Calibration Question

I just completed my first screen calibration with Spyder3Pro.

When it finished the ambient light reading, it said it was very high and that I should use 200cd/m2., which I did, and I also used the native white point and 6500K. Screen looks better but I haven't tried a print yet.

Here's my question: The sun is setting through the window in the room I use for editing. The blinds are closed and no lights are on, but admittedly, it is still relatively bright in here. Should I recalibrate tonight when there is no light coming in and, if so, do I turn on the lamp I use when editing at night?

When I calibrate, I let my monitor warm up for at least two hours.
Next, I make sure all the lights in the room are as they would be during a normal editing session.
For me, that means one light on outside my studio editing room. All lights in the editing room are off. This however is personal preference, you can calibrate with lights on or off!

I'll retry tonight. I tried a couple prints and they are still too dark. Monitor was on for about 3 hours when I started so I think it was plenty warm. I think the afternoon sunlight is throwing things off.

Calibrate in the same light as you view/judge prints. The idea is for your monitor to predict print tone, not for it to provide somebody's idea of a pleasant viewing experience. My monitor is calbrated to 90 cd/m^.

tzalman wrote in post #12323502
Calibrate in the same light as you view/judge prints. The idea is for your monitor to predict print tone, not for it to provide somebody's idea of a pleasant viewing experience. My monitor is calbrated to 90 cd/m^.

Like Elie says, you want to match your prints in light that is good. But, the fact that your prints are too dark is the indicator that your monitor is too bright.

There doesn't seem to be a hard fast setting for all monitors -- try lowering things to 100 and see how that works and take it from there.

I recaled tonight under the conditions that I would normally be editing - night time, no sun, only one lamp on with no direct light on the screen. This time I went from 200cd/m2 to 120 cd/m2. Print was still too dark. So I went into the screen menu and changed the color temp from 6500k to 5000k and now the print is almost a perfect match to the screen.

Do I recal now the temp change on the screen or do I recal and lower the cd/m2 to a lower number? What does cd/m2 stand anyway?

Interesting! I don't know how "good" that is, since the temp affects the color accuracy, whereas the brightness is, well, brightness.

cd/m2 stands for "candelas per square meter", candelas of course being a unit of brightness.

There is a little discussion of this in this page:

http://computer.howstu​ffworks.com/monitor6.h​tm

I just got it by doing a Goggle on "monitor brightness cd m2 so can't vouch for how good the page info is but here's the search result:

http://www.google.com …urceid=ie7&rlz=​1I7ADRA_en

I went ahead and recaled it after the temp change and the prints still appear very close to the actual screen. I'll leave as is until I find something better or someone comes up with a suggestion.

Now that I think about it, I guess if I am using a picture edited on an uncaibrated screen and slightly underexposed, then the screen and print would match but the true colors on the monitor wouldn't show since it is wrong to begin with. The test pics after the calibration looked good. I'll have to keep pondering at it.

Tony, thanks for the info. I knew it had to do with brightness, just couldn't pull the terms out

huntersdad wrote in post #12324532
I recaled tonight under the conditions that I would normally be editing - night time, no sun, only one lamp on with no direct light on the screen. This time I went from 200cd/m2 to 120 cd/m2. Print was still too dark. So I went into the screen menu and changed the color temp from 6500k to 5000k and now the print is almost a perfect match to the screen.

I'm gonna get flamed again for having a hard opinion on this, but I do believe you should calibrate in dim to dark conditions, ensuring that NO light is leaking under your sensor while it rests on the monitor screen. If you have other light sources affecting the calibration sensor, your profile will be corrupted.

I personally think the best calibration and editing light level is similar to that in a movie theater before the movie begins.

Also, in addition to warming up the monitor, warm up the calibration puck by running the calibration twice. Use the second try. You don't need to reset your monitor back to factory default settings. Just start with your last settings and tweak as required.

huntersdad wrote in post #12324532
Do I recal now the temp change on the screen or do I recal and lower the cd/m2 to a lower number? What does cd/m2 stand anyway?

cd/m2 means Candelas per square meter. Candela is a physical measure of emissive light, while Brightness is a purely perceptual phenom.

huntersdad wrote in post #12324702
Now that I think about it, I guess if I am using a picture edited on an uncaibrated screen and slightly underexposed, then the screen and print would match but the true colors on the monitor wouldn't show since it is wrong to begin with....

Until you get this under control, ONLY use standard test images. Don't adjust or softproof a test image... Just print it and compare with your screen.

http://www.northlight-images.co.uk …le_pages/test_i​mages.html

read this by the best in this area http://www.luminous-landscape.com …_my_prints_too_​dark.shtml

Thanks guys. Looks like I have some readin gto do tomorrow as I home with a sick child. I did do a 2nd full recal under the conditions that I would normally edit with the lamp on. As I physically held the calibration monitor to the screen, I am pretty sure very, very little if any light got under it.

Thanks for all the help.

This is an interesting thread, as I am soon to buy a new monitor and calibration tool.
Thanks, I am going to keep my eye on this one.

huntersdad wrote in post #12329676
Thanks guys. Looks like I have some readin gto do tomorrow as I home with a sick child. I did do a 2nd full recal under the conditions that I would normally edit with the lamp on. As I physically held the calibration monitor to the screen, I am pretty sure very, very little if any light got under it.

Thanks for all the help.

Well, don't take the opposite approach lightly. A lamp that has a color temp especially could mess with things, and consumer lamps will have one -- either tungsten or flourescent.

I keep my editing ambient pretty low, dim daylight or a low, distant lamp. In fact, a lot of professional photography retouchers use a monitor hood, so there is very little ambient light.

Maybe try a few different calibrations, stored with different/descriptive names -- the first two could be in your "normal" editing light with brightness adjusted accordingly and the second two in a dim abient lighting and the brightness adjusted down accordingly. Do the dual approach mentioned above for both -- first, after the monitor has warmed up, and then the second, after the colorometer has warmed up with the first one. That way you will have time to test things out and decide which approach works best. Or maybe you will find use for more than one!

ChasP505 wrote in post #12328480
I'm gonna get flamed again for having a hard opinion on this, but I do believe you should calibrate in dim to dark conditions, ensuring that NO light is leaking under your sensor while it rests on the monitor screen. If you have other light sources affecting the calibration sensor, your profile will be corrupted.

I personally think the best calibration and editing light level is similar to that in a movie theater before the movie begins.

Also, in addition to warming up the monitor, warm up the calibration puck by running the calibration twice. Use the second try. You don't need to reset your monitor back to factory default settings. Just start with your last settings and tweak as required.

No flame from this quarter Chas. In an interesting recent thread on the Luminous Landscape forum, started by Ethan Hanson who is testing calibration hardware for the Drycreek site's survey, he recommends leaving the puck lying on the screen for half an hour before running the calibration to warm it. There is even mention in the thread of wearing a black shirt to avoid light from the screen being reflected back to it. This seems a bit extreme, but a dark room would definitely be good.