The sky is 'Purest Blue'
December 30, 2011 3:42 PM   Subscribe

Those of us who enjoy old-school chemical photography often need to calculate f-stop and exposure times. Of course you can use a ginormous table but there exists a solution from a more elegant age in which the sky can be purest blue above a very narrow old street. Marvel at Kaufmann's Posographe, a wonder of the analog age.
posted by LastOfHisKind (22 comments total) 31 users marked this as a favorite
 
What an incredibly cool device. Seems to be a custom mechanical slide rule for exposure.
posted by sammyo at 3:55 PM on December 30, 2011


Neato
posted by Windopaene at 3:59 PM on December 30, 2011


All the gears and cogs in the world aren't as steampunk as this.
posted by saturday_morning at 4:00 PM on December 30, 2011 [7 favorites]


I feel ashamed for downloading a light meter app on my iPhone yesterday. This is really cool.
posted by book 'em dano at 4:09 PM on December 30, 2011


Neat, but I think I'll stick with my Sekonic L-758c.
posted by nathancaswell at 4:18 PM on December 30, 2011


Yes, but did it actually work?
posted by schmod at 4:26 PM on December 30, 2011


What a lovely device. I wish he had a photograph of the mechanism inside; the sketch there doesn't really give it justice.

Just today I was playing with my new Canon Powershot S100. It has the usual whiz-bang point and shoot features we take for granted now; I can specify any 2 of f-stop, shutter speed, and ISO and it will perfectly calculate the third with a built-in light meter, of course. Also it uses signals from space to locate where I took the photo to within about 10 feet. Oh, and the camera is the size of a pack of cigarettes and the film canister can hold 2500 photos. We live in an age of marvel.
posted by Nelson at 4:26 PM on December 30, 2011 [3 favorites]


This device gives me the same feeling I got from looking at an old pallet jack.

I once worked in the front office for a roofing company, and they had rented out an old shipping warehouse that had a lot of old tools in it. Buried in the clutter was a pallet jack, which they dug out, oiled, and put back into service. I'm pretty sure the date of manufacture was sometime in the early 1920s, although I'm no longer positive.

That thing was the most amazing piece of machinery. It had a hydraulic lifting mechanism that you engaged by pumping the same handle you then pulled the load around with. You could lift absolutely enormous loads with it, through the simple magic of mechanical advantage transmitted through fluid, and then move them smoothly around anywhere the floor was good. When you got it where you wanted to go, you pulled a trigger, and the lifting bed retracted smoothly, without jarring, and gently set the load in place on the floor.

At the time I was looking at it, it would have been about 75 years old, made before electricity was even commonplace, and yet it was one of the most perfect little machines I've ever worked with. Obviously, I don't know what its maintenance history was, but I think it worked just as well in the mid-90s as it did when it was made.

It was that humble tool that finally drove home to me that those quaint, bewiskered folks in all our history books, despite their backwards ways, were searingly intelligent. Further, I then realized that the only real difference between modern man and a caveman is the body of knowledge we've collectively accumulated.

So a pallet jack convinced me of the worth of a modern education, and this device echoes that same exact feeling. What could a mind that marvelous have done with all the additional knowledge we've accumulated since 1920?
posted by Malor at 4:37 PM on December 30, 2011 [9 favorites]


Malor, is it significantly different from one of these? Because what you described sounds like what I use at work, and about as remarkable as an adjustable wrench or a claw hammer.
posted by idiopath at 4:41 PM on December 30, 2011 [2 favorites]


Paging Mr. Gibson, Mr. William Gibson!
posted by valkane at 4:49 PM on December 30, 2011


Neat calculator.

When I taught pinhole photography as part of a technology class, I had my kids use the Sunny 16 rule. That worked well enough for them - easy to remember and easy to work with.
posted by plinth at 5:04 PM on December 30, 2011 [3 favorites]


Yes, idiopath, it was very similar. It was also made around 1920.

There aren't many designs that last, nearly unchanged, for that kind of time. The fact that they've changed so little over the years, and that you can find something that intricate and yet that old to be completely commonplace, shows just how brilliant it was. Nobody's really done better in almost a hundred years. Maybe longer -- I don't even know when pallet jacks were first designed.

Okay, from Wikipedia:

Pallet jack history -- This New Truck Gets Under the Load and Lifts It, Popular Science monthly, December 1918, page 54,

I mean, goddammit, think about that. That was designed almost a hundred years ago, and it's barely been improved on since.

If that doesn't amaze you, you've got a perspective problem.
posted by Malor at 5:15 PM on December 30, 2011 [1 favorite]


I remember when I was first in art school, we had a visiting artist, I forgot who but she was just becoming famous. One of the grad students started questioning her. He said he loved how accurate the exposure was in her B&W photos, how did she do it? Did she use a spot meter? Incident meter? Zone System? Special development?

She said she just used the exposure guide from the data sheet that came with the film.
posted by charlie don't surf at 5:30 PM on December 30, 2011 [3 favorites]


I actually went to art school for photography in the early '90s. As a teenager and a young adult, I loved, loved, loved vintage equipment and photography magazines from the '60s and earlier. If you were careful, did your homework, and had a sharp eye for quality, some of the vintage equipment... Koni-Omega and Mamiya medium format rangefinder systems, Tiltall tripods, wood tripods with modern Gitzo heads, pocketable Japanese fixed-lens rangefinders... it would be better than brand new equipment at three times the price.

The magazines were a relevation, the practical chemical knowledge and the optical physics formulae and calculations the photographer needed to know in order to take a perfect photograph were amazing. It really helped me to understand what the equipment was doing and how it did it.

The best advice I ever gleaned from those magazines was the exposure formula photographers used when capturing action in good light. It relied on a strong knowledge of darkroom processes, both in film development and in printing, but if you mastered it, you were sure to come away with a winning image despite what equipment or film you were using, everytime.

As we are now in an age of RAW capture and digital post-processing, the formula works better than it ever did. It takes into account too-bright highlights and shadows that are too black, allowing you to bypass your camera's finicky matrix-metering in swift moving situations. No matter how intense things get, as long as it's daytime, this will see you through:

f/8, and be there.
posted by Slap*Happy at 6:15 PM on December 30, 2011 [3 favorites]


Oh wow, it's like steampunk, except it actually does something
posted by DoctorFedora at 6:59 PM on December 30, 2011 [2 favorites]


Good lord. What was the actual rule of thumb? Bright daylight was f/16 at a shutter speed of 1/ISO film speed, I believe.
posted by mrhappy at 8:08 PM on December 30, 2011 [1 favorite]


oopsie. plinth has this covered.
posted by mrhappy at 8:10 PM on December 30, 2011


Sunny/16 rule - I've never had success with this.
posted by Slap*Happy at 8:18 PM on December 30, 2011


I took manymany rolls of plusX and triX, and ektacolor, thru a Crown Graphic 2 1/4 x 3 1/4 without any meter, using that rule. Worked fine!
posted by drhydro at 8:34 PM on December 30, 2011


If you're impressed by this device, I'm guessing you were out kissing girls when you should have been at home playing with technic lego. :-)

It seems insanely complicated the way that speaking Japanese seems insanely complicated - when it's a foreign language that you haven't learned to think in. But it's a natural language to people who are used to it. Though I guess mechanical computing can be added to the list of dying languages.
posted by -harlequin- at 10:15 PM on December 30, 2011


Look at the aspect ratio and rounded corners. This would make a superb iPhone app, if only as a working reproduction.
posted by Scoo at 10:39 PM on December 30, 2011 [2 favorites]


I'm with Malor: some of these things are fabulous expresions of human thought manifested in the physical world. I clearly remember realizing that I could use that pallet jack to move a ton of stuff, all by my 130 lb. self.

In the same way, a (pre- "full auto") 35 mm lens is a sophisticated calculator that allowed the photographer to bridge the gap between his or her knowledge of f-stops and film speed, and the hugely variable world of light.

And, judging by the number of times I've seen links to this over the last couple of years, I'm not so sure the age of mechanical computung is over.
posted by sneebler at 8:33 AM on December 31, 2011 [1 favorite]


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