Whats the difference

I'm pretty sure no one here has asked this because you all know.

what is the difference between a telephoto and a zoom lens??

they both bring things closer right? so how can there be a difference.

please use simple english and pictures so i can understand

cheers

A telephoto is a fixed focal length e.g. 400mm
a Zoom has a variable focal length e.g. 150mm to 500mm

In my experience, 'telephoto' is usually used in reference to a longer-than-normal focal length, fixed focal length lens. Anything from 75mm and upwards, I guess - and I've heard the term in conjunction with 'short' and 'long'.

100mm would be a short telephoto; 300+ would be long, but these aren't fixed definitions by any means.

Zoom lenses are all of variable focal length, and would not necessarily include long focal lengths.

A telephoto zoom, although not a particularly common term, for instance, might be 100-300mm. You definitely wouldn't hear the Sigma 10-20, which is a zoom, described as a telephoto.

You can have a....

wide-angle lens or a wide-angle zoom lens. A 14mm lens would be a wide-angle lens. A 12-24mm zoom would be a wide-angle zoom. The same holds for all ranges.

In 35mm film photography any lens greater than 50mm was considered to be telephoto. I supose that with a sensor crop factor of 1.5, then this would now mean that over approx 33mm is telephoto.

A zoom lens has an infinately adjustable focal length, between its range.

Actually, you are all very nearly correct.

A zoom lens having a minimum focal length of around 50mm and a maximum focal length of much greater than 50mm was always termed 'telephoto zoom'. A zoom lens having a maximum focal length of around 50mm and a minimum focal length of much less than 50mm was always termed 'wide angle zoom'.

Otherwise, a fixed focal length lens of greater than 50mm was termed 'telephoto' and a fixed focal length lens of less than 50mm was always termed 'wide angle'.

But that was in the days of film, terminology may well have changed in recent years.

Were there equally definitive definitions for formats bigger than 35mm?

(edit: lest George berate me for tautology, perhaps I should say "unequivocal definitions")

Generally speaking folk who use larger format, from 6x6cm through to 10x8in cameras are experienced, probably mostly professionals.

Professionals generally just talk in terms of focal length, in 35mm, digital or any other format, since when you are using camera equipment every day you will know their relationship to format size.

For example, I'd often hear 'can I borrow your 250 for the Hassel'. I've never heard 'Can I borrow your telephoto for the Hassel.'

I've also heard 'long focus' used in reference to plate cameras but these are actually long focus rather than telephoto.

Is it really any different in the amateur world? Everywhere you look on this forum people refer to lenses by their focal length - often not even referring to their manufacturer with the common ones.

What's the difference between these?

ok to put it simply, zoom lenses are variable but telephotos are fixed (unless it has a large starting focal length that gets bigger then it would be a tele-zoom) and the finished visual picture isnt any different.

eg. a zoom lens that has a maximum length of 100mm (lets say its minimun is 50mm for arguements sake) the picture taken with this lens at full zoom (100mm) would look exactly the same as a telephoto lens at 100mm.

Is that anything close or am i way off the mark?

No not really Danny.

Telephoto
In photography and cinematography, a telephoto lens is a lens where the focal length is significantly longer than the focal length of a normal lens. For a 35 mm camera with a 24 by 36 mm format, the normal lens is 50 mm and a lens of focal length 70 mm or more is considered telephoto.

In addition to making objects appear closer then they are, the resulting image will also have a certain degree of perspective distortion.

The original meaning of telephoto lens was a lens with optics containing a telephoto group, that would allow the lens to be physically shorter than its focal length. Compare with the opposite effect used in retrofocus lenses, which have greater clearance from the rear element to the film plane than their focal length would permit with a conventional optical design.


Zoom
A zoom lens is a mechanical assembly of lenses whose focal length can be changed.


Simple
Telephoto = A lens with a focal length greater then 70mm on a film camera or 105mm on a digital crop camera (all Pentax DLSR).
Zoom = the ability to change the focal length of the lens.


This is different matter though since this more about the focal length then the definitions.
Focal length is something every lens have, you have had that definition at school!

The focal length is the point where all the light of the lens focus or defocus.
I'm sure this illustration will help you to remember.



To answer your question a 100mm prime lens (fixed focal length) will have a similar image (magnification) as a zoom lens set on 100mm.
But the image does not need to be the same since there are more factors besides focal length that makes the image, zoom lenses have often more distortions then prime lenses so that's why.

If you mean the compression of perspective that you get when photographing distant objects (usually, granted, with long focal-length lenses), it has nothing to do with the focal length of the lens, and everything to do with the distance of the camera from the subject.

The idea that that perspective compression is caused by the telephoto lens is quite misleading - it's simply a result of the tendency to photograph distant objects with telephoto lenses.

Take a picture of the same scene with a wide angle and a telephoto, from the same place, and compare the crop of the wide angle shot that corresponds to the field of view you get with the telephoto. Enlargement losses aside, the perspective should be identical.

well, you can all call me stupid and what not, but I couldnt be anymore confused if i tried. I think i'm more confused now than when i started.

i know about the perspective things, if your up close and take a photo everything have a bit more perspective, but if you go backwards then zoom in the photographed object in the previous picture and make it the same size then things liik different

I thought your post last night at 19:15 was fine - as you summarised, zooms are variable focal length, telephotos are fixed, and a picture taken with a zoom set to focal length x should look much the same as one taken with a telephoto of focal length x.

There's a lot of extra information in Anvh's post that, with respect, perhaps isn't quite in the simple terms you were looking for! That doesn't at all make you stupid, which you clearly aren't.

Exactly.

aah right, so really there isn't THAT much difference, unless you want to be all technical. Photography is just a hobby to me I'm not planning on being professional, so thanks to you all for the help I know a little bit more and the rest will come with practice

cheers