How much zoom does a 70-300mm lens give you?

[jg123]

I was reading a description of this lens and it said:

Canon EF 75-300mm F/4-5.6 USM III Lens, With Canon 1-Year USA Warranty Compact and lightweight 4x telephoto zoom.

zoom, what exactly does that mean? I only have a p&s right now and it has 8x optical and 32x digital zoom. So is the 75-300mm going to be about half the zoom of the optical amount I have now?

 

[Big Mike]

When they say "X amount of zoom"...they are just comparing the minimum focal length to the maximum focal length.

The 75-300mm lens for example. 300mm is about 4 times as long as 70mm...so it's a 4X lens.

A lot of digi cams have a greater range of zoom. The longest focal length is 8, 10 or 12 times as long as the minimum focal length...so there is your 8X, 10X & 12X. Digital zoom is just cropping the image, I recommend avoiding it.

If you want to know how much magnification you get with a lens...they are usually compared on the standard of a 35mm film camera. So for example, the spec for your digi cam might be 'equivelent of 30mm to 240mm' (just an example)...or something like that. That means that the magnification or view...is equivelent to 30mm-240mm as viewed on a 35mm film SLR.

A typical entry level digital SLR has a factor of 1.5 or 1.6 (Nikon & Canon)...so to compare the 75-300mm (on a typical DSLR) to your camera, you would use the factor and say that it is 'equivelent to 120-480mm'

 

[djacobox372]

The typical point and shoot fully zoomed out is roughly equivalent to 35mm, so 300mm would be 8.5x zoom.

"super zoom" P&S usually start out wider to achieve the extra zoom range, something like 28mm, so 300mm would be 11x in those cameras.

Also keep in mind that most DSLR's have a inherit 1.5x digital zoom due to the sensor size compared to film.