From: Elizabeth McAlpine (email suppressed)
Date: Tue Nov 02 2010 - 05:35:05 PDT
Some years ago I made a very long exposure still image not nearly as long
as you are suggesting but it was about 7 hours I found that shooting on to
duplicating film helped lengthen the exposure it has a very low IOS I also
used a lot of ND filters on the front of the camera which helped to lengthen
the exposure time I was shooting in candle light and the print ended up
having a very red cast I was never sure if it was caused by the candle
light or the duplicating film but it worked for my purpose
working with pinhole aperture will defiantly increase you exposure times.
best
Elizabeth McAlpine
On 02/11/2010 12:03, "Jason Halprin" <email suppressed> wrote:
> Well...Long story short, a very long exposure of months or years would be very
> difficult or nearly impossible to meter for. When you meter for a shot you are
> basing the characteristics of the film on the straight-line portion of the
> characteristic curve - meaning that the film has a more-or-less linear
> relationship between exposure and density.
>
> If you were to expose for months, you would be exposing in the "shoulder" area
> of the curve, that area where an increase in exposure results in an ever
> decreasing ratio of exposure to density. Essentially, you are working with a
> situation where most of the possible silver-halide has been activated, and the
> film no longer has linear, predictable results.
>
> Now that that's out of the way, I would propose making your own pin-hole
> aperture (f64 ? smaller?) and centering this on the back of the lens to lower
> the amount of light getting to the lens. Also, use a very slow film...and
> test, test, test. Don't expect a doubling of exposure time to result in a stop
> of increase in density (it won't be nearly that much). It would seem the
> easiest option would be to rig a cable release on an SLR camera so that you
> can leave it open, on a tripod, for a very long time...vary your exposure, and
> take good notes.
>
> -Jason Halprin
>
>
>
> From: Aditya Mandayam <email suppressed>
> To: email suppressed
> Sent: Tue, November 2, 2010 6:40:11 AM
> Subject: [Frameworks] Extremely Long Exposures - for Months and Years
>
> Hello, I am interested in making extremely long exposures: of the
> order of many months, perhaps a few years.
>
> E.g: http://photoslaves.com/open-shutter-by-michael-wesely/
>
> I asked this question on photo.net <http://photo.net> as well:
> http://photo.net/black-and-white-photo-film-processing-forum/00XKLr
>
> I would like to know how to meter for such long exposures. What amount
> of light does one assume? Average brightness of a day over a year?
>
> Thank you.
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