When migrating your input catalog, Avalanche will create several extra collections in the ouput library (whether it is Lightroom or Luminar) in order to reference specific images it encountered. This article describes thos collections.
First, there are 3 collections that give a hint on how well the original settings of an image were preserved:
- Exact Conversion: this collection contains all images for which Avalanche is pretty confident that the image looks excatly the same as in the source. This will happen if the original image was untouched (As Shot) or if the type of settings that were applied were totally reproducible in the destination (a crop, a rotation, a flip, some straighten operation,...)
- Approximate Conversion: this collection contains all images for which the adjustements that were applied on top of the possible geometrical adjustments, are adjustements for which Avalanche has a Machine Learning model or a reasonable model to predict the output: White Balance adjustments, exposure adjustments (exposure, brightness, highlights, shadows, whites, blacks), tonal adjustments (vibrance, saturation,...), Black and White conversion, vignetting, sharpening,...
- Lossy Conversion: this collection contains all images for which the conversion has lost settings or could not replicate the source. Images in this category are all images for which a non local adjustment (brush, masks,..) has been applied or a complex effect has been applied (a Sky replacement in Luminar cannot be migrated to Lightroom for example). All images in that collection should be looked at carefully.
Note that if an image has seveal virtual copies (aka versions), it can happen that some versions will fall in one collection and some in another depending on the adjustements applied.
In the case of Aperture > Lightroom conversion, we create an additional collection set called Complex Stacks. This is because LR has a limitation that imposes all versions in a stack to be in the same folder. If the source catalog (for example Aperture) lets you create more versatile stacks, such a stack could not be represented in LR. Therefore this collection set contains all the stacks that could not be represented as a stack in Lightroom but were represented as a collection.