Re: [Leica] Colour rendition

[Alan Ball <AlanBall@csi.com>]

Erwin,

How will we be able to have "pissing contests" if you and ISO put an end
to discussion?

Alan

Erwin Puts wrote:
> 
> The topic of colour rendition of lenses (warm, neutral, green, yellow) has
> popped up quite frequently. these days. As usual accurate measurements are
> available, but the photographic press is relying on subjective
> interpretations.
> The ISO 6728 "Determination of ISO colour contribution Index (ISO/CCI)"
> sets the rules for determining the contribution of lenses to the colour of
> the final camera/film image. The ISO standard defines the  spectral
> sensitivity of an 'average' colour film (neg and trans) and then determines
> the contribution of the lens to see what deviation you get. This is my
> favorite approach: standards and measurable deviations from this standard.
> No more interpretations of what is warm or neutral.
> Of course I would add Leica adhers to this standard. Full results can be
> found in a soon to be released report by my very humble person. As an
> appetiser; the ISo 6728 stipulates a CCI of 0/5/4 as standard. Forget for a
> moment what CCI 0/5/4 means. It is just a normative quantity, but
> measurable by instruments and so much more reliable   than any human
> observer can be.
> The following Leica M lenses have a 0/5/4 measurement and canbe considered
> to all intents and purposes as "neutral" in an objective sense. This list
> is not exhaustive, just a sample. I need some more stuff for my next
> report!!
> 
> Elmarit-M 2,8/28 (recent version)
> Summicron-M 2.0/50 (recent version)
> Apo-Telyt-M 3,4/135.
> 
> Much more in the near future.
> 
> Erwin