Idea pitch: Electrochromic glass shutter, would it be possible?

[Drew Bedo]

If someone ever does perfect an electronically controlled glass shutter it could be quite a thing.

for LF applications, this could be a front mounted arrangement.

The real application might be in smart phones, both for the camera function, but also for blanking the screen.

[John Layton]

Variation on the theme here...what about an electrochromic (or optichromic?) plate placed above an enlarger's negative stage, which could be used for variable density (dodge and burn) masking? Plate would first be used to create a scan from a given negative, then placed (with usb cable still attached to computer) above negative stage, then this image could be manipulated in accordance with the user's desires for the actual negative underneath. Settings (forever tweak able) would be stored for future use, allowing plate to be reused afresh for other negs. Hmmm...likely another of my caffeine-aided fantasies!

[Pere Casals]

Another option is to get one of the 4x5 press cameras with a focal planer curtain shutter.

Yes... a choice is installing an Speed Graphic focal plane shutter just behind the lens.

A more refined hacking would be installing a SINAR-COPAL shutter like Tim Layton, this a nice hacking: https://www.timlaytonfineart.com/sinar-copal-shutter

A SINAR shutter weights around 550gr... IIRC

[Dan Fromm]

Mentor, Papi, Mentor. Not Speed Graphic.

[LabRat]

Variation on the theme here...what about an electrochromic (or optichromic?) plate placed above an enlarger's negative stage, which could be used for variable density (dodge and burn) masking? Plate would first be used to create a scan from a given negative, then placed (with usb cable still attached to computer) above negative stage, then this image could be manipulated in accordance with the user's desires for the actual negative underneath. Settings (forever tweak able) would be stored for future use, allowing plate to be reused afresh for other negs. Hmmm...likely another of my caffeine-aided fantasies!

Exists already, for decades... But in a simpler form...

Polarization lightsource... A pola screen is over condensers (an IR filter is in front of lamp to prevent damage to screen... Another pola is on lens that can be rotated...

B/W neg has clear and areas with increasing density... Clear areas pass polarized light without much change, but increasing density de-polarizes light that passes through it... So if there is a lower polarizer to cross-polarize, clearer areas are cut, but dense areas remain about the same (except for overall ND cut)... So this masks clearer areas allowing neg contrast cut...

I have used it with Leitz Focomat/Valoys for 35mm negs that were dense/contrasty, but with many fine details in the excessive toe, but rarely, just customer negs that were weird developed that wouldn't print within the paper... Always wondered what would happen if they tried to have those negs re-printed by someone else??? ;-)

Steve K