K3 16mm scan — Lines not scratches?

[Knopfloch]

I just received the digital files back from a test roll of 16mm film shot on a Super 16 modified K3.
Overall I'm happy with the quality of the scan.
BUT there are a couple of lines running through the center of the frame which don't appear to be scratches.
Have a look here:
https://vimeo.com/193331897/610fb85eed
I'm not familiar with the technology of this camera but assume that the light is not hitting the film directly through the lens but is reflected over some mirror system?
This might be the source of the problem with the mirror being scratched?

Any advice here would be great.

Also each new shot starts with a wonky focus shift in the top left corner. Is this due to the brutal mechanism of this camera and the abrupt start of the transportation, causing a short vibration? Is this a general problem in cameras like this?

Thanks for your help.

Markus

[Andreas Wideroe]

Hi Markus,
I'm prette sure that is a scratch coming from the camera gate.

I suggest you do a thorough cleaning of the gate. I see there's lots of dust there too.

It's a nice camera. I have one too which I used quite a bit some years ago.

Enjoy,
Andreas

[Knopfloch]

Thanks Andreas, yes I talked to another K3 user who also reckons these are scratches.
What boggles me is that they partially disappear when zooming in, so I thought it's something optical.
Obviously there was lots of dust in there, looking at that black blob top right!
So I'll check and clean the inside thoroughly.

Still wondering what's causing that jitter at the beginning of each shot.

Cheers

Markus

[Will2]

Some of those modifications were done with a file and are not always that smooth. The location makes me think it is the gate too. Run your finger along the gate edges and see if you feel anything. Shouldn't be too difficult to buff it out. The gate comes out easily with a screw driver.

[slashmaster]

That scratch on the right happened while the film was being shot! The corner of that gate has a sharp piece peeling up the emulsion as it runs. It looks exactly how it looks when a machinist runs something on a lathe or mill! I'll bet the shavings from it are all over the inside of your camera! Not too sure about the scratch in the middle. Is it on the base side of the film?

[Knopfloch]

good point on the 'shavings'. I assume the black blob on the top right is exactly this milling mess.
I'll take a proper look at gate and all other potential components that could be damaging the film.
thanks for your input everyone.
m