Anyone used a gravity shutter?

[David Mitchell]

Hi all,

Bit of an odd one here, has anyone used a gravity shutter here? Basically its just a falling sheet with a slit in it, depending on how big the gap is the faster or slower the speed of the shutter is - much like the curtain shutters.

Just wondering if anyone had used one before?

Example:

Gravity shutter | CasedImage

 

[Dan Cattermole]

Errrr no, sorry David. Have you got one?

 

[Stan Hesketh]

No Goddamit, but now i want to use one Why do people have to put temptation in my way?

 

[Larry Bolch]

We had a Harris shutter where I worked a long time back. It had a red, green and blue filter that would pass the lens as it dropped, creating rainbow colours of anything that moved. The effect is similar to this one I did of Snoqualmie Falls.

 

[David Mitchell]

No I don't have a gravity shutter, but I just like the simplicity of a falling plate with a slit in it for shutter speeds. I do have a Purma special which does use gravity for its shutter settings, however its still spring loaded.

That Harris shutter looks interesting, I guess you can get all sort of effects with a simple shutter - I am also guessing if you used filters but different sized slits you could expose different colours seperatly ie a shorter shutter speed for anything blue eg the sky to stop over exposure.

 

[Pete Askew]

I had one in mind when I was building the DIY camera but, in the end, the paper was way too insensitive for one to be of any use.

 

[Larry Bolch]

That Harris shutter looks interesting, I guess you can get all sort of effects with a simple shutter - I am also guessing if you used filters but different sized slits you could expose different colours seperatly ie a shorter shutter speed for anything blue eg the sky to stop over exposure.

The Harris shutter used a specific set of RGB filters used by the printing trades for colour separations for making printing plates for colour presses. Colour balance was automatically very good. I do have such a set of gel filters that I often used with film.

In the case of Snoqualmie Falls, I shot a series of exposures from a tripod with an early digital camera, then combined the red, green and blue channels from separate exposures to achieve precisely the same thing. Where there is no motion, things look perfectly normal with a proper white balance. The colours indicate differences. Of course, this can be done over time for moving shadows, clouds, waves or whatever may move.

 

[Nihat Iyriboz]

Thank you for sharing, David. Learning as you do.

Patent WO1991019136A1 - Gravity shutter - Google Patents