Archived posting to the Leica Users Group, 2008/03/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Peter, When Modern Photography tested the Zuiko 50 F1.4 lo these many years ago they determined that it was closer to a 1.7is lens than a 1.4 in actual transmission or T stop. Therefore when the experiment is run you will in fact find not much difference in exposure from a marked F2 to F1.4 as the lens does not transmit but 1/3 stop more light. On Tue, Mar 4, 2008 at 3:45 PM, Peter Klein <pklein@2alpha.net> wrote: > Richard: Would you do me a favor? Meter something once at a medium > aperture. Then take a series of equivalent manual exposures. Such as: > > 1/30, f/4 > 1/60, f/2.8 > 1/125,f/2 > 1/250,f/1.4 > > Are resulting images the same exposure, or is f/1.4 much darker? If you're > game, try the whole range of f-stops. Do things get out of whack again at > f/11 or f/16? > > I noticed that with my E-1 and a Zuiko 50/1.4, I got only about 1/3 stop > more light going from f/2 to f/1.4. So the 50/1.4 was really only a > 50/1.8 for practical purposes. This might have something to do with the > angle the light hits the sensor wells, and something gets cut off faster > than about f/2. > > There were actually two factors. Not only did the sensor respond > differently at extreme apertures, but metering was also off at both > large and small stops. So the effects of the two factors combined, making > things very confusing until I separted them. > > The result was the the OM lenses couldn't be relied upon without knowing a > compensation factor for wide open and closed down. All this behavior has > been reported by others (with the usual Internet flamefests over the > cause, and whether the reporter knows how to use his camera). > > I wonder if the E-3 is the same, or if it's more forgiving with > OM lenses. > > That said, if you have a OM Zuiko macro lens, try it with the E-3 and you > might just marvel at the image quality. My 50/3.5 OM Macro gave me image > quality on the E-1 like no other lens I tried. And the 100/2.8 makes a > nifty 200mm-equivalent telephoto. > > --Peter > > > Who says it can't be done? > > http://www.dragonsgate.net/pub/richard/PICS/_3031364.jpg > > http://www.dragonsgate.net/pub/richard/PICS/_3031365.jpg > > http://www.dragonsgate.net/pub/richard/PICS/_3031366.jpg > > > > The trusty 50/1.4 Zuiko at 1.4. The E-3 VF is definitely as good if > > not better than the OM-4 when it comes to manual focusing. > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > -- Don don.dory@gmail.com