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#1 L K Keerthi Basu

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Posted 18 September 2005 - 10:30 AM

dear friends,

Can you please provide me any web link to learn about the working principle and the operating technique of SPOT METERs.


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#2 Lars.Erik

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Posted 18 September 2005 - 01:46 PM

Try this one:

http://www.sekonic.c...tVsReflect.html

and you might want to buy this book. It's been a great friend of mine anyway

http://www.theasc.co...atalogno=401930
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#3 oscar jimenez

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Posted 19 September 2005 - 11:55 AM

Some good reading to get you started:
"The negative" by Ansel Adams. Once you learn the Zone System, you'll be very much in touch with your spot meter, actually beetween incident and Reflected, the last one is my fav. After this book ( related to B&W photo ) should refer to other literature focused on Color Zone System, for color reflectances have their own natural "placements" in the zone system.
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#4 L K Keerthi Basu

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Posted 21 September 2005 - 11:49 AM

Some good reading to get you started:
"The negative" by Ansel Adams. Once you learn the Zone System, you'll be very much in touch with your spot meter, actually beetween incident and Reflected, the last one is my fav.  After this book ( related to B&W photo ) should refer to other literature focused on Color Zone System, for color reflectances have their own natural "placements" in the zone system.

<{POST_SNAPBACK}>


Thank you,

As you said about I read Adams "The Negative","The Print" and "The Camera" they were really precious books to the cinematographers and photographers. Actually Iam Collecting Notes and information on the Internal Parts , Mechanism and the Working Principle of Spot meters in digital also.
Please helpme in knowing this information in weblinks or guide me with some referrance in books, If you include Color temperature meters also I will be really grateful to you.

L.K.Keerthibasu
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#5 Fran Kuhn

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Posted 25 October 2005 - 08:00 PM

Iam Collecting Notes and information on the Internal Parts , Mechanism and the Working Principle of Spot meters in digital also.
Please helpme in knowing this information in weblinks or guide me with some referrance in books, If you include Color temperature meters also I will be really grateful to you.

L.K.Keerthibasu


Actually, this may be of some help. At the very least, it's some pretty interesting and sometimes scary info about spot meters. Don't know if it applies to today's latest-and-greatest, but here goes.

Back in my still photo days, I subscribed to this thing called the Zone VI Newsletter put out by a grouchy-but-loveable old-timer named Fred Picker. Fred was one of these you-can't-get-there-from-here types up in Vermont. Though he was not the world's best photographer, he was ultimately a lovely guy who was always coming up with some nifty new ideas and equipment to help people with their photography, particularly in the realm of large-format black-and-white. At some point he managed to cross paths with a fellow photo enthusiast named Paul Horowitz, who just so happened to work at the Lyman Physics Laboratory at Harvard University.

Fred and Dr. Horowitz became good friends and conspired on several equipment-related projects. They quickly concluded that the existing light meters--particularly spot meters--were lousy at, well, metering light. Some of the things Dr. Horowitz testing revealed were pretty unsettling, but basically the meters were utterly non-linear in their response and often inaccurate because the designers had failed to take into account things like the meter's internal lens flare, manufacturing inaccuracies causing non-alignment of the spot in relation to the actual area metered, and metering inaccuracies created by ultra-violet and infrared light reflectance. (Green leaves would often meter at a value four or five stops higher than they would record on film because the chlorophyll in foliage was reflecting 100-percent of the infrared. The meter would "see" the infrared, but panchromatic films didn't respond to it at all. As a result leaves metered at Zone IV (gray) ended up recording at Zone I (really, really dark) on film.

Picker and Horowitz collaborated on a modification of the then state-of-the-art Seconic Digital spot meter which included adding an internal flare baffle and installing some kind of very high priced NASA-developed ultra-violet/infrared cut-off filter material. They ended up with a meter that met the following criteria: resistant to internal flare; accurately meters ultra-violet and infrared; accurate regardless of light intensity and subject color; accurately compensates for on-camera filtration; accurate under all temperature conditions, and here's the kicker: accurately meters in exact relation to the spectral response of the film. In other words, if you point it at something and it tells you it's Zone II, it will be Zone II when the film comes out of the fixer. Not Zone II 1/2. Or Zone I 3/4.

Now, that last criterion is also the big problem with this meter because it required the Zone VI guys settle on one type of film to tie the meter's spectral response to. That film is good-old Tri-X. Not a problem if you shoot Tri-X, as many of the large-format shooters did back then. But as great as it is, it's not exactly a top-seller over at the Kodak Motion Picture Division today. (By the way, that modified meter really works as advertised. I have one and still use it when I feel like breaking out the old 8 x 10.)

Anyway, a description of the Zone VI Meter project is in the Zone VI Newsletter Number 37, November 1983. I believe the Newsletter copyright was acquired by Calumet Photographic of Chicago, IL when the purchased the company from Picker in the mid-1990s. It may be possible to get a copy from them to help you with your project. Or better yet, maybe Dr. Horowitz is still around up there at Harvard.

Hope this helps.
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#6 L K Keerthi Basu

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Posted 26 October 2005 - 10:54 AM

Thank you FKP-1.

That really helps me.


L.K.Keerthibasu
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Tai Audio

Visual Products

Broadcast Solutions Inc

CineTape

The Slider

Wooden Camera

Abel Cine

Technodolly

Ritter Battery

Rig Wheels Passport

CineLab

Aerial Filmworks

Glidecam

Gamma Ray Digital Inc

Metropolis Post

Media Blackout - Custom Cables and AKS

rebotnix Technologies

FJS International, LLC

Paralinx LLC