How do I tell if an image is exposed correctly when I can't trust the LCD? [duplicate]

Question

I used exposure compensation when I take my shots and adjust it whenever it needs adjustments. Most of the time I shoot using Manual mode.

My problem is, when I'm out on a sunny day I can't judge whether my shot is overexposed or underexposed because the sun is too bright. Sometimes when I checked my viewfinder the image looks perfectly exposed to my eyes, but when I check it on my computer when I get home the images looks underexposed or overexposed. I tried to judge my shot's exposure using histogram, but still having a hard time. The only thing I understand about the histogram is that, the right side is the highlights and the left side is the shadow.

How do you judge whether the shot is overexposed or underexposed when you are out on a sunny day?

Answer 1

Histogram is the best way to judge.

How are you shooting? If you're shooting in JPEG, you should check your camera settings to see if you have the brightness turned up or contrast down or something strange like that.

Assuming you're shooting in raw and opening the files in something like lightroom, then you're probably actually overexposing.

Because the image on your camera screen is corrected, the histogram is the only way to judge because it's the only way to see the full dynamic range your camera captured.

The histogram displays, as a graph of dark to light, the amount of information in your photo. The higher the graph, the more information you have at that brightness level.

As a result, for an evenly lit scene, you want your histogram to be a bell curve with the peak centered in the middle. This means that the majority of the data in the photo is recorded roughly at your camera's best recording levels, with best dynamic range around the scene.

However, the most important thing to watch for is big bars on the sides of your histogram. This represents "clipped" data, data that is too bright or dark to be recorded.

If your histogram is roughly centered, without bars on either side, you can shape the photo however you want in post-processing and it should open at the right brightness level.

There are cases (such as a backlit subject) or a subject in a spotlight) where you want that subject and only that subject to be recorded, so your histogram will be skewed bright or dark because the part you care about is a small portion of the whole image.

For the most part though, try to keep the histogram centered.

Answer 2

Depending on what camera you use, under exposure may not be a problem at all. Typically most modern serious sensors give you a lot of leeway in downward latitude. You can always readjust your exposure in lightroom if you shoot raw. I have successfully pushed the raws from my camera by 3 stops (although I don't recommend that!).

But digital sensors are notoriously bad with highlights. In order not to get blown out highlights you may want to shoot for the highlights, in the sense that you try to measure exposure for the highlights, hoping that most (and certainly not all) shadows will be recoverable.

A more practical suggestion is to turn on the overexposure highlight mode on your camera. Most consumer level and professional cameras can color-code blown highlights in image preview. If you turn this on, you can always make sure you don't have blown overexposed areas. See here.

If the subjects are mostly still, you can also practice bracketing. Putting you camera on exposure bracketing lets you have three consecutive photos of a scene with a certain exposure difference. You will be able to discern which one is the best later on at home. See here.

It is very difficult to judge the exposure of a photo on the tiny LCD monitor of the cameras on a sunny day. Those LCDs are simply not designed for that. So, you may want to implement one of these compensation techniques.

By the way, the histogram is pretty simple to interpret. If you have the impression that on any of the two sides of the histogram the curve is coming to an abrupt end, you probably have an under (left) exposure or over (right) exposure. Normally the histogram curves end gracefully with a visible tail at the end of the exposure distribution. If the curve seems to be cut off, you can say that something is wrong with the exposure (unless you choose to do so for aesthetic reasons). See here.

Hope this helps...