Every week I receive emails from photographers who are confused about one thing or another in Lightroom Classic. So I thought it would be helpful to cover some of the most commonly asked Lightroom Classic questions. Which of these areas are you confused about? Hopefully none!
1. Which version of Lightroom am I using?
Adobe has changed the name of both apps so many times that even experienced users may wonder what the official name is of the version of Lightroom they’re using.
The quickest way to tell is to go to Help > System Info. The current version number is listed right at the top.

This is important to know if you post questions on a forum. Letting people know what version of Lightroom you’re using helps you get a better answer.
2. Should I use Lightroom Classic or Lightroom?
Let’s get this one out of the way. This is most likely to confuse newcomers to Lightroom as Adobe pushes the Lightroom app (formerly Lightroom CC) rather than the photography plan which includes Lightroom Classic. But for most photographers, Lightroom Classic is definitely the way to go.
If you’ve any doubts about this, just remember that Lightroom stores your photos on Adobe’s servers, and charges you for it at a rate of $10 per terabyte. That can get expensive, fast.
Lightroom also lacks many of Lightroom Classic’s more advanced features. For example:
• There’s no Maps, Print, Book, Slideshow or Web module.
• You can’t print photos from Lightroom.
• You can only export photos in JPEG or DNG formats.
• You can’t export photos directly to apps such as Exposure or Luminar (only to Photoshop).
• You can’t install plugins to extend its functionality.
If you’re using Lightroom, then realize you’ve made a mistake, then make the switch now. The longer you wait, and the more photos you add to Lightroom, the more difficult it gets.
Learn more: Which Lightroom Version Do I Need?
3. How do I resize photos in Lightroom Classic?
In Lightroom Classic you can only change the size of your photo when you export it. Go to Image Sizing in the Export Window (marked below) where you can set the size in pixels, centimeters or inches. This is useful if you need to export your photo at a certain size for printing (you could also use a Print module template).

Cropping, by the way, is a separate action from resizing that’s done in the Develop module. You can’t crop a photo in the Export window, you can only resize it.
4. What color space am I using?
If you’re used to developing photos in applications like Photoshop, where you have to choose which color space to work in, then you may get confused when you can’t find any option to change the color space in Lightroom.
That’s because Lightroom works in its own proprietary color space that’s based on ProPhoto RGB, which has a wider color gamut than the sRGB and Adobe RGB Color spaces. This helps retain as much color information as possible from your Raw files.
The only place you can set a specific color space is in the Export window (see File Settings), where you decide which color space to assign to your exported photos (hint: pick sRGB unless you have a really good reason to make another choice).

5. Why is there a Comments or No Comments panel in the Library module?
Not everybody has a Comments panel in the Library module. But it’s there if you have synced Collections or have exported photos to Flickr using Published Collections.
If somebody makes a comment on a photo (for example, in Lightroom for web or in Flickr) or marks it as a favorite then it appears here.

When the Comments panel is closed, it tells you how many comments the selected synced/shared photo has.

If the selected photo hasn’t been synced or exported to Flickr then you’ll see a Collection is not synced message in the Comments panel.

How do I use Comments?
Why is this useful? Imagine that you have taken some photos of your son and want to show them to his grandma so she can pick her favorites. Here’s how you do it.
• Put the photos you want to show her into a Collection.
• Sync the Collection.
• Right-click the Collection name, go to Lightroom Links > Make Collection Public.
• Right-click the Collection name again, go to Lightroom Links > Copy Public link.
• Give this link to Grandma, who opens it in her browser where she can mark her favorite photos (she’ll need a free Adobe account to do this, which of course Grandma already has).
• Back in Lightroom Classic you’ll see which photos Grandma has marked as a favorite and any comments she’s made.
Here’s the clever bit. Lightroom Classic shows a yellow speech icon next to Collections with new comments.

If you click on the Collection and go to Library > Review Comments then Lightroom sets Sort in the Toolbar (press ’T’ if you don’t see the Toolbar) to Last Comment Time.

This puts the photo with the most recent comment at the start of the Collection (it’s also a nifty way of seeing which photos in a Collection have comments for sorting purposes).
The speech icon is also displayed as a thumbnail tag in Grid View.

6. Should I enable GPU acceleration?
GPU acceleration is when an application uses your computer’s graphics processing unit to make certain processes, such as rendering photos on a monitor, faster.
When Adobe first added GPU acceleration to Lightroom it turned out that Lightroom ran more slowly, not faster as intended, for some users.
For this reason you always have the option to turn GPU acceleration off. Also, Lightroom Classic won’t let you use GPU acceleration if there are known compatibility issues with your graphics card (the option is grayed out).
Since the 8.4 update Lightroom Classic also uses GPU acceleration to help speed up some Develop module calculations, so the photo updates faster when you move a slider.
You can set GPU acceleration by going to Preferences > Performance. Set it to Auto to let Lightroom Classic make the decisions. Or select Custom to decide for yourself whether to use the GPU for image processing (this option is grayed out if not supported by your graphics card, see below).

If you have any doubts about whether GPU acceleration is making Lightroom run faster, then set it to Off.
What if I have more Lightroom Classic questions?
Of course, if you have any more questions about Lightroom Classic then let us know in the comments.
9 comments
Question: what affects the choices of the positions of the sliders in the B&W (HSL ) panel when you have turned an image to black & white and use the ‘Auto’ button?
Thanks in advance
Chris
Hi Chris, according to Adobe the aim of the Auto button is “to set a grayscale mix that maximizes the distribution of gray tones. Auto often produces excellent results that can be used as a starting point for tweaking gray tones using the sliders.” I’ve never come across anything more detailed than that and my guess is that Adobe prefers it that way. But from that we can tell that the aim of Auto is to give you a good range of gray tones, and that it’s intended as a starting point rather than the finished result.
Hi Andrew, first of all thank you for the numerous tips and articles on photography and processing, which I have found invaluable.
I currently use Lightroom 6.14 and do not wish to subscribe to the monthly payment options. I am considering purchasing Luminar or On1 and would really appreciate knowing your view of these applications.
Kind regards
Will
Hi Will, both Luminar and ON1 Photo Raw have their good points. Neither one is as powerful as Lightroom when it comes to organizing and searching your photos, but both have more options when it comes to developing them. To be honest the answer to this question is so subjective all I can say is download the trials for both applications and give them a try. You’ll probably find you like the interface of one better than the other, or that one has tools that are more useful to you and your style of photography. Hope that helps!
Thanks Andrew! I shall do as you suggest.
I am new at light room. I have always used photoshop 15, 16, 17, 18 etc. Which would be best for me as a beginner.
Hi Patricia, you’ll be fine with Lightroom Classic, it’s a fairly easy program to learn how to use, it just looks complicated at first until you learn what all the different parts do. Download the trial and give it a try! There are plenty of tutorials on here to help.
If I have lightroom classic on my desktop, can I also load it on my tablet without another subscription?
Hi Betty, yes you can. Log into your Adobe account in the Lightroom app on your tablet to get syncing and use both.