Standard Color Temperatures

[Ken Lee]

Is 5000K the standard color temperature for viewing photos and artwork ? Is it the standard for print viewing devices ? Should we calibrate our monitors to 5000 K ?

Is 80 cd/m2 the standard brightness for viewing ? How can we measure that with a light meter at home or in a gallery ?

[percepts]

The correct colour temperature for viewing prints is the same one as the print will be displayed in.
The correct colour temp for colour matching to a standard is the colour temp the standard dictates.

EV9.15 = 80cd/m² near as damn it (at 100 ISO)

If you have the manual from the Minolta Spot Meter F it has a handy little chart for dong the conversion from EV to cd/m² and Foot Lamberts.

[Ken Lee]

"The correct colour temperature for viewing prints is the same one as the print will be displayed in".

;)

Do galleries and museums follow any standards when lighting a room for photographs - or is the D50 standard used only by the printing industry ?

I ask because most of our homes and offices are illuminated by a mix of incandescent, florescent, and daylight. According to this article on Luminous Landscape, entitled Print Viewing Stations (http://www.luminous-landscape.com/reviews/accessories/pdv-3d.shtml):

"...while 5000K (D50 as its called), is the standard in the pre-press world, you may find that setting your monitor to D65 (6500K) gives you a setting which is more amenable to your other work. That's what I use.

... I was pleased to read in Harold Johnson's definitive book on inkjet printing, Mastering Digital Printing, Second Edition – that he too has found that 6500K works better than 5000K as a monitor setting, even when trying to match a D50 light source."

[bob carnie]

Ken
What percepts says I would agree with.
I use a graphiclite.com TRV-1e beside my moniter for basic balancing images to my monitor. Within the printing areas I do have daylight (northlight), halogen and daylight florescent lighting.
Basically I will walk a print around in the different light to get an overall impression.
I will always ask the client what kind of light source is at the gallery or space where the images are being shown, For large shows and if its local I will do a site inspection if I think its needed.
Within the printing industry there are standard light viewing boxes that are being used, but I think more for the technicians to be able to sign off the layouts as the proofs are run.
I would imagine the answer for you will always depend upon where your work is being viewed and buy the appropriate lighting for your space.
Walk into 10 different gallery's and you will see all kinds of lighting setups.
Bob

[Bruce Watson]

The standards we have, like D50 and D65 aren't really intended just for print viewing. They are intended for color evaluation and repeatability. IOW, to allow multiple parts of the workflow to all show the same colors. For example, the standards allow stardards compliant and profiled monitors and prints printed through profiled printers to match. And to do this, one has to define the light the print will be viewed in, and that the monitor will emulate -- so the quality of light matches. Another way to look at it is that the standards try to eliminate as many variables as possible.

You'll often find standards compliance in a studio or pro lab where people are working with digital files that they display on a computer monitor, and prints from a print device (inkjet, lightjet, offset press, whatever). The point is to get these workers closer to WYSIWYG, so that the image they see on their monitor closely matches the image they see on paper.

When you take the matching requirement out of the equation, like you would at a gallery or museum or a home, the need for the standard and for standards compliance goes away. There's no way to compare the print in these environments to the intent.

As Mr. Carnie says, every gallery and museum I've been to in the last ten years have all used different lighting. Some bright, some dim. Some dirty old quartz halogens (around 2800K if we're lucky), some nasty fluorescents, but many mixed with a fair amount of daylight mixed in (and reflected off of painted walls that have their own color problems).

I personally calibrate my montitor to D50, and use Solux 4700K bulbs for print viewing. The Solux bulbs aren't D50 compliant, but they are a close match. I get very close to WYSIWYG, but still need a few work prints. This would be true in any case because of the difference between a monitor (light source) and a print (reflective source).

But in my "gallery" (aka living room) I'm using dumb old quartz halogen lights good for around 3000K. And this does cause the prints to look warmer (B&W) and yellower (color). What can I say? It's an imperfect world.

That said, I suspect it's the warming caused by low color temperature lighting that causes so many people to prefer colder tone (bluer) papers for their prints. So it has its effect.

I think Mr. Carnie has the right idea. Carry the print around to various lighting and see how it changes. If you can, print for the final display lighting. But once a print leaves your hands there's no way to know what lighting will be used to view it. So compromise is the order of the day maybe.

[percepts]

I would add that having a viewing station with a colour balanced bulb to any standard is useful for the purpose of consistency when judging your prints as they come out of the printer or tray. Not so much as a colour matching tool but just so you have your own standard reference for making judgements of what is correct for you without having to take the print to another room or waiting for daylight to make an assessment.

And correction (typo):

Ev 9.11 = 80 cd/m² at 100 ISO (near as damn it)

[Ken Lee]

Thanks for your helpful replies !

In a related vein, given that I print with an Epson 2400, are there any papers known to exhibit less metamerism ?

Were it not for that M-word, I presume that warm-tone monochrome images would look much more alike, under different lighting conditions.

[Brian Ellis]

The only standards many museums seem to have these days is to dim the lights to a point where you can't fully appreciate the prints.

[percepts]

In a related vein, given that I print with an Epson 2400, are there any papers known to exhibit less metamerism ?

Ilfor MGIV FB ;)

[Ken Lee]

"Ilford MGIV FB"

I confess: I have become addicted to the controls available in Photoshop. I have strayed from printing in Silver and Platinum/Palladium for this reason. I still have my enlarger, my UV printer, etc. but they sit idle. I confess !

Metamerism is my punishment - justly deserved !

[bob carnie]

Or Harmon digital fibre paper through wet chems.


Ilfor MGIV FB ;)

[Ken Lee]

"EV9.15 = 80cd/m² near as damn it (at 100 ISO)"

I use a Pentax Digital Spot Meter, which gives readings in EV. Would a value of ~9 be "close enough for government work" ?

Using Color Eyes Display Pro, I have found that my monitor (soft proofing in Photoshop) matches my prints at around 60 cd/m2 - a bit lower than that "standard" of 80.

"Walk into 10 different gallery's and you will see all kinds of lighting setups."

Gotcha. I have decided not to work with a standardized D50 or D65 viewing box, but rather with the mixture of room lighting and daylight I find at home and work. If we can't standardize on color temperature, at least we can get a sense about the typical range of luminance.

Hence my question about measuring with a light meter. I plan to poke around home and work and see what the values actually are.

[percepts]

according to my spotmeter manual:

EV 8 = 36 cd/m² at ISO 100
EV 9 = 72 cd/m² at ISO 100
EV 10 = 140 cd/m² at ISO 100

So yes EV 9 is pretty close to 80 hence the 9.11 I gave in the correction. I doubt your meter goes to that level of accuracy. 9 is close enough.

[percepts]

Here is the conversion chart...

30074

[Ken Lee]

Thanks !

I doubt your meter goes to that level of accuracy. 9 is close enough.

It gives something like 9.0, 9.33, 9.67, 10.0 etc.