I'll laugh with you guys as I figure "perfect" accuracy is +/- half stop when you consider the potential for all the other compounded errors or subjective judgement calls when metering. Meter accuracy, meter color response, what to meter, meter flare, and on to lens flare, processing differences and on and on.......
I was just out with a friend and we were getting almost two stop differences in metering off of the same silver weathered wood at an old mine. We were both metering off of what looked like middle gray but the portion he chose had a bunch of thin dark weathered cracks and mine didn't. They looked the same to our eyes but not to the meter.
Sekonic claims 1/10 of an EV for the model I have. Well they claim
Originally Posted by Ed Sukach
"Repeatable accuracy ±0.1EV or less"
They also claim:
Calibration constant Reflected metering: K=12.5
OTOH Minolta claims:
Reflected light: K = 14
Repeatability ±0.1 stops
I thought 12% was the standard.
Occasionally, manufacturers speak with forked tongues.
Originally Posted by Robert
I wonder about the inclusion of the word "repeatablity" ... If one was to set a meter on a rigid support and measure a non-changing, evenly illuminated target, I have no doubt that the multiple readings could *repeat*, that is, one would get the *same* readings, all the time, within ~ 0.1 "EV". Not hard to do. Accuracy, where the reading you get conforms to the *true* value, is not the same thing. Accuracy is conformance to true values - "repeatablity" is properly known as "precision"- so "repeatablity accuracy" means -- I'm not quite sure.
This whole 12% - 18% reflectance bias is a pain in the butt, anyway... that all depends on the *assumption* of the meter manufacturer - whether the "average " scene reflects 12% or 18% of the light falling on it... and that is directly related to the reflectance of the objects in the scene.
One intersting "test" is to take a meter reading of an 18% gray card, and in the same light, take an incident meter reading and note the difference.
I wish someone would produce the *ultimate* meter - one with different, selectable, reflectance values ... like the metering system in the Olympus OM-4. One has the choice of 5%, 18% or 95% reflectance - and spot, averaging, and true Off-the-Film flash metering. That has been called the most sophisticated metering system they ever built a camera around.
Ed Sukach, FFP.
I found a reference to an Ansi standard # PH3.49-1971 that supposedly sets the standard to 12% +/- 2%. I tried checking the Ansi website but it seems you need to be a member to find anything.
I found this:
From David R. Spielman Brooks Institute of Photography
I think Sekonic did something about that in the L 608, they were griped so much and people generally called to cuss them so much that I think they incorporated a way to calibrate the meter to the owners taste. I might be wrong but I think it was one of the new features in the L 608.
Originally Posted by Ed Sukach
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I just got a Minolta Spot Meter F! Hopefully it will do me well for a number of years. Now I just have to get rid of my Auto Spot II....
We have a couple of those, no complaints. I really like the fact that it uses an AA battery to power it instead of anything fancy and hard to get.
Originally Posted by Silverpixels5
I have to say, at the price point, the Sekonic 508 is the best for me. That 608 is a bit steep.
Does anyone know if they have fixed the problems or did they just go to the 608?
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[FONT=Comic Sans MS]DaVinci never wrote an artist's statement...[/FONT]
I have a Pentax Spotmeter that uses a 9v battery, the kind you use in fire detectors, and some weird round cell. Does anyone know what powers what? I'm thinking there must be a way to convert the round cell to something more modern and easy to get.
I wish I could afford one of those pocket spot meters Aggie had at Barnbaums workshop.
My Auto Spot II uses a 9v and a round cell as well. I'm not really sure what that cell is and I've never had to change it out.