Do a test with your cameras. Use an incident light meter to shoot a grayscale, a color swatch, and a tri-tone test target on ASA 400 slide film, setting the exposure 100% manually. Set the camera to meter and set the exposure automatically too. Then do the same thing with your digital camera, setting it to produce 'normal' or 'standard' JPEG output.
Differences on the incident light meter exposures will tell you how the ISO calibration differs. Differences on the camera metering tells you how the metering calibrations differ. The results should look the same on the incident meter exposures and will likely differ on the cameras' meter exposures. Most digital camera meters are calibrated to protect from highlight saturation by underexposure as digital sensors 'hard clip' at saturation. Film has a softer roll-off at the point of blocking up highlights, even slide film. Once you understand how the characteristics of your digital and film cameras' metering calibration differ, the rest should be mostly obvious. G On Fri, Mar 15, 2013 at 1:49 AM, Bipin Gupta <[email protected]> wrote: > I started off with 120 film rolls on TLRs to 35mm film on my trusted > Pentax K1000 SE and now to Pentax K20D & K-5 DSLRS. The fastest film I > used were 400 ASA back then, and were able to capture night scenes of > streets and motels with their colorful flashing neon lights pretty > bright and clear - camera hand held. > But with today's hi-tech DSLRs I need ISO 1200 to 1600 to capture the > same night scenes handheld. I agree I am an old fart now, but assuming > ASA = ISO (can I?), why this huge jump from 400 ASA to 1200 ISO in the > digital world for the same night scenes?? I am certain LEDs and neon > signs are brighter today then circa 1978 when I worked at GM Cleveland > and Hudson. > Can some kind PDMLer folks solve this mighty mystery for me? > With my humble Regards. > Bipin - from that far away enchanting land. -- Godfrey godfreydigiorgi.posterous.com -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
