The best way to asnwer this is probably to refere to the Zonse System: http://www.luminous-landscape.com/tutorials/zone_system.shtml which is opreatin with 9 zones. Zone 1 is totally black, Zone 5 is 18% grey and zone 9 is pure white. So, if your neg/image has all 9 zones, pure white will be about 4 stops brighter than the average grey. Normally we don't really want pure white (burned out highlights) in the picture. Not large areas anyway. This makes practically white 3 stops brighter than the average grey.
I would expect 2-3 stops "overexposure" as compensating for a measurement in snow a bit above the necarary adjustment. I'd go for +1 - + 1?. This goes for the white flower as well, but normally the flower image will not be totally shadowless, thus not pure withe. I'd say 1 stop would be enough. Measuring back lit scenes is actually quite easy. Turn arround and measure the scenery in ordenary light. Turn back and use the mentioned measuremnet for the shot. Regards Jens -----Oprindelig meddelelse----- Fra: Kostas Kavoussanakis [mailto:[EMAIL PROTECTED] Sendt: 5. august 2005 11:53 Til: [email protected] Emne: Qs about metering - The rule of thumb says that, in order to get a very snowy picture to look white, you add +2 to whatever the (say, CW) meter says. Will the +2 correction work with a white flower on a macro (ie mostly white) shot? - How many stops between 18% gray and pure white? Is it 2, as per the rule of thumb? - Assume a backlit (setting sun, still white light) white flower. How do you meter that sod? The palm method does not work, I don't think, because the white flower-petals are translucent but the palm isn't. If you get the palm to face the source of light, one's metering device/own body shadows it. Or can you take an accurate enough reading even if spot metering the palm from an angle? Thanks, Kostas
