Meter Me This?
Who Can you Trust Nowadays?
(We know it’s definitely not your meter.)
Recently we’ve been running into the fact that (a majority of the time) the meter reading on set isn’t quite right, so today we decided to get to the bottom of things. We gathered all the meters we had in the office and put them to the test once and for all. To start, we brought out our Leaf Aptus 22, Phase P25 and Canon 5D (all shooting tethered to the same computer). The three meters we’re using are a Sekonic L-758DR, Sekonic L-508 and a Minolta Flash Meter IV.
Now for the pseudo-scientific method. We took all three meters and cameras into our “back office” (it’s really our outdoor storage space), took an ambient reading, and shot using said readings. Below are the results.
Our Minolta meter was reading f16.8 at 1/500th of a second. The Sekonic meters were reading f8.3 at 1/500th of a second. Below are photographs of all three meters, the first was shot using the Canon 5D and the Sekonic settings, the second shot with 5D and the Minolta settings. Trust us, this initial discrepancy is just a sign of things to come.
Meters, shot with Canon 5D, Sekonic exposure settings.
Meters, shot with Canon 5D, Sekonic exposure settings.
Now that we had our readings we pulled out the big guns. For the rest of the images we shot with the Leaf Aptus 22, Phase P25, and the Canon 5D using both meter readings. We shot all images into Adobe Lightroom, viewed the histograms, and adjusted the exposure to our best possible image integrity. Here are the results…
Canon with Minolta exposure settings
Canon with Minolta exposure settings plus 4 stops.
Canon with Sekonic exposure settings.
Canon with Sekonic exposure settings plus one and a half stops.
Leaf with Minolta exposure settings.
Leaf with Minolta exposure settings plus 4 stops.
Leaf with Sekonic exposure settings.
Leaf with Sekonic exposure settings plus one and a half stops.
Phase with Minolta exposure settings.
Phase with Minolta exposure settings plus 4 stops.
Phase with Sekonic exposure settings.
Phase with Sekonic exposure settings plus one and a half stops.
Phase with Sekonic exposure settings plus two and a half stops.
Our conclusion… It seems as if the Minolta meter was just wrong and makes it a bit of a moot point so we’ll concentrate on the Sekonic reading and images. The Canon 5D seems to give an optimal exposure when over exposed by 1.5 stops, the same holds true for the Leaf back. The funny thing is that the Phase back seems to be a whole stop darker than the Canon and Leaf. This means that for our reading of f8 at 1/500th we would need to actually expose and f4 if we wanted to keep our shutter fast and still receive as much file information as possible. This especially creates a problem when depth of field is needed yet fast shutter speeds are also desired. Sure, we could go up in ASA but imagine if your 400 speed film needed to be rated at 64 to give you an optimal exposure. You’d probably be a little bit angry wouldn’t you?
A lot of you will probably bitch about how we should have calibrated the meters for the test. To those people I ask, when was the last time you calibrated your own meters? This test was more of a real world test (like most of our tests) where we took a random sampling of available meters from a rental house, one of our personal meters and a loaner test meter right out of the box.
This test helped clear up why so many lighting assistants look at us like we are insane as we keep asking for more light for the proper exposure.
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4 Responses to “Meter Me This?”
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August 24th, 2007 at 2:05 am
[...] This made us start looking at the metering process as a whole which lead us to an impromptu metering test. See Frank’s article Meter Me This. It also prompted me to create this new exposure category for our blog and get off my ass and publish some articles. [...]
August 24th, 2007 at 6:12 pm
I recently did a similar test and found similar results. If you really wont to mess with your head try out the same test with flash.
November 5th, 2007 at 12:59 am
Call me a stickler, but it’s a moot point, not a mute point. And to prove my ultima-high nerd quotient, here’s a link: http://en.wikipedia.org/wiki/Mootness
March 7th, 2008 at 6:29 pm
use a meter as a ballpark tool for strobes. never trust it .dont use them on location at all . all i need is my hand . i trust histo’s