Update: When I wrote this page I was using Duet Display for retouching, especially to help me when I had to apply the brush carefully on a small area of a photo. There wasn’t any other app to do this at that time, however, Duet is far from perfect for this kind of task. Duet Display is not intended to be used as a graphics tablet, which is what I want it for with Lightroom, Photoshop or Affinity Photo. That’s why now I recommend Astropad to do all the fine retouching, masking, etc. with a stylus.
Using a second display is said to increase your productivity by 50%. I don’t know how much productivity the Internet says that you would gain when using Lightroom, but having another display can help you browse the photos in your catalogue. It helps me! How? Easy, using an option which surprisingly I haven’t heard a lot about: Secondary Display, under Window > Secondary Display > Show. Doing this will make a window appear and you can see the Grid, Loupe, Compare and Survey modes of the Library module and Filter View. Drag this window to your extra monitor and this way the Develop module stays on your main screen and you won’t need to go back and forward between Develop and Library modules.
When you’re on the go you don’t normally take your heavy/big extra monitor with you. However, if you have an iPad you can use it as an extension of your laptop screen. There are various apps which do this, but I recommend Duet Display. Contrary to other apps which sync both devices through WiFi, Duet Display does it using the Apple Lightning cable, which is better as it can hold more data transfer, and you don’t need a WiFi network. Also, it charges your iPad while you are using it, but you should have your laptop plugged or the battery will drain really quickly. The creators of this app say there is zero lag, and this will depend on the power of your computer and iPad. Duet Display gives you various options of quality display and frame rate which can help you to avoid screen delay. I don’t have any lag at all with a MacBook Pro 2014 and an iPad Air 2 using Lightroom CC 2015 and 30 fps mode.
Once connected, drag the Lightroom Secondary Display to the iPad (Duet will fit the window automatically to the iPad) and you have your extra monitor. What’s more, because it’s an iPad it’s touch-screen, of course! You can edit a photo in the Develop module on your laptop just touching that photo on the Library Grid View on the iPad with your finger, easy. Really cool, but up to here there is nothing new from having your second monitor at home.
Now is when things get even cooler.
Sometimes when I’m using the brush tool to mask a part of a photo it’s really difficult to be accurate, especially when the area is small or not smooth shaped. So very often I make mistakes and paint outside the area I want to edit. So I have to zoom in and remove bits of mask here and there using the erase brush. In some cases I even need to edit it in Photoshop to mask it well. This is why some photographers have a interactive pen display or similar drawing tablet to do heavy editing.
So I said things were going to get cooler. Let’s go for it.
Drag the main window of Lightroom to the iPad. Press ‘D’ to go to Develop Module, press ‘Shift+Tab’ to hide all panels and lastly press ‘K’ to enable the brush. Now the whole screen of your iPad is a Wacom tablet. I use a Bamboo stylus to edit, but any cheap stylus or even your fingers will do it. Remember: D-SHIFT-TAB-K.
On the photo below I wanted to apply clarity only to the road, so I used Duet Display and my stylus to brush it on my iPad easily. Maybe this is not the best example as the area to brush is big enough to do it on the laptop, but you get the point. And I like the photo!
Although I only use Duet Display when I don’t have my external monitor handy or with specific cases using the brush, I tried, just for fun, to connect both (external monitor and iPad) to my laptop and it worked well, so the iPad can be used as a third display, (by default Duet Display will always be the last screen on the right). It works even as a fourth display, to suit your needs whatever they are! Four displays will count as a 50% more productive four times, that’s 500%! ;) Although for going infinite and beyond I still prefer coffee.