Ad
Ad
Ad
Pages: [1]   Bottom of Page
Print
Author Topic: Monitor luminosity  (Read 5697 times)
AndreG
Jr. Member
**
Offline Offline

Posts: 84



WWW
« on: March 22, 2009, 09:02:43 AM »
ReplyReply

Hi all,

Please excuse me, the topic as surely been covered before. I just attended the Epson Print Academy that was held yesterday in Toronto. I came back with a nagging question...

My calibration on a Eizo C241W is set to 110 cd/m2 - minimum black level, white point at 6500K and Gamma at L* (The latter what a remnent when my ColorEyes calibration software was working).
 
It served me well till now but just before I print I have to add a brightness level correction using Screen set at 25% when I print with Photoshop. If I dont, the print will be darker that the screen and yes, the print is also be too dark viewing them with 5000K Solux lamps or even the in the sunlight. Jeff Schewe do not do this when he is matching the print at proofing.  

So my question is: should I lower the monitor Brightness by 25% (110cd * 75%) to 83cd, 6500K and set the Gamma to 2,2  and work from there?

Is this sound logic or method or what is the right way to correct the problem?

Thank you
« Last Edit: March 22, 2009, 09:47:47 AM by pratic » Logged

Scott Martin
Sr. Member
****
Offline Offline

Posts: 1311


WWW
« Reply #1 on: March 22, 2009, 04:29:04 PM »
ReplyReply

One way or another you need to achieve luminosity matching between the display and the lighting you are viewing your prints under. So you can either turn down the display or increase the luminosity of your lighting. If you are already at 110 cd/m2 it sounds like it would be preferable to increase the luminance of your lighting.
Logged

Jack Varney
Sr. Member
****
Offline Offline

Posts: 392


WWW
« Reply #2 on: March 22, 2009, 09:12:13 PM »
ReplyReply

"So you can either turn down the display or increase the luminosity of your lighting. "


Since practic says his prints are too dark, even in sunlight, what brighter light would you suggest for viewing? This luminousity theme is repeated, with good reason I think, over and over on the LL forums.

Using an Eye One Display with Match 3 software I am able to achieve very good color matching to print on a LCD monitor (ViewSonic VX910) that is not recognized by any photographers I know of. Colorwise great, luminousitywise not so good. Can't calibrate luminousity low enough, in fact, levels below about 100 are not distinguishable from say, 70.

So, I have found the following choices sort of practical:

1. Use a levels layer with a mid tone decrease of about 30% so long as contrast is not severly comprimised.
2. Use a screen adjustment.
3. Turn my room lights as bright as possible while editing, takes a lot of light though.
4. After calibration go to the "On Screen" monitor adjustments and reduce brightness to nearly minium (this is something like a 70% reduction).

Surprisingly, number four seems to work best. I thought that reducing brightness so drastically would make darker values become indistinguishable at this point but my monitor is able to differentiate the darkest color steps.

The nuisance is , for me, the unpredictability of the process. I expect my prints to be viewed in light far lower than in sunlight!

Am I way off base in my approach?

Comments, suggestions. and criticism welcome!
Logged

Jack Varney
ddk
Sr. Member
****
Offline Offline

Posts: 274


WWW
« Reply #3 on: March 22, 2009, 09:41:04 PM »
ReplyReply

Quote from: pratic
Hi all,

Please excuse me, the topic as surely been covered before. I just attended the Epson Print Academy that was held yesterday in Toronto. I came back with a nagging question...

My calibration on a Eizo C241W is set to 110 cd/m2 - minimum black level, white point at 6500K and Gamma at L* (The latter what a remnent when my ColorEyes calibration software was working).
 
It served me well till now but just before I print I have to add a brightness level correction using Screen set at 25% when I print with Photoshop. If I dont, the print will be darker that the screen and yes, the print is also be too dark viewing them with 5000K Solux lamps or even the in the sunlight. Jeff Schewe do not do this when he is matching the print at proofing.  

So my question is: should I lower the monitor Brightness by 25% (110cd * 75%) to 83cd, 6500K and set the Gamma to 2,2  and work from there?

Is this sound logic or method or what is the right way to correct the problem?

Thank you

I assume that you're using CN now, though CE would give you identical results if gamma is set to 2.2, I have the same monitor and my luminance is set to 80 to match prints from my printers, you're too high at 110cd!
Logged

david
-----------------------
www.pbase.com/ddk
Wayne Fox
Sr. Member
****
Offline Offline

Posts: 2823



WWW
« Reply #4 on: March 23, 2009, 01:24:06 AM »
ReplyReply

Quote from: pratic
Hi all,

Please excuse me, the topic as surely been covered before. I just attended the Epson Print Academy that was held yesterday in Toronto. I came back with a nagging question...

My calibration on a Eizo C241W is set to 110 cd/m2 - minimum black level, white point at 6500K and Gamma at L* (The latter what a remnent when my ColorEyes calibration software was working).
 
It served me well till now but just before I print I have to add a brightness level correction using Screen set at 25% when I print with Photoshop. If I dont, the print will be darker that the screen and yes, the print is also be too dark viewing them with 5000K Solux lamps or even the in the sunlight. Jeff Schewe do not do this when he is matching the print at proofing.  

So my question is: should I lower the monitor Brightness by 25% (110cd * 75%) to 83cd, 6500K and set the Gamma to 2,2  and work from there?

Is this sound logic or method or what is the right way to correct the problem?

Thank you

Are you saying something has changed?  You say 110 served you well, till now, suddenly your prints are too dark?  Sounds like something else is a problem (lots of discussion about this lately).

There is no magic number for luminance of the display.  The number is determined by adjusting until monitor white brightness matches paper white brightness under your viewing conditions.

 I would recommend you download and print a good test file to ensure it prints with acceptable density, just to verify something else in your workflow isn't the problem. I don't think a setting of 110 should yield extremely dark prints as you describe.  Personally my luminance target is 115.

Logged

AndreG
Jr. Member
**
Offline Offline

Posts: 84



WWW
« Reply #5 on: March 23, 2009, 05:55:41 AM »
ReplyReply

Hi,
Thank you for taking the time to answer me.

Yes 110cd served me well but I was systematicly adding a Screen layer set at 25% which was propably not a good thing. The color rendition and saturation can be affected. The session at the Epson Printing Academy put this nagging question forward.

 The EIZO CG241W has an automatic brightness sensor to compensate to the room light intensity. I usualy work in a dimmed room and with a Solux table lamp in the corner of the room at night.

" I assume that you're using CN now, though CE would give you identical results if gamma is set to 2.2, I have the same monitor and my luminance is set to 80 to match prints from my printers, you're too high at 110cd! "

Thank you this confirmation. Yes, I am using CN now. It offers a 80cd, 50K and 1.8 gamma Preset. Your parameters for printing are they: 80cd, 65K, Gamma 2.2? I am using a PC workstation.

Jeff Schewe suggest to set the Gray to Gamma 1.8 when using ProPhoto gamut under the Color settings of PS. I imagine there is no corolation with the calibration but since we are on the subject.

Thank you again for sharing.


Logged

digitaldog
Sr. Member
****
Offline Offline

Posts: 8763



WWW
« Reply #6 on: March 23, 2009, 06:34:43 AM »
ReplyReply

Quote from: Onsight
One way or another you need to achieve luminosity matching between the display and the lighting you are viewing your prints under. So you can either turn down the display or increase the luminosity of your lighting. If you are already at 110 cd/m2 it sounds like it would be preferable to increase the luminance of your lighting.

Agreed totally since its getting progressively harder these days to find LCD's that can hit luminance much lower than that.

Forget the numbers "advised" by the CMS manufacturers, use what it takes to get a visual match. Same with color temp. If you're working with multiple users and in differing locations, now more than ever, you need to setup a well defined reference environment where everyone follows the same settings and views the prints the same way.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
digitaldog
Sr. Member
****
Offline Offline

Posts: 8763



WWW
« Reply #7 on: March 23, 2009, 06:39:27 AM »
ReplyReply

Quote from: Beachconnection
Since practic says his prints are too dark, even in sunlight, what brighter light would you suggest for viewing?

If indeed the prints are too dark pretty much wherever you view them, then the issue is the document or how its being printed, its not a display calibration issue. Here's where you need to output a document that has known RGB (or CMYK) values and figure out where the problem exists. I have such a "Printer test file" on my site, there are others all over the net (Bill Atkinson's is also excellent, wider gamut etc). Could be the printer settings, could be the profile. Somehow the OP will have to track down where this issue is rearing its ugly head.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
digitaldog
Sr. Member
****
Offline Offline

Posts: 8763



WWW
« Reply #8 on: March 23, 2009, 06:42:56 AM »
ReplyReply

Quote from: pratic
The EIZO CG241W has an automatic brightness sensor to compensate to the room light intensity. I usualy work in a dimmed room and with a Solux table lamp in the corner of the room at night.

Turn that off! Last thing you want is having the display alter its behavior throughout the day. You don't want ambient light changing anyway, control this.

Quote
Jeff Schewe suggest to set the Gray to Gamma 1.8 when using ProPhoto gamut under the Color settings of PS. I imagine there is no corolation with the calibration but since we are on the subject.

That's for copying and pasting grayscale (RGB channels) for his B&W conversion technique. Since we are advising you to use ProPhoto RGB for color work, and because the original would have a 1.8 TRC Gamma, when you copy and paste individual color channels for his technique, you want to maintain the grayscale gamma to match and that's done in the color settings. Should have no direct bearing on your dark printed color images.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
ddk
Sr. Member
****
Offline Offline

Posts: 274


WWW
« Reply #9 on: March 23, 2009, 07:52:21 AM »
ReplyReply

Quote from: pratic
" I assume that you're using CN now, though CE would give you identical results if gamma is set to 2.2, I have the same monitor and my luminance is set to 80 to match prints from my printers, you're too high at 110cd! "

Thank you this confirmation. Yes, I am using CN now. It offers a 80cd, 50K and 1.8 gamma Preset. Your parameters for printing are they: 80cd, 65K, Gamma 2.2? I am using a PC workstation.

I'm on a Mac and yes, those are my settings. Gamma 1.8 was an old mac thing but never worked for me, for prints I need the monitor set Gamma 2.2, CE's L setting looked good but was off compared to prints. My color space is Adobe RGB from camera to finished file and all papers/printers are profiled. What I see on the screen is as close as can be to my final prints and I haven't thrown anything out because of wrong color, brightness, etc. in a very long time.

Logged

david
-----------------------
www.pbase.com/ddk
JeffKohn
Sr. Member
****
Offline Offline

Posts: 1671



WWW
« Reply #10 on: March 23, 2009, 08:32:13 AM »
ReplyReply

The optimal lumonisity will depend somewhat on your ambient lighting, but it doesn't surpise me that 110 would be too bright. This is an area where dedicated graphics monitors come into their own, as general purpose displays may not calibrate to lower luminosities well.  I'm using an Eizo CG241W, and I calibrate for a luminosity of 95 cd/m2 using ColorNavigator. I get a good match with prints, although the deepest shadows aren't quite as open as on display (which I think is to be expected due to the inherent differences between LCD's and prints).

BTW I would recommend against using the L* option for calibration. It opens up the darkest shadows more than gama 2.2 would. This might seem like a good thing, but it's actually counter-productive if you care about matching prints because you're not going to get that kind of shadow detail in prints.
« Last Edit: March 23, 2009, 08:34:25 AM by JeffKohn » Logged

AndreG
Jr. Member
**
Offline Offline

Posts: 84



WWW
« Reply #11 on: March 23, 2009, 08:56:27 AM »
ReplyReply

Quote from: JeffKohn
The optimal lumonisity will depend somewhat on your ambient lighting, but it doesn't surpise me that 110 would be too bright. This is an area where dedicated graphics monitors come into their own, as general purpose displays may not calibrate to lower luminosities well.  I'm using an Eizo CG241W, and I calibrate for a luminosity of 95 cd/m2 using ColorNavigator. I get a good match with prints, although the deepest shadows aren't quite as open as on display (which I think is to be expected due to the inherent differences between LCD's and prints).

BTW I would recommend against using the L* option for calibration. It opens up the darkest shadows more than gama 2.2 would. This might seem like a good thing, but it's actually counter-productive if you care about matching prints because you're not going to get that kind of shadow detail in prints.

Thanks for the clarifications, after following your recommendations I printed Bill's test file with PS and I am very very close to solving my problem: native RGB, 95cd, blacks lervel .2, 65k and 2.2 gamma seems to be it in both LR and PS but with edge for LR. Yes, there's always the last 10% that is hard to acheive as you stated and the inherent difference between the display and reflection of the paper.

At the Montreal's presentation two years ago, Jeff Schewe was quite explicit about setting Grey at 1.8 when working in ProPhoto. At the time he was explaining in great detail how to set up for color management. I am lost here because this is way over my knowledge.
Logged

JeffKohn
Sr. Member
****
Offline Offline

Posts: 1671



WWW
« Reply #12 on: March 24, 2009, 12:27:17 PM »
ReplyReply

Quote from: pratic
At the Montreal's presentation two years ago, Jeff Schewe was quite explicit about setting Grey at 1.8 when working in ProPhoto. At the time he was explaining in great detail how to set up for color management. I am lost here because this is way over my knowledge.
I think that was in reference to your working space for grayscale images, which doesn't really have anything to do with the gamma curve used to calibrate your monitor. Using Gray Gamma 1.8 makes sense when using ProPhoto RGB, so that both working spaces have the same gamma and copying/pasting between them is a easier.
Logged

digitaldog
Sr. Member
****
Offline Offline

Posts: 8763



WWW
« Reply #13 on: March 24, 2009, 01:01:36 PM »
ReplyReply

Quote from: JeffKohn
I think that was in reference to your working space for grayscale images, which doesn't really have anything to do with the gamma curve used to calibrate your monitor. Using Gray Gamma 1.8 makes sense when using ProPhoto RGB, so that both working spaces have the same gamma and copying/pasting between them is a easier.

Exactly right.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
Pages: [1]   Top of Page
Print
Jump to:  

Ad
Ad
Ad