Archived posting to the Leica Users Group, 2003/06/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Simon, No one else has jumped in on this so let me try a least a comparative method. You will need something with a stable and measurable light output. Perhaps a slide viewer if your electrical supply is stable. You will also need a light meter that reads incident light. My proposal would be to measure the raw light coming off your light source through the diffusion cone of your meter. Then measure the light coming from the lens through the diffusion cone. I would do these at all marked stops and chart it in say EV. If you did this for several lenses you would have some idea of relative output. Don dorysrus@mindspring.com - -----Original Message----- From: owner-leica-users@mejac.palo-alto.ca.us [mailto:owner-leica-users@mejac.palo-alto.ca.us] On Behalf Of animal Sent: Friday, June 27, 2003 3:01 PM To: leica-users@mejac.palo-alto.ca.us Subject: [Leica] lens testing question Hi,i,m looking for a way to accurately measure the true speed of an old lens.Any suggestions? Thanks,simon jessurun - -- 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