Confused about my lenses

I have a Nikon d7000 and use a Nikon 18-200 lens on it. I also have a d600 and use a 28-300 on it. I am trying to figure out why my 18-200 zooms in closer to the same subject than my 28-300 does. I'm expecting an explanation something like it's because of the different formats, but why have I never heard of this before? I'm hoping for something other than being just plain stupid!

The D600 is presumably full frame and the D7000 a cropped frame.

Take the same lens and put it on both cameras at the same focal length setting. The lens is the same in both instances.

However, the D7000, having a smaller sensor, only sees the centre of the image compared to the D600. Therefore, it acts as being a stronger telephoto effect. This is called the crop factor.

To get the same field of view on both cameras you will need different focal lengths. This has always been the case, and it's the format of the camera that causes it.

For a standard field of view, the "standard" lens for each format is different. So a 15mm lens on a Minox spy camera, a 35mm lens on an APS-C DSLR, a 50mm lens on a full frame DSLR, an 80mm lens on a 6x6cm medium format camera, all give about the same field of view.

Hope that helps!

John

I suspected as much - thanks John.

Considering the fact that the sensor area of the Nikon D600 is more than twice larger and the pixel size is larger, the Nikon D600 will outperform the Nikon D7000 at pixel level. if you look at images from both cameras at 100% view, the Nikon D600 will have less noise at higher ISO which makes remotely convinced.