I'm glad all of you are having success with my tester. If any of you are facebook users, I have a facebook group set up to share your set up photos and tips on using the meter. Just search for "Phochron XA" in the search window. I am starting my next production run of these now, and I hope to market them through amazon and possibly through distribution. Mike C, I received an email from another user (Carl B of Canada) regarding his testing of a Hasselblad :
"Last night I tested a 150mm hasselblad lens using your tester. The end result it worked perfectly. I actually tested two 150mm lens to see the variation and to see if they were close to one another. Here is how I completed the process.
150mm lens attached to the hasselblad body. Set the aperture to widest, as in my lens it was F4. Remove the film back. Set up the tester to be aligned to the front of the lens. Note, the light that comes with the sensor is not strong enough, so I used a pocket sized led flash light. Place the flashlight behind the rear baffle/blind about one inch distance from the baffle. Do not touch the baffle as they are easily damaged.Cock the camera, set the shutter speed, flash light on, release the shutter. You will see a nice square wave form on the tester screen.
VERY IMPORTANT. WHEN TESTING THE SLOWER SHUTTER SPEEDS, IT IS VERY IMPORTANT NOT TO RELEASE THE SHUTTER BUTTON TOO EARLY AS THE BLIND CAN CLOSE BEFORE THE SHUTTER HAS COMPLETED ITS TIMER. THIS IS WHAT HAPPENED TO ME DURING THE HALF SECOND SHUTTER SPEED TEST. I RELEASED THE SHUTTER BUTTON EARLY.ENSURE YOU DO NOT RELEASE THE SHUTTER BUTTON TOO EARLY ON THE SLOW SPEED SETTING AND YOU WILL GET ACCURATE MEASUREMENTS.
The test results were very consistent and repeatable for each shutter speed."
Note that he tested the Hassy with the light source in the rear. What ever you do, never put anything into the body. The blind can come down and be damaged.
Thanks again for your support, all of my feedback so far has been positive, except for some feedback on the US postal service!