4. Quick Start
If you want to make a print right now and read the details later, this page will get you there. Every step referenced here is covered in more depth in the sections that follow. For a video walkthrough of assembly and installation, see https://www.youtube.com/watch?v=d-F-m982txo.
1. Connect the ΔStop
Plug both the relay unit and the delta ΔStop into a grounded wall outlet. Connect the relay unit to the ΔStop in the port labeled Enlarger using the supplied cable. Plug your enlarger into the relay unit in one of the two Normally Off outlets. The time display will light up when power is connected.
2. Focus Your Enlarger
Turn the Mode selector to Focus. The enlarger lamp will stay on continuously so you can compose and focus your image. Turn the Mode selector away from Focus when you're done, and the lamp will turn off.
3. Make the First Test Strip
Turn the Mode selector to Test. Set the Base Time dial to 30 seconds (a forgiving default for most negatives at f/8 or f/11; adjust for thin or dense negatives as you gain experience). Set the Test Interval dial to 1/2 stop. Place your paper and test strip mask on the easel, then press Start. After the first exposure of the whole paper, cover 1/7th of the paper and press start again. Repeat this until you've reached the last 1/7th of the paper.
4. Refine with a Second Test Strip
Develop the first strip and evaluate it under white light. Pick the step that looks closest to the exposure you want. Turn the base time knob to reach that exposure. The Print Stop lights will illuminate to show you which test strip step the new base time falls within. That step becomes the base for a second, finer test strip: set the Base Time to the time of the winning step, and turn the Test Interval dial down to 1/4 or 1/8 stop. Run the second strip the same way. This second pass brackets your best guess with precision, and the correct exposure almost always lands on this strip.
Most negatives are well-served by this two-strip workflow. Some printers prefer to stop at 1/4-stop refinement; others go to 1/8 for highly detailed prints or delicate tonal transitions. With practice you'll develop a feel for when a finer interval is worth the extra sheet of paper.
5. Choose Your Print Stop
Turn the Mode selector to Print. Evaluate the refined strip. Decide which step represents the exposure you want for the final print. Count how many intervals that step is above or below your base time and turn the Print Stop Select dial to match.
6. Make the Print
Place a fresh sheet of paper on the easel. Press Start. The ΔStop will expose the paper for the calculated time based on your base time and Print Stop selection.
That is the full workflow. One focus pass, two test strips, one final print.
If you already print with f-stop timing, the ΔStop should feel familiar within a few sessions. If you are new to f-stop printing, Section 7 explains why this workflow produces more consistent results than linear-second timing, and Section 8 walks through each operating mode in detail. A video demonstration of the ΔStop in use is available at https://www.youtube.com/watch?v=eNQ6Frt7SIs.