RB67 Extension Tubes and Instant Film back

Posted April 12th, 2012 by jbitd

Here I’ll show you how to make anything bigger on your film by getting your camera closer and using extension tubes, or macro tubes.

Every lens has a minimum focusing distance, and macro tubes allow the lens to move further from the camera, focusing even closer, so you have higher magnification of objects. This does have the disadvantage of stopping down the light and causing a very shallow depth of field, but both of those things can be easily dealt with by adding more lights or using flash and stopping down the aperture.

Next, I talk about using a cheap digital camera as a light meter. If it has fully manual settings and you can set the ISO to match your film, then you can find the correct exposure for the scene on the digital camera, and translate the aperture and shutter speed to some equivalent setting on the film camera. This has the advantage of always working in snowy and dark scenes, for example, where you would need to know that a light meter will give you a value that will not result in blowing out highlights, except that you want snow to be overexposed and white. With a digital camera you don’t have to understand those behaviors of light meters.

Finally I talk about instant film backs that use Fuji film and I say their main advantage is allowing you to know the exposure is compensated correctly. The digital camera settings plugged right into the lens would only work if you are using no bellows extension or filters or extension tubes. But if you are using polarizers, ND grads, and bellows extension, you may not recall how many stops to compensate for. Instead of exposure bracketing on film and hoping you got it right, just take a sample shot with instant film. Their only disadvantage is taking abysmally long times in below freezing temperatures. For example FP-3000B should develop in 20 seconds at room temperature however when it was just below freezing it took over twenty minutes for it to be almost done. I just gave up waiting because my sunset was disappearing faster than I could adjust for with those film previews taking so long. Any other season of the year it’s a wonderful tool!

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