New poster, but have benefited immensely from this discussion, and hopefully will have more to add. I recently have gotten into video, and had an interest to digitize my family’s small collection of super 8 videos. I figured I’d try to build a telecine-type device to do it, and as my background is in microbiology, why not try to use a microscope as the image collector?
I’m still very early in the process, but thought I’d put out some of the things I’ve discovered in trying to use a USB microscope to do this.
I did some calculations early on - the horizontal field of view at max maginication of the Celestron Pro scope(pushed all the way to the object) is about 7mm, judging from the videos online.
Super 8mm frames are 0.211" 0.158" 4:3
There are a number of capture resolutions on the scope (theoretically, see below) - 1280 x 960 (1.3 MP) - 1600 x 1200 (2 MP) - 2048 x 1536 (3 MP) - 2592 x 1944 (5 MP So, if assumed we captured at max resolution all the way up to the scope (without modifying): 5.79/7 *2592 = 2143 x 1611 image for each frame or about 3.5MP per frame. Not too bad.
Selection: I looked around at a number of cheap scopes, and it seems there are actually only a few low-cost scopes made. Actually, there are only low cost scopes that are direct USB scopes, the next step up includes a screen, and then you’re looking at a separate scope and camera, which are much more expensive. I think there is likely only a few manufacturers, but they are OEMed to many different firms that put them out. I ended up purchasing the “Crenova® UM012C USB Digital Microscope 5MP Video Microscope”. This is theoretically the same microscope as the “Celestron 5 MP Handheld Digital Microscope Pro” and other brands, but was the cheapest at the time on Amazon.
Plugging it in to a windows computer (I’ve tried windows 7 and 10) and the drivers will automatically load. It installs as a webcam (which it essentially is, but with a different lens), so any software that can interface with windows to capture webcam video can use it. The disc that came with the scope didn’t read, so I downloaded the microscope software from the Celestron site, and it worked fine. I took some shots with the scope the worst/least cared about super 8 movie that I had. As a first proof of concept, I put it on top of a tablet for backlighting and used the scope to take some shots. You can see the pixels behind the frame. I tried a bunch of different resolutions, using the Celestron-supplied software, but didn’t see much of a difference above 2MP. Of course, that might change with proper diffuser and backlighting. Also the film has a number of scratches and imperfections so more study is needed.
I had originally thought that I might build a variant of the http://kinograph.cc/ but then finding this forum made me think that the better route would be using a projector to move the film. This is my current plan.
As far as software, I have tried a number of libraries. Microsoft Expression, opencv, and AForge. I’ve had the best luck with AForge, which has a good forum, and lots of example code. I’ve modified a demo app for my purposes that allows me to adjust the capture resolution and capture jpgs from the image programmatically using Visual Basic. I think this will work well to allow me to develop the scripts for the automation. I’m not sure if I’m going to do the Arduino path, or more direct control like a Labjack. Another TBD.
I just got a Sankyo Dualux-1000 today, which seems to work well. I took out the lens, and pressed the scope in and it’s about the same diameter, and it stuck in place. While it is not optimally placed (it is too far away from the film currently for a good capture) I took some shots that might be interesting. Also, I was using my bike headlight as the light source, so not an optimal test, but another proof of concept. The front part of the scope seems to be screwed on, so it might be easy to unscrew it and get it closer. It would be nice to do this non-destructively to the projector. It would also be nice not to have to use any additional lenses, and just snap the film directly.
More details on the Microscope: Though it is advertised as 5MP (2592x1944), I can only seem to get that resolution out of the Crestron software. When I use other programs to adjust/capture I only get up to 2048x1536 I’m not sure why –
· It could be that the camera is not 5MP, and they are just upscaling – I don’t have anything good to look at with good detail at that resolution, so eyeballing it to date hasn’t worked.
· It could be that that 5MP mode uses some special driver mode that isn’t available to DirectShow which is what my software uses. There is also a ‘snapshot mode’ for webcams, which tends to be high resolution, but my initial search hasn’t found a higher rez mode.
In all though, I’m not sure how high a rez I’ll need, or if 5MP will be overkill.
Modes from the Directshow driver reported from the scope:
Stream Format Properties Tab for Microscope
Color Space/ Compression; Frame Rate/ Output Size
MJPEG - 15FPS - 2048x1536 (default)
MJPEG - 15FPS - 1600x1200
MJPEG - 25FPS - 1280x960
MJPEG - 30FPS - 800x600
MJPEG - 30FPS - 640x480
No adjustments available on Frame Rate or On the 'compression' tab
YUY2 - 5FPS - 2048x1536 (Default)
YUY2 - 5FPS - 1600x1200
YUY2 - 10FPS - 1280x960
YUY2 - 20FPS - 800x600
YUY2 - 30FPS - 640x480
No adjustments available on Frame Rate or On the 'compression' tab
I don’t know much about color space or compression quality difference between MJPEG and YUY2 in terms of practical outcomes, anyone have any tips?
I’ll be working on this over the course of the winter and will update as it progresses.
