really dumb step wedge question

[Max Wendt]

Okay - I'm totally ashamed to be asking such a stupid question, but here I go...

I'd like to do some testing using a step wedge. I shoot 8x10. How do I attach a step wedge to the film for the exposure? Do you just tape it on there or what?

I've look through the archives, but the old answers are all rather vague about how you "sandwich" it in, and how it might be a tight fit, etc.

[hangs head, shuffles off for cover...]

[Matt Miller]

Relax Max (always wanted to say that), you're not the only one. The last time I used a step wedge, it was for an aerobics class back in the 80's. I'm pretty sure that's a totally different thing though. I have no idea how to use a step wedge either, but would like to know as well.

[Don Cameron]

Max

You take pictures of positive step wedges, and the negative types are used in the darkroom.

www.doncameron.com

[Hans Berkhout]

I use 4x5. (Do this in total darkness) I place the negative emulson side up in an old neg. box, one of the upstanding box edges is removed (cut off). Teststrip on top of the neg, then I place a 3x6" heavy piece of glass (with smoothened edges) on top of the strip/neg. Now you're ready to expose.

The box is mutilated for easier access. You can also tape it to baseboard surface so as not to lose it in the dark.

[Larry Gebhardt]

I use mine with an enlarger and not in the camera. I guess if you wanted to test in camera you would need a diffusion device over the lens.

[Max Wendt]

Yeah - the idea is to point the camera at an evenly-lit surface and focus on infinity.

Having it right on the film eliminates the need to compensate for bellows extension (or a really huge step wedge).

[Brian Ellis]

It would help if you told us what kind of testing you want to do. Step wedges are usually used in the darkroom, not in the camera.

[Max Wendt]

Sorry - I've seen it here more than a few times, so it seemed like kind of a common thing to do. The most recent description I've seen of this is Ken Miller's post to: http://largeformatphotography.info/lfforum/topic/498741.html

[John Cook]

Stouffer step wedges were standard equipment in the days when we lithographers used litho film in big horizontal process cameras. I could go into a long speech on the subject, but computers have made the techniques obsolete and the materials are no longer manufactured. Although I think Stouffer is still around and has a website.

The problem with exposing film (in contact with a step wedge) on a light box or under an enlarger is that it eliminates all the variables introduced by your camera, such as internal bellows flare, lens flare, shutter and diaphragm anomolies, etc.

I think you would be better off testing under clear sunlight with a gray card, incident meter and your favorite camera/lens combination (focused on infinity).

[Tim Curry]

Max, two different ways to test this out.

8X10 - just fasten two small pieces of tape to opposite corners (or 4 if you are worried about perfection) and place the step wedge to the film in the film holder. Find a white wall. Meter for zone V and overexpose by 5 stops. Process and evaluate on the paper of your choice. Take notes on E.V. exposure, processing and printing.

4X5 - just trim a sheet of 8x10 to 4X5 in a paper cutter and use a 4x5 film holder in a reducing back or 4X5 camera. Use the same procedure as above for metering.

Contact me off list if you have any questions. This question came up last night with a friend and her 8X10 we need to test for. tim

[Max Wendt]

Thanks Tim - so tape is the magic answer after all. :)

(BTW, I understand the basics of testing - I just wanted to try the step wedge in order to save some film...)

[Jeff Corbett]

I assume you are trying to determine film speed and development time. You will need a densitometer to interpret the results. Just tape the step wedge (I have a 4x5 Stouffer wegde) onto the centre of the 8x10 film. I expose on my guestimated zone VI in the camera, aimed at a uniformly lit surface, focussed at infinity, etc. That will put zone I or III (whichever you use for determining film speed) somewhere in the middle of the wedge. See The Ansel Adams Guide - Basic Techniques of Photography, Book 2 (by John P. Schaefer, copyright 1998). Chapter 3 is on film testing. Chapter 4 addresses determining film speed and development time. I'd actually recommend getting both books 1 and 2.

[Bob Chambers]

The John Schaffer book "Basic Techniques of Photography" vol. 2 describes the use of a step wedge for zone system testing. It is very quick and eliminates making multiple exposures. Scotch tape is used to attach the wedge to the film in the holder.