Tag: exposure compensation

Making Black Tones, Black – Photography Experiments

Making Black Tones, Black

Tell me, what’s wrong with this picture?

You might say, “Not much (but it is horribly boring).” And you would be right on both accounts. Not much is wrong and it is boring.

But what if I presented this image as it should have been shot with proper metering?

Do you see the difference?

The difference is the first image is okay, but black is not black. This is because your camera is set to believe the world in front of it is not black or white, but neutral gray. Goofy, you might say, but it is true.

The effect this has on photos is, when the area in front of the metering spots (see this post for a refresher on where your camera’s metering spots are) is predominantly black or dark, your camera is set to assume there is something neutral gray there instead. It then tries to match the metering to neutral gray, making black items not so black. They move toward neutral gray.

What do you do to fix this?

Here’s the experiment you can run:

1) Set you camera on a table and switch it to Aperture Priority mode.

2) Set your ISO to 400 and place a black object in front of your camera, about four feet away. Make sure the black object takes up the central area of the field of view, as in the image above. It can fill the whole screen if you like.

3) Take a photo.

Take a look at your photo and I’m willing to bet it is like the first image. The black object is not really black, but moving toward neutral gray. Now then…

4) Change the Exposure Bias/Exposure Compensation of your camera to -1.3. This is one and one third stops under-exposed.

5) Take another photo.

Done!

Can you see the difference in the two images? Take a look at the histogram for each.

The one that is better exposed (hint: the second one) should be pushed more to the left side while the first one is trying to be more evenly spread. You don’t want even, you want black to be black!

When To Use This Technique

You will use this technique any time there is a large black or dark area that takes up most of the metering spots of your camera. Otherwise, your camera will make an incorrect exposure.

This problem can be eliminated completely by shooting in Manual Mode, at which point your camera will complain you are about to mess up. At that point, you ignore it and shoot any way.

The important part to remember is your camera’s meter is a tool for figuring out which ISO, Aperture and Shutter Speed to use. It is not perfect and makes an assumption about the world in front of the camera. When that world does not meet your camera’s assumption, you need to make adjustments. Or shoot in Manual Mode.

Questions? Pop ’em like Pez in the comments section below. or email me at peter@peterwestcarey.com.

Photography Basics – A 43 Day Adventure, and its companion 40 Photography Experiments, are series written by professional photographer Peter West Carey. The series are designed to unravel the mysteries of photography, helping you can take better pictures. Subscribe here to receive all the updates and bonus material. Your comments are always welcome.

If you enjoy the series, consider learning photography first-hand on a professionally led international photo tour in Nepal or Bhutan. More information can be found at Far Horizon Photo Tours.

November 7, 2018
Exposure Compensation And Bias Are Your Friends – Photography Basics

I have some bad news.

Your camera is not perfect.

Don’t worry though, none of them are. The saving grace to this dilemma is the Exposure Compensation (sometimes called Exposure Bias) feature on DSLRs, smartphones, mirrorless cameras, drones and a lot of point and shoot cameras. It is a little button that looks like this.

Exposure Compensation

The exposure compensation button works by forcing the camera to over expose or under expose, according to its current settings, by a set number of stops. Hence the symbol for it is the + and – signs.

Typically the range is -3 to +3 stops but some cameras will have a -5 to +5 range. Cameras are pretty similar in how the setting actives; simply press or hold down the button and then turn one of the camera dials. On phones you will typically tap the screen to set exposure then drag up or down to change it.

Your user manual explains exactly how your exposure compensation feature works.

How Handy is Exposure Compensation?

Exposure Compensation can be helpful when you know your camera is going to mess up or is already messing up. As explained in the Metering Modes post, your camera is not perfect and can only meter a limited area of the view. Plus, your camera has to make decisions about what’s important in the frame and try to make everything come out all average. But it makes mistakes.

We’ll use an image of a tugboat on Puget Sound from Seattle as an example of a challenging shot where exposure compensation helps.

Program mode, ISO 100, f/11, 1/500 – The camera is doing all the exposure calculations here:

This is with the camera’s default setting using evaluative metering. I could switch to spot metering and point it at the tugboat. Instead, I use a camera dial to selectively over expose by one stop.

Over Exposing

Here’s the same shot over exposed by one stop.

Getting better. The tug is a little more visible.

Below are shots over exposed by two stops and then three stops.

As the exposure gets higher and higher, we can see the tugboat more and more, although we lose detail in the background.

I chose this image because these types of decisions come up all the time when shooting sunrise or sunset.

Now For Under Exposing

Swinging the other direction, we’ll under exposed by one, two and three stops.

We get more detail in the clouds lit by the setting sun, but we lose our main subject along the way.

As you can see, there is a big difference in exposures across a swath of seven stops of light (-3 to +3 stops). What is most pleasing to some, in this case, might not be pleasing to others.

How is it Useful?

The over/under exposure compensation is a quick way to correct your camera’s wrongheaded bias towards too harsh or too dull of light. In this example, the shot that was underexposed by one stop has a good chance of being salvaged and enhanced in a computer.

This quick setting can also help insure faces aren’t hidden in darkness by shadow when all around them is bright light. It’s better to blow out the details in the surroundings than leave a face too dark.

On Your Phone

To use exposure compensation on a phone, tap the screen and move your finger up or down to over or under exposure. It’s super easy.

Tomorrow we’ll cover Histograms!

Questions? Pop ’em like Pez in the comments section below. or email me at peter@peterwestcarey.com.

Photography Basics – A 43 Day Adventure, and its companion 40 Photography Experiments, are series written by professional photographer Peter West Carey. The series are designed to unravel the mysteries of photography, helping you can take better pictures. Subscribe here to receive all the updates and bonus material. Your comments are always welcome.

If you enjoy the series, consider learning photography first-hand on a professionally led international photo tour in Nepal or Bhutan. More information can be found at Far Horizon Photo Tours.

October 17, 2018