What is ETTR?

ETTR histogram.jpg

What is ETTR? Will it make your photography better if you understand it? Learning new tips will always make you a better photographer in the end. No matter how good we are as photographers we need to always keep learning new techniques to stay on top of our game.  

For years now I have battled it out with clients and friends that their cameras are good enough for low light photography and long exposures. The number one problem is everybody is afraid of noise! Well sometimes it is not the camera, it’s the operator. How could it be my problem you ask? Let’s go over a few things to help you out.

 

People often think cameras have limitations, they set these limitations in their head and are afraid to go past them. I will agree every camera has a threshold but I’m going to tell you some tips to get over "your" set limitations. First off is noise, let’s talk a little bit about why images have noise. Noise can happen for many reasons; some operator fault others can be just the gear. First let’s talk about heat. The warmer the sensor the more noise you will have in an image. This can be caused by rapid fire with your shutter for prolonged periods of time. So, remember sometimes spray and pray is not always the best answer to capturing a clear photograph.

 

Another can be the ambient temperature, you can’t stop this unfortunately other than trying to keep your gear in the shade or a cooler area when not shooting. But remember not to put it in the air conditioning, because once you take it into the heat you will not only create condensation on the lens but also on the sensor. No different than in the winter taking your gear into a warm vehicle or a house right after being outside for a while. One tip for this is to put your gear in a bag and let it come to room temperature on its own, crack the bag open a bit and slowly let the temps reach the inside of the bag.

 

Long exposures are also a something that creates heat inside a camera, so remember the more you shoot and the longer that shutter is kept open the more heat you will create. Take some time between images, if it’s a now moment then keep on shooting. If it’s not take a moment and then shoot, possibly re compose or look at your last image and see if you actually exposed it properly.

 

“Wait to expose properly can create less heat in my camera you say?”  Well not exactly but it can create less noise. So, let’s go into some detail on how a proper exposure can help you eliminate noise. And I challenge you to go out and test this theory! Let’s talk about ETTR, ETTR stands for Expose to The Right. On a histogram, you have three points to keep in mind when shooting. On the left you have your darks or blacks, this could be effected by shadows, blacks, dark colours or a dark or under exposed photo. In the middle of your histogram you have the mid tones, this can be earth tones or properly exposed colours. The right side of the histogram is the highlights. This could be whites, reds, orange, yellows or over an exposed image.

 

People when they tend to shoot they underexpose and image or overexpose an image. When we are shooting ideally, we need to keep our exposure from climbing up the sides of our histogram. When people shoot long exposures, they don’t often look at their histogram. You need to see if you have almost reached the right-hand side of the histogram, if you haven’t then you need a longer exposure, to open up your aperture or increase your ISO. This is a huge problem for people when they are shooting and creating noise on their own in their images.

Let me tell you how this works if you are somebody who edits their photos. If you under expose an image or shoot it to dark what is the first thing you will want to do with this image when you start editing ? I’m guessing you will try to lighten it up? Well this is one of the number one ways you now just made some noise or more noise in your image. Let me explain why this happens. If you shoot a picture and the pixels are too dark it has very limited information available in the pixel. Meaning when you try to brighten it you stretch that pixel for all it has to look properly exposed, but in reality, you are just creating noise. The way we can help eliminate this is to keep the exposure more to the right. But hold on don’t go too far right! If you blow out an image or over expose the image you will have zero information left in the pixel so you will not be able to darken it and bring back some detail. So, as you can see this is a balance game of trying to always capture the best exposure by looking at your histogram.

 

Now let’s go over a real-world scenario and tell me this hasn’t happened to you. You are out shooting wildlife and it’s a dark or grey day and your subject is a dark tone to begin with. You hold up your camera and you think wow I have to crank my ISO just to get a decent shutter speed. But then you get that little voice in your head that says my images are going to be to noisy if I keep my ISO up that high. So, you turn down your ISO and shoot as wide open as you can with the lens you have to give yourself a higher shutter speed. So here you are shooting a moving animal at shutter speeds of less than 1/500th of a second?? But in reality, you look at the back of your camera and realize wait I’m trying to get faster shutter speed by under exposing to compensate for a low ISO. Tell me this isn’t sounding familiar to you? What you need to do is start increasing that ISO and keep that histogram to the right. This will help eliminate some noise when shooting at a higher ISO.

 

Now before you curse me out because you just made art with your camera by pushing it to limits that are past it’s threshold. Take your camera out at home and practice some shots and load them up on a computer to see what is the max you can push your camera before it is too much. Take some under exposed images at a lower ISO and some exposed images to the right at a higher ISO. Trust me you will be thinking me for this tip😉

 

Remember, we can always use a noise removal software if we need to remove excessive noise. I was once told by another professional photographer “if people look at your image and all they see is noise then you took a boring photo” If all you do with your images is post them on social media then don’t worry about a little noise. Facebook is so bad at destroying image quality most people won’t even notice 😜

 

Well that’s my tip for today! Happy shooting!!

Chris Pepper

 

 

If you wish to join me shooting some long exposures of Northern lights in Yukon check out these links below.

 

https://www.northof49photography.com/southern-yukon-2018

 

https://www.northof49photography.com/autumn2018