mm or 35mm), but if you are considering using the microfilm reader for enlargement, it may be an option.
This module I do know, and used for a different application (timelapse of a building construction), and the outdoor pictures are fantastic, even when I am only capturing JPEG for storage savings. Raw is available too.
The capturing may be as simple as a one liner using libcamera-still. Below the python code I use for file-naming with a time stamp.
import os
from time import strftime
file_name = strftime("%Y%m%d_%H%M%S")
os.system("/usr/bin/libcamera-still --verbose 0 --gain 1 --autofocus-mode manual --lens-position 6.44 --ev -0.5 --denoise off --framerate 1 --output /home/cam64/mnt/8mm/daily/"+file_name+".jpg")
Note that in this code, I intentionally do not use the autofocus, using a fixed lens position setting. It avoids focusing on different planes as the building was being constructed, and it shortens the capture time by skipping the autofocus sequence. It is nice that once you find the optimal focus, focus can be set in the capture command.
It needs a minimum of a Raspberry Pi 4, but the Pi 5 -which was not available when it first came out- is best. Also note that the flat cable for connecting the hawkeye to Pi4 is different than connecting to Pi5.
Reality check for 64MP Resolution
Here is a quick reality check of the resolution for 64MP
Sensor resolution (without considering the bayer filter): 9152 Ă— 6944 px Newspaper Page size: 22.75 Ă— 15 in (22.75" mapped to 9152 px) Effective sampling: 9152 / 22.75 = ~ 400 ppi 9 pt font = 9 / 72 in = 0.125 height Pixel height for 9 pt text: 0.125 Ă— 400 = 50 pixels height
In short, if optics are adequate, a 64MP sensor image will translate to about double the fine resolution (spatial) of a fax machine.
Here is a 50x50 pixel crop of an outdoor picture taken in jpeg with the hawkeye module. The letters are the writing in a construction crane.
Sounds like a very interesting project, please keep us updated of your progress.
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