Easy way to make single-location test-strips

[albada]

The big advantage of having every step in a test-strip cover the same area of your image is that you can place the most important parts of the image there and see how they look with all the exposure-times.

For example, every step above contains the foreground hill, trees and sky. But such a localized test-strip is hard to make because you must move the strip after each exposure and mask everything outside that exposure.
Here's an easy-to-make tool for creating such test-strips.

Start with a hanging file-folder. These are available in office-supply stores and online. Then cut it down like this.

Draw regularly spaced lines as shown above. I taped on a thin strip of white paper with lines so they would be easier to see in safelight. The diagonal sheet of paper is an example of a test-strip consisting of a 4x5 cut in half -- a size I often use when making 4x5 prints.

Hold the device on the easel with hobby magnets as shown above. If your easel lacks a steel surface, make the bottom larger so you can hold it down with weights instead of magnets.

After an exposure, raise the left flap, slide the paper to the right to the next line, and lower the flap.

Ralph Lambrecht, on pages 472-476 of his excellent book, Way Beyond Monochrome (2nd ed) tells us how to make a test-strip printer out of .25-inch-thick plastic sheets that are hinged. My printer above is a simplified version of his device.

I made it large enough to handle a 4x5 test-strip (from an 8x10 cut in quarters). I have found that 4 inches is usually enough to cover the important items in an 8x10.

Mark Overton

 

[Andrew O'Neill]

Clever!

 

[nadav]

Great idea. I can’t believe I never though to use magnets on the easel before.

 

[RalphLambrecht]

Yeah, thought of that

 

[ic-racer]

I like to get the print correct to either 1/4 stop or 1/3 stop. To do that I use this little test strip frame. I lets me put the test strip in the same location each time. It never made any sense to me to make random exposures on a full sheet of paper because there is no way to know what the next exposure in the sequence will be without processing and drying the first strip, and so on.

 

[Luckless]

Still working through my basics of darkroom processing, but I really like how slick and handy simple jigs like this can be. Having options for how and where you pull test info from is a good thing after all, and not every image is going to demand the exact same testing.

I have a jig I made up that does similar, but with two core changes. [Beyond using weighted objects to hold things down, but I'm liking the magnet option enough to consider finding a sheet of steel to lap as a base plate]

1. I cut the flaps such that they will leave an unexposed full white band on the top edge of each test slice [near the flap hinge], and allow me to burn the bottom edge completely black. This gives me two clear data points to compare to.

2. I use a long carrier sheet to hold the test strip, which is just a strip the same width as my test strip, but long enough to stick out the end of the jig. A small bit folds over the far end of the test strip so that I can pull the strip along without having to flip the whole cover open to adjust the position.

Lift the pressure block off, slide to next mark on the carrier sheet, drop block and hit the light for the next interval.

My first version was made of random scrap cardboard, but would leave some random drag marks on my test strips. Remade it with smooth finished heavy cardstock, and the drag marks went away.

 

[pentaxuser]

Yeah, thought of that

And a really excellent piece of equipment it is Ralph I had mine laser-cut out of black and white plastic and use your f stop table for times

Thanks

pentaxuser

 

[Sirius Glass]

The big advantage of having every step in a test-strip cover the same area of your image is that you can place the most important parts of the image there and see how they look with all the exposure-times.

For example, every step above contains the foreground hill, trees and sky. But such a localized test-strip is hard to make because you must move the strip after each exposure and mask everything outside that exposure.
Here's an easy-to-make tool for creating such test-strips.

Start with a hanging file-folder. These are available in office-supply stores and online. Then cut it down like this.

Draw regularly spaced lines as shown above. I taped on a thin strip of white paper with lines so they would be easier to see in safelight. The diagonal sheet of paper is an example of a test-strip consisting of a 4x5 cut in half -- a size I often use when making 4x5 prints.

Hold the device on the easel with hobby magnets as shown above. If your easel lacks a steel surface, make the bottom larger so you can hold it down with weights instead of magnets.

After an exposure, raise the left flap, slide the paper to the right to the next line, and lower the flap.

Ralph Lambrecht, on pages 472-476 of his excellent book, Way Beyond Monochrome (2nd ed) tells us how to make a test-strip printer out of .25-inch-thick plastic sheets that are hinged. My printer above is a simplified version of his device.

I made it large enough to handle a 4x5 test-strip (from an 8x10 cut in quarters). I have found that 4 inches is usually enough to cover the important items in an 8x10.

Mark Overton

Yeah, thought of that

I like to get the print correct to either 1/4 stop or 1/3 stop. To do that I use this little test strip frame. I lets me put the test strip in the same location each time. It never made any sense to me to make random exposures on a full sheet of paper because there is no way to know what the next exposure in the sequence will be without processing and drying the first strip, and so on.

View attachment 262779
View attachment 262785
View attachment 262786

All great ideas. Thank you.

 

[albada]

Yeah, thought of that

Ralph, I don't know whether you noticed, but I copied your idea and gave you credit for it in the original posting by writing this:

Ralph Lambrecht, on pages 472-476 of his excellent book, Way Beyond Monochrome (2nd ed) tells us how to make a test-strip printer out of .25-inch-thick plastic sheets that are hinged. My printer above is a simplified version of his device.

Mark Overton

 

[albada]

I like to get the print correct to either 1/4 stop or 1/3 stop. To do that I use this little test strip frame.

Do you use your device by placing the strip on it such that it perfectly covers the black frame around its perimeter? If so, the purpose of the frame is to let you place each strip in exactly the same location. In essence, that would make it an easel-within-the-easel. Unless I misunderstood.
Mark Overton

 

[dkonigs]

A jig like this (or Ralph's original version) would certainly be useful. I've made my own test strip jig (via 3D printer) for normal test strips, because none of the existing ones can do the 7-patch spread my f-stop timer prefers (and I can't seem to line things up consistently by hand). However, I don't have anything that can do single-location test strips like this. Unfortunately, these jigs might not work so well for the 8x2" strips I normally prefer to make (or anything easy/efficient to cut from 8x10" paper), and I also wish there was a good solution to avoid hitting the edge of the easel as you move across such a strip.

 

[RalphLambrecht]

Ralph, I don't know whether you noticed, but I copied your idea and gave you credit for it in the original posting by writing this:

Mark Overton

thank You Mark.

 

[albada]

A jig like this (or Ralph's original version) would certainly be useful. I've made my own test strip jig (via 3D printer) for normal test strips, because none of the existing ones can do the 7-patch spread my f-stop timer prefers (and I can't seem to line things up consistently by hand). However, I don't have anything that can do single-location test strips like this. Unfortunately, these jigs might not work so well for the 8x2" strips I normally prefer to make (or anything easy/efficient to cut from 8x10" paper), and I also wish there was a good solution to avoid hitting the edge of the easel as you move across such a strip.

Here's a solution to both problems (the 8x2" strip, and hitting the edge): In my jig, the center slot is 4" long to accommodate a 4x5" strip. Modify it by cutting the slot to be only 2" long, leaving 2" covered near the hinge. Make the slot 1.25" wide. To use, make 4 exposures the usual way, which covers half the 4x5 sheet. Now rotate the strip 180 degrees, and make the remaining 3 exposures. You have one segment remaining which you can leave white, burn to black, or both (covering half of it), or anything else. The exposures on the 4x5 will be arranged like this:

1234
X765​

This device is compact, so you won't hit the sides of the easel as much, and each exposure is a bit larger than what you're getting now. The disadvantage is you get 4 strips per 8x10 instead of 5.
Mark Overton

 

[dkonigs]

Here's a solution to both problems (the 8x2" strip, and hitting the edge)

Thinking about this a little more, having a "flexible" jig can actually provide a big advantage here. When the jig is flexible, there's really no reason it needs to be rigid and flat anywhere but the center where its open to enlarger light. So if the magnets/frame are just in that area, it can flex up over the sides of the easel. The main catch is that you'd need to make sure its sealed light-tight closed on the edges, which would make it harder to open and move the paper. Maybe the solution to that is some sort of inner "carrier" piece you can move with some sort of rod that sticks out the side.

Or the easier solution is probably to just find a way to open the easel far enough that its not actually in the way at all.

 

[Laurent]

Nice idea! I have Ralph's book and delayed several times making his device. I finally printed this on the Prusa: https://www.thingiverse.com/thing:3145985

 

[ic-racer]

Do you use your device by placing the strip on it such that it perfectly covers the black frame around its perimeter? If so, the purpose of the frame is to let you place each strip in exactly the same location. In essence, that would make it an easel-within-the-easel. Unless I misunderstood.
Mark Overton

Yes, it is just a frame outline. My enlarger easels are essentially in the dark, little or no safelight falls on them, so the white with black border shows up so I know where to put the test strip each time. It is slightly weighted and has a foam rubber base so it does not either move around or damage the easel surface.

 

[ic-racer]

Many years ago I did make a device like the Op shows. To get a ballpark exposure for the main test print, I'd use a little piece of paper and do a small test exposure first. However, it turns out many times that would be pretty close and I could just make a second and third and so on little test exposure to zero in. I just started working that way and stopped using the device to make the big combined test print.

 

[dkonigs]

Nice idea! I have Ralph's book and delayed several times making his device. I finally printed this on the Prusa: https://www.thingiverse.com/thing:3145985

I keep contemplating printing that, but there's a good chance its not the right size for me. And since people who share 3D-printable stuff seem to be allergic to actually sharing the original CAD models, I'd probably have to re-create the design to get something in the dimensions I want.
(Also a bit worried that its thickness could cause issues, or that I'd have some trouble making the "handle" piece long enough without figuring out a way to print it in multiple pieces.)

 

[radiant]

One can build this "device" from a cardboard and few magnets.

I have used such thing (self built) for year now and it is really priceless tool. I couldn't live without! But I think the larger the better, don't waste paper area! I just designed new one for 5x7" paper (original was for postcard size), feel free to contact if you need the dimensions.

 

[Patrick Robert James]

Way back when I first started in the darkroom I had a test strip printer that pulled the paper through with a pin. IIRC it was small and plastic and commercial. Might have been made by Paterson, but that was almost 30 years ago so don't quote me on that. I don't know what I ever did with it.

 

[Laurent]

I keep contemplating printing that, but there's a good chance its not the right size for me. And since people who share 3D-printable stuff seem to be allergic to actually sharing the original CAD models, I'd probably have to re-create the design to get something in the dimensions I want.
(Also a bit worried that its thickness could cause issues, or that I'd have some trouble making the "handle" piece long enough without figuring out a way to print it in multiple pieces.)

I had to resize it a bit, as it was a bit too long for my printer ( 0.6 mm too much!) so that was easy using the slicer. I'm not the designer, so cannot offer the files, but I agree it's a pity things do not come with their sources.

In this design, the 9x12 version uses 1/4 of a 18x24 cm (7x9.5 inches) sheet, which is comfortable enough for me (I usually print small, 8x10 inches is my maximum print size).

It prints in two sessions, one for the main piece and on for the other ones (this is also because I wanted to print the top white so that I can see the print I'm making, and I did not care about having white top for the two other parts)

 

[Gelsilver]

I cover the piece of test paper with a 4"x8"x1/4" piece of glass to hold it in place. The desired location of the test paper is indicated by attaching two pieces of tape on the easel - I use black photo tape for this purpose, a color that's easy to see in my darkroom. So all I need is a piece of glass, adhesive tape and pieces of printing paper.

Hans

 

[AgX]

How do you get multiple single-location strips with this approach?
What is black photo tape?

 

[eddie]

Way back when I first started in the darkroom I had a test strip printer that pulled the paper through with a pin. IIRC it was small and plastic and commercial. Might have been made by Paterson, but that was almost 30 years ago so don't quote me on that. I don't know what I ever did with it.

I also remember a commercial version, but also don't remember the brand. Paterson popped into my head, but so did Spiratone.

 

[Gelsilver]

How do you get multiple single-location strips with this approach?
What is black photo tape?

You get pieces exposed all to the same image area. View them side by side and judge.

It's black masking tape. One can use any tape as long as it's easy to see (and easy to remove) on the enlarging easel. Two pieces about 1" length will do.