Welcome back to your exploration of efficient darkroom printing. In our last session, you successfully calibrated your Ilford EM10, establishing a precise link between a known-good print and a set of numbers on the meter's dial. You've essentially created a personalized reference system for your specific paper, chemistry, and contrast filters.
Today, we put that calibration to work. This lesson will show you how to use your calibrated EM10 to determine the correct base exposure for a completely new negative. This is the practical payoff for the meticulous work you did previously and the key to achieving your goal of moving beyond the time-consuming process of making test strips for every print.
The Logic of the Calibrated Meter
Before we walk through the steps, let's briefly revisit the principle at work. Your calibration established a target light intensity that, when exposed for your standard time, produces a perfect shadow with detail. Now, for any new negative, the goal is to adjust the light from the enlarger so that the key shadow area on the baseboard matches that exact target intensity.
The EM10, set to your calibration number, is the tool that tells you when you've hit that target. By adjusting the lens aperture, you are controlling the intensity. Once the green light is on, you have matched the calibrated intensity. Since the intensity, exposure time, and paper are all constant, the resulting density in that part of the print should be correct.
The Workflow: From New Negative to First Print
Let's walk through the process of making a print from a negative you haven't printed before.
Step 1: Setup and Assessment
Place your new negative in the enlarger carrier. Based on your assessment of the negative's density and contrast (as we covered in Module 2), choose a starting contrast filter—for example, a Grade 2. Set the enlarger to the desired print size and focus the image on the baseboard.
Step 2: Consult Your Calibration Data
Look at the calibration table you created in the last lesson. Find the row for your chosen paper and the Grade 2 filter. Note two values: the Calibration Number and the Standard Time.
Step 3: Program the Meter and Timer
Set the dial on your EM10 to the calibration number you just looked up. Then, set your enlarger's timer to the corresponding standard time from your table.
Step 4: Meter and Adjust
Now for the crucial step. In total darkness (no safelight), turn on the enlarger lamp.
- Place the EM10's probe on the brightest area of the projected image where you want to retain detail (this corresponds to the shadow area in the final print).
- Keeping the probe still, slowly adjust the enlarger's lens aperture ring. Do not touch the EM10 dial.
- Watch the LEDs on the meter. As you change the aperture, the light intensity on the probe changes. Stop adjusting the aperture at the precise point where the red LEDs go out and the green LED illuminates.
You have now set the correct exposure. The aperture is now configured to deliver your target light intensity.
Step 5: Expose and Process
Remove the EM10 from the baseboard, place a sheet of photographic paper in the easel, and make the exposure using your pre-set standard time. Process the print as you normally would.
The official Ilford instructions provide a concise summary of this exact procedure.
[PDF] EM10 Instructions - Ilford Photo
This section from the official manual describes the standard operating procedure for using the calibrated meter.
Please read the short section titled "3 Use". Notice how it confirms the workflow we just outlined: set the calibration number, place the meter, and adjust the lens aperture until the green light is on.
The result of this process should be a print with a base exposure that is very close to, if not exactly, correct. You have effectively bypassed the need for a traditional test strip.
A Practical Application: Changing Magnification
One of the most powerful uses for this workflow is maintaining consistent print density when you change the size of your print. When you raise the enlarger head to make a larger print, the light on the baseboard becomes less intense due to the inverse square law. Without a meter, you would have to create entirely new test strips. With the EM10, the process is trivial.
The following article provides an excellent, clear guide on this specific application.
Using The Ilford EM-10 Density Meter - Photo 35 mm Black&White
This article from Photo 35 mm Black&White offers a practical, real-world perspective on using the EM10, particularly for changing print sizes.
Read the passage that begins with an example of going from a 5x7 to a larger print. The key takeaway is that after making a successful small print, you calibrate the meter on that setup, then raise the head, and use the meter to find the new correct aperture, without changing the EM10 dial or the exposure time.
This procedure perfectly illustrates the core concept: the EM10 and your standard time are the constants. You simply adjust the variable—aperture—to match the light intensity to your calibrated standard, regardless of the magnification.
Refining the Process: What if the Contrast is Wrong?
Your first print made with the EM10 might have the correct density in the shadows but incorrect overall contrast. Perhaps the highlights are too gray, or they are completely blown out. This means your initial choice of contrast filter was wrong, but your exposure is correct. The workflow for fixing this is remarkably efficient.
Let's say your Grade 2 print was too flat. You decide you need more contrast and switch to a Grade 4 filter.
- Leave the enlarger height and focus untouched.
- Go back to your calibration table and find the calibration number for Grade 4.
- Set the EM10 dial to this new number.
- Place the probe on the exact same shadow area you metered before.
- Adjust the lens aperture again until the green light comes on. The aperture will likely be different because the Grade 4 filter has a different density.
- Expose a new sheet of paper for the same standard time as before.
As the Ilford manual notes, this systematic approach is essential for working with multigrade papers.
[PDF] EM10 Instructions - Ilford Photo
This section of the manual describes the specific workflow for adjusting contrast with variable contrast papers.
Read the paragraph in the "Helpful hints" section starting with "When making a print from a new negative". This confirms the procedure: if the grade is wrong, you simply remeasure using the calibration number for the corrected grade and repeat the process.
This iterative process of adjusting contrast while the EM10 maintains the correct base exposure is a cornerstone of an efficient and repeatable darkroom workflow.
Conclusion
You are now equipped with a powerful technique that directly addresses your goal of making refined prints more efficiently. By using your calibrated EM10, you can move from any negative to a well-exposed work print with minimal testing, freeing up time and resources to focus on the more artistic aspects of printing.
Key Takeaways:
- The calibrated EM10 is used to replicate a target light intensity for any new negative.
- The core workflow is: set the calibration number, place the probe on a key shadow, and adjust the lens aperture until the green LED is lit.
- The exposure time remains constant (your "standard time" from calibration).
- This method is extremely effective for maintaining consistent density when changing print magnification.
- If your initial contrast choice is incorrect, you can easily adjust it by changing the filter, setting the corresponding new calibration number on the EM10, and re-metering.
Next Lesson Preview:
Our method relies on metering a "key shadow." But what happens with negatives of unusual scenes? A high-key image (like a subject in the snow) has very few dark shadows, while a low-key image (a nighttime scene) might be composed almost entirely of them. In our next lesson, we will explore these scenarios and learn how to identify situations where EM10 readings require intelligent manual compensation to produce the desired result.