Misfiring Neurons Just another geek with a blog

Lightroom 3 Beta begins with big improvements in image quality

I have been using Lightroom since one of the early pre-1.0 beta releases, and have enjoyed using it ever since. The release of the first public beta of Lightroom 3 last week was naturally an interesting event – what have they cooked up this time? According to the official release notes the major improvements are in the ACR rendering engine which processes raw sensor data into nice looking images. However I just wasn’t seeing any of the supposed improvements when looking at my files! Eventually I realized my mistake – because I imported some DNG files which had already been through Lightroom 2, the new beta was using the same old “process” in order to maintain the same appearance. As Larry Wall would say – “this is not a bug, it’s a feature!”

Lightroom was actually doing the right thing by preserving the original look of the images. All that was needed was to either reset the development settings (killing my adjustments in the process), or update to the latest process version (this is available from the Settings menu when in the Develop module). I have noticed that some of my images require a lot less sharpening under the new process and so would look rather over-sharpened when simply converted to the latest process. In other words there is a good reason why Lightroom does not automatically put your old images through the new process – it’s different enough that the results of your original adjustments may simply not look as good as they should. My advice would be not to do large-scale en masse conversion of entire folders or catalogs, rather convert individual images and reassess the adjustments made.

Now that I am seeing the output of the latest rendering engine, I can tell you that this alone will be worth the price of the upgrade for me. Colour noise handling is vastly improved, the luminance grain is tighter and there may even be a tad more detail visible in some borderline cases. Have a look at the following side by side crops and judge for yourself (click to see in full):

All files use the default Lightroom noise reduction settings – the colour noise reduction slider was set to 25, and luminance noise was set to 0.

The improvement in the G10 images is very impressive. Also note the much reduced vertical banding in the 50D ISO3200 sample #4 above (this is the only crop that is not 100% because the banding was not as obvious at the 1:1 magnification size). Overall, I am seeing ever so slightly more detail (e.g. the stitching in sample #2, eyebrow hairs in sample #3) and vastly reduced colour noise with a more pleasing grain pattern. The Nikon D700 does not show a huge improvement – I had to go through quite a number of ISO 6400 photos to find one that shows much of a difference, mostly because the files are so good to start with. The story is similar with the Pentax K10D in that it doesn’t show much improvement – the files are fairly noisy in the first place and stay that way even under the new process.

All the above files have easily discernable differences at full-screen view on my HP LP2475w (24” 1920x1200 LCD, or around 30% magnification depending on which camera the file comes from), except for the Canon 50D @ ISO 400 and the two Pentax shots. The differences between Lightroom 2.5 and 3.0 Beta rendering for these three images are basically invisible at smaller magnifications.

Another small but important improvement that I’ve noticed is the smoother movement of the adjustment sliders. Previously, some computationally-expensive adjustments would make the sliders very notchy as the image preview was being rendered every time you changed a value. Now the sliders can move freely all the time. This is a classic case of better use of multithreading leading to more responsive software. I haven’t done any actual testing but it seems as though the new beta is also utilizing my dual core CPU better during import/export. It only makes sense as CPUs with four or eight threads of execution are becoming increasingly popular, and Lightroom 2 has some known deficiencies in such configurations.

The Lightroom 3 beta is available to all at Adobe Labs (free registration required).