What happens when the optical axis of Xinda Xiaohei is crooked?

The optical axis is crooked, which is an internal injury. It can't be seen from the outside, and the repair cost is very expensive. Don't think it's none of your business, please read on.

There are many specific symptoms of optic axis bending. Don't say the complicated ones, just say the simple ones.

First, the focal plane is inclined. For example, the focal plane and the focal plane of the camera CMOS must have a strict parallel relationship in order to focus on a complete plane accurately. Even if the optical axis is only a few tenths of a millimeter, it is very annoying. It is not out of focus, nor out of focus, but the focal plane is partly clear, partly unclear, and often not completely unclear. So many people who don't understand think that the sharpness of the lens is not good, which really wronged these tens of thousands of things.

Second, as long as the optical axis is obliquely curved, then any parallel lines parallel to the focal plane must be curved and the extension lines will intersect.

Well, if you can't figure out what's going on at the moment, don't worry. In short, the optical axis is crooked, not that it can't be found, but many people can easily blame the lens for not being good enough and the definition is not high enough. Let's get down to business. How is the optical axis crooked? There are three main reasons.

Cause 1: Suffering from violent shock.

This situation is rare. It is not easy to hit a vibration of magnitude that can cause the optical axis to tilt. You don't always jump off the third floor with your camera behind your back, do you? And if you shake this vibration-damaged lens, there is basically noise inside, which is easy to find. By the way, many lenses with anti-shake components, when they are not turned on, if they hit vertically, something is moving inside, which is normal. If the optical axis is broken, you have to tilt it sideways and it will move sideways to the inside.

The second reason is that the quality of this lens is not so good.

The lens is either out of the factory or crooked, but the assembly process of the parts is not good, and the structure is deformed and loosened after a period of time. This is more common in cheaper lenses. There is nothing you can do about it. You get what you pay.

The third reason is the focus of today. The most common reason is that the lens optical axis is tilted by you.

The optical axis is parallel to your lens. It's okay to jump vertically, especially afraid of jumping horizontally. The longer the lens, the easier it is to tilt the optical axis. You may think, don't be alarmist, how can something so expensive and sophisticated be crooked after a few bumps? Yes, it's really no problem to take pictures with it.

What are you afraid of? For example, go on road trip, the camera was put in the car for more than half a month. The probability of a slight tilt is really not small, and it will become more and more embarrassing in the future. Think about it, it bumps for 8 hours every day, and you 1 year bumps for 3 months. Just try it. This kind of knife hurts people, and dripping water wears away stones is fatal. Besides, as I said just now, it doesn't break with a click. If you don't know that the optical axis can be tilted, you will feel that your lens sharpness is not good.

So how to avoid it? It's simple. Put the camera upright. Look at the design of the inner container of shoulder-mounted camera bag. Put the long head vertically, and there is absolutely no camera bag with the long head horizontally. Then the point is that when we usually put the camera bag in the car, it is often flat for safety reasons. Isn't that what we've been fighting? Form a good habit. If it bumps for a long time, make sure that the long lens bumps vertically. It's no problem to put the camera bag upright in the car. In the first half of the year, I ran 20,000 to 30,000 kilometers by car. My friend asked me why the lenses in the camera bag were all placed vertically, wasting such a large loading space.

So, how do you judge whether the optical axis of your lens is slightly offset? I advise you not to trouble yourself. The phenomenon is nothing more than that you are dissatisfied with the sharpness of your lens. You suspect that it is out of focus or the optical axis is inaccurate, but you can't tell whether the reason is from the optical axis.

What I said on the internet was that I tested it myself, which is a bit divorced from reality. If I test myself the way he says, I can only detect a very serious deviation. Because this requires that when shooting the test, your lens should be absolutely perpendicular to the test plane, or even a millimeter apart, and it is impossible to do it without instruments at home. If you are a professional lens, and then you are not very satisfied with its sharpness, you always feel that this lens is not as good as the legend, and then you often bump for a long time by car. I suggest you go to a regular brand maintenance department for a test. Testing is not expensive, and some brand testing is free.

Don't trust those small camera shops and repair shops. 200 yuan can't correct the optical axis Therefore, sophisticated things can be installed for you even if they are not crooked. Correcting the optical axis cannot be done with a screwdriver.