# Two Monitors and a Color Issue



## Patricia Mitchell (Aug 16, 2020)

I use two monitors, and I just recalibrated them yesterday. The colors are the same (I've dragged images across and verified) ... but they are NOT the same when I'm working in Lightroom. For some reason the second monitor sticks with the original image color (which I also see if I move back to Library rather than develop ... can someone explain why that is happening, please?), although when I use the spot remover tool I see changes take place. Do I have something set incorrectly? (Normally I zoom in on my main monitor and keep the second one on the full image.) I don't know that this was happening before, but it sure is now. 

Btw, I've reverted back to the 9.2.1 version because of the issues that Adobe has yet to resolve with the spot remover and edges of an image.

I know you all will easily explain what is going on. You've been terrifically helpful!


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## Samoreen (Aug 16, 2020)

Hi,

Let's assume that there's no problem with the calibration of both displays (which is likely to be the case since the problem sometimes disappears during editing as you mentioned above).

Lightroom uses 2 different ways of displaying images in the Develop module and in all other modules (there are many reasons for this, essentially performance). Also, it doesn't use the same working color space in the Develop module (Prophoto instead of sRGB). So, there is necessarily a difference and we have to admit that the only safe way to preview images in LR before exporting or printing is to do this in the Develop module while zooming at 100%  (1:1). This explains why you can sometime see your changes when returning to Develop mode while they were not necessarily visible in library mode. However, the difference should not be that big.

Another issue is related to the different color spaces and possibly to the gamut of your monitors. In Develop mode, your image uses a color space that is equivalent to Prophoto. If you are using a wide gamut display, you might see colors in Develop mode that are out of gamut in Library mode (since LR uses the sRGB color space in that mode). So, these colors  will not be displayed and translated to another color belonging to the sRGB color space. The same problem may occur  if your main display is wide gamut while the secondary display is not or reversely.

Also, the preview in Library mode might not be updated immediately, depending on your preview settings and your hardware configuration. There will be less problems when using high quality previews on a system having a powerful CPU and plenty of memory.

*Conclusion* : the only safe way to evaluate (preview) an image in LR is in *Develop mode while zooming at 100%*. All other preview modes are not reliable. However, this is not a problem for most users. Usually, the differences are small or very small. So, it could be useful to give us information about your settings (_Catalog Settings | File handling_ - try to see if enhancing preview quality fixes the problem) and about your hardware configuration.

In _Catalog Settings | File handling  _you should set the _Standard Preview Size _either to Auto or to a value slightly higher than the width (in pixels) of you bigger display_. _Try setting the  _Preview Quality_ to either Medium or High. You can also look at 2 settings in _Preferences | Performance_ :

- Camera RAW Cache settings (try to increase the Cache size)
- Preview Generation Settings (try to enable the _Generate Previews in parallel_ option if not already done)

Before testing these settings, I recommend that your purge all your previews. This is just to be sure that we have no problem with previews generated while other settings were used (_Library menu | Previews | Discard everything_).

Hope this helps.


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## Patricia Mitchell (Aug 16, 2020)

Samoreen said:


> Hi,
> 
> Let's assume that there's no problem with the calibration of both displays (which is likely to be the case since the problem sometimes disappears during editing as you mentioned above).
> 
> ...




I think I was a bit unclear. So sorry! 

When I'm in the the Library module the images appear the same on both monitors. When I move to Develop the second monitor continues to look the same as it did in Library while the main monitor has the changes I've made, although if I have used the spot remover tool those areas are correct in both. It seems to be a color/saturation issue of some sort. 

BUT ... update ... I looked at other images and they are all fine. It's just a red rose that is so very different. So who knows what's up?! (Guessing someone here does!)

But I will attempt to do the things you've mentioned. Thanks so much.


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## Johan Elzenga (Aug 17, 2020)

Is your monitor a wide gamut monitor? A DCI-P3 monitor perhaps? The develop module uses its own preview, based on ProPhotoRGB. The previews used in all other modules are AdobeRGB. On a wide gamut monitor (especially a DCI-P3 based one) you may see that difference for certain colors.


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## Patricia Mitchell (Aug 17, 2020)

Johan Elzenga said:


> Is your monitor a wide gamut monitor? A DCI-P3 monitor perhaps? The develop module uses its own preview, based on ProPhotoRGB. The previews used in all other modules are AdobeRGB. On a wide gamut monitor (especially a DCI-P3 based one) you may see that difference for certain colors.



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27 inch 4k UHD resolution (3840 X 2160) IPS display
HDR 10 Compatibility
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## Samoreen (Aug 17, 2020)

Samoreen said:


> Prophoto instead of sRGB



My mistake : wherever I wrote sRGB, this should read Adobe RGB. This doesn't change anything to my other statements. Just, the possible color shifts between Prophoto and Adobe RGB are smaller.


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## Samoreen (Aug 17, 2020)

Patricia Mitchell said:


> Cutting and pasting description: LG 27UK850-W 27" 4K UHD IPS Monitor with HDR10 with USB Type-C Connectivity and FreeSync



Are both monitors identical ?


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## Johan Elzenga (Aug 17, 2020)

Patricia Mitchell said:


> Cutting and pasting description: LG 27UK850-W 27" 4K UHD IPS Monitor with HDR10 with USB Type-C Connectivity and FreeSync


I can't find the specifics of this particular monitor (other than that it covers 99% of sRGB), but many LG monitors are DCI-P3 and so are the latest Apple monitors (MacBook Pro and iMac). DCI-P3 is about as big as AdobeRGB, but it is not the same. DCI-P3 is larger than AdobeRGB in some areas, such as red and yellow, and smaller in other areas such as green. It is very well possible that you see more red in the develop module than in the library module on such monitors.


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## clee01l (Aug 17, 2020)

Johan Elzenga said:


> I can't find the specifics of this particular monitor (other than that it covers 99% of sRGB), but many LG monitors are DCI-P3 and so are the latest Apple monitors (MacBook Pro and iMac). DCI-P3 is about as big as AdobeRGB, but it is not the same. DCI-P3 is larger than AdobeRGB in some areas, such as red and yellow, and smaller in other areas such as green. It is very well possible that you see more red in the develop module than in the library module on such monitors.
> 
> View attachment 15143


Another spec lists sRGB 99% and AdobeRGB 73%.  i.e. the envelop is less than full sRGB (see your illustration) and far less than AdobeRGB or P3.  

I have a dual monitor set up using an ASUS (sRGB) monitor and an iMac (DCI-P3)   I calibrate each using an i1DisplayPro and separate color profiles managed for each.   Whether in Develop or Library Loupe view, the color rendition is different for the same image in the same module on different screens.   I've never had two identical monitors to compare and have resigned myself to accepting the difference.   I do my Developing process on the  DCI-P3 screen even though it is a 21" screen and the other (sRGB) is 27"


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## Johan Elzenga (Aug 17, 2020)

clee01l said:


> Another spec lists sRGB 99% and AdobeRGB 73%. i.e. the envelop is less than full sRGB (see your illustration) and far less than AdobeRGB or P3.
> 
> I have a dual monitor set up using an ASUS (sRGB) monitor and an iMac (DCI-P3) I calibrate each using an i1DisplayPro and separate color profiles managed for each. Whether in Develop or Library Loupe view, the color rendition is different for the same image in the same module on different screens. I've never had two identical monitors to compare and have resigned myself to accepting the difference. I do my Developing process on the DCI-P3 screen even though it is a 21" screen and the other (sRGB) is 27"


I agree that it is best to accept there are some differences and learn to live with it. Contrary to popular belief, color management can *not* make all monitors look exactly the same.


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## Patricia Mitchell (Aug 18, 2020)

Johan Elzenga said:


> I agree that it is best to accept there are some differences and learn to live with it. Contrary to popular belief, color management can *not* make all monitors look exactly the same.



I fully understand and certainly will live with it. I just don't understand why they ARE identical in Library mode but not in Develop. But I will now stop worrying about it and move on to other things.


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## Johan Elzenga (Aug 19, 2020)

Patricia Mitchell said:


> I just don't understand why they ARE identical in Library mode but not in Develop.


I tried to explain that already. The library module is AdobeRGB, the Develop module is a much wider gamut (ProPhotoRGB). That means that the difference between the monitors may be hidden in the Library module, because in that module the colors of the image are limited to AdobeRGB whereas the difference between the monitors could be that one of them can display some colors that fall outside of AdobeRGB. The image in the develop module would show this, because it is in ProPhotoRGB color space.


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## Patricia Mitchell (Aug 19, 2020)

Johan Elzenga said:


> I tried to explain that already. The library module is AdobeRGB, the Develop module is a much wider gamut (ProPhotoRGB). That means that the difference between the monitors may be hidden in the Library module, because in that module the colors of the image are limited to AdobeRGB whereas the difference between the monitors could be that one of them can display some colors that fall outside of AdobeRGB. The image in the develop module would show this, because it is in ProPhotoRGB color space.


Sorry ... I'm so very slow! I'd love to blame Covid, or the horrendous smoke from wildfires here. Most likely just my old brain, though. Thanks (again) for the explanation and I think I'll stop now.


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