Yesterday David asked the question… “If I am using CS4 (PS4) and I upgrade to LR3, if I choose “EDIT WITH PS” will I get a warning message regarding ACR versions (6 vs 5)? I assume that PS4 does not support ACR 6 and will thus not maintain ACR mods from LR3 if I edit with into PS4? Is this correct? Implications?” So here’s an sneak preview from Adobe Lightroom 3 – The Missing FAQ…
What happens if I’m still using an older version of ACR and Photoshop?
If you’re using a mismatched version of ACR, it may not understand all of Lightroom 3’s new settings, and therefore the rendering may be different. Besides the new camera support, there are a few other changes involved, depending on the version number. In recent years, there have been changes to the demosaic, new sliders added such as Grain, existing sliders redesigned resulting in the introduction of Process Versions, and now the new lens corrections too.
The demosaic, in basic terms, is the initial translation of the raw data into an image, which applies to all of the photos regardless of your Process Version setting. ACR 5.6 and earlier use an older demosaic, whereas Lightroom 3 and ACR 5.7 and higher all use the new demosaic. The visible difference is an increased amount of detail in the newer demosaic, which can affect the amount of sharpening and noise reduction you choose to apply. If you open a Lightroom 3 photo into a version of ACR with the old demosaic (5.6 or earlier), for example, opening a photo directly into CS3 with ACR 4.6, then it will appear softer and less detailed than Lightroom 3, even if you’ve used sliders that it understands. If you open into 5.7 or later, the demosaic will match.
There are also new sliders which older ACR versions may not understand, for example, Grain and the post-crop vignette Highlight Priority and Color Priority options are understood by 5.7 but no earlier.
Further down the line are the processing algorithms, including Fill Light, Noise Reduction and Sharpening, which have changed so significantly this time that they now come in 2 different versions – Process Versions 2003 and 2010, more often shortened to PV2003 and PV2010. We discussed those in more detail in the Develop chapter.
And of course, last but not least, there are the new lens corrections which require ACR 6.1 or later.
Here’s a quick reference of the most recent ACR versions for each Photoshop release, and the differences you’re likely to see if you open the files directly into Photoshop.
|Demosaic||PV2003||PV2010||New Sliders||Lens Corrections|
|CS3 / 4.6||Mismatch||Close||Mismatch||Mismatch||Mismatch|
|CS4 / 5.7||Match||Close||Close (no UI)||Close (no UI)||Mismatch|
|CS5 / 6.1||Match||Match||Match||Match||Match|
CS3/4.6 – New sliders are ignored. If you only use sliders that were available in 4.6, with PV2003, it’s close but 4.6 also uses an older demosaic which can result in sharpening and noise reduction differences. Best to let LR render the file and then open that into Photoshop.
CS4/5.7 – No lens corrections are applied. There are other minor differences (i.e. sharpening slightly different) but otherwise it’s very close. 5.7 can read LR’s settings but there’s no UI to change the new settings. If you haven’t used lens corrections, the differences may not notice unless you’re looking for them, so you can probably open directly into Photoshop.
CS5/6.1 – Fully compatible with LR 3.0
There’s an additional dialog which often appears when the ACR version is mismatched, offering you the choice of ‘Render Using Lightroom’ or ‘Open Anyway’, although it’s currently missing with 5.7. More on the consequences of that dialog soon!
If you’re still on CS4 and you’re using LR 3.x, set the secondary external editor to CS4 so that it’s automatically forced to render the TIFF/PSD file, since the mismatch dialog is missing.