I see this meme come and go here on Facebook. I figured that it would be worth it for me to comment on how I feel about this statement.
I encourage everyone to shoot on Manual Mode, but I'm talking from the perspective of a landscape photographer. In landscape photography we are typically in no hurry and it's important to control your camera settings to make sure that you have, what I call, the three essentials captured properly - focus, dof, and exposure. You don't want to have the camera choose one or two or even all three of the settings that allow you to affect the three essentials. In most every case you will want to control all three by having absolute control over the critical settings, shutter speed, aperture and ISO.
Now with that being said, as photographer who practices more genres than landscape there are absolutely times when switching to an Automatic Mode on your DSLR helps greatly to increase your chances at getting great photos. Most all DSLR cameras come with Manual, Aperture Priority, Shutter Priority and Priority Modes. There are practical reasons for each mode.
Let’s say that you’re photographing a wedding and you’re doing candid photos of the attendees. Do you really want to have to meter your light, adjust your camera, focus and take a shot? The moment passes in a blink of an eye sometimes. In any situation where the subject changes quickly or there’s a lot of action the Auto Modes will come in handy. Aperture or Shutter Modes would help greatly.
In Shutter Priority Mode you can set the Shutter Speed to your desired speed - The slowest shutter speed that you will need to create a clear image with no motion blur - Then set the ISO to Auto and set the Maximum and the Minimum ISO that you want and then let the camera set the aperture.
In Aperture Priority you can set the aperture to your desired setting f/stop - Many times a shallow DOF which helps your shutter speed and softens the background - Then set the ISO to Auto and set the Maximum and the Minimum ISO that you want and then let the camera set the shutter speed.
When I shoot in an Auto Mode these are the two that I typically choose - Aperture Priority and Shutter Priority - with Aperture Priority used the most.
The third is called Program Mode. Program Mode is Automatic, allowing the camera to control all of the settings, but if you decide to change the shutter or aperture, is goes into “Flexible Program Mode” once you turn either dial. When you make the change the camera will compensate with the other setting that you didn’t affect. In other words if you are shooting in Program Mode and you turn the shutter dial the camera will change the aperture to keep the exposure proper.
Here’s how I look at it. Learn to shoot in Manual Mode. Learn your camera until it becomes instinctual. Learn how to nail the exposure and the DOF and how to deal with ISO. Learn Manual Mode because it will allow you to know when it’s going to pay to switch to an Auto Mode. If you understand Manual Mode you will understand just what it is that your camera is doing when you ask it to take over some of the work for you. There are many times when you will never consider an Auto Mode, but they’re there if you need them.
It reminds me of one of my favorite scenes in Top Gun when Maverick is chasing the instructor and says, “He's too close for missiles Goose, I'm switching to guns!”.