Space bar won't open photos in Mojave

You are not alone with this sentiment, see:

Re: Is v.4 of Photos (Mojave) different than v.3?

The spacebar is now used to start and stop videos - a video will play a preview in the thumbnail and I can start and stop it by hitting the space bar. It is now similar to iMovie, but to quickly open or close an image i have now to use the return key.

I went to the Preferences > Keyboard > Shortcuts > App Shortcuts > Added Photos. For Menu Title I entered "Open Viewer" and for the keyboard shortcut I pressed Fn with Space.

At the same time, I followed the procedure for closing picture preview.

Preferences > Keyboard > Shortcuts > App Shortcuts > Added Photos. For Menu Title I entered "Close Viewer" and for the keyboard shortcut I pressed Fn with Space.

Until Apple fixes this, upon loading Photos, just hit the Return key once, then the space bar will work. No need to use your mouse to invoke the image menu.

I hate this as well. Now you must hit the "return" key to have the function previously used by the space bar. I do not like this. Was looking to see if we could change this by a setting but I haven't found it yet.

Same annoying problem here. I tried hitting the return key when first opening Photos since it was the default way to open a thumbnail (besides double clicking), and it no longer works, but after tapping the return key once, then the space bar works without clicking in the Image pull down.

Funny that Apple left the spacebar as a way to, say, look at a pdf file in a Finder window, but someone thought the spacebar was not the way to open a photo!

This worked after a restart and several closing and openings of the photos app

Thanks

Go to preferences > keyboard > shortcuts > app shortcuts > Photos > and add a shortcut. For Menu Title enter "Open Viewer" and for the keyboard shortcut press the spacebar whilst holding the Fn key. Add another one for "Close Viewer". Problem solved

Go to the previous page in this discussion. "Eric in Boca" totally and completely solves this blunder by Apple. You might have to use Return once at the start of a Photos session (when you open Photos anew), but then the spacebar will work exactly as before! There is another answer marked "solved" but it doesn't solve anything. It just tells you to use the Return key.

You may want to look at the date of the post, artist999, September 26, 2018. That was two days after Photos 4.0 and Mojave had been released. At that time we were still wondering, if this is a bug or intentional. The day before the Photos User Guide had still been describing the space bar shortcut like it has always been, so it looked like a bug. I posted my reply after I had seen, that Apple had updated the list of keyboard shortcuts to include the new behavior, when it became clear, that the changed behavior is unfortunately fully intentional (Photos keyboard shortcuts on Mac - Apple Support). If it were a bug, unexpected, incorrect behavior - we could hope for a bug fix. But with a new intended behavior - broken be design, there is not much hope for a fix by Apple.

The same happened for the "R" shortcut for the Retouch tool. Two weeks ago I received a reply to my bug report that "Photos is functioning as designed". It included a link to the updated list of shortcuts. https://support.apple.com/guide/photos/photos-keyboard-shortcuts-on-mac-pht6e593 112/mac

I haven't been able to make it work with a new shortcut key, or clicking the image menu, or clicking the return key when first opening photos. The only thing that works for me is the return key. Frustrating. I left feedback on the link to apple.

You can also use trackpad to preview or close a photo. Just double tap the trackpad instead of pressing the space bar. Perhaps Apple wants us to use more gestures instead of the keyboard.

I'm experiencing the same thing. I have to click "IMAGE" before this shortcut will work. Small price to pay for a great fix to an otherwise stupid decision.

AGAIN, YES AGAIN, JUST CLICK ON YOUR RETURN KEY ONCE WHEN FIRST OPENING PHOTOS, THEN THE SPACEBAR SHORTCUT WILL WORK.

Go through all the posts again carefully. It DOES work, but you have to enter the names of the 2 shortcuts exactly as the instructions say: case sensitive. And remember, in a NEW session, like when you restart your computer and open Photos, you have to hit Return the first time you want to Quick Look a photo. But after that, the space bar will work.