Old talk-Hope you don't get stuck with your friends

Discussion on the size and stereoscopy of the slice

-- Some friends in the group are struggling to upgrade the fuselage FF or buy a new 24G

There are a lot of arguments on the internet... after reading a bunch of ideas, make sure you vomit blood and don't say it. The more you see, the more you get confused.

To put it simply, the key to the difference between stereoscopy lies in the depth of field...

I think a lot of people will not be able to see a picture after reading it. There are basically three ways to display it in a three-dimensional and hierarchical way.

1. Ratio of light
2. Color Layers
3. depth of field

The above three methods... the simplest way to present a stereoscopic sense is the depth of field level, so everyone loves large aperture focusing mirrors ..
Using a large aperture to present a stereoscopic effect... this method is simple and the most common person will talk about the depth of field... About 99% of people will directly think of the aperture size value.
But in fact, not only the aperture value is affected

A total of three factors will affect the depth and depth of depth.
1. aperture value... the larger the aperture, the deeper the depth of the scene... the deeper the depth of the field.
2. Focal CIDR... the same as the aperture in large hours... the wider the focal CIDR... the deeper the depth of depth... the less the depth of depth...
3. The distance between the camera and the object to be taken... the closer the distance... the lighter the depth of field... the deeper the opposite.
Remember the above three reasons

Let's look at the APS-C vs FF body

The same shooting distance... make a picture of the same distance...
To make the same picture, use the 35mm focal point on the FF body...
Then APS-C must use a 24mm focal point to take the same picture.

According to a previous condition shooting on a webpage in Japan, we compared the depth of field difference.

APS-C 24mm focal range aperture 2.8 shooting
The depth of field is similar to that shot at FF 35mm aperture 5.6.

Why... very simple... compared with the FF body because of the wide range of APS-C focal segment... similar to the following principles...
Use the 24mm focal segment to capture the 1.5x range in the FF image ..
Although the diagram and the angle of view are similar to the FF + 35mm focal segment image, the depth of field of depth must be relatively deep when shooting with a wide lens...

Reverse thinking... if FF is shooting with a 35mm 2.8 aperture... APS-c, which of the following lenses can be used?
? Around 24mm 1.4 aperture... suppose 24g is used to replace... so you can imagine that at the same shooting distance...
APS-C with 24 Open 1.4 aperture under the same diagram... with FF 36mm 2.8 aperture... can be shot with the same depth of depth feeling
So that the APS-C spent a lot of money to buy 24... the results of the effect is equivalent to FF + 24-70 2.8 35-end 2.8 aperture shooting effect lost it

Another question
Suppose FF body with 24G 1.4 aperture shooting, APS-C with what lens can take such a depth of depth feeling?
About 16mm 1.0 aperture 

Is there such a lens? No. If you have one, I cannot afford it.
Some people may say why we should compare the same shooting distance?
In many cases, the shooting distance cannot be changed. For example, if you are shooting friends at the dining room...
Everyone is shooting the same distance... similar to the figure at this time FF body will always win the APS-C body... about two grids of Depth

You can take a half-length portrait with a shortest depth in the KTV... FF + 50 MM.
APS-C... assuming the 85 MM focal segment is used to compensate for the problem of depth of field... it is often not refundable unless a hole is made in the wall.
So the same shooting distance is a key and cover door

So what about the same lens, the different shooting distance, the same aperture, and the same composition?
Imagine taking a full-body portrait in FF + 180... APS + 180 and taking a full-body portrait... then aps-c should go further and take a longer shot ....
In the same aperture, the depth of field naturally goes deeper.> the above simple logic is easy for tangled friends to take a look.