What is the 50mm standard lens of SLR mainly used for shooting?

Well ... well, I'll introduce you to some basic knowledge, and I hope you can find the answer from it ~

Let's talk about the focal length of the lens first ~

The smaller the focal length, the larger the shooting range (wide-angle lens) ~ The larger the focal length, the smaller the shooting range (telephoto lens)!

As shown in the figure:

Then it's time to discuss portraits ~

Why are some shots more suitable for taking portraits? The reason is in the following figures:

This is a screenshot of a photo taken by the same person at the same distance and different focal lengths. Look carefully at her nose ~ ~ ~ Is it big or small?

Yes, your eyesight is very good!

The reason is the distortion of the lens! The smaller the focal length, the more serious the distortion, and the larger the focal length, the smaller the distortion!

[This is a wide angle and the distortion is very serious]

[This is the lady just now, lens focal length 135 (medium telephoto)]

So, that's why people call a lens with a focal length of 85- 135 a portrait head! (So, it is necessary to take pictures.)

Does that mean you can't take portraits with a lens before 85mm?

Of course not ~

There are two situations: one is when the wide-angle effect is needed, and the other is when it is far away from the lens (which can reduce the influence of distortion).

Finally, tell me about your machine with a lens ~

Pentax KX belongs to APS-C camera, and the lens focal length needs to be multiplied by the conversion coefficient of 1.5 to be the actual focal length ~

Your 70-2 10 lens is very suitable for taking pictures! But without a wide angle, it is not enough to shoot architecture and tourism ~ I suggest adding a wide angle ~

50mm fixed focus, excellent imaging effect! Big aperture, buy it ~ it's good for upgrading technology ~

The head clarity of 50mm is the closest to the human visual angle ~ perhaps it is the reason why it was changed to 75mm in the post-APS-C era, so it is closer to the focal length of the portrait lens, so many people call it "portrait head" a bit far-fetched ~

In addition, there is no limit to the focal length of the scene, any lens with focal length can shoot the scene ~ ~ What kind of scene can be shot with what lens, which has nothing to do with the best focal length of the portrait ~ If it is insisted that it is suitable for shooting the scene, then I think it is quite suitable! Especially when shooting night scenes at night, you can turn the highlights of street lamps into circles with large apertures. How beautiful!

Novice, it is most important to master those apertures, shutters, light and exposure first ~ because this is the basis of all shooting.

Special thanks to the pictures uploaded by unknown authors on the Internet! There is also an illustration in a photography textbook!