LIGHTROOM: The view module does not reflect the developed image

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  • Updated 7 years ago
  • Not a Problem
  • (Edited)
Hello, I may have stumbled into a bug. I installed Lightroom 4.1RC2. I used it to develop a photo, using the new 2012 process settings, and adding a vignette effect on the sky. (BTW, I have the same photo developed in Lightroom 3, and apart of the banding the result was fine) This resulted in some banding in the sky, so I used a moire brush to smooth the area. In the develop module it worked like a charm, giving me a perfectly smooth sky. But if I look at the image in the viewing (browsing / normal) module the sky is all "patched" with darker bands of extreme saturation near areas more normals. In attachment you may see screenshots at 100% of the problem, that can illustrate it better than words (01 = develop module, 02 = viewing module). The "bands" appear only in the browsing mode, not in the exported tiff image that instead is exactly as good as viewed in the develop module. Thanks. Luca
P.s.: the image has been developed from the Canon CR2 file of a Canon Eos 5D Mark II

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GIANLUCA BEVACQUA

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Posted 7 years ago

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LRuserXY

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Basically, there may be two reasons for this (assuming it is not a bug in your case):

1. Previews are stored in AdobeRGB JPEGs, with less tonal resolution (8 Bits/channel, Gamma 2,2) as the develop module (16 Bits/channel, linear Gamma).

2. JPEGs use compression, which exhibit typical artefacts, which also can lead to such banding, especially in critical regions with subtle tonal changes as in your example.

#1 cannot be changed. Concerning #2: Did you look at the photo at normal size ("fit")? Then a) try to render a 1:1 preview (or zoom in/out), or b) set your preview quality to "high" (in the catalog-specific settings). Changing the preview quality may require some development change to refresh the preview (not 100% sure about that).

Perhaps this helps... if not, the problem has to be investigated further.
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GIANLUCA BEVACQUA

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Hi, thanks for your help.

#2 Unfortunately the same banding is shown even looking at normal "fit" sizes, and I yet use the "high" setting.

1# Actually I did a bit of research, exporting the image at various settings and checking the resulting files in Photoshop CS5.

Here I found that I had a perfect result only exporting it as 8bit tiff in adobeRGB. With 16bit exporting it got progressively worst, going from srgb to adobe to pro photo (this last one was the worst, absolutely unusable). But converting each one of the images, independently of the original color space, at 8bits OR in Lab color mode made each one of them turn out perfect.

I thought I had nailed the thing, or at least the solution...until I opened the same files in Apple Preview. Here the 16 bit pro photo one looked perfect, and the one at 8 bit in adobeRGB looked like rubbish!

At this point I used the Photoshop option to desaturate the monitor colors of 20% to be able to see a wider gamut and now all the files finally looked exactly the same, without banding. So at this point I'm pretty sure it is the gamut of this type of image that is causing problems with my monitor (that by the way is the one of a mid 2011 iMac 21.5").
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John Spacey

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The second monitor view does have a bug in which it doesn't look the same as the view in the develop module. Known issue and there's thread somewhere about it
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Dorin Nicolaescu-Musteață, Champion

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The Develop preview is 16bpp and dithered (otherwise it would still have banding, because you monitor is 8bpp). Exports to 8bpp are dithered. Converting 16->8bpp in Photoshop does dither too.

On the other hand, Library previews are 8bpp and not dithered on conversion. And of course exports in 16bpp are naturally bot dithered.

Hope, that explains why:
a) Develop looks better than Library,
b) ironically, 8bpp export looked better than 16bpp.
c) again, ironically, converting from 16 to 8 bpp in Photoshop gives a better on-screen look.
d) In 8bpp, the wider AdobeRGB looks worse that smaller sRGBs space.
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GIANLUCA BEVACQUA

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@ John
Sorry, but the problem is not on a secondary monitor (or at least not only), but on the primary one.

@ Dorin
Thanks, I think this is the origin of the problem, given the limited gamut of the iMac screen (give or less it covers the sRGB space).

This explain also because I'm having troubles only with few images like this one: this shade of blue is a problematic area, just near the boundaries of what my display is capable to manage.

And by the way your explanation about dithering I think is correct, in fact with less severe banding cases I was able to avoid the problem adding an insignificant amount of noise to the image in Photoshop (we're talking about a 0.16% gaussian monochrome noise).

So I here hereby declare the problem solved! ;)

It is definitely not a Lightroom bug.

Maybe it's time to buy a wide-gamut display...
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Dorin Nicolaescu-Musteață, Champion

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You don't need a wider gamut, but more tonal resolution (bits per pixel).