Exposure conundrum

[Anscojohn]

I dealt with this once and thought I would toss it out to all the experts.
The customer was really adament: her camera (a 35mm Nikon SLR) always overexposed her black and white film, but never her color film. Go figure.

 

[msage]

I dealt with this once and thought I would toss it out to all the experts.
The customer was really adament: her camera (a 35mm Nikon SLR) always overexposed her black and white film, but never her color film. Go figure.

If we are talking about traditional BxW film, it might be her dev.

 

[archphoto]

Color OK ?
> ASA B&W set propperly ? >>> yes >>> wrong processing
>>>>>>>>>>>>>>>>>>>>>>>> no >>> her own fault, adj ASA to obtain propper EI

Reasoning: C41 is standardized, allways the same, B&W can vary

Peter

 

[glaiben]

Was she not changing ASA/EI between color and B&W films (assuming they were different)?

 

[Anscojohn]

Was she not changing ASA/EI between color and B&W films (assuming they were different)?

******
She was changing her ASA correctly. Processing was correct.

 

[Anscojohn]

She used a filter for B&W and did not correct for it ?

****
No filter for either.

 

[archphoto]

Only thing left for me: too sensitive film for her chosen apperture e.i. 5.6 at 800 ASA or higher

 

[JBrunner]

Her red dress always came out black.

 

[removed-user-1]

Ok, film processing was correct, no filter factor to deal with, and film speed was set correctly... needless to say, it's very unlikely that the camera was only misfiring coincidentally with the loading of B&W film. Could it be that she simply didn't like the printing? Maybe it's a question of different exposure latitudes of the films in use and the resulting prints.

 

[Anscojohn]

She was really adament about it. What it finally came down to was something that had nothing to do with the fact of color film versus black and white film. What a lot of questioning finally brought to light was that she always shot TRI-X at normal ASA (this was a before ISO standards) and always shot Kodachrome 25 at normal ASA.
Her camera's meter had a non-linear exposure problem that only came into play at higher ASA settings. But the customer saw it as a "black and white film" versus a "color film" problem since that was the way it manifested itself in practice.

 

[nickandre]

I'm getting the sense that this is some sort of riddle.

Her red dress always came out black.

On what basis did she judge the overexposure?

 

[removed-user-1]

What Nikon camera was that? Sounds like a symptom an old Photomic meter might exhibit if it was failing.

 

[nickandre]

Guess I missed the deadline...

 

[Anscojohn]

I'm getting the sense that this is some sort of riddle.
******
In a sense it was because one has to go from where the person asking for a solution to the problem is "at." They can't always provide the info we need to solve the problem in the first go around. I used to try to train the kids who worked for me to speak "customereeze." This was not a pro shop with professional customers; just every day people. Learning to ask the right questions was very important.

 

[Anscojohn]

What Nikon camera was that? Sounds like a symptom an old Photomic meter might exhibit if it was failing.

******
Don't remember. I know it was not an F, though; a Photomic would stick in my memory. Some of the various situations were pretty amusing: like the lady who insisted the lab "had mixed her pictures up with someone elses." Yup, it happens. And she got half a roll of her pix, and some of another person's. Yup, that happens to. And, not only that, the lab mixed up her pictures with her mother's pictures. Hmmm, sez I to meself, sez I as I put the tracer book back.. It transpired they were on vacation together; with the same P and S cameras; Is it possible, I finally ask, that perhaps you just picked up her camera by mistake one day......???. Oh, yeh, I guess that's it, sez she.

 

[MattKing]

I have a couple of Olympus bodies that feature metering off the film. I've always wondered if there is any significant variation of reflectivity between film types. I was going to suggest that as a cause, if no one else came up with a solution.

Matt

 

[Anscojohn]

I have a couple of Olympus bodies that feature metering off the film. I've always wondered if there is any significant variation of reflectivity between film types. I was going to suggest that as a cause, if no one else came up with a solution.

Matt

*****
That's an interesting point, Matt. One would ASS u ME that the emulsion reflectance would be pretty consistent; but I wonder......

 

[Q.G.]

There are slight differences between films, yes.
So you need to learn how your favourite films behave, and possibly adjust your metering accordingly.

Old data, but illustrative all the same:

 

[BetterSense]

Is that data from Olympus? I understand that most common-speed exposures were actualy metered mostly off the shutter curtains, and only longer tripod-domain exposures metered off the film itself.

 

[Q.G.]

It's data from Hasselblad, to be used with their OTF flash metering.
They measured the reflectivity of the films available then.

You're partly right about the curtains.
Anything of 1/60 and longer is meassured entirely (or as near as) off film.
Faster speeds progressively more off the curtains, increasingly less off the film.

P.S.

Or have i got it wrong now, and is the OTF measuring only used for longer speeds indeed?

 

[BobNewYork]

I'll add one more for AnscoJohn. Many years back, in my dad's camera shop back in the U.K. a woman came storming in complaining that the lab had printed her pictures upside down! You got it...........she was holding the stack of photos.......UPSIDE DOWN!! I'm really not kidding! This must be forty years ago now and that sort of thing kinds sticks in your memory!!!!

 

[Anscojohn]

I'll add one more for AnscoJohn. Many years back, in my dad's camera shop back in the U.K. a woman came storming in complaining that the lab had printed her pictures upside down! You got it...........she was holding the stack of photos.......UPSIDE DOWN!! I'm really not kidding! This must be forty years ago now and that sort of thing kinds sticks in your memory!!!!

******
I can believe it, totally. And just consider....these people VOTE!

 

[bob100684]

I'll add one more for AnscoJohn. Many years back, in my dad's camera shop back in the U.K. a woman came storming in complaining that the lab had printed her pictures upside down! You got it...........she was holding the stack of photos.......UPSIDE DOWN!! I'm really not kidding! This must be forty years ago now and that sort of thing kinds sticks in your memory!!!!

people do that a lot, they also say things like "i need a 10x8 not an 8x10 because its horizontal".....

 

[Anscojohn]

people do that a lot, they also say things like "i need a 10x8 not an 8x10 because its horizontal".....

*****
And how about the young bride who could not understand why the shoes that showed in the 5x7 did not show in the 8x10.

 

[Q.G.]

I don't understand that either.