(Tech) No Zoom, Just Plain Prime

I recall seeing a post on a social network a picture of a window of a building. The person who took it was saying something like, "This is what 26x is capable of..." 

I know it's no big deal. Though I was able to outdo it without any huge X-times zoom. So how was it done?

The answer is actually quite simple: Change the focal length. More specifically, Change the lens.

Contrary to popular marketing, the "zoom" doesn't indicate how far your camera will allow you to see. It's actually focal length that allows you to do that. (You can read up on focal length for further understanding here.) 

Zoom is just an indicator as to how far you can change your focal length. For the sake of this discourse, we'll only focus on Optical Zoom*. It is calculated by dividing the maximum focal length by the minimum focal length.

Zoom = maximum focal length / minimum focal length

This does not necessarily mean your camera or lens can shoot at far away objects. Let's have some examples:

Taken with a 3x zoom lens at maximum zoom (@42mm)

This one is taken with a 3.75x zoom lens at maximum zoom (@150mm) and a 2x tele converter (@300mm equivalent)

As you can see, zoom doesn't matter- only the maximum focal length. The longer the focal length the farther your lens can reach. Let's see an example below:

This isn't taken with a zoom lens. It was taken with a simple prime lens... A simple 500mm prime lens.

Adding my tele converter gives me this. A 1000mm equivalent. This is what a no-zoom lens is capable of.

Another thing to consider is the focal length multiplier (or crop factor. They pretty much mean the same). Smaller sensor areas in cameras have higher focal length multiplier than larger sensors. This gives a "cropping effect". Focal length is usually expressed based on the 135 film format. Most affordable digital cameras have a sensor area smaller than that of film. In effect that crops out some of the areas by a factor. A 50mm in 135 format becomes 75mm in a typical DSLR camera (Most Sony, Pentax and Nikon DSLRs have a 1.5x multiplier. Canon has 1.6x). DPreview has a very informative entry regarding focal length multiplier here.

My example above uses a 4/3 format, so that means it has a focal length multiplier of 2. To recreate the shot I made at 500mm on film, one will need a 1000mm lens! So you will notice focal lengths that are usually very short on smaller cameras (let's say something like 4mm?).

Next time you're shopping for a lens or a camera, you'd be better off doing your homework. Don't let the marketing fool you. You're better off checking the focal length. You'd have to do a bit of some math but it's actually easier than you think. Happy sniping! :)

*The other zooming method is Digital Zooming, which basically just stretches the pixels of an image instead of adjusting the focal length of the lens to magnify the projected image. This degrades image quality and you're better off avoiding it if you can.