Archived posting to the Leica Users Group, 2025/08/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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