adjusting brightness/contrast while profiling

[kkopchynski]

Hello,

I have been using Spyder for a number of years. In earlier versions, I was presented with a gradated white and black wedges and told to adjust brightness/contrast until all gradations could be seen. In more recent versions, and on a colormunki I recently worked with, this step is gone. Getting proper brightness seems very important. Was this step eliminated because users found it too hard to do? Or has there been some improvement in monitor and projector technology where this step is no longer needed?

Thank you
Kevin

[BobShaw]

I think it is just that the software is better and you don't have to do it manually before you start. Spyder 3 was like that.
Spyder 4 just tells you the target brightness and current brightness and asks you to change it and then it measures it again.
If it is not changing the brightness at all then that is a problem.

[digitaldog]

I have been using Spyder for a number of years. In earlier versions, I was presented with a gradated white and black wedges and told to adjust brightness/contrast until all gradations could be seen. In more recent versions, and on a colormunki I recently worked with, this step is gone. Getting proper brightness seems very important. Was this step eliminated because users found it too hard to do?

Probably because it's unnecessary or didn't work (or both). If you want to setup proper brightness, you have to do it as explained here:
http://www.luminous-landscape.com/tutorials/why_are_my_prints_too_dark.shtml

[kkopchynski]

Andrew,

Thanks for the reply and link. I agree that your article is a great way to help someone reliably get predictable results from their printer. For a projector in this (photo club) situation, there seems to be a different/other/additional goal: assuming that the maker has used good calibration techniques, how do I ensure that I will project their image without blowing highlights or blocking up shadows? Or, from the maker's point of view, assuming that the projector is accurately profiled, how do I best profile at home to be sure that what is projected at the club is as similar as possible to what I see at home? The use of the black/white wedges to adjust contrast-brightness seemed to be important to achieve these goals. Or, is it that if I calibrate at 120-140 cd/m2, specify whitepoint 6500 and "gamma" 2.2, the highlights and shadows will simply fall into place correctly?  I would like to believe this but my gut tells me that I had better have the brightness and contrast for the device close to some neutral value suited to the device first for those numbers to be effective. In other words, if my monitor or projector is displaying everything at 80% brightness or greater as pure white, those other settings will not cure that problem.

Thanks for any further thoughts you may have.
Kevin

[digitaldog]

Thanks for the reply and link. I agree that your article is a great way to help someone reliably get predictable results from their printer. For a projector in this (photo club) situation, there seems to be a different/other/additional goal: assuming that the maker has used good calibration techniques, how do I ensure that I will project their image without blowing highlights or blocking up shadows?

You account for this in the calibration targets for the resulting profile you'll build from the projector.

Or, from the maker's point of view, assuming that the projector is accurately profiled, how do I best profile at home to be sure that what is projected at the club is as similar as possible to what I see at home?

You really can't. The environment the projector resides is part of the entire profiling process. Unless your home and the place you'll have your club are behaving the same, there will be differences. No different from calibrating and profiling your display and wondering how do you transport that to another display or computer system; you can't.


 

The use of the black/white wedges to adjust contrast-brightness seemed to be important to achieve these goals. Or, is it that if I calibrate at 120-140 cd/m2, specify whitepoint 6500 and "gamma" 2.2, the highlights and shadows will simply fall into place correctly?  I would like to believe this but my gut tells me that I had better have the brightness and contrast for the device close to some neutral value suited to the device first for those numbers to be effective. In other words, if my monitor or projector is displaying everything at 80% brightness or greater as pure white, those other settings will not cure that problem.

That's why using a set of color reference images to evaluate the calibration is important!


http://www.digitaldog.net/files/2014PrinterTestFileFlat.tif.zip


http://www.digitaldog.net/files/Gamut_Test_File_Flat.tif


http://www.roman16.com/en/

[kkopchynski]

Andrew,

I actually do a lot of comparing to reference images after I am done with the colorimeter. I guess I've been pretty much on the right track. Thanks for this reference image, it will be a good addition to the collection!

best regards,
Kevin