How accurate are exposure meters? Not very....

[Don Dudenbostel]

What I see as potentially useful information from your tests is that, if you photograph under varying color temps (e.g. indoor incandescent, outdoor daylight, etc.) then it would be a good idea to calibrate your process for each of those general scenarios.

The importance of this info ignores the other variables of photography. I agree with h p mktng Bob S that shutters are highly inacurate and vary with age and temperature. Ask don't assume there's no human error, film manufacturing tolerance and lab error. I've seen way too many errors of a major nature from kodaks film consistency and from lab errors. Overall these errors average out but not always. Certainly meters vary but every part of the process is subject to variables. My guess anyone expecting to achieve one shot perfection is going to be seriously disappointed.

Interesting to see the variables in meters but highly impractical to worry about in real world shooting.

[bglick]

> Interesting to see the variables in meters but highly impractical to worry about in real world shooting.


I would strongly disagree with this assertion. The thread covered many of the applications that critical exposure is very important. Its possible you did not read through the entire thread, which is often the case.

For many of us Don, it is extremely practical to prevent exposure reading errors that can be full stop or more. When I get paid to shoot a job, I need to produce properly exposed chromes. Because there is "other" potential errors in the down chain, is certainly no reason to dismiss one potential large error which exists in the first step of proper exposure. I never followed this logic. Specially if there is a simple method to avoid the error. It's possible with the type of photography you do, this issue is of no concern for you, so be it..... but I don't think its prudent to assert that everyone works as you do.


I have about 15 LF lenses, 8 35mm lenses and 12 MF lenses.... the worst shutter I own is off by 3%.... I test my shutters every few years, its remarkable how accurate modern shutters are.

[Drew Wiley]

I certainly don't always makes things this complicated! I developed a very specialized tool for modeling very precise interpositives, internegs, and color separations in color printing which has saved me a great deal of film and money.
Once protoypical models are in place for a certain category of work, the procedure
becomes vastly simplified. Similarly, the 8X10 chrome I accidentally ruined today
with a double exposure was made under diffuse fog almost like a softbox: any
averaging meter would have done an excellent job. But then the fog started lifting
and I was working with some extemely intricate shadow patterns which changed
every few seconds. I made both an FP4 zone-system style exposure and an E100G
chrome. I was visualizing the placement on each film curve very precisely, in
accordance with a finished print. I doubt an internal Nikon meter could have read
my mind, especially in such complex lighting! These devices are wonderful for the
photojournalist, sports, and wedding photographer, but I was working on the very
edge of tolerances for this kind of color fim exposure. I really like to dance with
the light, even though the odds are against me!

[timparkin]

Perfectly predicting the correct exposure value may never be 100% reliable-- but at something like $10/pop for a sheet of 8x10 color transparency film nowadays, it doesn't take a lot of wasted film to motivate one to improve upon a meter or metering regime if it can be improved.

Could somebody market it? Perhaps it's closer to hand than we think if we're stuck in some mindset of "tradition".

Killer app for an iTouch, iPhone (or my Blackberry Storm) for a LF photographer: a $9.99 download that matches the camera phone's spectral and DR response to various film types, and displays a histogram. (I'd pay more-- a lot more!)

I've had this in mind since I saw the first iphone - All it needs is a manual exposure mechanism and some calibration -

[bglick]

> Killer app for an iTouch, iPhone (or my Blackberry Storm) for a LF photographer: a $9.99 download that matches the camera phone's spectral and DR response to various film types, and displays a histogram. (I'd pay more-- a lot more!)


After reading the Nikon links above, a product like this would be very feasible.... but with the market shrinking every year, I doubt anyone would perfect such a product....

the revolution in electronics "allows" products like this to be a successful product,

but at the same time,

the revolution in electronics "prevents" products like this from being a successful product :-(

(i.e. the revolution caused the mass movement to digital capture)

Regardless, I think in the mid 90's, the meter companies missed an opportunity to benefit from Nikons successful metering technology, and offer something similar in a hand-held meter, mostly for chrome shooters. At that time, pro photogs shot chromes, not digital....

[Robert Fisher]

Bill great point about E6 in the 90's. I was using a pair of F5's for wildlife photography and NEVER would have considered negative film. In fact I don't know of ANY serious Nikon wildlife shooter using negative film at that period of time. I also wondered why Nikon never marketed a killer meter using their technolgy.

[Kirk Keyes]

If a meter is calibrated at one color temp, it should be relatively accurate at that color temp. Which I would suggest they are.

I beleive there is an ISO specification for meter calibration. It recommends that calibration should be made at 4800K. This gives the best balance between tungsten and daylight color temps.

But a manufacturer is free to calibrate at whatever temp they wish.

[Ivan J. Eberle]

The feasibility of an iPhone app actually seems great because it's not a new product with a manufacturing or tooling or R&D cost. It's just a software application for an existing product--one with a funky retro film hook.
Nikon should seriously do this. Call it "F5 and Be There", or something equally catchy.

[BrianShaw]

I beleive there is an ISO specification for meter calibration. It recommends that calibration should be made at 4800K. This gives the best balance between tungsten and daylight color temps.

But a manufacturer is free to calibrate at whatever temp they wish.

See page 5, post 45...

or

Page 84:
http://books.google.com/books?id=Q7u...andard&pg=PA84

[Leonard Evens]

Someone has probably already said this, but let me chime in just in case. You should always test your exposure meter in connection with your actual experience using the equipment you have. There are so many variables---exposure meter, fil, lens settings, etc.---which can be off that it doesn't make sense to look at each separately. It is how they work together that matters.

Books on the Zone system go into detail about how to do this, but the basics are quite simple. Look at shadows and highlights to see if there is an overall shift in one direction or the other.