Guillotine Shutters unusual sources

[Carsten Wolff]

Nice idea, esp for unusual (e.g. large petzval & other large aperture lenses)
Came across e.g. this by chance, http://www.pietrelli.com/en/prodotti...otine-shutter/ . ....needs to be made fast, though lol.
However, because getting a rectangular blade with runners on both sides to reliably move at a repeatable speed is may be one of the reasons why people moved past those shutters. I am wondering though if not a simple sectional shutter (somewhere between a Packard, a Jim Galli and a Guillotine) could be another great way to make something for those lenses, either as an in-between, or as a front mount. ..Akin to movie camera shutters; in this case, as simple spring loaded disc section rotating around an axis.... Would be so easy to make, too.

Anyway, have fun, you all.
Carsten

[Jac@stafford.net]

[... snip good stuff ...]
However, because getting a rectangular blade with runners on both sides to reliably move at a repeatable speed is a good reason why people moved past those shutters quickly. [...]
Anyway, have fun, you all.
Carsten

Speaking for some of us DIY people, Carsten, any information is appreciated. Thanks very much for that.

So far, the large shutter's travel (constraints of large apertures) makes it difficult to make a fast guillotine shutter.

For most of us LF people with fat lenses, a slow shutter is okay! I'm good with that. Participant RedGreenBlue showed one super simple (even pretty) shutter a bit earlier. I love it.

OTOH, I have a couple ingenious guillotine shutters that use two blades to achieve short exposures. The trick is to place the very thin shutter gate (guillotine) between the interior lens elements and it is completely controlled by a more bulky external control. Interesting, I think.

Thank you again for contributing.

[Dan Fromm]

Jac, to add to Carsten's suggestion, if you want to make a guillotine shutter that gives short exposures, make one with a narrow slit. This idea stolen from Graflex curtain shutters.

Also from S.F.O.M. and Omera aerial cameras. These beasties have a sort of rotating venetian blind shutter (not what you want). What's interesting about them is that these cameras change shutter speed by changing the entire blind assembly. Fast shutters have more slats, narrower slits, than slow ones.

[Jac@stafford.net]

Jac, to add to Carsten's suggestion, if you want to make a guillotine shutter that gives short exposures, make one with a narrow slit. This idea stolen from Graflex curtain shutters.

Also from S.F.O.M. and Omera aerial cameras. These beasties have a sort of rotating venetian blind shutter (not what you want). What's interesting about them is that these cameras change shutter speed by changing the entire blind assembly. Fast shutters have more slats, narrower slits, than slow ones.

The narrow slit in a Guillotine shutter is, I think, the idea of two contrasting blades - that is two blades moving from each side toward the center. Correct me if I'm wrong. Perhaps I should post pictures of the mechanism.

The Venetian blind concept is entirely new to me! I'm stunned! More to explore! Thank you, Dan.

[Dan Fromm]

The narrow slit in a Guillotine shutter is, I think, the idea of two contrasting blades - that is two blades moving from each side toward the center. Correct me if I'm wrong. Perhaps I should post pictures of the mechanism.

What I had in mind was one sliding blade like this:

____________________
| ............................ |
| ............................ |
| ............................ |
| ............................ |
| ............................ |
| ............................ |
| |________________| |
| ............................ |
| ............................ |
| ............................ |
| ............................ |
|___________________|

Height as needed. The slit traverses the front, middle, or rear of the lens. The "..." are there so the | will space out as intended.

[Tin Can]

I agree with a sliding slit using gravity is easy to make. Make a handful of varying aperture slits, like a roller shutter. Add spring assist...

But I will stick with Packard shutters 4.5" and under. They work great and sync is easy. Also easily installed inside a camera. Try that with a slider. I can't spell quiliteen!

I have a 5" Packard NOS and it doesn't work!

Has an extra leaf and jams.

[Jac@stafford.net]

I agree with a sliding slit using gravity is easy to make. Make a handful of varying aperture slits, like a roller shutter. Add spring assist...

Rubber bands work, too.

Anywho, this is just one of the between-lens guillotine shutters. It has opposing blades. The hole fits between the lens elements and the rest is outside in an enclosure. It is super thin. A rotary solenoid drives it.



The darker part of this front view of the camera is the shutter enclosure outside the body.

[coisasdavida]

I'd like to contribute with two links.

First an old one that I read maybe 15 years ago, but it is still up: https://people.rit.edu/andpph/text-slit-scan.html

Second a much recent implementation of the same idea by a student of mine:

[Tin Can]

Both very interesting!