Author Topic: you dont know what a long exposure is... (Read 1304 times)

lisandra · « **on:** January 30, 2012, 07:24:23 PM »

SO you once did a 7 hour exposure of the night and have been bragging about it for years? let me smash your effort to the ground, in fact 7 hours is nothing.

The following photo was a six month exposure from the 21st of June till the 21st of December, 2011. It was with a pinhole camera made of a soda can lined with a photographic piece of paper. The simple camera continuously recorded the Sun's path each day as a glowing trail burned into the photosensitive paper. In this case, the spot was chosen to look out over the domes and radio telescope of the University of Hertfordshire's Bayfordbury Observatory. Dark gaps in the daily arcs are caused by cloud cover, whereas continuous bright tracks record glorious spells of sunny weather. In June, the Sun trails begin higher at the northern hemisphere's summer solstice. The trails sink lower in the sky as December's winter solstice approaches. A washed out, noisy, blurry, tilted, and badly tinted photo managed to blow everything out there out of the water. It was bought by NASA.
Thats what I call commitment...

Jman · « **Reply #1 on:** January 30, 2012, 07:35:27 PM »

So, you once did a six month exposure and have been bragging about it to your friends? Let me smash that effort to the ground. This guy did one for a whole YEAR.

http://www.thestar.com/news/article/1109339--year-long-exposure-of-toronto-skyline-produces-dreamy-image

lisandra · « **Reply #2 on:** January 30, 2012, 09:19:00 PM »

holy crap...

Blaufeld · « **Reply #3 on:** January 31, 2012, 12:39:06 AM »

It must be a tremendous hassle sitting next to your camera for a whole year.

voyager · « **Reply #4 on:** January 31, 2012, 01:35:12 AM »

The stars look like digital information. That is so cool.

E-M5 Pete · « **Reply #5 on:** January 31, 2012, 04:23:03 AM »

Adash, sounds like a challenge. You do paper pinhole photos.

I wander, if fixing the paper without going through developer/stop bath will preserve the original photo?

Amazing, the arch is really cool.

Sent from my iPad

lisandra · « **Reply #6 on:** January 31, 2012, 06:58:25 AM »

Somebody explain how do you calculate for something like this. It has to be a tremendously small hole to allow a 6 month exposure, or am I missing something?

Eureka · « **Reply #7 on:** January 31, 2012, 10:54:45 AM »

Quote from: lisandra on January 31, 2012, 06:58:25 AM

Somebody explain how do you calculate for something like this. It has to be a tremendously small hole to allow a 6 month exposure, or am I missing something?

Just what I was thinking of, but I never wrote it. Hehe, since I'm not so sure about things in photography I thought maybe I would make myself funny if I wrote that question

E-M5 Pete · « **Reply #8 on:** January 31, 2012, 11:04:50 AM »

a pinhole is usually around f/128, or f/236, but, you can machined ones much smaller.
Remember, Photographic paper has an ISO like 5, and to get enlargements under a highly concentrated light, the exposure is like 20s for a moderate f/11 on the enlarging lens.

Adash has done some Paper Pinhole exposures. I am sure he can explain it better. BUT, he develops them, These exposures are so long, the image is "Fogged"onto the paper w/o developer, that would totally turn the paper black.e

adash · « **Reply #9 on:** January 31, 2012, 12:15:05 PM »

Quote from: lisandra on January 31, 2012, 06:58:25 AM

Somebody explain how do you calculate for something like this. It has to be a tremendously small hole to allow a 6 month exposure, or am I missing something?

You don't calculate things in pinhole. You can establish a reasonable success ratio by trial and error. You can guesstimate for a given light and try. Then in the darkroom you can find out how close you were. I have about 50% success in the shade, maybe 80% in the sunlight, and only two out of ten exposed properly indoors. For an exposure that long you should probably stack ND filters, and I guess one out of ten will be ok, due to the reciprocity failure. Actually I don't have experience with exposures longer than 6 hours.

Quote from: M5-User on January 31, 2012, 04:23:03 AM

Adash, sounds like a challenge. You do paper pinhole photos.

I wander, if fixing the paper without going through developer/stop bath will preserve the original photo?

Amazing, the arch is really cool.

Sent from my iPad

Fixing the undeveloped image will destroy it. You're going to get a clean white sheet at the end.

On the emulsion speed - it is usually from about 1 ISO to 5 or 6, with spectral sensitivity for red much lower. Note that the photo is on a colour paper, which is a totally new domain for me. A friend once shared that commercial coloir paper is generally more sensitive, with Kodak making it at about 25 ISO, but generally lmuch more sensitive to blue than others. I never did colour pinholes however, mainly because of the exotic chemicals and the added complexity of working in total darkness.

BTW, although silver halide, paper emilsion is much less tolerant to wrong exposure than film. Much less than digital too.

asterinex · « **Reply #10 on:** January 31, 2012, 12:57:59 PM »

Quote from: Jman on January 30, 2012, 07:35:27 PM

So, you once did a six month exposure and have been bragging about it to your friends? Let me smash that effort to the ground. This guy did one for a whole YEAR.

http://www.thestar.com/news/article/1109339--year-long-exposure-of-toronto-skyline-produces-dreamy-image

Do you really think 1 year is long ?
What about this

http://www.itchyi.co.uk/thelatest/2010/7/20/the-longest-photographic-exposures-in-history.html
The German photography artist Michael Wesely has created even longer exposures. Using large format cameras (4x5 inches) he captured the light of his objects for up to 3 years in monochrome or colour.

cosinaphile · « **Reply #11 on:** January 31, 2012, 02:58:02 PM »

amazing thread , i would like to try and beat this record, but i havnt a clue how

jeanba3000 · « **Reply #12 on:** February 04, 2012, 04:22:16 PM »

Michael Wesely doesn't use pinhole cameras, he uses large format cameras with wide field lenses (like Super Angulon) and dark neutral filters, regular analog films and the Schwarzschild effect of non-reciprocity of film sensibility : the light sensitivity of a film exponentially decreases with the increase of time exposure, to a point where the film is nearly insensitive to light.

lisandra · « **Reply #13 on:** February 04, 2012, 10:51:55 PM »

fascinating thread this turn out to be...
Still, ISO 5 and f236 doesnt seem like a 6 month exposure, days maybe. Its the logic completely different? You cant tell me I cant calculate for something adash, Itll drive me insane

adash · « **Reply #14 on:** February 05, 2012, 02:38:32 AM »

Quote

You cant tell me I cant calculate for something adash, Itll drive me insane

Not sure about calculations, Lisandra, but I can share my previous experience:
Sunlight, ~16EV: 2 to 4 minutes, depending on the hole diameter and distance;
Light shade, maybe 13EV: 10 minutes approximately;
Heavier shade, ~11EV: 20 - 40 minutes;
Indoors, diffuse daylight, ~3 to 5EV: 6 hours.

If paper is ~3 ISO, you can try to figure out the F-number. From that, you could try to guesstimate the necessary ND for a particular time of exposure. I am not willing to go into such long exposures, as no particular scene around me is interesting or spectacular as the observatory above. If you're willing to try, make sure your boxes are light-tight and the hole as small as possible (search google, the basic idea is that the hole must be as large as the tip of the pin, almost invisible to the naked eye, unless held against the sun). Stack NDs if you need to, and as many as you guesstimated, and leave several boxes. Then collect one box in 1/2 the desired time and check it out. 1/2 of the exposure is easy to detect, as mostly the brightest spots will be visible. If nothing is visible, then probably you need to leave the rest of the boxes for double the desired time. Trial and error is the way to go, because as stated above, for longer exposures ISO sensitivity will be much lower due to the reciprocity failure.

Photographic paper has a different behavior than film, if not exposed properly, it is almost impossible to "push" without bringing out too much fog.

lisandra · « **Reply #15 on:** February 05, 2012, 06:05:14 AM »

Sounds extremely cool, but daunting as well...

adash · « **Reply #16 on:** February 05, 2012, 06:23:05 AM »

Start over with normal exposure times, in a tin can, for example. Find an existing photographic darkroom, or make one in a completely dark room with running water. I made mine in a small toilet with a sink and started over with three trays and a safelight. Now I also have an enlarger, but I can not process colour paper and films yet, because they require precise temperature control. B&W photo paper is fun to work with, as you can process it conveniently with a safelight, but colour paper is a pain in the @ss, because you have to do it in an almost complete darkness.

you dont know what a long exposure is...