Hi, I have just starting to use a new RH Designs StopClock Vario f-Stop enlarging timer and I am seriously missing something when it comes to making a test strip as per the accompanying instructions. I would really appreciate it if anyone out there that uses one of these timers or the StopClock Pro can read this thread and point out where I am either making an incorrect assumption or I am making a sequencing mistake.

I set the timer for 1/4 stop increment mode and the base time for the strip at 2.83 seconds (the closest time to 3 seconds that the timer would give me at the 1/4 stop setting) and pressed the test strip mode button. I then carried out a standard test strip as per the instructions: I pressed the Start key and gave the first exposure of 2.83 secs to the whole paper. I then covered about an inch of the paper and gave the next incremental exposure and so on. The exposures that the timer gave were 2.83 secs followed by 3.36, 4.0, 4.76, 5.66, etc. for a total of ten steps. I was then instructed to press Exit to end the sequence and process the strip. I developed and fixed in the usual manner and assessed the test strip.

The best exposure was at the fifth step, the 5.66 seconds. It was at this point I think that things fell apart. The instructions say you are to count the number of increments above the base time that represents the best exposure. In this case it was the fourth increment on the strip above base (5.66 secs). The instructions then said to push the Up key by the same number of increments that had been determined from the test strip, so in this case I pressed it four times. What this did visually was to move my base exposure of 2.83 secs that was already reading on the display, up to 5.66 secs. At this point I was instructed to focus and compose my working print then push Start to make the exposure.

If you have been following closely I think you know where this thread is going to go. I exposed my working print at the 5.66 seconds as I was instructed to do and guess what, the print didn't look like the fourth incremental test strip above base at all, it looked almost like my first incremental test strip above base, and why wouldn't it? That strip got the overall base exposure of 2.83 seconds plus the 3.36 seconds for the increment to make a total of 6.19 seconds. I had just exposed my working print at 5.66 seconds. No wonder they looked alike. The print was no where close to looking like the fourth increment above base. There in lay the problem. What am I not doing correctly? I assumed that when I was instructed to exit the test strip mode then push the Up key incrementally four times and then make the exposure, that some how, the built in computer would also add in the total exposure time that the fourth increment had actually received, namely: 1) the 2.83 seconds from the overall base exposure, plus 2) the 3.36 seconds from the second exposure, plus 3) the 4.0 seconds from the third exposure, plus 4) the 4.76 seconds from the fourth exposure, and finally 5) the 5.66 seconds from the fifth exposure. This didn't happen. instead I got a 5.66 second exposure period. Is my assumption about the timer incorrect?

If you do the math and add up the total exposure time that the fourth increment actually receives, it comes to 20.61 seconds. In other words, for my working print to look like the fourth increment above base, I needed to expose the paper for 20.61 seconds not 5.66.

I can understand that if the instructions had simply asked me to focus and compose my working print and then expose my print by putting the timer back into test strip mode, making sure I was still in 1/4 stop increment mode and leaving my base time set at 2.83 seconds and then pressing the start key 5 times in a row,(base plus 4 increments), then the print would have received an exposure time of 20.61 seconds and my print would have matched the fourth increment exactly. However, the instructions didn't say to do that. They definitely tell me to exit the test strip mode and they definitely tell me that to make the final exposure I only need to press the Up key to match the chosen increment and make the exposure. Doesn't work.

I have gone over these instructions several times and have had other people look at them as well and we have all come to the conclusion that I am, in fact, following the instructions exactly as printed, but I am not getting the result that I expected. Since I haven't been able to find any threads where this issue is addressed I can only assume that other people's timers are giving them the proper results and that I am doing something very wrong. How do I get the timer to give me the correct exposure, as determined from the test strip, by following the instructions as written in the guide book?

Thanks, Hedd-wyn