Before there was Lightroom (Classic), we had Photoshop, Bridge, and the Adobe Camera Raw (ACR) plug-in that formed the foundation to many photographer’s digital imaging workflow. In the 10+ years since Lightroom’s debut I think it’s safe to say that many of those photographers have made the migration over to Lightroom. So much so that it’s far more common to see articles, videos, and tutorials about Lightroom than about ACR. That said, there are still people using ACR because that’s what fits their needs. I’m not here to convince anyone to change the software they’re using, but rather to provide a look into what’s the same, what’s different, and how to decode whether a given Classic resource applies to ACR, and vice versa. 

Origins 

Lightroom was created as a way to take the powerful editing capabilities in the ACR plug-in and build a more efficient workflow around it, from capture to output, aimed specifically at digital photographers. As a result, Lightroom Classic shares the same editing and rendering capabilities as the ACR plug-in, but in a different wrapper that includes features and functions for importing, organizing, and output that don’t exist in Camera Raw itself. Due to this common origin, Lightroom and Camera Raw have evolved as separate products, but they continue to be developed and updated in parallel to retain that consistent editing and rendering capability. 

Because of this, the conventional wisdom is that everything in Classic’s Develop module is also in ACR, and everything in ACR is also in the Develop module. But in actual use, I think the answer is a good bit more nuanced than that, and that’s what we want to explore. 

Differences 

So much is the same between the two programs that I just want to focus on the differences to help you navigate between the two programs. Now, if you’re a Classic user you might be wondering why this would be helpful, but there are a few scenarios where a Classic user might encounter the ACR plug-in: 

  • You use the Photo>Edit In>Open as Smart Object in Photoshop workflow from Classic.
  • You use the Filter>Camera Raw Filter in Photoshop.
  • You have some reason to open a RAW photo into ACR from Bridge or Photoshop (rare, but not unheard of). 

We’ll look at those specific cases later on, but I think there’s value in Classic users knowing their way around ACR too. 

The Interface 

The biggest cause of disorientation at first for anyone opening one program or the other is the difference in where things are located. In Classic, all of the editing tools are located within the group of panels on the right side of the Develop module. ACR also has a group of tabbed panels on the right side of the interface, but it also provides access to a suite of tools along the top of the interface. 

In both Classic and ACR, if you’re unsure of what a given icon represents, just place your cursor over the icon to see a tooltip appear displaying the name of the tool and its keyboard shortcut. I highly recommend that new users spend time becoming familiar with the icons this way. Note that keyboard shortcuts aren’t consistent between the two applications, so be prepared to use your mouse a lot more in the program with which you’re less familiar. 

Here are a few quirky differences in the two interfaces of which to be aware: 

  • The White Balance Tool appears in the top tool strip in ACR, but in Classic you’ll find it in the Basic panel.
  • The Targeted Adjustment Tool appears in the top tool strip in ACR, but in Classic you’ll find it in several different locations: the Tone Curve, HSL, or BW panel (depending on what you want to adjust).
  • The Straighten Tool appears in the top tool strip in ACR but is included within the Crop tool in Classic.
  • The Transform Tool appears in the top tool strip in ACR but is a panel of its own in Classic.
  • ACR has left and right rotation buttons along the top, but the rotation options in Classic are found under the Photo menu (or on the thumbnails in Grid view of Library).

There’s one tool that can be found in ACR that doesn’t exist in Classic, a that you can change the color space used by the Histogram and Color Sampler in ACR via the Workflow Options dialog (accessible by clicking the link at the bottom of the window). Classic’s color space can’t be changed in a similar way (unless you’re soft proofing). 

It’s in this Workflow Options dialog that you can configure ACR to open a copy of the edited photo as a smart object in Photoshop, if desired. In Classic, you’d go through the Photo>Edit In>Open as Smart Object in Photoshop menu to do the same. 

You’ll also find an option in this dialog to change the pixel dimensions of the photo opening in Photoshop from ACR. Most people leave this at the recommended Default setting that uses the native pixel dimensions (minus any cropping), but Lightroom doesn’t have any way to change the pixel dimensions of the copies sent to Photoshop for editing (aside from cropping). If you need to resize the photo as part of your edit in Photoshop workflow from Classic, you’d have to either resize it in Photoshop after it opens, or go through Classic’s Export dialog, then open the exported copy in Photoshop. In both programs, the ideal is to stick to the largest color space and highest resolution (pixel dimensions) possible for editing the master version of the photo. 

In Classic, the closest parallel to the Workflow Options dialog in ACR is found in the Lightroom (PC: Edit)>Prefer­ences dialog under the External Editing tab. Here you can configure the color space, bit depth, and file type of copies sent to Photoshop with Lightroom adjustments. The default settings are recommended. Changing these settings has no effect on what you see in the Develop module. 

Presets 

Both Classic and ACR support the saving and using of editing presets. In Classic, this panel is found on the left side of Develop, while it’s found on the right side in ACR. ACR doesn’t support the organization of presets into folders that you can do in Lightroom, so they’re simply listed in alphanumeric order. 

Batch Editing 

I do think Classic makes it easier to perform batch editing on photos, as it’s designed to be more efficient in this regard, but it is possible to batch edit in ACR. If you open multiple photos into ACR, you’ll see a Filmstrip appear on the left side, while in Classic the Filmstrip appears along the bottom. 

To sync settings across multiple photos in ACR, you’d edit the selected photo, and then Shift-click to select the other photos you want to sync in the Filmstrip. Click the flyout menu at the top of the Filmstrip to access Sync Settings and open the Synchronize dialog. Here you can check only the settings you want to sync and then click OK to perform the sync. 

The parallel option in Lightroom works in a similar way, except the Sync button appears on the bottom of the right panel group. 

Merge to HDR/Merge to Panorama 

In the flyout menu at the top of ACR’s Filmstrip you may have noticed the options for Merge to HDR and Merge to Panorama. This is a powerful way to select relevant RAW photos (depending on how they were captured originally) and merge them into an HDR or pano version that ends up as a fully editable DNG file. Lightroom has this same ability, but it’s found by selecting the relevant photos and going to the Photo>Photo Merge menu. The results are the same, but the route to get there isn’t easily discoverable to new users. 

Virtual Copies and Snapshots 

Due to Classic’s use of a catalog (database) to manage your photos, it has the ability to create additional sets of editing instructions for photos, and these are called virtual copies. These only exist in the Lightroom catalog but can prove to be a very useful way to create multiple versions of your photos. ACR doesn’t support virtual copies because it doesn’t use a catalog. Both programs support the creation of snapshots, however, which is a way to preserve different editing states right within the photo itself. In Classic, the Snapshots panel is found on the left side, while in ACR it’s nested among the tabs on the right. 

Output to Photoshop 

In ACR, when you’re finished all of your edits, you have a few options. You can click one of the buttons along the bottom of the interface to determine what happens next:

  • Click Save Image(s) to access the Save Options dialog where you can configure the parameters for the copies that will be created at the location of your choosing. This is helpful if you have no need to go through Photoshop, and just want to save a copy in a specific way.
  • Open Image(s) to open a copy with ACR edits (including Workflow Options) into Photoshop for additional editing. This also saves the ACR edits to the source photo’s XMP metadata. If you turned on the Open in Photoshop as Smart Objects option in the Workflow Options dialog, this button will say Open Object(s) instead. Tip: Hold the Shift key to temporarily change the Open Image button to Open Object.
  • Click Cancel to abandon edits and not save them to the source photo.
  • Click Done to write changes to XMP and close the ACR window without going to Photoshop or creating new copies.

In Classic, all of the edits you make are written to the catalog as you work, so there are no Done or Save buttons. If you need to abandon your edits completely, you can click the Reset button to go back to the default settings. If you wish to continue editing in Photoshop, you’d go through the Photo>Edit In menu and choose the desired option. If you have no need to edit in Photoshop, but want to save edited copies, you’d go to File>Export to access the Export dialog (very similar to the Save Options dialog in ACR), where you can configure your desired output parameters. 

An important note for Classic users to keep in mind is that if you start with a RAW photo and choose Photo>Edit in>Open as Smart Object in Photoshop, a copy of the RAW photo with Lightroom settings is embedded in a smart object layer of the new TIFF (or PSD based on External Editing settings) file. While in Photoshop, if you double-click the smart object to edit the embedded RAW photo, it will open in ACR, not Lightroom. Since this is a new copy, this won’t affect the original RAW photo back in Lightroom. Just be prepared to continue your editing in the ACR interface. 

Conclusion 

While the editing and rendering ability of ACR and Classic are the same, and they contain a parallel set of editing tools, there are some key differences to be aware of before you jump into the program with which you’re least familiar.