Kodak Gold 200 strange characteristic curve

[Anon Ymous]

Hi

I was reading the Gold 200 datasheet and found something strange in the characteristic curve. The blue channel seems to lose density with increased exposure in the beginning, but increases from some point on. It is at a very early stage, as seen at the figure below. So, the question is, how can it be possible? Or is it some sort of error when plotting the curve that went unnoticed?

 

[bernard_L]

I would not lose sleep over this. My bet is accidental measurement errors (densitometer), going through some software to transform the discrete points into a "nice" smooth curve. See the hump at logH≈-1; same thing.

 

[Anon Ymous]

Oh, I won't lose sleep over it, just curious. The hump on the other hand isn't that strange as far as I know. I think PE has mentioned in the past that several emulsions can be used for each layer, so this could explain the hump. Perhaps PE could elaborate on this too.

 

[Rudeofus]

Color negative film employs DIR couplers to control contrast and saturation. Note, that this chart is the result of one exposure with white light, and not the result of three independent measurements with three colored light sources. It is quite possible, that weak development in R and G channel inhibit the B channel until exposure is strong enough to overcome this effect.

 

[Photo Engineer]

It could be a tiny error in the blend of emulsions used for the yellow layer.

PE

 

[Anon Ymous]

It could be a tiny error in the blend of emulsions used for the yellow layer.

PE

Which one? The hump, or the reduction of density? I suspect you mean the hump.

 

[Photo Engineer]

You cannot tell from this example. You would have to look at a single (3 part) coatout of the affected layer.

PE