Today’s Question: I have read a lot about preview files in Lightroom: Standard, 1:1 and Smart Previews. What would you suggest? Should I just render Standard and allow the 1:1 to be built as required? It looks like Smart Previews are of most use if I want to edit with out the external hard drive connected where I store my photos. The only time I might use this is on a plane.
Tim’s Quick Answer: I recommend always generating Standard previews for your images in Lightroom when the issue arises, such as when importing photos. I generally only recommend generating 1:1 previews if you tend to zoom in on many (or most) of your photos. And Smart Previews are primarily for working offline or for improving performance in the Develop module.
More Detail: With the key exception of the Develop module, where the preview is rendered based on the original capture based on the current adjustment settings, you could say that Lightroom is always presenting a preview image rather than the “source” image. The only real question is whether that preview is loaded from a preview cache or generated on the fly. The former provides improved performance over the latter.
When you are viewing your images at a “normal” full-image view, such as when using the “Fit” zoom setting, you are viewing the Standard preview for the image. If a Standard preview does not exist for the current image, one will be generated at that time. This can cause you to see a reduced-quality preview briefly while that Standard preview is generated.
For this reason, since you’ll need a Standard preview for any image you view in Loupe view, I recommend generating Standard previews for all images during import (or later in your workflow if that step was skipped for any reason).
If you zoom in on an image (such as with the 1:1 or 100% zoom setting) then you’ll need the 1:1 preview. Again, if a 1:1 preview does not exist for the current image when you zoom in, Lightroom will generate that preview on the fly. This will, again, involve a brief delay while the preview is generated.
I don’t personally tend to zoom in on a significant percentage of my photos, so I prefer not to generate 1:1 previews. I don’t mind a brief delay when I do need to zoom in on a specific image, and would prefer to conserve hard drive space instead. If you do tend to zoom in on a relatively high percentage of images, however, then you may prefer to generate 1:1 previews on import (or later in your workflow).
The Smart Previews enable you to work in the Develop module, or to export or otherwise share photos, even when the source image file is not available (such as when an external hard drive containing photos is disconnected from your computer). In addition, you can enable an option in Preferences to make use of Smart Previews in place of the source image within the Develop module in order to improve performance. If either of these scenarios appeals to you, then you may want to generate Smart Previews during import (or later in your workflow).
So, in summary, I personally prefer to generate Standard previews for all images. I let Lightroom generate 1:1 previews on an as-needed basis, but you may prefer to generate them for all images. And while I don’t generally employ Smart Previews in my workflow, they can absolutely be beneficial in certain situations.