# Luminance (120 cd/m2 vs 150 cd/m2), LR and clipping



## Modesto Vega (Mar 29, 2015)

As I was editing a photograph, iProfile alerted me that the screen needed re-profiling. So I shut down LR and re-profiled both displays. Before re-profiling the displays the photo I was editing didn't have any clipping warnings on the histogram. After re-profiling, the same photo has both clippings warnings showing a blue triangle (I know what this means). I am slightly confused about this behaviour, although I have a vague idea of might be going on.

Before re-profiling the displays where set to 120 cd/m2, because of an experiment I was doing with printing following a conversation in another thread with Tony Jay. The new profile reverts to my standard 150 cd/m2 setting.

The histogram does not appear to have changed and I would not expect it to change. However, the clipping warnings showing now where not there with the previous profile. This appears to suggest, please note the tentativeness, that with a lower display luminance I can push the clipping further than with a higher screen luminance. I have never come across this before but I have also never follow the sequence of steps I have just followed.

Any comments or thoughts are very welcome


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## Modesto Vega (Mar 29, 2015)

Just some more information because this is starting to look like a bug. I had a -10 shadows adjustment on the photo mentioned on the OP. When I changed it to -8 both clipping warnings disappeared, this is odd as I would only expect 1 warning to disappear, not both. Even more odd is that when I dial back -10 shadows, the clipping warnings did not reappear. I have no clue what is going on.


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## robosolo (Mar 30, 2015)

Modesto Vega said:


> As I was editing a photograph, iProfile  alerted me that the screen needed re-profiling. So I shut down LR and  re-profiled both displays. Before re-profiling the displays the photo I  was editing didn't have any clipping warnings on the histogram. After  re-profiling, the same photo has both clippings warnings showing a blue  triangle (I know what this means). I am slightly confused about this  behaviour, although I have a vague idea of might be going on.
> 
> Before re-profiling the displays where set to 120 cd/m2, because of an  experiment I was doing with printing following a conversation in another  thread with Tony Jay. The new profile reverts to my standard 150 cd/m2  setting.
> 
> ...



The main reason for profiling your monitor is so that you will be able  to color match between your display and either print output or Web  output. There are lots of "informed" opinions as to what these  i1Profiler settings should be. For several years I used such suggested  settings with fairly good monitor/print matching. Eventually I started  using some very white Canson Edition Etching paper, and those settings  just weren't giving me good matching. I called X-Rite and eventually  spoke to a secondary level tech, who gave me the settings that the  company officially recommends. They were quite different from what I had  been using. Here are the X-Rite recommended i1Profiler settings:

*WP = D65*
Luminance = 90 cd/m2**
Contrast Ratio = Native***
Patch Set = Large
ADC = Check the box if your monitor supports it.
All other settings = Default*

(*) I originally used D50 or D55 (which makes the display look kind of  yellowish) because paper profiles are scanned at D50 (5000 K) and I  reasoned that I wanted to match the paper's actual white. The tech said  that X-Rite designs their software so that an i1Profiler setting of D65  will produce prints that are intended for viewing under sunlight Kelvin  temperature lighting of D50.
(**) You may not have a monitor that can be adjusted that low. Mine  (Dell U3011) can only get down to about 91 cd/m2. If you set the  i1Profiler to 90, and you're using ADC (automatic monitor adjustment),  it may not get to 90 - but it will make the monitor's luminance as low  as possible. If you do the adjustments yourself (you will actually see  how low your monitor can go). The main point here is to adjust the  luminance as low as possible if you intend to edit in a low light  environment. Higher settings of luminance are OK for brighter editing  conditions, such as under bright office lights.
(***) This X-Rite suggested setting of Native for the Contrast Ratio  surprised me the most. I'd been told by other 'experts' to use settings  of 150 for matte papers and as high as 250 for glossy.

The bottom line is that I changed all my i1Profiler settings in  accordance with X-Rite's recommendations and have never before had such  close monitor/print matching in both colors and tones.
One last word on gammut warnings, pay attention to them once you've  properly calibrated your monitor - especially the output gammut  warnings. They are telling you that your printer's inkset cannot  reproduce the highlighted colors you're seeing on the monitor in the  final print. If the warning highlights are small, then it won't matter  much. But, if you see something like an entire blue sky highlighted,  then you can adjust the HSL to at least get the printed color to match  the monitor's.


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## Modesto Vega (Mar 31, 2015)

Thanks for the information, it is quite interesting. Just a number of points:

1) With a setting of 150cd/m2 I am getting prints which are very close to what I see on a calibrated display, much closer than when I used 120cd/m2 and don't understand why, please see point 4.

2) I tend to print, through a lab, using Harman Warmtone paper for colour an Fuji C-type for black and white. Before switching to 150cd/m2 the Harman Wartome prints lack punch, they weren't luminous enough.

3) I have noticed that the prints that at 150cd/m2 are not close to the screen are low key photos or photos combining low key and high key areas without much detail in between.


4) An area I am unclear about is that with a monitor calibrated to 90cm/m2, I am likely to be more aggressive with my adjustments, in particular recovering details in the shadows. There is nothing wrong with this but I am not used to work that way and want to understand it before making the change.

5) I chose 150cd/m2 after reading a book by Jeff Schewe: The Digital Negative


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## Tony Jay (Apr 1, 2015)

Modesto, when it comes to setting monitor luminance there is no one magic bullet correct setting.
It absolutely depends on the environment in which you are editing.
The broad principle is to edit in a room where the walls and fittings are neutral toned and the dimly lit.
In this instance a low monitor luminance is best - mine is set to 95 cd/m[SUP]2[/SUP].

However the brighter the environment then the higher the luminance needs to be set.
Nonetheless a luminance of 150 cd/m[SUP]2[/SUP] is almost certainly too high for almost any indoor setting.

I cannot stress enough that the viewing environment for the print is also important.

Ultimately, this is a season to taste setting - if your prints do not look correct (either too dim with little contrast or too bright with unrealistic contrast) then luminance needs to be changed.
There is simply no arbitrary "right" answer.

Tony Jay


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## robosolo (Apr 1, 2015)

Modesto Vega said:


> Thanks for the information, it is quite interesting. Just a number of points:
> 
> 1) With a setting of 150cd/m2 I am getting prints which are very close to what I see on a calibrated display, much closer than when I used 120cd/m2 and don't understand why, please see point 4.
> 
> ...



The lighting in your editing environment and even the color of the walls all affect what settings for screen brightness work best. I do all my own printing on a wide format printer and do not send out to a lab, which means I have full control over the whole process - from monitor screen to print. No matter whether you use a lab or I use my own printer, the appearance of the final print is also influenced by the type of paper used (glossy, luster, matte, surface texture) and the viewing environment's lighting and color. All these factors make it difficult to determine exactly what settings are 'best' for the i1Profiler and frequently experimentation is the only answer. The values given to me by X-Rite should be a starting point.
Jeff Schewe's Digital Negative is not his latest book and I would suggest you read his excellent book The Digital Print. Also, Fine Art Printing by Steinmueller and Gulbins is definitely worth reading. 
150 cd/m2 sounds rather high for an editing monitor's brightness. I don't know the lighting conditions under which you are editing, but the conventional wisdom is to keep the area dark and as color neutral as possible. Also use a monitor hood; you can fashion your own out of black foam board, tape and Velcro instead of buying one. Then set the monitor brightness as low as it will go with 90 cd/m2 being the goal (even if you can't get quite that low). If you must edit in brighter conditions, then at least keep it no higher than 120 cd/m2.

robosolo


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## Modesto Vega (Apr 3, 2015)

robosolo said:


> The lighting in your editing environment and even the color of the walls all affect what settings for screen brightness work best. I do all my own printing on a wide format printer and do not send out to a lab, which means I have full control over the whole process - from monitor screen to print. No matter whether you use a lab or I use my own printer, the appearance of the final print is also influenced by the type of paper used (glossy, luster, matte, surface texture) and the viewing environment's lighting and color. All these factors make it difficult to determine exactly what settings are 'best' for the i1Profiler and frequently experimentation is the only answer. The values given to me by X-Rite should be a starting point.
> Jeff Schewe's Digital Negative is not his latest book and I would suggest you read his excellent book The Digital Print. Also, Fine Art Printing by Steinmueller and Gulbins is definitely worth reading.
> 150 cd/m2 sounds rather high for an editing monitor's brightness. I don't know the lighting conditions under which you are editing, but the conventional wisdom is to keep the area dark and as color neutral as possible. Also use a monitor hood; you can fashion your own out of black foam board, tape and Velcro instead of buying one. Then set the monitor brightness as low as it will go with 90 cd/m2 being the goal (even if you can't get quite that low). If you must edit in brighter conditions, then at least keep it no higher than 120 cd/m2.
> 
> robosolo


With regards to my editing environment, the walls are white and do not currently use a hood. My editing display is a 24 inch Samsung S27B970, I am quite happy with the results I get from this monitor. When I got this monitor I used the same calibration settings as with the previous one, which was another Samsung, the setting was 120 cd/m2. Although my prints were close to my display, it was only when I hiked the luminance to 150 cd/m2 that I started getting prints which when viewed under tungsten or natural lighting where very close to my display. I strongly suspect that more or less at the same time I changed something else, it is this "something else" which I am trying to isolate and understand. I do think that 150 cd/m2 is too high but hesitate to change it until I understood why I am getting the good results I am getting with this setting.

I do my editing during the day with sunlight coming through window curtains, I cannot do much about the window, or at night, the timing greatly depends on my workload.

I do also have the Digital Print and will re-read it just in case I didn't catch something. I am aware of the differences between papers, I settled with Harman Warmtone after some experimenting; I do also like using Canson Baryta but I don't use it very often mainly because I find it is very easy for prints to develop a scratch. My prints are probably optimised for Harman Warmtone, although not deliberately.

Just to reiterate something I have said before in other threads: I am not looking for the right answer, I am looking for understanding. The combination of my settings and results have me scratching my head; I am happy with the printed results but do not understand why those settings leading to these results,


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## robosolo (Apr 4, 2015)

Modesto Vega said:


> With regards to my editing environment, the walls are white and do not currently use a hood. My editing display is a 24 inch Samsung S27B970, I am quite happy with the results I get from this monitor. When I got this monitor I used the same calibration settings as with the previous one, which was another Samsung, the setting was 120 cd/m2. Although my prints were close to my display, it was only when I hiked the luminance to 150 cd/m2 that I started getting prints which when viewed under tungsten or natural lighting where very close to my display. I strongly suspect that more or less at the same time I changed something else, it is this "something else" which I am trying to isolate and understand. I do think that 150 cd/m2 is too high but hesitate to change it until I understood why I am getting the good results I am getting with this setting.
> 
> I do my editing during the day with sunlight coming through window curtains, I cannot do much about the window, or at night, the timing greatly depends on my workload.
> 
> ...



I would highly recommend a monitor hood, given the editing environment you are describing.

I would also suggest that you create a new monitor calibration profile based upon those X-Rite recommendations. If you don't like what you're seeing, then just change back to your regular calibration - which will still be listed in Windows.

If you like Canson baryta but find it too soft and easily scratched, then you could try Canson Platine. It is very similar to baryta but is much tougher and does not scratch easily.
robosolo


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