16mm Movie Film transfer using "Silent Pictures" feature

[Meloware]

I am getting some wonderful results in my effort to capture 16mm movies using Magic Lantern and my T4i (650D). The camera's shutter mechanism would quickly wear out if cycled for each film frame. Magic Lantern's Silent Picture raw mode solved the problem I had with using my camera. I am now able to take many tens of thousands of pictures, without using the shutter mechanism.
I have a modified 1970s Bell & Howell projector. The original projection lamp, fan, motor and lens, were removed. I added my own optics, a stepping motor (with a $10 Chinese motor controller) and LED illumination to project images directly on my camera's sensor. The camera and projector are automated by a circuit board controller of my own design.
Managing a 31 megabyte DNG file for each movie frame is very demanding on memory and hard disc storage. The worst issue is dealing with the write speed of SD camera memories slowing down as they fill. It is practically possible to only capture 5 or 6 frames a minute. It takes days to transfer a single 10 minute reel of film. It might be faster, if I could get a "camera ready" signal out of my Canon, once it's able to take the next picture. This bottleneck is sad, but it is still possible to do great work.
Please allow me to share the results of using Magic Lantern. Notice the first 4 videos.
http://industrialhistory.org/education/videos/

Chris (Meloware)
Museum of Our Industrial Heritage, Greenfield Massachusetts, USA
http://industrialhistory.org


// Adding the first video here.  Audionut.

[garry23]

Chris

I'm not going to comment on the ML based part.

As a mechanical engineering I just wanted to thank you for sharing your heritage.

Cheers

Garry

[boszmann]

Hello Chris,

This may help you

Open source film scanner http://kinograph.cc/

[a1ex]

The worst issue is dealing with the write speed of SD camera memories slowing down as they fill. It is practically possible to only capture 5 or 6 frames a minute. It takes days to transfer a single 10 minute reel of film. It might be faster, if I could get a "camera ready" signal out of my Canon, once it's able to take the next picture.

Some tips to speed up the process:
- save the files as MLV, rather than DNG
- if you have coding skills, offload the file saving process to a background task
- to get a sync signal when it's finished, you could monitor the LED activity (or the display activity) with a photodiode. Or you can tweak the code to emit a short beep. Or - more complex to program - send a signal via PTP (USB).

[Meloware]

Thank you for the suggestions. I fear the bottleneck is truly the camera. I might consider buying the T6i, which supports the faster SD cards, but there is no ML build to support it. I am not buying another camera, unless I am able to use it for my intended purpose.

I thought about using the LED and a photodiode. It would be awkward, but I could build the electronics and logic for that. I didn't realize my camera has a 'beep'. I have done some coding, but haven't investigated ML, so don't know if I could modify it or not. A standard SD memory can make its initial saves in about 3.5 seconds, for a DNG image. Eventually it needs up to 6 or more seconds. A 'camera ready' status signal will help, but still wouldn't allow me to record 100 frames per minute.

MLV? Is that available in 'Silent Picture' mode? How would I control how and when an exposure is taken? I am triggering the 'half shutter' signal, with my controller board. Coding makes my brain hurt, but if ML could be modified to record MLV, in Silent Picture mode, using the half shutter signal, I would consider it. Is there any resolution or quality loss, as compared to the DNGs I get now, in Hi-Res mode?

I appreciate the suggestions, but I fear that 30MB images are simply going to take this long with standard speed SDs. The 650D doesn't support the faster memories.
BTW, is there a 'dead pixel' removal utility anywhere that will operate on your DNGs? That is a filter I need, and nothing I have tried seems to work.

[a1ex]

At 40MB/s and 30MB image, the theoretical limit would be only 80 frames per minute (on SD cards). I think achieving 1 frame per second should be doable without much effort (not with the current implementation, but after pipelining the process a bit).

Regarding MLV, just look in the menu and try it

[simonm]

@meloware:

That video is wonderful. It looks as though you had a near-perfect print to work from. I'm sure you didn't!

How did you deal with dust, tramlines, base scratches, stretchmarks, etc.? But more importantly, film weave? I assume the "Taps" one was shot on 35mm - it doesn't look as though much expense was spared in its production.

The other interesting thing was the soundtrack. I assume it was standard (Academy curve) variable area. How did you digitise it?

Very impressed.

S.

PS: I'm aware this is rather off topic for ML itself  - please reply by PM if you feel it's appropriate.

[Janke]

Don't PM - let us all know!

[Meloware]

Magic Lantern made it possible to take tens of thousands of exposures, without mechanical wear on the camera. My T4i/650D is sadly slow in saving the raw frames, but the quality is great. I modified a 1970s film projector to take a snapshot of each frame of film, as 18 Megapixel Raw images. It only runs at the rate of about 6 frames per minute. I then harvest  the full SD chips, and save them to my PC. The filesize of each frame is 31 Megabytes.

ImageMagick allows me to convert the awkward DNG (Adobe Digital Negative) format into a form that is more easily used by other programs. AviSynth then stabilizes the frames and removes dust and scratches with its amazing temporal tools which look forward and backward in time, before deciding to remove noise, scratches and dirt.

Blender 3D's compositor feature allows me to center box and crop my captured image frame sequence. The Blender compositor feature allows you to animate corrections needed to fix unexpected bounces or jerking. I render out of Blender to make my final, full movie frame sequence.

Avidemux finally is used to make a web usable file. It combines my sound track and encodes the video in a nice, clear fashion.

simonm: "Taps" I made from a 16mm print. Our museum has an 8 x 10 photo glossy photo of what we believe to be a still taken during a film shoot at GTD. The movie camera, in use, clearly can be identified as being a "Mitchell 16". Many or most of these productions may have been filmed in 16 millimeter, not 35. Other things you asked about I have yet to control.

I captured the sound by playing the optical track through the projector, with its old tube amplifier. I then edited it properly to remove hum and the other obvious stuff.

The survival of these films may be evaluated at three levels. How much wear and damage does the print suffer? Is the base still in good condition? The clear, "plastic" base of safety film is perishable over time. Vinegar odor is a sign the film print is beginning to break down. Eventually, it will crystallize and disintegrate.

Color pigments are most often the first quality to lose. The color movie has a film emulsion which contains colored pigments. This defines the movie's colors. These color pigments fade over time, with the first victims being the Cyans and Blues. "Taps" has better color than later prints of other films I have from the 1960s and after.

Thanks for the asking, and I hope this continues to attracts some interest.