lightmetering off the glass

[Lot Wouda]

I read an answer from David Nash on a question concerning light meters. He advis ed light metering off the ground glass, thus automatically compensating for belo ws extension, made possible by a Booster extension on a Minolta meter. I would l ike to know more of this. What is this booster? Do you make any preset adaptatio ns on your meter? Do you have to compensate for the brightness (opacity) of the ground glass? How do you test this, if so? Can it be done with a Gossen Variosix F (without lumisphere and without spot-adapter)? Thanks in advance for your rea ctions.

[Sean Billy Bob Boy yates]

Various companies make adapters for ground glass readings. Gossen makes a probe that attaches to the LunaPro SBC or the Luna Pro F, Horesman makes a cassette that slides into the back like a film holder and of course SINAR makes the SINAR-6 an adaptation of a Gossen meter that uses a cassette ala the Horesman. You can check out the various manufacturers web pages and write or call them for info.

I suppose they work well, but In the 3 studios I worked in no one used one, let alone owned one. I once saw some students from Columbia College in Chicago shooting a Frank Lloyd Wright house with an 8 X 10. They were using the Gossen probe, I think, metering off the glass, and intending to shoot Polaroid. Since they were worried about the expense of the 'roids, they were metering, metering metering metering.....you get the picture. Granted, they were students, I didn't ask 'em how long they'd been going to school, etc., but a simple incident reading in the shadow and in the bright areas or a spot reading of same would've gotten 'em close faster and with less a lot less hassle.

[Sean Billy Bob Boy yates]

Sorry, had to make way on the keyboard for my spouse, but, call B&H (1-00-947-6650) weighty tome, "The Professional Photo Source Book". It includes descriptions of the various systems.

The Horseman seems sort of like turning your 4 X 5 into an S.L.R. metering wise, it averages the entire frame. The SINAR & Minolta systems allow pinpoint readings of different areas within the composition. Apparently the SINAR-6 is no longer available, now it's the Broncolor FCM 2 No published price in B&H. The Minolta booster srp's at $240.00 (+/-) Gossens' system, the Profi select TTL is mentioned, but I couldn't find a description. Again, seems like a lot of work and expense to me when, with practice you can get what you need with a Pentax Spotmeter or equiv.