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DIY, 8mm film scanner Kotokino Mark IV (2020)

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Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#11

Post by throwaway22032 »

_Microft wrote: post #8
jshipc wrote: post #4

Various sources list the Canon 1000D shutter life expectancy at between 25,000 and 100,000 activations. If the 8mm film is 16 frames per second, then this setup should be able to capture between 26 to 104 minutes of film before consuming the expected lifespan of the camera shutter. Edit: Changed math from 24 frames per second to 16 fps to reflect the 8mm film fps standard playback speed of 16 fps.

From the article: "To minimize jitter of the system, and to enable 22 shots per minute, the mirror must be moved into the permanent up position." This makes it sound like they are using an electronic shutter instead which circumvents the lifetime issues.

The mirror being up likely refers to the viewfinder mirror. I haven't used a DSLR, only mirrorless, but I wonder if that could be independent of the shutter.

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#12

Post by _Microft »

throwaway22032 wrote: post #10
jshipc wrote: post #4

Various sources list the Canon 1000D shutter life expectancy at between 25,000 and 100,000 activations. If the 8mm film is 16 frames per second, then this setup should be able to capture between 26 to 104 minutes of film before consuming the expected lifespan of the camera shutter. Edit: Changed math from 24 frames per second to 16 fps to reflect the 8mm film fps standard playback speed of 16 fps.

I don't know about the Canon 1000D but almost all cameras I've used recently have electronic shutters. There is a rolling shutter penalty so you wouldn't want to use it in the "real world" for moving subjects but if you synchronise it properly (e.g. move one physical frame, take photo, move one physical frame) and ensure that there is no movement during the exposure then this shouldn't make a difference. Even the wor…

They are advancing the film one frame at a time and are taking static images. There's a switch getting actuated that triggers image capture once the film has advanced. The first video in the article has close-ups of the process.

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#13

Post by _Microft »

throwaway22032 wrote: post #11
_Microft wrote: post #8

Earlier quoted context omitted.

From the article: "To minimize jitter of the system, and to enable 22 shots per minute, the mirror must be moved into the permanent up position." This makes it sound like they are using an electronic shutter instead which circumvents the lifetime issues.

The mirror being up likely refers to the viewfinder mirror. I haven't used a DSLR, only mirrorless, but I wonder if that could be independent of the shutter.

That's exactly the mirror that gives (D)SLR's the R ("reflex") in their name. It's in the path between sensor and lens and redirects the image towards the view finder. When taking a picture this mirror moves out of the way and the image is projected on the film/sensor instead. The advantage of that system is/was that the photographer can preview the image as it will get captured.

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#14

Post by throwaway22032 »

_Microft wrote: post #13
throwaway22032 wrote: post #11

Earlier quoted context omitted.

The mirror being up likely refers to the viewfinder mirror. I haven't used a DSLR, only mirrorless, but I wonder if that could be independent of the shutter.

That's exactly the mirror that gives (D)SLR's the R ("reflex") in their name. It's in the path between sensor and lens and redirects the image towards the view finder. When taking a picture this mirror moves out of the way and the image is projected on the film/sensor instead. The advantage of that system is/was that the photographer can preview the image as it will get captured.

Ah, so there's no shutter at all then? As in, the mirror itself forms the shutter?

For some reason I figured there were both. Makes sense I guess.

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#15

Post by google234123 »

jshipc wrote: post #4

Various sources list the Canon 1000D shutter life expectancy at between 25,000 and 100,000 activations. If the 8mm film is 16 frames per second, then this setup should be able to capture between 26 to 104 minutes of film before consuming the expected lifespan of the camera shutter. Edit: Changed math from 24 frames per second to 16 fps to reflect the 8mm film fps standard playback speed of 16 fps.

A mirrorless camera can probably be found used for 200$ so that would be better

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#16

Post by ginko »

throwaway22032 wrote: post #14
_Microft wrote: post #13

Earlier quoted context omitted.

That's exactly the mirror that gives (D)SLR's the R ("reflex") in their name. It's in the path between sensor and lens and redirects the image towards the view finder. When taking a picture this mirror moves out of the way and the image is projected on the film/sensor instead. The advantage of that system is/was that the photographer can preview the image as it will get captured.

Ah, so there's no shutter at all then? As in, the mirror itself forms the shutter? For some reason I figured there were both. Makes sense I guess.

There is a separate shutter.

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#17

Post by RobotToaster »

throwaway22032 wrote: post #14
_Microft wrote: post #13

Earlier quoted context omitted.

That's exactly the mirror that gives (D)SLR's the R ("reflex") in their name. It's in the path between sensor and lens and redirects the image towards the view finder. When taking a picture this mirror moves out of the way and the image is projected on the film/sensor instead. The advantage of that system is/was that the photographer can preview the image as it will get captured.

Ah, so there's no shutter at all then? As in, the mirror itself forms the shutter? For some reason I figured there were both. Makes sense I guess.

No, in most* cameras there's still a shutter behind the mirror, the mirror can't move that fast so would limit the top shutter speed too much.

*The Ihagee Exa is the only one I know of that used a mirror guillotine shutter.

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#18

Post by m463 »

_Microft wrote: post #8
jshipc wrote: post #4

Various sources list the Canon 1000D shutter life expectancy at between 25,000 and 100,000 activations. If the 8mm film is 16 frames per second, then this setup should be able to capture between 26 to 104 minutes of film before consuming the expected lifespan of the camera shutter. Edit: Changed math from 24 frames per second to 16 fps to reflect the 8mm film fps standard playback speed of 16 fps.

From the article: "To minimize jitter of the system, and to enable 22 shots per minute, the mirror must be moved into the permanent up position." This makes it sound like they are using an electronic shutter instead which circumvents the lifetime issues.

For a DSLR the mirror is independent of the shutter.

Mirror lockup mode is usually used to lower vibration or speed up picture taking, but the shutter still has to actuate.

EDIT: details of 1000D and shutter:

https://en.wikipedia.org/wiki/Canon_EOS_1000D

https://en.wikipedia.org/wiki/Focal-plane_shutter

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#19

Post by m463 »

I wanted to scan some old family super-8 movies. You can buy film scanners that will do the job on amazon. The only problem seems to be that they will encode the video, but nobody seems to convert the magnetic audio track.

EDIT: example - https://www.amazon.com/dp/B0CN93JSX6

Re: DIY, 8mm film scanner Kotokino Mark IV (2020)

#20

Post by numpad0 »

throwaway22032 wrote: post #14
_Microft wrote: post #13

Earlier quoted context omitted.

That's exactly the mirror that gives (D)SLR's the R ("reflex") in their name. It's in the path between sensor and lens and redirects the image towards the view finder. When taking a picture this mirror moves out of the way and the image is projected on the film/sensor instead. The advantage of that system is/was that the photographer can preview the image as it will get captured.

Ah, so there's no shutter at all then? As in, the mirror itself forms the shutter? For some reason I figured there were both. Makes sense I guess.

That will expose the bottom side of the film longer than the top, unless there's a second mirror that folds up :)

ref: https://youtu.be/SynB6Qypk4c?si=wmLgwjTQNeDtqCYl&t=64

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