Jump to content

Recommended Posts

<p>I searched and didn't find this exact question addressed, and looked to find a place on the NEC website to ask support, but couldn't find one. So forgive me if this has been beat to death and I'm just too stupid to find it!<br /> I have been using my NEC P221 for a few years after reading its praises here, mainly for the unique feature set, price point, ease and quality of profiling hardware/software, and the supposed ability to "dumb it down" to srgb. (I send any print work to various labs that require srgb and I am concerned with how the images look on client copmuters, and don't do any landscape prints inhouse on inkjet printers, so no need to try to convince me I don't want to be in srgb.)<br /> Using the Sprctra Sensor Pro, the latest Spectraview software, if I calibrate and profile choosing either Native or Adobe RGB gamuts, gamma 2.2, I am able to obtain a low luminance (say 100 cdm2) and low contrast ratio (300:1,) and low delta e (.30.) setup is able to reach a black point that is necessary for the 300:1 ratio @ 100 cdm2.<br /> However, when I try to calibrate and profile choosing 100 cdm2 luminance, 2.2 gamma, 300:1 contrast ratio, and sRGB gamut, while the desired gamut, white point, and gamma are reached, the desired black point is never reached, the results are somewhere around a 1,000:1 ratio and a delta e of around 6. The same results occur if I raise the luminance to 120 cdm2.<br /> Is there something wrong with my monitor, or is this a harware limitation when choking the gamut down from native to srgb?<br /> TIA,<br /> Charles</p>
Link to comment
Share on other sites

<p>Nothing is wrong if you get the visual match to the print. Assuming that's the goal you set for targeting the calibration. If not, I'd have to ask what you've set the calibration to provide and does it match? If so, you're fine. See:<br>

http://www.luminous-landscape.com/tutorials/why_are_my_prints_too_dark.shtml<br>

Usually you find it's time to replace a display when you cannot hit the cd/m2 value you wish, the backlight is waring out. </p>

Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)

Link to comment
Share on other sites

<p>Hi Andrew, thanks for the quick response. I had already read your article and that is why in fact I was trying to reach the 300:1 contrast ratio, as you seem to imply might be a good place to start in the article. If you re asking me what the target values I put into the Spectraview software, D65, 100 cdm2, 2.2 gamma, srgb gamut.</p>

<p>the calibration hits all those reasonablyclose, but does not reach the necessary black point to provide 300:1, whereas it will reach the necessary black point if the wider gamuts are selected instead of srgb.<br /> the monitor has no problem reaching a much higher luminance.<br /> As far as does it match the print? I'll let you know when my Solux Gooseneck with 50watt 4700K 38degree with plano-convex diffuser gets here! (ordered yesterday)</p>

Link to comment
Share on other sites

<blockquote>

<p>I was trying to reach the 300:1 contrast ratio, as you seem to imply might be a good place to start in the article.</p>

</blockquote>

<p>Depends on the paper. Matt paper will be much lower. </p>

<blockquote>

<p>the calibration hits all those reasonablyclose, but does not reach the necessary black point to provide 300:1, whereas it will reach the necessary black point if the wider gamuts are selected instead of srgb.<br /></p>

</blockquote>

<p>Are you using the settings in SpectraView to emulate sRGB? If so, then it's forcing a different contrast ratio on that calibration to hit the sRGB spec. You should be able to enter any custom value for contrast ratio within reason but this is tied into the cd/m2 value too, it has to! It's the ratio between black and brightest '<em>white</em>'. So what's more important? Nailing a contrast ratio or getting a backlight intensity that produces a match to the print (I'd say yes for print matching). You can <em>force</em> the contrast ratio within a soft proof using the output profile and setting it for Ink Black/Paper White simulation. </p>

Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)

Link to comment
Share on other sites

<p>Andrew-If I choose "sRGB Emulation" then the contrast ratio target is locked at "Monitor Default" and Intensity "Maximum. I get a contrast ratio of 1171:1. (Luminance 219 cd/m2, bp 0.19 cd/m2) I guess that is what you mean by "If so, then it's forcing a different contrast ratio on that calibration to hit the sRGB spec."<br /> If I go to "Photo Editing" I can then change the gamut to Adobe RGB, set a Luminance target of 120 cd/m2 and a contrast ratio of 300:1. I get a nice calibration with a contrast ratio of 261:1 and a delta e of 1.32 (black point .45 cd/m2)<br /> <a href="http://s780.photobucket.com/user/cwbeas1/media/ADOBE%20300-1_zpskkwguudp.jpg.html" target="_blank"><img src="http://i780.photobucket.com/albums/yy88/cwbeas1/ADOBE%20300-1_zpskkwguudp.jpg" alt=" photo ADOBE 300-1_zpskkwguudp.jpg" border="0" /></a><br /> If I go back and change the gamut to sRGB it will still let me set a contrast ratio target of 300:1 (unlike "sRGB Emulation) but the claibration will not set the necessary black point to reach a 300:1 ratio. The result is a blackpoint of .11 cd/m2 and a ratio of 1096:1.<a href="http://s780.photobucket.com/user/cwbeas1/media/SRGB%20300-1_zpsb1wovofv.jpg.html" target="_blank"><img src="http://i780.photobucket.com/albums/yy88/cwbeas1/SRGB%20300-1_zpsb1wovofv.jpg" alt=" photo SRGB 300-1_zpsb1wovofv.jpg" border="0" /></a> So I guess my question is why won't it set the black point somewhere closer to .45 cd/m2 like it does when the gamut is set to Adobe RGB?</p>
Link to comment
Share on other sites

<blockquote>

<p>So I guess my question is why won't it set the black point somewhere closer to .45 cd/m2 like it does when the gamut is set to Adobe RGB?</p>

</blockquote>

<p>When you use emulation for sRGB, you are unable to make any additional edits to the calibration because the software is forcing you to produce sRGB as best it can. <br>

What <em>may</em> work (and I'm not sure any of this is necessary or useful) is to jot down the targets used for the sRGB emulation, then enter that into a custom target setting and fill in the areas you want that differ from the hard wired sRGB settings. See page 39 of the SpectraView manual about this. </p>

Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)

Link to comment
Share on other sites

<p>Thanks again Andrew. After reading that section of the manual it looks like that isn't possible on this particular monitor. I do now have a better understanding of how this works, so time well spent. Im anxious to see how my prints look under the Solux compared to the monitor.<br>

May I ask one other unrelated thing- do I recall correctly reading here where you said something to the effect that gray balancing is preferable for raw images and white balance better for jpegs? If so do you have something written somewhere on that?<br>

<br />TIA.<br>

Charles</p>

Link to comment
Share on other sites

<blockquote>

<p>do I recall correctly reading here where you said something to the effect that gray balancing is preferable for raw images and white balance better for jpegs? If so do you have something written somewhere on that?</p>

</blockquote>

<p>Since raw is linearly encoded and half of all the data is contained in the first stop of highlight, it's '<em>better</em>' to white balance on those tones than gray balance on those tones. For gamma encoded images, gray balance. You'll usually see a WB tool in a raw converter like ACR/LR so it's easier to remember. While you can use gray to balance in raw, it's possible to get sub optimal results instead of using a non specular white. </p>

Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)

Link to comment
Share on other sites

<p>Andrew-I spent half the night reading posts of yours on this and still didn't find exactly the one I remembered seeing before, but this is close: <br /> "Even in Lightroom/ACR, WB on a raw is a completely different story than on a rendered (baked) JPEG or TIFF. IF you capture raw data, WB first, then move to other tools to correct the color's you feel need editing."<br>

<br /> Let me ask a hypothetical the answer to which hopefully will clear this up for me. <br /> <br />Say I have an image I capture with my Canon 5D using raw + Large fine jpeg (with Stabdard picture style) and auto white balance of a scene that includes a Color Checker. The image is close to correctly exposed with the CC white square in the low 240s and the lightest gray patch is close to but not exactly reading R=G=B. I bring the two files into LR , and although the image looks pretty good. my curiosity wants to see if it looks any better so I want to export copies out of LR.<br /> <br />Are you saying it would be best to "white balance" the raw using the white CC sqaure, and "gray balance" the jpeg using the lightest gray patch on the CC?</p>

<p>PS-I'm not sure about the etiquette of high jacking one's own thread, so if I need to repost this as a new topic, will happily do so.</p>

Link to comment
Share on other sites

<blockquote>

<p>Are you saying it would be best to "white balance" the raw using the white CC sqaure, and "gray balance" the jpeg using the lightest gray patch on the CC?</p>

</blockquote>

The 2nd white patch is recommended. But yes, for raw data, WB there, for rendered images, gray. It's totally possible you'll see no difference depending on the image, exposure etc. But you might see a difference and Adobe among other's recommend using a non specular white to WB raw data, again due to the distribution of data in these linear encoded files.

Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)

Link to comment
Share on other sites

<p>>>>"The 2nd white patch is recommended."<<<<br /> IIRC in some of those earlier posts you were referring to the CC Passport, so to be clear,I have the full size Color Checker, not the Passport. Are we talking about the same square when I say "the lightest gray square" and you say "the 2nd white patch? On mine, I'm talking about square #20, "Neutral 8"<br /> I reread an admittedly old article of Jeff Schewe's where he talks about not using a "gray card" for this and I understand him to mean something like the old 18% cards, and says >>>"Camera Raw includes the White Balance tool (it looks like an eyedropper) to enable users to custom white balance on known neutral samples. To be clear, this tool is designed to be used on light, nonspecular neutral tones, such as the second brightest patch on the ColorChecker.t is not designed to be used on a gray card sample. A gray card’s tonality is too far down the luminance scale."<<<<br>

http://www.adobe.com/digitalimag/pdfs/ps_workflow_sec3.pdf</p>

<p>so if we are talking about the same square (Neutral 8) for "white balancing" raw, then what square are you talking about to "gray balance" already rendered images?<br /> I have been using theNeutral 8 for both raw and out of camera jpegs (which I rarely shoot) for years and wanted to know if the collective wisdom has changed to using patch #19 " White."</p>

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...