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Comment by jshipc | Hacker News Reader

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.

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The article does not mention this, but many Canon (and I assume other brands) have an option to use only the electronic shutter. For a non-moving subject such as this, it's the perfect option.

But it's a good caveat to consider when doing such a project.

They talk about shutter lockup which would imply electronic shutter, I think.

The shutter is separate on DSLR. (And SLR.)

I have other canon cameras that could be used with the shutter opened and digital acquisition with Magic Lantern via USB(with hacks).

But today I believe it is much better to use Digital cameras like the Raspberry Pi HQ cameras with good lenses. You don't need hacks, and the sensors come from recent mobile phones modules that have much better quality and technology than old camera digital sensors.

The lenses you can get for an SLR tho are much better than what rPi cameras usually come with. If you use film era fully manual lenses you can get amazing quality for next to nothing. If your shooting objects that are still, taking longer exposures or exposure brackets is trivial. I wish there was an GUI program for tethered cameras that still had an option to capture multiple frames each time you trigger it and average them for an output frame. It's strange that feature was removed, in the SD video era there were lots of options for that.

The specific camera model doesn't seem very important its probably whatever they had on hand - presumably you could just replace it with a camera with an electronic shutter and as long as it has the same remote shutter port you could take many millions of exposures.

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 worst culprits like a 61MP mirrorless (huge overkill for this task) with ~100ms readout could trivially keep up with 22 shots per minute.

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.

Good point. More recent mirrorless interchangeable lens cameras can disable the physical shutter and use only the electronic shutter, which would relieve this problem.

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.

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.

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.

I think (some? most?) motion picture cameras used a rotating mirror for shutter.

Correct, it’s like a mirrored fan blade and rotates continuously.

Ironically, with mirror reflex system what you see through the finder are precisely the moments not captured on film. Very quick events, muzzle flashes for example, can be missed entirely.

Notably, some Bolex cameras (and others?) used a beam splitter system where you do see what the film sees, with no flicker from the shutter. The tradeoff is a dimmer image in the finder, and you’d need to overexpose to compensate for the lost light.

Curiously, there was also a Canon SLR with a beam splitter.

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

Technically, many dSLRs use beam splitter principle and secondary mirrors to feed the image to AE/AF device at the bottom side of mirror box.

Sony also made some SLR that used beamsplitters https://en.wikipedia.org/wiki/Sony_SLT_camera

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

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

The older Standard 8 format used 16 frames per second. Super 8 is 18 or 24 fps

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

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