6 month solargraph made with camera obscura

'Allo. About two years ago I posted a (there was a url link here which no longer exists) asking for help with a project of mine. I wanted to build a camera obscura out of a home depot shed and do a 6 month exposure with it. Well I finally did it! It took me about a year to write up the final plans and get a grant, and another year to build the shed, do the exposure, and stitch together the resulting photograph. Almost everything that could have gone wrong went wrong, but I still got a pretty awesome result! Attached is a scaled down version. Each of the tiles you see is an 11x14 sheet of enlarger paper. The original negative was about 8 feet wide by 6 feet tall.

Cool!

Very nice! Is it colour paper, or does b/w paper develop a colour cast in the image eventually? (I've never done this with an exposure of more than a few hours.)

-NT

It's black and white photo paper. It just happens to create a visible color negative after being exposed for a really long time.

That is very cool!

awesome job. That's really cool.

My darkroom is a shed. I wish what was in front of it was pretty enough to be worth doing this

Wow, that is... genius. Seriously, I don't have the right words to tell how much I like it

I did a few solargraphics myself, but they were mostly on tiny pieces of paper in black 35mm film cans and only exposed for a few days or weeks. The biggest one was a tall tin with three sheets of 9x13cm paper, adding up to 27x13cm or about 10,5x5 inch, and 3 months exposure... that one had me jumping in joy, but yours just made my jaw hit the floor.
I'm inspired to try again with a bigger format and relatively small hole. Maybe 1,5 by 2 feet with a 0,5mm hole for about the same sharpness as your picture.

Thinking about how solargraphy makes a digital scanner necessary, I thought of another, completely analog way... What about taking a photo of the exposed sheets with positive film (medium or large format for best resolution) and enlarge that onto paper for a true positive silver print of the solargraphic negative? The paper negative can be exposed to a little light before going completely dark (it already does so in the scanner), so that shouldn't be a problem when you're fast enough. A diffused flash might be useful to minimize unnecessary exposure... Of course, I wouldn't try that with such a big project and the danger of destroying it, but I think it's possible if you're careful. I'll try it next week with a small camera that has been sitting on the windowsill for 10 days.

As for the colors: Those are usually completely random and rarely as realistic as in this picture. I don't know where exactly they come from, but I think it's just the color correction in the scanner doing something funky. Definitely not the black and white paper magically turning into a color negative by overexposure (unless I misunderstood the whole chemistry of silverbased paper). I usually got reddish purple skies with bluish sun and corrected them afterwards, since it was digital anyway.


@Existing Light:
You would lock yourself out of your darkroom for months? Are you mad? And for the motif just put something pretty in front of it... "Now for your portrait, please hold perfectly still for a few days"

moki said:

Thinking about how solargraphy makes a digital scanner necessary, I thought of another, completely analog way... What about taking a photo of the exposed sheets with positive film (medium or large format for best resolution) and enlarge that onto paper for a true positive silver print of the solargraphic negative? The paper negative can be exposed to a little light before going completely dark (it already does so in the scanner), so that shouldn't be a problem when you're fast enough. A diffused flash might be useful to minimize unnecessary exposure... Of course, I wouldn't try that with such a big project and the danger of destroying it, but I think it's possible if you're careful. I'll try it next week with a small camera that has been sitting on the windowsill for 10 days.

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Sounds like a great idea man, I'd love to see how it turns out!

moki said:

As for the colors: Those are usually completely random and rarely as realistic as in this picture. I don't know where exactly they come from, but I think it's just the color correction in the scanner doing something funky. Definitely not the black and white paper magically turning into a color negative by overexposure (unless I misunderstood the whole chemistry of silverbased paper). I usually got reddish purple skies with bluish sun and corrected them afterwards, since it was digital anyway.

Click to expand...

Hmm I'm not sure. I didn't scan my negatives, they were much too large. I photographed the 6 large tiles with my 5D Mark II and pieced them together in Photoshop. The original negatives definitely had some color, very very low contrast, but I could definitely discern some variances in color. And I didn't apply any color correction either. I also took a digital photograph of the building (my high school) to compare and the colors don't seem to be random. Hmm..

pokerplayer269 said:

Sounds like a great idea man, I'd love to see how it turns out!

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Well, I came upon another problem with that... since the paper negative is usually very low in contrast, you'd need to enhance the contrast somehow, but there is no positive film with a high enough contrast. Maybe taking the photo on a graphical b&w film, making an inter-positive... or -negative, whatever, I'm confusing myself. Anyway, copy that high-contrast picture onto another piece of negative film and enlarge that onto paper. Or maybe simply taking a low-contrast positive, enlarging that and lith-developing the paper would do the trick. I'll have to try that some day.
Of course, you'd lose the color which brings me to:

pokerplayer269 said:

Hmm I'm not sure. I didn't scan my negatives, they were much too large. I photographed the 6 large tiles with my 5D Mark II and pieced them together in Photoshop. The original negatives definitely had some color, very very low contrast, but I could definitely discern some variances in color. And I didn't apply any color correction either. I also took a digital photograph of the building (my high school) to compare and the colors don't seem to be random. Hmm..

Click to expand...

I'm utterly perplexed. I just made a rather short exposure (about two weeks) and there seems to be some very slight coloring. You can see the picture here (link). I took a photo of the (tiny) negative with an EOS 50D and custom white balance, then inverted the picture and increased contrast as only digital modifications. I guessed, the colors where just my mind playing tricks, because it knows, how this stuff is supposed to look. Sadly, analyzing the colors in Photoshop also confirms that there is a little greenish blue in the sky and yellow in the sun. The paper had been old and yellow, so that would explain the greenish blue sky when inverted and the silver has a slight bluish tint that would make the sun seem yellow, but that doesn't explain the detailed color in your picture at all.
There are colors... I can't deny it, but I can't explain it either. It would mean, that a certain wavelenght of light does something to the silver-bromide or other chemicals in the paper and emulsion to make the exact opposite visible color appear. I hope, someone can explain this to me scientifically... any chemists and physicists around? Sorry, "god did it" won't do as an explanation...

Doesn't variable contrast paper respond differently to different wavelengths of light? Maybe that has something to do with the colors..

That's beautiful!

I stumbled upon some of your original posts/queries about this project a couple of months ago. I was googling around about a similar idea. Glad to see you were able to make it happen (and got a grant!) and very cool results! Congrats!

That is beyond cool. Sorry I don't have anything more intelligent to say about it. Thank you for your project.

That is just absolutely awesome!