P: SDK: photo:getDevelopSettings() sometimes returns nil for Temperature and Tint

@johnrellis In my test catalog, no matter the version ofLrCC, I haveDNGss that appear with Temperature and Tint "nil"

I already shared one of those files (which is not mine) in one of my previous replies above: AWilliamsFam00400.dng (for some reason now I can't attach files when I reply)

The bug doesn't seem to be in the  photogetDevelopSettingss() but rather in the files themselves that, for some reason, do not have Temperature nor Tint at all.

In the mentioned file theSDKK tells me there is no temperature at all (and theUII also shows ZERO Temperature)

ExifTool gives me this if I search Temperature

.

I can't reproduce the precise bug recipe in LR 13.0.1 using this version of the test catalog upgrade to LR 13:

https://www.dropbox.com/scl/fi/8cqymzcvhrm0kl9nb27t6/Temperature-13.2023.10.26.zip?rlkey=rou0f7m8snhovd840ooidbmpq&dl=0

The correct values for Temperature and Tint are always returned. 

@C.Cella, what do you observe when you execute the steps of the recipe using the upgraded LR 13 test catalog?

"If the fields return nil, check for IncrementalTemperature & IncrementalTint. It should work."

The problem with this purported workaround is that the settings IncrementalTemperature/Tint represent the Temp and Tint sliders for non-raws, with values in [-100..100]. Whereas the settings Temperature/Tint represent the Temp and Tint sliders for raws, with values in [2000..50,000] and [-150..150] respectively.

So when examining a raw, if you observe Temperature is nil and IncrementalTemperature non-nil, that is by definition a bug.

You can verify the meaning of these settings three different ways:

1. Opening .xmp sidecars for raws in a text editor and using Exiftool to examine the XMP metadata of non-raws, or

2. Creating two presets with White Balance selected, one from a raw and one from a JPEG, and opening the presets in a text editor.

3. Using the Show Catalog Metadata plugin, which displays the results of photo:getDevelopSettings().

In addition, I repeated the bug recipe with LR 12.5 using the modified "get-temperature.lua" script below, and it never returns non-nil values for IncrementalTemperature/Tint when Temperature/Tint are nil, contradicting Engineering's claim:

import "LrTasks".startAsyncTask (function ()
    local s = import "LrApplication".activeCatalog ():
        getTargetPhoto ():getDevelopSettings ()
    import "LrDialogs".message ("Results", string.format (
        "Temperature, Tint:\n%s, %s\n" ..
        "IncrementalTemperature, IncrementalTint:\n%s, %s",
        s.Temperature, s.Tint,
        s.IncrementalTemperature, s.IncrementalTint))
    end)

@Rikk Flohr: Photography 

Problem with the suggested solution is that getting IncrementalTemperature and IncrementalTint return, predictably so, nil value for RAW files that usually return Temperature and Tint correctly.

.Seems to me that for some RAW files or DNGs, Temperature and Tint don't exist and instead IncrementalTemperature/Tint are used...that's why the SDK can't return them.

EDIT.

I have DNGs affected in my test catalog AND I suppose something went wrong when they were created/converted form the RAW.

@johnrellis 

I have created a second scrip based on your own and and used IncrementalTemperature & IncrementalTint and indeed it returns the Temperature and Tint even for Raw Files that could not return Temperature and Tint.

.

From engineering: "If the fields return nil, check for IncrementalTemperature & IncrementalTint.
It should work."

Thanks for adding your experience and escalating this John.

Yes, I had tried using code to toggle to the Develop module and grabbing the slider values that way - but, as you said, it's very klutzy and quite slow. However, I can't think of any other ways around this bug so I will revisit it to see if it will satisfy as a temporary workaround.

Adding bug number and setting status

I've hit an edge case in my plugin development and could use some help. Essentially, I'm unable to access a photo's white balance settings of 'Temperature' and 'Tint' from the Grid module if Lightroom Classic hasn't initialized them. If I open the Develop module on the same photo and then go back to the Grid and try again - they are accessible. But otherwise they remain nil initially (and I need to grab them to perform relative operations on them!).

Here are some basic steps to reproduce the issue, all done from the Grid view:

1. Select a photo
2. Right-click photo -> Develop Settings -> Reset
3. Run my plugin on the selected photo, from File -> Plugin Extras -> Name of My Function
4. When trying to access the white balance values of 'Temperature' and 'Tint' from my code (see following code for the basics), they are nil:

local currentDevelopSettings = currentPhoto:getDevelopSettings()
local currentTemp = currentDevelopSettings["Temperature"]​
local currentTint = currentDevelopSettings["Tint"]

Is there a best practice for initializing these values via code so that I can go on to work with them? I've tried a few things, but have hit wall after wall and am looking for fresh ideas.