Silverbased

I love my 1965 Minolta Autocord, a twin-lens reflex with an outstanding lens and a wonderful feeling of solidity.

Yet TLR viewing has been hard for me to get used to. The waist-level finder is great for giving an overall impression of the composition; yet the groundglass image often becomes washed out in bright ambient light. Also, at waist level it’s sometimes hard to judge whether the focus is exactly right.

Using the Autocord’s pop-up magnifier does a better job of blocking glare, and lets you focus accurately. But the view of the whole frame is not very satisfactory. It’s a slight strain to see the corners of the groundglass from so close, and this also worsens their dimness.

Hence I’m trying out a new solution: A homemade “chimney” magnifying hood. Besides blocking stray light, it seems to give a nice viewing compromise—large enough to focus easily, yet giving a good overall sense of the framing.

I built one earlier, failed version of this idea. It was too tall, and its rigid box construction made it unwieldy to pack along. This time I created one that unfolds, so that when flattened it can be stowed in a camera-bag side pocket. And I used a higher-magnification lens, reducing the height to only 3″taller than the TLR’s own viewing hood.

This version is just made from scrap leftover Crescent board, partly scored through its faces along the fold lines. I sprayed flat black paint onto the inner surfaces, then tacked a magnifier behind the eye hole using hot-melt glue.

The rounded tab blocks light from entering the side of my eye socket. But it also has a second thickness of cardboard glued to it, under which you tuck the flap with the magnifying lens. This holds it in position when the sides are rubber-banded together.

I’m a left-eyed viewer—so naturally righties would build this so the rounded shield was on the opposite side.

Focal Lengths, Powers, and Diopters

The height of the chimney depends on the power of the magnifier you use; and it can take a little searching to find a good lens for this.

Recall that the focal length of a lens is the distance behind it where objects at infinity will come to focus. Turn the light paths around, and it’s also the distance where close objects will appear to your eye to be at infinity. For a quick check of a simple lens’s focal length, you can use the sun, measuring how far behind the glass a sharp image forms.

The lens I found had a focal length of about 165mm. In terms of magnifying “powers” this would be considered a 2.5x magnifier. I’m nearsighted—I can’t focus at infinity—so I made the chimney’s height a little shorter than the focal length.

I think a magnifier of slightly higher power, say about 140mm f.l., would work nicely and make the chimney even more compact. (But a “3x” magnifier would be 125mm f.l.)

A natural question for a photographer to ask is, “could I use a leftover close-up attachment for this?” The answer is “probably not.” Close-up lenses are specified in Diopters, and usually range from +1 to +4.

But the desired focal lengths here would translate to 6 or 7 diopters. And I don’t ever recall seeing a close-up attachment that powerful on the market.

Today we’ve got an easy and fun DIY project that is guaranteed to improve your flash photos: A simple diffuser for your strobe made from a plastic food tub—the Tupperflash!

Why Are We Doing This?

Sometimes you want to take pictures in a place where the ambient light is so dim that electronic flash is the only way get a photo at all.

However the typical flash, just a few inches from the camera lens, is the harshest and ugliest form of illumination ever invented. The blasted, shadowless “deer in the headlamps” look is particularly unflattering for people photos.

For mood lighting in your living room, you don’t use a single bare light bulb, do you? Of course not. You soften and spread the light with a lampshade, right? Adding a diffuser to your flash gun is the same idea.

And better yet, move the flash away from the lens, too—this adds shadows to give better three-dimensionality and softer modeling to faces.

Choose Wisely

Finding the right plastic storage tub for this project can take some scrounging. Fortunately many thrift stores and rummage sales are overflowing with unwanted plastic containers. You’re looking for one about 6″ across, and its lid must be frosted, milky white plastic—not color-tinted, and not perfectly clear.

The tub bottom can be any color or shape, but it should be at least three inches deep to leave room for light to bounce around. Authentic vintage Tupperware bowls are perfect for this; but we’re illustrating the project with a Rubbermaid Take-Along tub (right)—a style that was currently on the market the last time I checked.

For the flash itself, you simply want an ultra-basic, dumb, AA-powered strobe. Any whizzy auto-exposure features (e.g. “thyristor” types) will be useless: The photocell would be blinded by the flash-lit insides of the Tupperware. However you can use an auto model in manual mode, if that’s all you have available.

Not all vintage flashes have flash-trigger contacts in their foot, but that’s a desirable feature. (Unfortunately the particular flash unit illustrated in this article turned out to be rather unreliable at triggering on certain cameras—so don’t go hunting for one just like it.)

Remove the lid of the tub, and spray the interior with silver spray paint. Paint does not stick very well to the waxy surface of many plastics, so roughen the surface with steel wool or fine sandpaper first.

We want all the flash’s light to be directed forwards; so spray two coats to insure that the tub’s sides are fully opaque when you’re done. White spray paint will also work, if that’s all you have handy. Or you could line the insides of the tub with aluminum foil, using spray adhesive or glue stick.

Mark the outline of the flash’s body on the bottom of the tub, positioning it so the flash tube is centered.

Cut an opening in the plastic, leaving tabs of about 1/2″ wide to bend back and tape to the flash. With some styles of flash, you may not have room for a tab on the bottom edge.

The plastic of some food tubs (like this one) is rather brittle—so cut and bend slowly and carefully. You can see I still ended up with some unwanted cracks.

Tape the tub’s flaps to the body of your flash unit. Avoid taping over the access door to the battery compartment.

This inside view shows the desired result: The flash tube is centered in the bottom, and the plastic tabs are taped snugly against the flash so that no light can sneak out the back.

Replace the lid to the food tub, and the diffuser is ready to use! The top illustration of this article shows how the completed flash would fit an SLR with a hot-shoe flash connection. Note that with some cameras, the width of the food tub might interfere with the lens, or block viewfinder windows—be sure to check that first that when selecting your container.

Going Sideways

As I mentioned earlier, light from directly beside the lens fails to give three-dimensional shading to your subject. Light from off-camera flash is much better at defining shapes and casting flattering shadows. So for the best tupperflash results, trigger the flash while holding the tub well off to the side or above your camera—either on a bracket, or held in your other free hand.

To fire the flash off-camera, here’s one simple solution: Hold the shutter open on the “B” (bulb”) setting, then pop off the flash using its test button. In many dim environments, the room light contributes a negligible exposure compared to the flash—but, if there are some ghostly blurs from the ambient light, that can be an interesting effect too!

(Your test button may be an unmarked red pushbutton , or even the clear cover of the ready-lamp on some flashes.)

For Extra Credit

But the “correct” way to trigger things is to connect an extension PC cable to the X-sync socket on your camera. If you’re lucky, your flash has a cable connector in its base using a plug style you can still buy today. However over the decades, different flash manufacturers introduced a bewildering variety of plug styles, and usually you aren’t so lucky.

Solution? Take any random PC flash cable from the clearance bin of your camera store; then cannibalize it by snipping off the useless connector.

Disassemble the foot on your flash unit and drill a hole to insert the snipped cable end. Solder the cable’s two wires to the flash hot shoe connection, and re-assemble. (If you don’t mind sacrificing the shoe-mount option, you could simply discard the flash foot, and splice directly to the wires from the flash.)

Getting Exposed

To figure the correct exposure, consult the table or calculator dial on the flash, based on your particular film speed and subject distance. Take the suggested f/stop, then open up two stops to compensate for the diffuser’s light loss. After seeing your results, you may need to adjust your personal tupperware fudge-factor up or down from there.

Oh—and the final bonus of this style of diffuser? You will get many photos of people grinning curiously at your crazy homebrew flash set-up. I promise it!

See examples from the Tupperflash in action on Vox’s Flickr stream.