A reader in the forum asked a great question today, and I thought I’d post it here as a tip.

Dan asked:

On the training videos you use the hot/cold feature to show blown highlights and blocked shadows. To set the white point and black point in my photos, I press the command key when adjusting Exposure, Recovery and Black Point sliders. Is there a difference between the two methods or are they just different ways to reach the same goal?

The short answer is “yes, they are different ways to reach the same goal”. But of course, there’s more to it than that!

Background

Just in case you’re not familiar with what he’s asking, here’s the skinny. If you enable View > Highlight Hot & Cold Areas (which by the way, I’ve re-mapped on my system to simply the letter ‘q’ as a keyboard shortcut, because I use it all the time), you will see red marks on parts of your photo that are “hot”, or blown out, meaning they are too bright to see/print/show any detail, and blue marks on areas that are “cold”, or too dark to see/print/show any detail. (You can actually adjust the threshold in the Preferences, under Advanced). This is critical if you’re adjusting for print, since anything too dark will just block up and go solid black in printing, but even if just adjusting for viewing on screen, it’s a really easy way to see where your highlights or shadows may have gotten too extreme, and you are losing detail.

Highlighting “hot” areas hereHowever there’s a neat trick that you can do; without toggling this view on and off, you can temporarily enable it by holding down the command key while dragging any number of exposure adjustments. It actually shows you a bit more info, because you see a progression of it blowing out, showing different colors where it’s getting brighter or darker, like this:

A close-up of the blown-out areas, same as the full screenshot aboveAnd there are the two options for viewing the hot and cold areas in Aperture. Neat!

So which is better?

It’s easy to argue that the command-drag method is better because you get more information. However as you can see in the second screenshot above, you no longer see the photo. Wherever your photo is within range, the screen goes black. You only see data where the problem areas are (which of course makes it really easy to spot, whereas a red mark on a specular highlight on the hood of a red car might be hard to spot using the other method!). So, either way, this might be good for you.

But here’s the reason I personally almost never use this, and prefer to toggle the Highlight Hot & Cold Areas on and off constantly.

When you toggle the Highlight on and off, you instantly see where the problem areas are, as the photo currently exists. However when you command-drag a slider, you have to drag for the highlighting to show up. There’s no way to see this data without moving a slider. Even if you command-click on the slider but don’t move it, this info doesn’t show up. Which means if you just want to see where your photo currently stands, you can’t. You have to change it, then change it back again. I don’t like this, at all. I’ve requested a change on this before, but so far, no luck.

Therefore, until this changes, I’ll continue to almost exclusively use my keyboard shortcut ‘q’ to toggle Highlight Hot & Cold Areas on and off.

UPDATE: You may have to revoke my ApertureExpert status, although ApertureAmateur doesn’t quite have the same ring to it. As reader Argun Tekant just pointed out in the comments below, if you press command and then click on the slider, the highlights do show up after all. Hmph. I will say in my defense that this aboslutely did not used to work this way, and since no one can counter otherwise, I’ll go ahead and claim that this bug was fixed recently because of my bug report. So there.

(sulking in the corner now)

However, I will still likely do it my old way, since I’m so used to it and it requires only a single stroke (not a key-click), but it’s good to know that the peeps in Cupertino are listening. Thanks guys!