Формула цветности?- color formula? does anyone ...

[nzeeman]

Формула цветности?- color formula? does anyone ...

does anyone knows what is Формула цветности (color formula)
i see that in russian lens specifications.
for example these are specs for industar 22:
Формула цветности: 7--0--0

 

[grifon]

it is whats known as "colour contribution index" or CCI

as far as i know it measures how much and in what direction the lens changes the colour of the final image. Basically, if you got a bunch of lenses with the same CCI, you can interchange them safely and not get colour differences.

 

[Gabriel M.A.]

Does this mean that, according to ISO, these lenses have a very blue cast?

 

[grifon]

maybe they "filter out" this much blue? the coating is usually really blue, so if blue is reflected out, not much of it gets in.

 

[nzeeman]

i found answer:
http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00473E

if anyone else is interested

 

[Hamster]

I have managed to look this up in a chinese translation of "????-???? ??????? ????????????" - Photo-Cinema Technical Encyclopedia, edition 1981.

Under "????????? ???????"

--My translation as follows:
COLOUR FORMULA

Colour formular for lenses indicates the len's quality of colour transmission; Expressed in term of the following 3 relationship:

D?-D?, D?-D?, D?-D?

D?,D?,D? - Optical density of Red, Green, Blue visisble spectrum effective areaa respectively, these three effective visible spectrum takes into consideration standard colour sensitive material's individul colour emulsion's spectrum sensitivity. Example of colour formular as (standard as of 1980):

D?-D?=11; D?-D?=00; D?-D?=00. Expressed as: 11-00-00. Accroding to a particular len's deviation from colour formular value, one can evaluate that particular len's colour transmission quality.

--END.

Do apologise for the poor translation of someone else's poor translation.

 

[ZorkiKat]

maybe they "filter out" this much blue? the coating is usually really blue, so if blue is reflected out, not much of it gets in.

Many of the 'blue' coated soviet lenses (usually late 50s to mid 60s Jupiters) tend to produce greenish yellow images. Not quite seen through the viewfinder (in the case of SLRs) or too obvious with colour photos printed from colour negatives. But when used on a digital camera, the colour cast differences become obvious. For instance, consecutive exposures made with a 1960s J-9 will look dramatically more yellow than another shot with a 1980s J-9.

Jay