Multiple Day Exposures

[CG]

... What is intriguing to me is how he got around reciprocity failure.

Reciprocity failure just might be your best friend if you seek reeeeely long exposures. Essentially you get a super slow film - just when you actually want such a thing.

C

[rwyoung]

3 month exposure, pinhole camera pointed west in the backyard. 4x10 sheet of B&W photo paper as the negative. Scanned and inverted for display.

See also http://www.solargraphy.com/

[Sheldon N]

Well, sort of but not really. The trouble with reciprocity failure is that it is exponential, so that your shadows suffer from it much more than your highlights. This increases contrast to the point where you have to pull development times way back (for B&W) to keep the highlights in check. At some very low light level, the film almost ceases to record image detail.

I would imagine that these guys are using a film that is fairly resistant to reciprocity failure such as Acros or Tmax.

Here's a interesting sidebar - if you use a film that is subject to reciprocity failure such as Tri-X and compensate for reciprocity failure (raise exposure to 1.48 power) then an exposure of 1 second is only 18 stops away from an exposure of 3 years. Throw on two 10 stop ND filters and you can theoretically shoot a 25 year exposure.

Crazy!

[Jrewt]

It's strange that this thread came about as I am getting ready to try some of these techniques. I of course knew that others had been doing this kinda of photography, but I couldn't find any names/examples, so the info in this thread just hit the spot.. As for the use of ND filters on 'normal' cameras, where does one source such strong ND filters?? I have looked and looked, and have found a few 4 and 5 stop filters, and an 8 stop that was a ridiculous 350$! This stuff is so interesting..

[Donald Miller]

As an aside to the discussion about ND filters I thought that I would mention something else that will add ND. You can stack two polarizers and adjust their orientation to each other to create quite a bit of ND.

[Sheldon N]

It's strange that this thread came about as I am getting ready to try some of these techniques. I of course knew that others had been doing this kinda of photography, but I couldn't find any names/examples, so the info in this thread just hit the spot.. As for the use of ND filters on 'normal' cameras, where does one source such strong ND filters?? I have looked and looked, and have found a few 4 and 5 stop filters, and an 8 stop that was a ridiculous 350$! This stuff is so interesting..

I use B+W screw in filters. They make a ND 3.0 (10 stop) filter that is around $100 depending on what size you need.

10 stops can get you roughly a 2 minute exposure in daylight with ISO 100 film.

[Jrewt]

Cool sheldon, where are you finding these 10 stop filters btw? BH sells up to 3 stops I believe.. I have found a few 4 stop ones on ebay, but most of the time they are to expensive.

[Sheldon N]

I got mine at B&H Photo. Here's a 77mm ten stop filter for $105.

http://www.bhphotovideo.com/c/produc...0_Neutral.html

I think you might be misreading the filter factor for the number of stops. A filter factor of 3.0 is ten stops. Each increment of .3 represents one stop of light, so 0.6 = 2 stops, 0.9 = 3 stops, and so on.

[CG]

Well, sort of but not really. The trouble with reciprocity failure is that it is exponential, so that your shadows suffer from it much more than your highlights. This increases contrast to the point where you have to pull development times way back (for B&W) to keep the highlights in check. At some very low light level, the film almost ceases to record image detail.

I would imagine that these guys are using a film that is fairly resistant to reciprocity failure such as Acros or Tmax ...

That makes sense, but people have been doing super long exposures sucessfully long before T grain films existed.

Thirty plus years ago I had a teacher who did architectural photos using very long exposures to get rid of people and cars. If I recall correctly, he did intermittent exposures over multiple days to ghost out parked cars. This was back in the days before TMax was even a gleam in some film designer's eye.

I should also mention Abelardo Morel has been doing wonderful very long exposures of cityscapes using an ingenious variation on literally room size pinhole camera photography, and his contrast and exposure seem dead on. I don't know what film he shoots, but regardless there's no technical barrier to prevent shooting for months or even years.

You are absolutely right that you do need some minute amount of light to create a usable exposure - but I suspect in most of the super long exposure situations that the issue is avoiding overexposure.

C

[Turner Reich]

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Last year a book came out from a photographer whose name escapes me, but he did long term exposures with a large pin hole camera, of construction projects and the like around NYC. His exposures took weeks or months.... the results were amazing. I should have bought the book darn it.

Aim it at the garden and you'll know where those rabbits are going all year 'round.