Archived posting to the Leica Users Group, 2006/12/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]And that slice of baloney? Eric Korenman wrote: > well - just like adding a tiny pinch of salt to your food. > The quantity may be minuscule but it can make all the difference. > > "add just a pinch more light, then scan" > > any decent modern camera can easily add that extra 1/3 of light. > > Eric > > > On 12/9/06, Walt Johnson <walt@waltjohnson.com> wrote: > >> >> Steve >> >> Might better ask if meters and shutters are accurate enough to make a >> difference. Don't know what kind of eye could readily spot 1/3 of a >> stop? >> >> Steve Barbour wrote: >> >> > >> > On Dec 8, 2006, at 4:32 PM, Eric Korenman wrote: >> > >> >> TCN does best at ISO 320. >> >> It gets way too thin at ISO 800. >> >> just 2 cents from shooting hundreds of rolls of the stuff. >> > >> > >> > >> > btw, is the latitude of this film so narrow/sensitive that shooting >> > at ISO 320 rather than 400 makes a visible difference? >> > >> > thanks, Steve >> > >> > >> >> >> >> Eric >> >> >> >> On 12/8/06, Walt Johnson <walt@waltjohnson.com> wrote: >> >> >> >>> >> >>> Steve >> >>> >> >>> It sounds as if you're going to underexpose by a stop. What >> result are >> >>> you looking for? >> >>> >> >>> Walt >> >>> >> >>> Steve Barbour wrote: >> >>> >> >>> > Walt and others... have you shot C41bw 400, at 800 with normal >> >>> > development? Results? >> >>> > >> >>> > I see this now as advantageous, have never done it, but I plan to >> >>> > try.... >> >>> > >> >>> > thankjs, Steve >> >>> > >> >>> > >> >>> > On Dec 8, 2006, at 6:41 AM, Walt Johnson wrote: >> >>> > >> >>> >> I think I'll start shooting all my Tri-X at 666 ISO. BTW >> has anyone >> >>> >> noticed the change (years ago) from ASA to ISO appears useless? >> >>> >> >> >>> >> Henning Wulff wrote: >> >>> >> >> >>> >>>> Doesn't it have something to do with logging rhythms. in .3 >> >>> >>>> increments? >> >>> >>>> >> >>> >>>> Henning Wulff wrote: >> >>> >>>> >> >>> >>>>> At 10:29 PM +0100 12/6/06, Philippe Orlent wrote: >> >>> >>>>> >> >>> >>>>>> I was just remembering my ISO scale on the back of my MP: >> >>> >>>>>> 50-100-200-400-800- etc. >> >>> >>>>>> >> >>> >>>>>> But the zones in between are divided in 3 parts. >> >>> >>>>>> >> >>> >>>>>> So between 50-100: 50/3=16,7 >> >>> >>>>>> Between: 100-200: 100/3=33,33, which would put 160 at 100 >> >>> and 2/3ds >> >>> >>>>>> Two full stops under brings us at >> >>> >>>>>> 400 and 2/3ds >> >>> >>>>>> Which is 400 + (800-400)x2/3= 666,7 >> >>> >>>>>> >> >>> >>>>>> I may be wrong, but it looks like Leica logics to me. >> >>> >>>>>> :-) >> >>> >>>>>> Philippe >> >>> >>>>>> >> >>> >>>>> >> >>> >>>>> ISO is not continuous. It's only defined for the discrete >> >>> >>>>> progression (from 100 to 3200) for 100, 125, 160, 200, >> 250, 320, >> >>> >>>>> 400, 500, 640, 800, 1000, 1250, 1600, 2000, 2500, 3200. >> >>> >>>>> >> >>> >>>>> No numbers in between, ie, there is not 'ISO 300' or 'ISO >> 666'. >> >>> >>>>> >> >>> >>> >> >>> >>> ISO combines the old ASA and DIN scales, and makes >> the measurement >> >>> >>> methods and ratings equivalent. DIN was logarithmic while ASA >> was >> >>> >>> arithmetic, with 400 ASA = 27DIN, 320 ASA = 26 DIN. For >> every step >> >>> >>> the ASA took an arithmetic step, and DIN took a logarithmic >> step. >> >>> >>> Different measurement methods meant that there wasn't a complete >> >>> >>> equivalency, but then they got together and came out with the >> ISO >> >>> >>> method and scaling, which allows for both an arithmetic and >> >>> >>> logarithmic scale. So now the old 400 ASA is approximately >> >>> ISO 400/27. >> >>> >>> >> >>> >>> Both systems jump in discrete, defined steps with intermediate >> >>> >>> values undefined. >> >>> >>> >> >>> >> >> >>> >> _______________________________________________ >> >>> >> 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 >> > >> > >> > >> > _______________________________________________ >> > 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 >