Shutter speed, aperture, and ISO are three values that every photography student must understand. In modern camera functions, the exposure modes are further classified as M, S, A, and P, which stand for Manual, Shutter Priority, Aperture Priority, and Automatic, respectively.

All four modes are equally powerful and useful. They are essentially the same.





I think saying this kind of thing would probably confuse beginners and make experienced people roll their eyes. Why divide it into four types if they are all the same? It would be better to just do one type thoroughly. It’s like pulling down your pants and farting — what’s the difference? Well, there is actually a difference.

I will briefly explain my reasons, otherwise I am afraid I will be brutally assaulted with a burlap bag when I go out. The reason I say all four modes are the same is because they all yield the same final value.




Impossible? Taking a photo of an object under the same lighting conditions with the same aperture and shutter speed can still result in differences in the values. I know many people would have this kind of response. The reason they answer like this might be because they forget about another control option: exposure compensation, which is the adjustment of EV (exposure value).

Speaking of my Sony A9 camera, it has a circular dial located in the top right corner, ranging from +3 to -3, divided into three smaller divisions for each equal interval.

For me, it is a bit challenging to rotate the single-handed thumb dial. Usually, I need to use my left hand to hold the camera steady and adjust the desired settings with my right hand. Meanwhile, I also need to observe the brightness of the image displayed on the camera’s LCD screen.

You can tell from my description that this operation is quite troublesome, it slows down the shooting speed, and is not suitable for certain shooting subjects.




Speaking of topics with the same values, if you don’t believe what I’m saying, you can pick up your camera that has adjustable exposure mode function, please don’t grab your phone and tell me it’s impossible, I will ask you… to spend money to buy one.

Then, please go to a well-lit area for convenient control of values and observing the screen.

Next, continue shooting in the order of M, S, A, P modes. When you switch from M mode and switch to another mode, you will notice that another value starts to change. At this point, you just need to adjust the EV value to obtain the same value as when using M mode.

(At the same time, please keep the ISO value fixed during the experiment.)



You may wonder why M mode is used as the reference. There is no special reason, just choosing one mode as the benchmark. It doesn’t matter which mode is chosen as the benchmark.

You can also use the S mode as a baseline to test the M, A, and P modes, using the same method except for the M mode, where exposure value adjustment is additionally required.

The conclusion is based on the fact that in the end, the camera requires you to achieve the same exposure by having the same light source angle, subject, shooting angle, and ISO.

The most intuitive way is to observe the histogram of a photo. If your camera allows you to display the histogram while taking a shot, you will find that as long as you set the aperture, shutter speed, and ISO to the same values, the resulting histogram will be the same.



After fixing the aperture, shutter speed, and ISO, the exposure will be the same. In other words, all the different modes are just for achieving the same exposure at the same aperture, shutter speed, and ISO.

Each pattern takes one of the values as a variable and fixes the other values, while the EV value is treated as an adjustable variable.

One can imagine it as an equation, where the right side is the result with a fixed value. The left side is a string of formulas, and aperture, shutter speed, and ISO are the variables of the left side formulas, while exposure mode is the framework of the left side variables. However the variables in the framework change, in the end, they will always be the same as the result value on the right side.







Why do we need so many different modes? Because each one has its own convenience.

Imagine, is it easier to handle two or three types of value changes at once, or one type at a time? Or even better, let the camera decide without any effort on your part. It’s truly a lazy person’s dream come true – as long as you have a finger to press the shutter, how wonderful is that.

In fact, it is as the Buddha said, using a “skillful means” to enter the world of “camera”.

Difficult operating methods can discourage people, so the simpler, the better. You know it, I know it, camera manufacturers know it. Technology always originates from human nature, and this phrase further illustrates this.




『Have you ever experienced opening the camera in a dark night, using the aperture priority mode, and then staring at the camera screen, feeling a lack of light and the image being too dark?According to online tutorials, I turned the exposure compensation dial to the highest value of +3, but still felt it wasn’t bright enough, so I had to increase the ISO value to achieve a desired brightness on the image.』

『Have you ever experienced opening the camera on a sunny day, using the shutter priority mode, and staring at the camera screen, only to find that the image appears overexposed, with the sunlight being too bright?According to online tutorials, I have already turned the exposure compensation dial to the minimum value of -3, but the image still appears excessively bright. Therefore, I had to reduce the ISO value in order to achieve a brightness level that I find acceptable.』

(In the above cases, the shutter priority mode is less likely to be like the aperture priority mode, because when the shutter speed is approximately higher than 1/2400, it should still be possible to capture a relatively acceptable image in bright sunlight.)










Speaking of this, don’t you think that S and A modes are actually the expert modes? In those modes, you have to control three variables (the other variable in X mode, EV value, ISO value), whereas M mode only requires attention to two variables. It’s actually the beginner mode.

Why is most of the internet saying that M mode is powerful and the expert mode? Because nobody pays attention to the use of EV values in S and A modes, especially not beginners or experienced players.

Are EV values not important?

Do you change the EV values when using S, A modes? If you forget to change them, do you feel like you are not getting the desired image?

It won’t change. Forgetting also doesn’t matter. Because its impact is not significant enough to affect the relative values or the shooting process, so we will still focus on the shutter value in S mode, aperture value in A mode, and especially in P mode, we won’t even bother with the EV value.

This situation happened to me, have you also had this feeling? I believe most people have experienced it too.

S and A modes only require attention to one value or ISO, and even P mode only requires concern with ISO. It only requires managing one to two values for photography, which is why beginners often start learning photography from S and A modes.


I was also confused about these modes when I first started learning photography.

I always don’t know which mode to use in different situations, I don’t know which mode to learn first, and I don’t know which mode to use for what context. In short, when I see the four modes, it seems like photography is a complex and mysterious art, even the operation is so complicated.

The content discussed on the internet also clearly explains the appropriate scenarios for each pattern and their benefits. It makes a simple question complex, making a complete novice feel that it is a difficult yet impressive subject.





我舉我自己而言,我拍攝通常都是把光圈固定在1.8 – 2.8左右,因為我都是拿大光圈鏡頭。除非是拍兩人以上的合照,或者今天我街拍想要盲拍,用小光圈可以確保盲拍得焦平面不會差太多,不然我都是光圈最大或者縮小1/3。




其實就是大太陽的時候,沒有任何遮擋物的光線下和陰影下的數值,傍晚或者晚上的相對數值。這沒有一定是什麼數值組合,就是你自己在一個很平常的白天或晚上,你自己覺得這個組合應該很常用就把它背下來。例如:我自己就會記大太陽下,ISO 100,光圈2.0,快門1/2000,陰影下光圈不變,ISO 400,快門 1/640。大概就是白天兩組,陰天一組,晚上一組。


Let’s simplify the problem. Just use the M mode.

Let me start with a few premises so that you can better understand what I mean by ‘M mode’ is the simplest mode.

First: You need to fix your shooting style, that is, your shooting values need to be fixed.

For me personally, I usually shoot with the aperture fixed at around 1.8 – 2.8 because I use wide aperture lenses.Unless taking a group photo or if I want to do some street photography without being noticed, using a small aperture ensures that the focus plane of my blind shots won’t differ too much. Otherwise, I usually use the largest aperture or reduce it by 1/3.

Second: Set shortcuts for other values to be changed.

Just change the values of aperture, shutter speed, and ISO without having to go into the camera menu, and make sure to set the direction of rotation for increasing or decreasing correctly.

Third: Memorize several sets of commonly used relative values.

Actually, it refers to the value under direct sunlight with no obstructions and the relative value in shade or during the evening or night.There is no specific numerical combination. Just memorize the combination that you think is commonly used during a normal day or night.

For example, I will remember: under the bright sun, ISO 100, aperture 2.0, shutter speed 1/2000; under shade, aperture remains the same, ISO 400, shutter speed 1/640. There are approximately two settings for daytime, one setting for overcast days, and one setting for nighttime.

Suddenly realized that there are zoom lenses where the aperture moves along with the focal length, which can be a bit more challenging.

Because you have to remember that the numbers will be larger when using a wide aperture prime lens compared to me. However, that’s also because you have more focal lengths available at the same time. If I were to simultaneously use two different focal length prime lenses, the basic variables wouldn’t differ too much.

東京|街拍|自助旅行|sony A73|索尼




My method of shooting is to fix the aperture and adjust the shutter speed and ISO according to the brightness of the scene I want to capture. Does this resemble aperture priority mode?

Of course, you can also lock the shutter speed and adjust your aperture and ISO as the shooting scene changes, which then becomes shutter priority mode!

Originally, you were supposed to change three values at once, but by establishing some fixed shooting habits, M mode can be transformed into S, A mode without worrying about EV values. Just mix all the modes together and make it simple and efficient.

I think there’s no need to discuss which mode suits which scenario. As long as you understand the meaning and adjustments of aperture, shutter speed, and ISO, you can break free from the constraints of modes, escape the control imposed by the camera, and truly achieve the photographic freedom you desire.

Yeah, does the last sentence sound familiar? Have you seen so-called masters on the internet all say the same thing? I just want to say that the last sentence is bullshit, it’s meaningless for beginners (I’m just slapping myself in the face).









Everyone goes through stages of not understanding completely, that’s okay.

Everyone goes through stages of having too much information to digest, that’s okay.

No one reaches the summit without going through the stages from the foot of the mountain to the waist and then to the top. As long as you put your heart into it, every experience you go through will become nourishment for the final result.

Go explore every mode of the camera, watch tutorials online, read about related content from every person. The more you see, the clearer it becomes what is relatively correct, and you will know the answer to your question.The time and energy spent in the process are valuable, and you may be pleasantly surprised with unexpected results, then come online to express your thoughts and attract others’ attention…

The last sentence is a joke, please don’t take it seriously.

If you are a beginner who has just started photography, do more research, observation, experimentation, and questioning. Apart from the optical formulas, there is no ‘absolute’ correct thing in photography. When someone says something is correct, question yourself: Is it really?

If you are already an experienced mentor, please do not tell beginners that this is the absolute correct way, unless it is part of a tutorial (although I do not agree with teaching this way either).