Re: Neutral grey under different lighting
Re: Neutral grey under different lighting
- Subject: Re: Neutral grey under different lighting
- From: Roger Breton <email@hidden>
- Date: Mon, 03 Sep 2007 14:21:33 -0400
> The whole thing started as I was asking myself whether I should send
> the lab files in Adobe RGB or already converted into their profile,
Ideally, I think you ought to be able to send them your files in your choice
of RGB space as that would keep your workflow "laboratory-independent". And
there wouldn't be much to gain the other way, IMO.
> so I sent them several gradients to see whether there is a
> difference.
You mean some in AdobeRGB and some in each lab's customRGB color spaces?
> Moreover, I noticed that on some images white areas would
> sometimes tend to pink (I only later realised that sometimes meant,
> 'when viewed under fluorescent light'). This was particularly
> annoying when white clouds turned pinkish.
How unatural, indeed.
> - My input:
> I created files defined in Adobe RGB with a large number of vertical
> bars starting at (0 0 0) increasing in steps of four, ie, (4 4 4)
> going up to (255 255 255). The whole range was split over several
> files, as to not having to make the bars too narrow.
Good methodology!
> - My daylight:
> Indirect sunlight, ie, overcast sky, or in in a room not directly
> exposed to the sun, or in a room behind blinds.
The inescapaple "nothern sky" light, otherwise known as "bluish" as opposed
to "yellowish", as in the case of direct sunlight.
> - About spectras:
> I only have the Eye-One Display with the Eye-One Match 3 software, so
> no spectra.
Alas, a filter-based instrument can't turn much spectral information :(
> - Perfectly neutral:
> Perfect in the sense that to the casual observer they would appear as
> neutral grey or only slightly warm or cold regardless of viewing
> conditions
I see. In relation with some abstract notion of what gray ought to look like
in the casual viewer's mind.
> and perfect in the sense that bright areas don't have a
> different cast as dark areas.
Aren't we all striving for that!
> (This what I am used to from b/w
> photographic paper, as I said I did not expect color photographic
> paper to match this fully.)
Yes, it's true that B&W photographic prints have that inherent quality. Same
chromaticities throughout the tone scale, from substrate to darkest tone. Or
do they?
> - The paper used:
> Fujicolor Crystal Archive Paper Supreme
I dug out some sample prints (unmanaged TC8.7 RGB images) I had done for a
photo lab, a while ago, and I did not observe any severe shifts of "colors"
in the grayscales as I took the prints from fluorescents, to tungsten to the
type of daylights you refered to above. Granted there were some subtle and
expected shifts in the appearance of the grays. But never as pinkish or
magentish as you reported. For the sake of completeness, I compared both the
glossy and the satin prints I had, Fujicolor Crystal Archive Paper but no
mention of the "Supreme" brand anywhere on the back of the prints. Maybe
Supreme is a more recent addition?
Out of curiosity, I pulled some Kodak Endura prints from the dust and made
the same observations as above. According to thse eyeballs, again, there
were no wild shift in the appearance of grays I could detect as I viewed the
prints (lot's of printed RGB gray scales sgain) under the various sources
cited above.
If anything, some shifts to slight green towards the middle of the tone
scale. A sign of less than ideal calibration.
> Markus
Roger Breton
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden