Modding the Kodak Reels 8mm Film Digitizer (Firmware Hack)

[Federico]

I love how you have restored the camera cover. You should add some cover for the circuit board, as there is a small amount of light that can leak through the PCB. In very dark images, with a lot of sensor gain, you can see circuit outlines, which is a tad bizarre. I just did my third unit, with the same F2.8 Lens.
With a piece of black masking tape over the circuit board.

HI @0dan0 thank you: I was thinking of the same iris reduction as well; thank you for the models!
The new holder looks nice: is the cable long enough to allow the front slide?
With the old model I struggled a bit because this is the part that required a very high cut in the main body of the scanner, only to allow the top half of the holder to slide down: now it should allow a tighter fit.

I've added the masking tape, for precaution, thank you!

One request on the firmware: could you please make the text beside the histogram a bit bigger? It's not a priority, but I believe that many of us struggle a bit wo read the values

One suggestion on the 3D printing: I the little grey tensors of the film seem eager to scratch the surface; do you think that printing some small pipes to put around (the tensors can be removed from the inside, the pipe slide in and the tensor fixed again) could help? something free to spin around the tensor. Besides they could be cover with something soft as suggested some post before, but moving the friction from the film to the pipes.

Ciao! Federico

Thank you!

 

[0dan0]

HI @0dan0 thank you: I was thinking of the same iris reduction as well; thank you for the models!
The new holder looks nice: is the cable long enough to allow the front slide?

One request on the firmware: could you please make the text beside the histogram a bit bigger?

Yes the cable (on my unit) was long enough, and it was much easier to mount the lens from the front than the top.

Font could be made bigger, but I had to create the font by hand, with some LLM help. So it is not a small task.

I'm not sure what scratches the film, I haven't done anything more than put PEC PAD on the rollers (which seems to help.)

 

[lrussell887]

Let me know if you seeing much jitter in 7.0, as the preview auto exposure was originally disabled to reduce jitter. Now the preview auto exposure biases to a short shutter, hopefully to achieve the same jitter reduction. I'm not seeing any jitter my brief testing.

I've been working on digitizing old family films on my Type B scanner and have more often than not been running into frame jitter issues with v7.1.1. I've tried two different SD cards, one Onn 64GB U3 card and now a SanDisk 64GB Extreme PRO U3 card with a V30 rating. Both formatted to FAT32 (not exFAT) with an allocation unit size of 32768 KB. I've also tried both default sharpness 0.0 (which results in a higher bitrate) and -2.0 and it still frequently happens with both, so best I can tell it has nothing to do with write speed. It starts and the beginning of the recording and persists throughout.

Do you have any idea what might be causing or it, or have any suggestions? I may try v6.9 but I'm hesitant to lose the other improvements you've made since.

I also really do want to thank you for your work on this firmware, the results overall really are a night and day difference compared to the stock firmware.

 

[ThePhage]

I can also report that several instances of my scans on a type C with 7.1.1 have frame jitter (frankly it happens more often than it doesn’t happen. Sometimes it’s significant, but sometimes very subtle and I have to look closely for it or compare to older scans of the same footage.

Would lowering the exposure bias using the provided controls potentially help? (Increasing shutter speed)

Or are there any other tweaks you can think of to reduce it?

I haven’t tried a wide variety of footage yet, but I have noticed that jitter happens more often with Super8 than 8mm (probably due to frame size).

Thanks again! When they are stable, my recent scans of 7.1.1 are blowing away the previous scans, including detail and color.

 

[omega]

I've written about it here before. Maybe it will help here too.
#573

 

[0dan0]

I'm only seeing this now in 5% or fewer captures, but maybe I'm lucky. As stated before, it also happens on stock firmware, but it would appear more often with the hacked firmware as it allows for a wider field of view. This is a design flaw, as it appears there is no good sync between the motor moving the film, and the frame grab. As @omega mentions, the friction and the tension from the take up reel are a contributing factor. I've decreased some friction on mine with Pec pads (and reduce scratching.)

The frame is only stationary of 50% of the time, 250ms per frame. As this unit is PAL 25Hz based, 40ms per frame (I'm assuming the worst rolling shutter timing.) So 40ms from 250ms should be easy, yet sometimes the tearing is on top, and sometimes the bottom (250ms apart), so the frame grab timing is a super sloppy (again this is in the original firmware design.)

I shot the screen at 360fps (GoPro HERO13 burst slow motion) and presented at 3.3% speed, so you can see all the subtle frame movement that is causing this problem.

I did another slomo test with slack on the track up reel, so the film movement is only from the sprocket feeder, and all the same extract motion is present. The cam that drives the sprocket is just a bad design.