MiroFoto

I have a question. Can you direct me to the source of zoom/magnification conversion understanding?
I tried to find it in previous posts, but it is kind of complicated.

Binoculars have a magnification value 8 or 10 , then size and clarity.......to understand the quality.
Cameras have zoom in 16-300 .....( in my case . It is a Tamron on Nikon 7100.) But how do I correlate it (magnification)to binoculars?
To make it more complicated some cameras have 4x 30x 65x zoom (30x is on my Sony bridge cam)

Is there any conversion table available? I know the lens zoom magnification relates to smallest value somehow.

Thank you for the advice. Miro

f8lee Loc: New Mexico

I think the simplest way to think about it is that a 50MM lens is "normal" (that is, has an angle of view close to the naked eye) on a full frame camera, so multiples of that will correspond to a binocular's magnification - so a 300MM lens (FF equivalent) would effectively be a 6X power.

If you use a crop frame camera (one that you'd use the "crop factor" to estimate angle of view) then that would be included in the calculus - that 300MM lens x 1.5 would be effectively a 450MM lens on a FF camera, so about a 9X power.

And bridge cameras use the FF equivalents when you see things like a 24-1200MM zoom - the actual lens is a tiny fraction of those focal lengths but the angles of view it generates (due to the smaller imaging chip) means that the FF equivalent would be those figures, so at it's most extended length is would be like a (1200/50) a 24X magnification.

Again, these are just rules of thumb, but they might help.

catchlight.. Loc: Wisconsin USA- Halden Norway

8 in the 8x30 is the magnification. If you assume normal vision is about 50mm, then 8x50=400mm (FF). Then multiply the crop factor if you need that equation.

BebuLamar

But to compare a camera to the binocular then not what's on the image that count but how big of an image one see in the viewfinder isn't that right.
So the same camera, same lens and if you put a magnifying eyepiece you will have more magnification.

gvarner Loc: Central Oregon Coast

👍

MiroFoto

Thank you . Miro

Bobspez Loc: Southern NJ, USA

Miro, The X factor on a zoom lens is just the longest focal length divided by the shortest, so a 55 to 300mm lens is roughly a 6x zoom. An 18 to 300mm zoom lens has roughly a 16X zoom. If a bridge camera has a 24 to 1200mm focal lenght, then it advertises a 50X zoom lens. It has nothing to do with the the actual magnification at the longest focal length, just the longest focal length divided by the shortest.

For binoculars, the first number is the actual magnification comared to the human eye. If you were to take your binoculars and camera and zoom lens outside and focus on a telephone pole, you will see a 7x binocular is roughly the same magnification as a 200mm lens on a DX camera, which gives a 300mm equivalent focal length. According to the 50mm rule of thumb, the 300mm equivalent focal length (of a 200mm lens on a DX camera with a 1.5 crop factor) ought to be about 6x magnification on a binocular.