0

I know that when you use lenses made for full frame cameras on a APS-C camera, you should calculate the crop factor. E.g., a 35mm lens designed for a full frame camera mounted on a APS-C body should give a field of view as if you used a 50mm lens on a full frame camera.

But there are lenses designed for APS-C cameras. For example, the AF-S DX Nikkor 35mm f/1.8G. When I was reading reviews, everywhere they mentioned that this lens is equivalent to a 50mm lens used on a full frame camera.

I am confused here, because this lens is made for a crop camera. And I think that when I am shooting a 35mm lens, I will actually get a 35mm field of view.

Let's say it otherwise: Does a 35mm DX lens mounted on a APS-C camera have the same field of view as a 35mm lens (made for full frame) mounted on a full frame camera?

Edit: Sorry for my grammar but my English is not native, and I am not so fluent with it. Basicaly my question is the following:

If I am shooting with my crop camera with a lens build for crop camera on it at 35 mm focal lenght, should I have same picture result as if Someone is shooting with Full-frame camera packed with full frame lens at same focal lenght of 35mm

This confusion became to me, as I was reading a lot of reviews for a lenses build for crop camera, where they keep saying that if I use lens for crop camera on a crop camera, I have to keep on mind that it is equivalent of shooting with 50mm lens (full frame lens) on a full frame body.

Ivo
  • 153
  • 1
  • 1
  • 6

5 Answers5

3

Does 35mm DX lens mounted on a APS-C camera would has same field of view as 35mm lens (made for full frame) mounted on a full frame camera.

A DX sensor will have the same field of view through two lenses of the same focal length, regardless of whether the lens is DX or FX. Lenses, DX or FX, are specified in terms of their focal length, not their field of view. A lens with 35mm focal length provides a certain field of view on a full frame (FX) sensor, and a different field of view on a crop (DX) sensor, but in both cases the focal length is still 35mm.

In other words, if you use the camera to take a photo with a Nikon AF-S DX 35mm f/1.8, and then change to a Nikon AF-S FX 35mm f/1.8 and take another photo, both photos will have similar fields of view. (They might not be exactly the same because the nominal focal length of a lens isn't always the true focal length, but they'll be really, really close.)

The thing that's different about a DX lens is that the image it projects doesn't have to cover as large an area, which means that the lens can be smaller, lighter, and less expensive.

Caleb
  • 31,682
  • 6
  • 65
  • 120
  • My mistake in using of terms.

    So if you use 35mm lens on your full frame camera, let say you will produce image like this in the frame above

    If I get DX lens on my APS-C camera and take a shot, it will be the same picture as yours, or it will be like zoomed in. (As you are using 50mm)

     – Ivo Feb 12 '16 at 19:00
  • @Ivo Updated to address your question. – Caleb Feb 12 '16 at 19:23
  • 3
    There are plenty of illustrations in some of the answers to the other existing questions that this one duplicates. – Michael C Feb 12 '16 at 19:57
3

Does 35mm DX lens mounted on a APS-C camera would has same field of view as 35mm lens (made for full frame) mounted on a full frame camera.

No, a 35mm DX lens mounted on a APS-C camera would NOT have the same field of view as a 35mm lens (made for full frame) mounted on a full frame camera.

Any 35mm lens(DX or FX) on an APS-C camera will have a narrower field of view compared to any 35mm lens on a full frame camera.

It is the sensor size that determines the field of view when both lenses are 35mm.

Mike Sowsun
  • 12,247
  • 1
  • 23
  • 37
2

Here's a phrase which is missing from your answers so far: there is no such thing as "a 35mm field of view".

That's the first step in understanding crop factor and these various sensor sizes. Many people consider the field of view a certain focal length gives on an FX (FF35) camera to be its "native" or "true" field of view because those cameras and lenses are the most common, but that's not really accurate. The focal length of the lens is the distance between the sensor and the nodal point of the lens (when it's focused at infinity). It tells you magnification but not angle of view.

A lens works by projecting a circular image into the camera. For size/cost reasons that circle is only as big as it has to be to cover the sensor/film frame in question (~46mm diameter in the case of an FF35 camera, smaller for DX, larger for medium format).

Take your DX camera with 35mm lens, and set up a shot of a house so that it fills the entire frame. Now, switch it out for a FF35 camera with its 35mm lens. The house is projected on the sensor at the same size. But the sensor is larger, so the whole frame isn't covered anymore. Now the lens is going to have to project a larger image circle, showing some of the scenery around the house, to cover the rest of it. Therefore, the magnification of your subject stayed the same but your field of view increased.

Now, mix and match. Put your DX camera back on the tripod, but this time put the FF35 35mm lens on it. It still projects the larger image circle containing the scenery around the house. But since you have the smaller DX sensor, there's nothing to record most of that projection and you're back to the house filling the frame just like before. All that's changed is that you're carrying a bigger and heavier lens.

Lenses of the same focal length will always have the same magnification but the maximum field of view / angle of view they're capable of will depend on the sensor / film frame size they were designed for.

Lee Saxon
  • 562
  • 2
  • 7
1

Both lenses are 35mm, anything captured in the center will have a similar depth look in the final photo.

However, the 35mm DX lens will show dark or blacked out corners on an FX camera.

On a FX camera:
DX lens will show dark corners or even a mask around the edge of the image.
FX lens will show as intended.

On a DX camera:
FX lens will look the same as the DX lens. (You are just not using the outer portions of the glass)
DX lens will show as intended.

cngodles
  • 171
  • 3
0

If you go to the Nikon website and look at the tech specs for the lenses, it will give you the information for each lens. For FX lenses, it will list how many degrees on both a DX and an FX body but it will only list the degrees of DX lenses on DX bodies.

I was just looking at this last night and you will get more degrees with the same length lens on an FX body.

brian dobyns
  • 1