1, the physical focal length of the lens: the longer the physical focal length, the smaller the depth of field.

2. Aperture of the lens: The larger the aperture, the smaller the depth of field.

3. Focal length: The closer the focal length, the smaller the depth of field.

Let's look at the influence of different radial planes on the depth of field:

1. If all the lenses are 50mm f 1.8, installed on a full-frame machine and an APS-C machine, and all the lenses are opened to the maximum aperture, the focusing distance is the same, then the depth of field is the same.

But on Quan Huafu, the physical focal length of the lens is 50 mm.

On the APS-C machine, the physical focal length of the lens is 50mm, but the conversion rate is 1.5 times, which is equivalent to 50* 1.5=75mm focal length.

Then, if Quan Huafu and APS-C cameras shoot scenes of the same size, the focal length of the full-frame camera is bound to be closer, while the focal length of the APS-C camera is farther. According to the previous point 3, a full-frame camera has a shallower depth of field when shooting the same picture.

2. If the focal length of one Quan Huafu lens is 135mm f3.2 and the other card machine is marked as equivalent 135mm f3.2, since the Quan Huafu lens does not need conversion rate, its effective focal length = physical focal length, both of which are 135mm. However, the card machine uses a 1/2.3-inch photoreceptor with a conversion rate of 5.6, and the equivalent focal length is converted into a physical focal length of 1 35/5.6 = 24 mm. According to the previous point of1,it is difficult for the card machine to obtain a shallow depth of field effect.

Finally, one thing is very correct. For film pocket camera, it will be better than G 12 in some aspects.