New record large glass plate

[PFMcFarland]

This guy just set the bar pretty high https://petapixel.com/2018/10/26/this-i ... ion-photo/
Make sure to watch the video.

PF

[Brazile]

Had seen that go by yesterday, but missed the video, so thanks very much for pointing it out, PF, I quite enjoyed it. Was greatly amused to see Gary Oldman pop up in the middle of it, unheralded ("Boy, that guy looks like Gary Oldman. Hey, wait a minute..."). The director seemed to enjoy showing the salted collodion being poured, but I wish she'd shown the sensitization -- that silver bath must have been something else, hate to think how much one plate's worth costs, plus would be curious to see how they did it without wasting any -- and the development and washing steps, which must be monumental as well. Still, an interesting project for sure: wet plate camera obscura.

I've wanted to turn one of my rooms into a camera obscura for years after reading one of Abelardo Morrell's books, but the idea of shooting a plate with it (dry plate in my case) is intriguing. Or an all-day exposure onto a niepceotype -- although I can't immediately see how to do a clean albumen coating on plate that big, spinning it seems out of the question. Although I must say, it seems to me that doing it in an abandoned house makes some aspects of the whole thing a bit easier...

Robert

[Julio1fer]

Very interesting, thanks for pointing this one. Amazing project.

Back in Nelsonfoto days I joked that someone would make exactly this one day, but never expected to watch it performed.

I am not familiar with wet plate technique. Several times in the video, they just pour a liquid on the glass and have four guys angle the plate until it is all covered - a portion of the liquid goes to the floor of course.

Processing in the dark is documented briefly about 28'30"" into the video. They get a kind of solarized result, not exactly inverted B&W. Wonder how it is done.

A good thing is that they do not need to care about dust, at these sizes.

[PFMcFarland]

I kept thinking after watching them pour the collodion that a sprinkler bar might have helped spread it quicker. The processing part looked even sloppier. I didn't realize that was Gary until I saw the credits.

PF

[Brazile]

Well, I'm no wet plate shooter, but I'm familiar enough with the steps from having considered taking it up once or twice. The basic idea is that you make or buy salted collodion (guncotton/nitrocellulose dissolved in ether and alcohol with a salt added to it), coat the plate, dip the plate into a silver nitrate bath (the silver reacts with the halide salt to form a silver halide, thus light sensitive), and then you shoot the plate nearly immediately (skinned over, but still basically wet) otherwise the light sensitivity decreases dramatically.

As soon as the plate is exposed, you have to develop it briefly (well less than a minute) in a ferrous sulfate solution, then wash it immediately and fix as usual.

It's that latter dance that I'd have liked to see with a plate that size, particularly development. I did see what they covered in the video, but it didn't really cover that part, I assume because of both the dim lighting and the fear of getting in the way of people in a big hurry to process a giant glass plate without damaging it. Tough job! Still an essential part of the story for me.

Not sure how the silver bath was done (my guess: probably just poured enough into the tray to cover the plate, let it sit briefly, then did their best to pour it off back into a bucket without losing much) but I assume the development and fixing was done the same way as the collodion pour. Must have used a massive quantity of developer, though, so they could just pour it on and cover the plate quickly, then pour it right off again. Fortunately that's a lot cheaper than silver nitrate...

Robert

[Brazile]

Oh, forgot to mention: the "solarization" appearance is in the nature of ambrotypes. They're actually negatives treated as positives. You put the negative plate against something dark, and the clear areas look dark because of the background, while the dense areas appear a bit lighter, because, well, silver is reflective. Similarly with tintypes, which are pretty much the same thing, but shot on darkened metal to begin with.

Robert

[Julio1fer]

Thanks for the explanations!

I wonder, how much silver nitrate would you need for a plate like this one?

Would be so expensive compared to the other items (glass plates, logistics of the shots)? It seems that they took several plates.

[Brazile]

Some very quick guesstimation. A 5'x7' plate would be about 3.25 m^2. To cover that to 1cm, you'd need 32.5 liters (1cc = 1ml). Let's say you use a 10% solution for the bath, which is close enough. That means a ratio of 10g/100ml, which means 3.25 kg to mix with the 32.5 liters (8-ish gallons) of water, or about 7lbs, Silver nitrate is $339/lb from Artcraft, so I guess about $2373 worth of silver -- although buying in that quantity would probably get you a discount.

Assuming I haven't shifted a decimal point incorrectly, that's pretty pricey for a shot! Now, to be fair: that silver bath is good for well more than one plate, assuming you have a good method for coating the plate and reclaiming the solution. But you'd need to spend at least that much for the first one, anyway. Of course, I think you need more than the above, because you might need more than 1cm of coverage. But it should be close enough to get the idea.

By way of comparison, looking at plate glass prices online, 3/8" (10mm) plate glass seems to run about $7/ft^2, thus about $250 for a 5'x7' plate.

Robert

[Julio1fer]

Your numbers look reasonable to me, Robert.

Maybe they have a technique for covering with less than 1 cm depth, but I doubt it with such a large area to manage.

At even 5 times reuse of the silver solution, it comes to about $ 700 a shot, if you count the plate glass. I hope that every plate was a bold and disturbing masterpiece!

[Brazile]

Ha ha, agreed!!

Robert