Archived posting to the Leica Users Group, 2004/03/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Charts, Smarts - go USE the cameras...If you end up liking the film results, use film. If you like the digital results, use digital...And btw, a "test" where you're not using the same lenses...in fact one of you is using a fabulously good prime and the other is using a zoom? LOL!! :-) - -----Original Message----- From: owner-leica-users@mejac.palo-alto.ca.us [mailto:owner-leica-users@mejac.palo-alto.ca.us] On Behalf Of Félix López de Maturana Sent: Monday, March 08, 2004 4:34 PM To: leica-users@mejac.palo-alto.ca.us Subject: [Leica] Re: Crude Film/Digital test, Leica/Canon >A friend bought a 10D and brought it over for a test drive. I >downloaded a test chart and we had at it. We posted two test charts >about 2 meters apart. I put a 50 Summicron lens on my R8 and he used a >zoom with a top range of 35 on his 10D (I am not sure what zoom it >was). That gave approximately the same coverage. We backed up so one >chart was dead center and the other one at the edge of the frame. Took >a shot at f-8. I was using Velvia and he saved his in the highest >quality jpeg, one step below Raw. He used manual focus as did I. We >both used tripods and mirror lock-up. We really wanted to do this >outside, but it was raining and windy. >Couldn't wait as he was leaving the next day for two weeks vacation. >Here are the results of the target at the center of the frame. We shot >at f-4, 5.6 and 8. I used the f-8 version because I thought it would >compensate for >any focus problem a bit more than the rest. The light in the hallway >was quite dim and the exposures at f-8 are about 2 seconds for me and >about 1 second for him (ISO 50 vs 100) Aram I did some tests in the past comparing different lenses. Main problem is, always, to get the chart you are photographying exactly paralel at the film-or sensor- and this is achieved by using a bubble level and using a completely flat table and attaching the chart there. Secondly you need placing your camera so that the optical axis hits exactly the center of the chart. Otherwise the corners will have softness not due to the camera but to the lack of right centering. You need use the bubble level for leveling the camera and you need, too, be carefully lifting the camera in his tripod up to the exact place. It takes trully a lot of time. You need natural light if possible measured with a colormeter so that colors match and metering with incident light meter or bracketing but everytime you move the camera you need to check again the paralellism. Not an easy task. In the samples you showed us something went wrong with the 10D who, inferior to the Summicron, is not that bad. Do again. With these kind of tests some myths may collaps. Regards Felix - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html