Archived posting to the Leica Users Group, 2025/08/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Martin, of course you are right and there are differences at the margins. However if I shoot film, digital and Sunny 16 at a given presumed ISO/ASA, then the standards imply though there is some margin for error, that the resulting exposures should be very similar if not match. This is at root why I was asking because all three should yield pretty similar results. The least reliable is likely to be Sunny 16 given that what constitutes what scenario is pretty subjective. I would have thought (?), Peter On 11/08/2025 14:49, Marty Deveney via LUG wrote: > The digital photography ISO speed is described in ISO standard 12232. The > relationship between light incoming and speed is largely arbitrary for > digital sensors. For film, the ISO standard is ISO 5800:2001 for colour > negative film, ISO 6:1993 for black and white negative film and ISO > 2240:2003 for colour reversal film. The standards for film are > chemico-physically defined as a given amount of illuminance range, combined > with a given exposure and a given development gives a defined negative or > positive output. The largely arbitrary standard for digital means that > even when the light is the same how the meters describe the light in terms > of time and aperture is different. > > On Mon, Aug 11, 2025 at 10:52?PM Adam Bridge via LUG <lug at > leica-users.org> > wrote: > >> I have no idea how film and digtal light meters should be different. >> >> Is there a reason for this? Light that lands on the sensor, to my aged >> brain, seems to be the same where it?s landing on film or on silicon. >> >> Adam Bridge >> >> >>> On Aug 11, 2025, at 2:11?PM, Marty Deveney via LUG <lug at >>> leica-users.org> >> wrote: >>> >>> Peter, the ISO standards for film and for digital light meters are >>> different. The two meters also measure light very differently. Have you >>> compared it to a film camera or a hand held meter? Or tried using it to >>> shoot film? >>> >>> I have not tried the TTA meter but use a Keks KMQ meter >>> https://www.kekscameras.com/store/p14/KEKSKMQLightmeter.html#/ and it >> works >>> really well. >>> >>> Marty >>> >>> >>> >>> On Mon, Aug 11, 2025 at 9:40?PM Peter Dzwig <pdzwig at summaventures.com> >>> wrote: >>> >>>> Thanks mark! You are the only person on the LUG saying they use one. Do >>>> you think it could be faulty? >>>> >>>> Peter >>>> >>>> On 09/08/2025 17:09, Mark Kronquist via LUG wrote: >>>>> I have and use several they are fine Mark in Oregon >>>>> >>>>>> On Aug 9, 2025, at 4:59 AM, Peter Dzwig <pdzwig at summaventures.com> >>>> wrote: >>>>>> >>>>>> All, >>>>>> >>>>>> thank you for all your replies. Fascinating. The one thing that they >>>> have in common is that it appears that no-one uses TTArtisan meters, >> which >>>> must say *something*. >>>>>> >>>>>> Peter >>>>>> >>>>>> On 07/08/2025 11:19, Peter Dzwig wrote: >>>>>>> Dear All, >>>>>>> Does anyone have any experience of these meters? I though that they >>>> had a good reputation, but see below... >>>>>>> I bought one (Series 2) because I wanted to test my M3 (my Weston Mk >> V >>>> has finally stopped working properly). I normally shoot "Sunny 16", but >>>> have been getting some odd results of late and wanted to understand if >> it >>>> was me, developing or what. >>>>>>> I was comparing what I would expect to get from Sunny 16 with my Fuji >>>> XE-2 and the LM. I tested in a variety of light levels and degrees of >> shade. >>>>>>> To my amazement the LM and the other exposures agreed on only one >>>> occasion, when I was pointing the LM and the XE-2 at a white wall in >> full >>>> Mediterranean sunlight (seriously f22)! Otherwise they were miles apart. >>>>>>> Both XE-2 and LM were set to 400ASA. When I shot the scenes with the >>>> XE-2 the images were, in general, fine. >>>>>>> Anyone any thoughts/explanations? Of course the XE-2 has a zoned >>>> meter, but still... >>>>>>> Thanks in advance >>>>>>> Peter >>>>>>> PS If anyone knows of someone in the UK who can replace the cell in a >>>> Weston V, please let me know >>>>>> >>>>>> -- >>>>>> Dr. Peter Dzwig >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Leica Users Group. >>>>>> See http://leica-users.org/mailman/listinfo/lug for more information >>>>> >>>>> >>>>> _______________________________________________ >>>>> Leica Users Group. >>>>> See http://leica-users.org/mailman/listinfo/lug for more information >>>> >>>> -- >>>> Dr. Peter Dzwig >>>> >>>> >>>> _______________________________________________ >>>> Leica Users Group. >>>> See http://leica-users.org/mailman/listinfo/lug for more information >>>> >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information -- Dr. Peter Dzwig