Mike in NY
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I recently ordered the DLG Temperature-Compensating Development Timer. I formerly had a Zone VI compensating timer, but sold it when I moved into a home where I had a climate controlled darkroom. I moved again a few years ago and my current basement darkroom is subject to seasonal temperature fluctuations, so I ordered the DLG unit.
When the timer arrived a couple of weeks ago, my first impression from a hands-on visual inspection was very good. The packaging immediately reminded me of Apple's, with foam fitting compartments inside an attractive fold-down box with a finished surface. As for the look and feel, the control unit feels sturdy, and the metal foot petal feels solid. The owner's manual discusses theory and principals of operation; temperature coefficients and compensation curves; operating instructions, and other information.
I finally got around to testing it this past weekend, and it performed extremely well. As noted in the user’s manual, the timer compensates for a temperature co-efficient of 2.5, which is equivalent to using Ilford’s time-temperature chart that can be read on page 4 here: https://www.ilfordphoto.com/amfile/f...9/product/708/
I ran four tests as follows:
Test #1
I placed both my Weston thermometer and the timer’s stainless steel probe into 1 liter of stirred water. My thermometer read 64.5 degrees F, which matched the 18 degrees C reading from the timer’s probe (the timer shows whole C degrees with no decimal places). I checked the Ilford chart and determined that a 2:00 minute development time at a “normal” temperature of 20 (C) should take about 2:30 at 18 (C). So I activated my stopwatch and the timer at the same time. When the timer read 2:00, the stopwatch read 2:29 – right where I expected it to be.
Test #2
I let both the stopwatch and the timer continue to run from the first test. I knew from the Ilford chart that when the timer got to 5:00, the stopwatch should read close to 6:00. Sure enough, it read 5:58. The temperature did not significantly change during this time.
Test #3
I prepared another liter of warmer water. My Weston thermometer read just over 75 (F), which matched the timer’s temp of 24 (C). I activated both the stopwatch and the timer at the same time. I knew from the Ilford chart that when the timer reached 3:00 the stopwatch should read just over 2:00. Sure enough, it read 2:05.
Test #4
I let both the stopwatch and the timer continue to run from Test #3. I knew from the Ilford chart that when the timer got to 10:00, the stopwatch should read just under 7:00. It read 7:03, but then I checked the temperature and saw that it had cooled about a third of a degree F, which explains the additional time that the timer “knew” was needed.
I’m glad I have a new compensating timer to replace the Zone VI model I sold years. This will make development a lot easier.
When the timer arrived a couple of weeks ago, my first impression from a hands-on visual inspection was very good. The packaging immediately reminded me of Apple's, with foam fitting compartments inside an attractive fold-down box with a finished surface. As for the look and feel, the control unit feels sturdy, and the metal foot petal feels solid. The owner's manual discusses theory and principals of operation; temperature coefficients and compensation curves; operating instructions, and other information.
I finally got around to testing it this past weekend, and it performed extremely well. As noted in the user’s manual, the timer compensates for a temperature co-efficient of 2.5, which is equivalent to using Ilford’s time-temperature chart that can be read on page 4 here: https://www.ilfordphoto.com/amfile/f...9/product/708/
I ran four tests as follows:
Test #1
I placed both my Weston thermometer and the timer’s stainless steel probe into 1 liter of stirred water. My thermometer read 64.5 degrees F, which matched the 18 degrees C reading from the timer’s probe (the timer shows whole C degrees with no decimal places). I checked the Ilford chart and determined that a 2:00 minute development time at a “normal” temperature of 20 (C) should take about 2:30 at 18 (C). So I activated my stopwatch and the timer at the same time. When the timer read 2:00, the stopwatch read 2:29 – right where I expected it to be.
Test #2
I let both the stopwatch and the timer continue to run from the first test. I knew from the Ilford chart that when the timer got to 5:00, the stopwatch should read close to 6:00. Sure enough, it read 5:58. The temperature did not significantly change during this time.
Test #3
I prepared another liter of warmer water. My Weston thermometer read just over 75 (F), which matched the timer’s temp of 24 (C). I activated both the stopwatch and the timer at the same time. I knew from the Ilford chart that when the timer reached 3:00 the stopwatch should read just over 2:00. Sure enough, it read 2:05.
Test #4
I let both the stopwatch and the timer continue to run from Test #3. I knew from the Ilford chart that when the timer got to 10:00, the stopwatch should read just under 7:00. It read 7:03, but then I checked the temperature and saw that it had cooled about a third of a degree F, which explains the additional time that the timer “knew” was needed.
I’m glad I have a new compensating timer to replace the Zone VI model I sold years. This will make development a lot easier.
