What the f means today is not what you think

Have you ever looked at something so old and wondered how it was used? Reading the markings on the object as if it could tell you. I did just that with my Kodak No. 2 Autographic Brownie camera originally purchased in 1921. I believing that it would be simple enough tool. 

I'm not going to get all geeky-photo-techie on you. For some of you who have delved past the auto settings on your camera you'll know that it can sound complicated with all these numbers and archaic terms such as aperture or f-stop, shutter speed and film speed or ISO. Much like the Bermuda triangle, the Exposure triangle may sound menacing and a place to get lost in, but for most of us we don't give it a second thought or probably never even heard of it.
 
The reason I'm bringing this up is not to give you a lesson on understanding your camera settings. If you need some tips there you can contact me directly. Really, I'd be happy to answer your burning questions.

"What I've been working out is understanding this 96 year old camera. And it continues to surprise me."

Take a look. The numbers on the top show a shutter speed of 1/25 of a second for a "clear" sunny day and 1/50 of a second for a "brilliant" sunny day. Fairly slow compared to today's models that can go as fast at 1/4000 of a second. There will be no freezing action with this one.

What we can also see at the top of the face  is a guideline for longer exposures for 1/2 second to a full second depending on the dullness of the day.

The original manual that came with this camera, and published in July 1920, goes on to say, "to judge the above divisions of "time" accurately, in using this shutter, the method most easily acquired is by counting."

Yep, the photographer counts rapidly, "one, two, three, four" to make up one second. Seems like a bit of guessing going on with timed exposures based on counting, judging the brightness of the day and on top of all that we can't be sure if we got the shot until the film is developed. A real test in patience and faith.
But I'm getting lost in the triangle details here.

Choose Clouds or Marine or something closer...what the f

I just wanted to show how interesting the face of this camera was and figure out what it means. On the bottom is a scale of aperture settings with corresponding numbers; 4, 8, 16, 32, 64. I automatically took them to mean the f-stops we are familiar with.

Only by chance did I come across an important distinction. Instead of f-stops, many of these old lenses are marked in the Uniform System (U.S.) established by Britian's Royal Photographic Society in 1881. You can see that on the face of this camera in the lower left-hand side right next to the screw. 

Whoah! That means what I thought was the average day setting of f8 for this old Kodak was really comparable to f11. Doesn't sound like much but given all the other variables it might just throw the whole exposure out of whack and I wouldn't have known until I were back home and developed it.

So, the lesson for today is this: The f means the f-stop of course and my discovery of the Uniform System for lens apertures. I'm grateful for the internet to find this stuff out so I can go out there, take some shots with this 96 year old Kodak and hopefully not f it up.

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If you really want to get geeky about it;
The U. S. (Uniform System) of marking stops for photographic lenses is based on the area of the opening. This system is generally used on rectilinear lenses.
The f. system is based on the diameter of the opening, and is used on anastigmat lenses.

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