----- Original Message ----- From: Sid Barras <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, June 22, 2002 9:13 AM Subject: Any optical engineers w/zone VI spot meters know this?
Hi Sid; Sorry to take so long to respond. I aimed my Zone VI modified Pentax Digital Spotmeter, and chose a neutral gray area (the street in front of my house). I metered it with no filter, and with a #87 IR cut filter. I got a 7 stop drop with my meter. Is is possible you are getting light leakage around your filter? Also, it is entirely possible that you don't have a modified meter. Does your meter have the "Modified by ZoneVI Studios" plaque cemented to it or does it just have the zone sticker on the dial? William Robb > Hi all, > > I've been attempting to establish an accurate exposure index for Kodak > HIE by using my Zone VI spot meter with an 89b opaque filter in front > of the lens. I establish a "zone 'V'ish location in the scene to be > photographed, like a patch of green grass, and I take a spot reading > with and without the 89b filter. > > Strangely enough, the readings only drop about one stop when I read the > same scene with the filter. This violates all my known (allbeit limited) > sensibilities about what should happen. > > If this filter is blocking everything below around 720nmm, and this > filter is altered for zone system use by limiting everything above and > below (approxmately) visual range, the reading I get should fall > tremendously. > > Obviously the meter does not trap every range above and below visual > light; so what is happening here? Is it an important consideration? My > goal is not to understand quantum physics, simply have a more accurate > way of establishing exposure for a film that defies, or seems to defie, > indexing. - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
