Archived posting to the Leica Users Group, 1996/08/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Wolfgang, The point of my message is that what started as a simple battery test ended up showing substantial differences, more than one stop, between the five meters. As you well know, I work for NIST, which is the new name for what used to be the National Bureau of Standards. I am surprised that you do not fully appreciate what "Traceable to NBS" means. This note is still found on many pieces of test equipment, even though NIST has been in existence for more than seven years. (A discussion of this problem does not belong on this forum.) DIN, though, stands for Deutsche Invented Number. Just joking! I don't agree with you calling the M6 just a consumer product. I really think that its light meter system was designed by someone with great insight. This is why I want to do more testing. This is because I am curious, a healthy trait, I believe. When you were a kid, did you ever open a watch or try to get inside a television set to see how it works? Frankly, I am stunned by your comments. Best regards, Chris At 09:04 AM 8/8/96 -0400, you wrote: > >> Godfrey DiGiorgi <ramarren@apple.com> wrote ... ><snip> ... > >> It sounds to me that the M6 and Pentax are calibrated a stop down ... ><snip> ... > >> "C.M. Fortunko" <fortunko@boulder.nist.gov> wrote ... > >> Subject: Re: PX625 Alkaline Battery Tests: Observations and Questions ><snip> ... > >> I wrote the original message. I do not want people to draw conclusions like >> that yet.... > > Hi Group - > > I fail to see the importance of Chris' exhaustive tests > of all his camera equipment. > > As far as I can tell, my M6 is right on. Any errors in > exposure have been mine and mine alone. > > I note, however, that for some EV-values, I can adjust > the exposure within a 1/2 stop with no perceptible > difference in two LED's intensities - so I don't > understand the usefulness of this comparative testing > with the M6-meter. I think that you're trying to use > the M6 meter for something it was really NOT designed > for. It's just an indicator display and an approximate > one at that. > >> I don't understand the reasons for the differences. They may have been >> affected by the focal lengths used and the internal construction of the >> different meters. > > Maybe. But please remember. All these things you're > testing are consumer products and to keep them affordable, > they're designed to a different standard than scientific > or military products. None of the cameras or light meters > you're testing bear the label `Calibration traceable to > NBS' or conforming to a particular `DIN Standard'. > > -- Wolfgang > >|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| >| Wolfgang Sachse Phone: +1/607/255-5065 | >| Theoretical and Applied Mechanics E-mail: sachse@msc.cornell.edu | >| Cornell University FAX: +1/607/255-9179 | >| Ithaca, NY - 14853-1503 USA Department Secretary: 607/255-5062 | >| WWW Home Page http://www.msc.cornell.edu/~sachse | >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > >