So I have been using Lightroom for a few years now, and I pretty much thought I knew how everything worked. But yesterday I learned a new trick ( which is kind of a combination of 2 things I already was aware of ) so I thought I would share it in a post.
When areas get too bright or too dark in an image those areas are said to be "clipped", and it means that the pixels in that area essentially contain no usable data, when viewed along with it's neighbouring pixels. So a clipped area will either be 100% white or 100% black on all three colour channels ( ie red, green and blue) and therefore have no colour value associated with it.
Generally areas of clipping should be avoided in a photo as they are effectively dead space, however some theories say that you should have an area of black in the image to give our brains a reference point to judge the relative brightness of the rest of the image. But that said generally areas of clipping should be avoided or limited.
Lightroom has a few ways of showing the areas of an image that are clipped ( I won't go into them all here ) and one of them is accessed using the J keyboard shortcut. This tool shows an overlay on the image with areas of white clipping shown in red and black clipping shown in blue ( see yhe image below ). This is very handy as you can see instantantly where the areas are, and it also shows the effects of the tweaks to remove the clipping as you do them.
But sometimes ( for example when editing black and white images as I was yesterday ) it is not ideal to have areas of red and blue across the photo as, for me anyway, it makes it hard to see the image as a black and white, and I find myself turning the clipping visualisation on and off to make sure the image is edited properly.
So what I discovered yesterday is that ( along with some other keyboard shortcuts ) if you press and hold down the J key for a second ( as opposed a press and release as you would normally for a key press where each press toggles the effect on/off each time ) the clipping visualisation is turned on, but when you release the key it is turned off again. So this makes it much easier to quickly check the clipping areas and get back to the main editing. And as an added bonus while the J key is pressed down you can adjust the sliders to remove or increase the clipping and the visualisation will update in real time.
That was my new trick, and I hope you found it of some use