Using Manual Mode with Auto ISO is very useful for fast-paced wildlife photography. In this article, I’ll explain how to set Manual Mode + Auto ISO, how it works, and why it’s so effective. Also, I’ll provide some tips on optimizing exposure and maximizing your image quality in this mode.
Manual Mode is one of the standard shooting modes in photography. Other examples include Aperture Priority, Shutter Priority, Program, Auto, and various scene modes depending on your camera. All of these modes are based around controlling the three main camera settings: aperture, shutter speed, and ISO. If you aren’t familiar with that, I suggest reading the linked articles to give yourself a refresher.
Generally, photographers think of Manual Mode as the right choice when you want to lock in the three major camera settings manually, leaving nothing up to the camera. But this isn’t necessarily the case. Cameras today give you the choice of setting ISO automatically even in Manual Mode.
With Manual Mode + Auto ISO, you still select your aperture and shutter speed, but the camera is left to choose your ISO. While this may be unintuitive at first, I’ve found that Manual Mode combined with Auto ISO is often the fastest way to have control over the most important settings in photography. For fast-moving wildlife photography, it is especially useful.
When Auto ISO is enabled in Manual Mode, your camera will read the ambient lighting conditions and select an ISO accordingly. However, you can fine-tune the ISO that it chooses by changing your metering mode and your exposure compensation. For example, if you set center-weighted metering and an exposure compensation of -0.7, the camera will select the ISO based upon a central region of the image and then lower it by 2/3 stop.
Personally, I always use Nikon’s Matrix metering mode, which analyzes the entire frame and sets exposure based on tone distribution, color, and composition. (Canon’s Evaluative mode and Sony’s Multi mode work similarly.) As for exposure compensation, it depends upon the scene. I always am prepared to raise and lower it as needed. For example, in snowy scenes with a dark subject, I usually add +2/3 stop to make sure my subject isn’t too dim. And with bright subjects against a dark background, I may lower it to as much as -1.0 stop to guard against overexposure.
The benefit of Manual Mode + Auto ISO is that you retain full control over your aperture and shutter speed. This lets you very carefully select the depth of field and how much you will freeze the motion of your subject. Meanwhile, with the camera shifting ISO in response to the light, you don’t have to worry as much about overexposure or underexposure.
Let’s consider some real-life examples. If you’re taking photos of a stationary subject in wildlife photography, a good starting point is a shutter speed of 1/500 second. This captures enough light without risking a blurry subject, at least if you’re shooting from a tripod or monopod. Shoot at your widest aperture unless you want more depth of field, and let the ISO float. In most lighting conditions, the camera will be able to pick a low ISO like 100:
If you see that the ISO has dipped all the way to the base value (either ISO 64 or ISO 100 on most cameras), you may start to risk overexposure because the camera can’t lower ISO any more. In that case, just bump your shutter speed a little faster. For example, set it to 1/2,000 second instead of 1/500 second.
Another time that you’ll need to use a faster shutter speed is when the subject starts moving. I always try to pay attention to my subject’s behavior and think about what shutter speed I’ll need. If it’s a bird that is about to take off, I will quickly rotate the shutter speed dial six clicks (that’s two stops) to set it to 1/2,000 second and make sure I freeze the moment. With Auto ISO enabled, I trust the camera to boost my ISO accordingly.
That’s the basic introduction to Manual Mode + Auto ISO, but you can also take steps to improve your image quality even further, at least if your subject is being cooperative.
For example, how do you actually know that 1/500 is the right shutter speed for a relatively stationary subject? What if you can get away with totally sharp photos at 1/250 second, so that your camera can set a lower ISO?
This part is about trial and error, as well as practice. With enough practice, you can usually tell just looking at your subject what shutter speed you’ll need. But here’s a pro tip. In Manual Mode + Auto ISO, you can very quickly switch between different shutter speeds while maintaining the same image brightness. If you’re wondering between (say) 1/500 second versus 1/250 second, take an image of both! In fact, take a whole sequence and maybe even start a little faster – 1/800, 1/640, 1/500, 1/400, 1/320, 1/250, 1/200, 1/160, 1/125, and 1/100. With practice, you should be able to take the whole sequence in a matter of seconds.
Then, start reviewing from the newest image and work your way back through the series. Set your camera to one-button magnification if available, so that you can immediately zoom in and check sharpness. This gives you the best idea of what shutter speeds are acceptable for the subject at hand. In this case, for example, 1/250 second proved to be plenty, since the subject was not moving very much:
Manual Mode + Auto ISO also gives you the full flexibility to play around with motion blur however you want. I like shooting with about a 1/10 to 1/30 second shutter speed while panning with the motion of my subject, giving a sense of speed and movement to the photo. This is easy to accomplish with Manual Mode + Auto ISO. However, note that you’ll risk overexposure unless you stop down your aperture like I did here:
If there are cases when you want more depth of field, Manual Mode + Auto ISO also allows you that flexibility. Here, for example, I noticed that I wasn’t getting every muskox in the photo to be sharp unless I stopped down a little bit, specifically to f/8. It was a quick adjustment, and the camera compensated for it by boosting the ISO slightly.
Please keep in mind the following information: Auto ISO cannot go lower than the base ISO. As a result, you must be careful to prevent overexposure when using a combination of a long shutter speed and wide aperture. You especially need to be careful in very bright light.
In those cases, I will sometimes switch to Aperture Priority mode + base ISO instead, or I’ll select a faster shutter speed (or narrower aperture) so that overexposure no longer occurs. Still, I would like camera makers to eventually add a parameter to manage this situation and automatically increase the shutter speed. I would name this implementation “Smart Auto ISO.” (I’d like to note that you can already accomplish something similar to this in Aperture Priority mode + Auto ISO + a custom minimum shutter speed. But unfortunately, there is no quick way to change the minimum shutter speed in this mode on any camera that I know of.)
Ultimately, using Manual Mode with Auto ISO is one of the best ways to achieve a high level of control over your wildlife photos without worrying about overexposure or underexposure. Most of all, it’s very fast.
Furthermore, using Manual Mode in general can help photographers improve their skills with the three main variables of photography – shutter speed, aperture, and ISO. This can lead to better long-term results as you better understand what you’re doing as a photographer. And all of this without slowing down the process or giving you inaccurate results.
I enjoy using Manual Mode so much that I even use it when taking landscape pictures. It helps me to slow down and get in the right frame of mind for a landscape. In addition, in difficult cases like photographing the Milky Way at night or getting the perfect texture in moving water, Manual Mode is essential.
I have a final tip for you. When you’re putting the camera in your bag at the end of the day, or moving to a different scene or subject, take the time to select settings for fast-moving subjects. For example, I usually turn off any exposure compensation, set the shutter speed to 1/1,000 of a second, and set the maximum aperture of the lens. This provides me with a good starting point if I’m in a hurry the next time I pull it out of my bag.
Of course, any of the photos and situations I used as examples could have been captured using other methods, and most experienced photographers could have developed a different way of working which they are used to. However, I’m pretty confident in the speed and accuracy of Manual Mode with Auto ISO. It allows for on-the-fly changes more quickly than the alternatives, and it still gives nearly complete control over how the photo will turn out. All of that pays dividends over time!
I hope you enjoyed this article on using Manual Mode with Auto ISO for wildlife photography. If you have any questions or feedback, please feel free to let me know in the comments section below.