Lightroom 2 and why you should shoot in RAW
Adobe has just released version 2 of Lightroom, their photography management/development application, and all I can say is that it is amazing. There are so many enhancements and upgrades that it's hard to know where to start. It's probably best to say that unless I actually want to do a whole heap of tricky retouching, I'm hardly going to fire up Photoshop at all anymore.
It's not perfect, however: a rather nasty bug in v2.0 stops all your old keywords from v1.4 from exporting with your photos, although a very simple SQL command (so simple, even I could do it!) fixes that problem. There have also been reports of Lightroom being everything from somewhat sluggish to completely glacial in performance, although my Mac Pro makes light work of just about anything, so I can't really comment on this!
Of all the tools, the selective adjustment brush was the most touted. With it, you can now mask areas and apply exposure, sharpness, colour, clariry (and more!) edits to specific areas of your photos without having to hand the image over to Photoshop. All your edits are non-destructive - just as in the previous version of Lightroom, all your edits are simply saved as instructions that are applied in real time to your image. The interface takes a little getting used to, especially for us Photoshop mavens, but once you've got the hang of it, it really is intuitive and extremely powerful.
However, my favourite tool is the adjustment brush's poorer, less glitzy cousin, the graduated filter. As its name suggests, this tool emulates the coloured or neutral density filters that you can physically place in front of your camera lens to achieve certain effects. My use for this tool so far is extremely prosaic - I use it to fix overexposed areas of sky.
We've all taken photos like this. While the foreground is fairly well exposed and detailed, the sky is completely blown out. If I had shot this picture in JPG, that would be pretty much the end of things - an 8-bit image simply wouldn't contain enough information for me to be able to regain all that lost detail in the sky. White is white, and would always remain so.
But when you shoot RAW, there is a ridiculous amount of information contained in the file (4,096 levels as opposed to JPG's 256 levels). And the important thing to realise is that most of this information is in the lighter areas of any image. As explained in this excellent article at Luminous Landscape, exactly half of the 4,096 levels of information are contained in the brightest fifth of the image, while there's a mere 128 levels of information in the darkest areas, the shadows.
What this means is that it's very possible to restore missing detail from overexposed areas when you shoot RAW. However, this was kind of a painful process before the new tools in Lightroom. To retain the properly exposed foreground but also get the corrected sky, I would have to export two versions of the file to Photoshop (one exposed for the foreground, the other for the backgroun) and then use layer masks to blend the two versions together. It's not something I'd do except for a photo I really thought was worth it.
With the new graduated filter tool, all I have to do is specify my exposure adjustment for the sky (around -2.0 to -3.0 stops, depending on how blown out things are) and drag out my gradient from top to bottom. The gradient is fully adjustable to taste after it's been applied, both in location and intensity. The results are nearly instantaneous and it's ridiculously easy to apply. Here's a before and after of the shot above, just so you can see how much detail can be regained using this technique.
This is an extreme example, requiring a full -3.0 stops to regain the detail in the clouds - probably about the absolute limit of this technique. But just think - there is that amount of information and detail just hiding in that brightest part of your image, and you have to shoot RAW if you want to be able to release it.
Posted in: adobe lightroom, chaosboy, photography on August 8, 2008 at at 9:42:00 AM
