recommended white point for calibration?

hi- me again.

i have read in some step-by-step instructions on monitor calibration that you should use

6500K as the white point for calibration, while others say you should always use the native

white point. how do you know which one to use?

thanks,

alexis

Alexis, I use what the software recomends. For my spyder, it is recomended to reset to the factory settings before running calibration.

Mike

If you have an LCD it's best to leave it at the factory settings. The

puck calibrator will measure that response and tell you what it is.

Then you have to see if this factory setting affects how prints look

under your available lighting.

Your level of tolerance and comfort to how different the two are is

going to be up to you. The closer your lighting color cast and

luminance is to your display the more comfortable your EDITING

experience will be to your eyes.

You can then have the calibration software to target to a different

color cast that meets your needs but it will have to do it through

the graphics card which can induce some image anomolies like

banding with certain LCD's of varying quality levels.

i have LCDs. i have read that the native white point is recommended sometimes for LCDs. i spent some time chatting with customer support at gretamacbeth yesterday and they recommend using 6500K as the white point, as this should be neutral white. my native white point was much higher, and gave less than optimal calibration (looked blue). another funny thing was the calibration software didn't work that well when i individually adjusted the RGB channels to 6500K - this gave me a marked pink tint. when i used the 6500K preset on the monitor controls it ended up spot-on, and i'm pretty happy with the way the color profile looks.

can't say what prints look like in comparison as i have generic inks at the moment and the last batch was pretty bad - the magenta ink was sub-par and everything looks pretty blue/green. i've been getting prints made, anyway, so hasn't really bothered me. but i'm dying to see how it looks with the calibration, so i'll have to pop for some nice ink next time around.

would be nice to use the software with one of the one-touch settings if you've got a lacie or eizo, since the specs are pre-programmed. but i'm pretty happy with how they look, and they compare well to other monitors when i view stuff online.

so, guess i've figured it out for now with my monitors and software.

i suppose that which you'd choose certainly depends on what type of work you're doing, your monitor and the software. there was a pretty steep learning curve - i had a self-calibrating apple studio CRT for 7 years that just blew a tube. sigh.

alexis

Alexis,

I have the same version of i1 as yours. Using it on Mac OS 9.2.2,

I get the pinkish appearance targeting for 6500K instead of using

the CRT's native state or eyeballed OSD adjusted RGB bias as a

preset native state.

Just wondering what color your R=G=B grays looked like after

calibration compared to what they looked like at the point the i1

Match software cleared the LUTs after the puck calibration

session. Mine keep shifting to either greenish, yellowish to red

brownish after each recalibration.

I was told by Barry at Gretag's tech support that's not suppose to

happen. I surmised I have an unstable, cheap CRT being it's a

1999 Optiquest Q91 I picked up at thrift store. Just want to see

what how yours is.

Whoops, that read wrong.

I meant the greenish, reddish, brownish appearance occurs

after the final profile is completed and loaded in the system.

hmm, well, i'm not sure how to answer your question. after calibration using the monitor's preset 6500K, the greys look good - not really a color cast to them. there is a slight difference in warmth between the 20" and the 17", but it's not very noticeable, and photos edited on either screen look pretty true on other monitors.

the problem occurred when i tried to adjust the separate RGB channels on the monitor when the calibration screen prompts you to the 'green zone' for 6500K as the white point. the greys went hot pink.

i know some older monitors have had color shift problems (even apple's last generation of ACDs, although supposedly that is fixed). dunno. you've got an old monitor that has probably crapped out on you. not to mention most likely an old graphics card as well if you're running mac classic. not that i'm an expert, but the i1 software is probably more sophisticated then any of the other components in your system. maybe eyeballing it is really the way to go. i'm running 10.4 with a brand new graphics card and new monitors, so i think this is really apples and oranges to try to compare our systems and performance.

i don't have the link handy on this computer, but there's some good calibration assessment websites that i found through links on this board. they let you assess the calibration of your dark point, and your gamma (as well as color tone on the greys).

i will post the link later tonight.

Thanks, alexis.

I figured out the problem after letting the CRT normalize to the

new calibration. It drifts and is kind of unstable so the new

calibration that's hammering the purplish native state into a

neutral appearance takes a while. It's old and I'm probably going

to get rid of it for one of the new high quality LCD's.

I've never seen this kind of behavior in a display, but then It's my

second monitor so I have only one other to compare to.

Thanks for the confirmation on your system. Glad it's working

out.

<p>Dear Mr. Tim,<br>

When you say that " If you have an LCD it's best to leave it at the factory settings " is this mean that gamma, brightness and contrast just set as default? How about backlight / brightness control that usually come in laptop keyboards? Do i have to set it to full / 50? / very low? i have 8 level to control back light in my laptop.<br>

I have Spyder 2 Pro that i want to use to calibrating for my LCD monitor.<br>

Thank you<br>

Dodi</p>

<p>The only thing you can adjust is the backlight which affects both contrast and brightness of white. You set the brightness of white to match the brightness of the paper lit by the lights you'll be viewing your prints under.</p>

<p>After setting brightness of white, leave everything else on the LCD at factory setting and just measure the response with the Spyder 2 Pro. After calibration and profiling, the Spyder software will give you the specs of what the factory settings delivered as measured in the form of gamma, color temp, black level and luminance (cd/m2).</p>

<p>These readings may be way off or close enough to 2.2 gamma, 6500K, .1-.3 black level, 90-120 cd/m2 luminance. If close enough, name and save this profile and use it as your system profile and be done with it.</p>

<p>Gamma isn't usually that way off. Color Temp can be off as much as 500K without influencing editing decisions. Black level is rarely off as well. Since luminance is controlled by backlight that was set by you according to page white of your prints, if it's below 90 cd/m2, you need to get brighter viewing lights or get the paper closer to the light.</p>

<p>If factory defaults are way off according to Spyder measurements, you may have to enter custom targets in the Spyder software that change the factory settings by way of manipulating the video card.</p>

<p>I don't accept factory defaults on my Dell 2209WA LCD because its native gray and white tones are too urine green colored and the highlight regions between 240-250 RGB go to white. I hacked the factory set OSD presets from instructions I got online to force the native appearance to look as close as possible to neutral gray and white and bring back 240-250 RGB grays.</p>

<p>After doing this my EyeOne Display calibration software does less work on the 8 bit video card correcting for these newly made/hacked factory defaults. I don't recommend you hack your OSD factory defaults. It's a big PITA.</p>