Macrophotography Exposure Calculator

Back in high school, I designed and built a slide rule exposure calculator to improve my macro photographs:

Macrophotography Exposure Calculator - front

Macrophotography Exposure Calculator – front

The base consists of three layers of thin cardboard glued together with Elmer’s Glue. The three slides have three layers of thinner white cardboard glued together, with offsets forming tongue-and-groove interlocks, topped with yellow paper for that true slide rule look:

Macrophotography Exposure Calculator - slide detail

Macrophotography Exposure Calculator – slide detail

Judging from the seams, I covered the hand-drawn scales with “invisible” matte-surface Scotch Tape. Worked well, if you ask me, and still looks pretty good:

Macrophotography Exposure Calculator - front - detail

Macrophotography Exposure Calculator – front – detail

The reverse side carries instructions under a layer of packing tape (which hasn’t survived the test of time nearly as well), for anyone needing help:

Macrophotography Exposure Calculator - rear

Macrophotography Exposure Calculator – rear

A closer look at the instructions:

Macrophotography Exposure Calculator - instructions

Macrophotography Exposure Calculator – instructions

The slides still move, albeit stiffly, and it might be usable.

I vaguely recall extension tubes on an early SLR, but memory fades after that. Getting the exposure settings close to the right value evidently posed something of a challenge and, given the cost of 35 mm film + development, it made sense to be careful.

Fortunately, even today’s low-end cameras make macro photography, at least for my simple needs, easy enough, with the camera handling the exposure calculations all by itself:

SX230HS - macro lens - 15 x 20 mA ring light

SX230HS – macro lens – 15 x 20 mA ring light

I’m definitely not on the level of a professional insect photographer!

Randy’s observation to Amy in Neal Stephenson’s Cryptonomicon comes to mind:

“… One of the most frightening things about your true nerd, for many people, is not that he’s socially inept — everybody’s been there — but rather his complete lack of embarrassment about it.”

“Which is kind of pathetic.”

“It was pathetic when they were in high school,” Randy says. “Now it’s something else. Something very different from pathetic.”

“What, then?”

“I don’t know. There is no word for it. You’ll see.”


  1. #1 by rkward on 2016-04-27 - 07:49

    Impressive! I made one while in college that was for A/D voltage calculations at all the common resolutions (8,10,12,14) and voltages (5,12). I had done a lot of CAD work, so it was a fold-together model with glued seams and a single sliding card and really just for fun. I also plotted out (HP 7475A no less) miniature equipment cabinets of my current employer that I was working on in order to create small desktop models, again for fun. These were the “Tab A”, “Slot B” type fold-together. To this day, I still make scale fold-together models in order to check proportions of various designs.

    • #2 by Ed on 2016-04-27 - 17:27

      scale fold-together models

      On those rare occasions when we move, we make paper doll houses with all our furniture and label all our hand-packed boxes with destinations. The movers think we’re soooo organized… but there’s probably no word for that behavior, either.

      • #3 by rkward on 2016-04-27 - 21:12

        Hah, that sounds familiar. CAD layouts before moving really do help know where things will fit.

  2. #4 by madbodger on 2016-04-27 - 09:12

    That’s a really nice assemblage! I can see a lot of effort with rulers, quality pens, and sharp blades there. There was a professional insect photographer at the Science Expo a couple of weeks back. He had built (and was selling) a rig with a carriage for the camera that provided the distance adjustement, and an X/Y positioner for the subject. There was also a 3D printed white shroud for the lense that let a pair of remote strobes provide diffuse bounce flash (like a ring flash, but less harsh).

    • #5 by Ed on 2016-04-27 - 17:32

      3D printed white shroud

      That’s where my efforts go off the rails: I really must do something better about the lighting. I saved a few micropositioners from the Starter Kit and, now that I have room for it, I should put together a photographic table with decent backdrops, lighting baffles, and all that good stuff.

      More projects!

  3. #8 by Red County Pete on 2016-04-27 - 10:16

    I was lucky; when I got interested in macro photography (just nibbled at the edges), the meters in my SLRs were Good Enough to get me there. I still have the equipment, but the Nikon F2 and the Nikkormat haven’t seen any film in ages. Pixels are so much cheaper than silver grains.

    On the last bit, I’m remembering some discussions on the differences between geeks and nerds. [grin]

  4. #9 by Vedran on 2016-04-27 - 10:20

    After I saw the first picture I started mentally composing the comment in the line of: “I can’t believe you didn’t sign that”.
    Rear picture shut me up pretty quick though… I just love your style… and fully intend to copy it at first opportunity :)