When is a lens a telephoto?

MrRamonG · Dec 11, 2009

Here's a simple and elementary question.

When is a lens considered telephoto? Are all zoom lenses telephoto?

Village Idiot · Dec 11, 2009

When it's above about 70mm, iirc. Telephoto deals with focal length, not zoom, which "tele" part might be confusing you with.

Pugs · Dec 11, 2009

A lens is a telephoto when the focal length is longer than a standard lens. And no, not all zooms are telephoto.

A standard lens reproduces an angle of view that is similar to what the naked eye sees. This is generally considered to be right around the 50mm mark, plus or minus 10-ish millimeters or so.

A wide-angle is any focal length below that and telephoto is any focal length above that.

If I'm wrong, someone please correct me so that I can learn, but this is what my understanding has been for the last twenty years or so...

MrRamonG · Dec 11, 2009

Thanks for the replies, but this leads to another question. Is a zoom lens, 18mm-135mm, a partial telephoto lens?

I've been kicking these questions around but I haven't been able to secure a straightforward consistent answer.

When someone says, you need to get a telephoto lens, i want to know what they are talking about. And if someone says, don't bother with a telephoto just stick with a zoom, what does that mean?

I think sometimes people spout off statements just to sound like they know what they are talking about.

Big Mike · Dec 11, 2009

And if someone says, don't bother with a telephoto just stick with a zoom, what does that mean?

It means that they really don't know what they are talking about...or at least don't know how to articulate it very well.

Technically, a Telephoto lens is one in which the optical centre lies outside the physical construction of the lens. Wiki.

The common use is that we call any lens that has a focal length longer than 'normal' a telephoto lens. 80mm would be called telephoto on a '35mm format' camera...but not on a medium or large format camera.

Dwig · Dec 11, 2009

MrRamonG said:
Thanks for the replies, but this leads to another question. Is a zoom lens, 18mm-135mm, a partial telephoto lens?

Yes, by one definition of "telephoto".

There are two rather different definitions of "telephoto":

1. Common parlance:
---- Normal lens: lens with focal length close the the diagonal measure of the image format, approx 26-28mm on APC-s & 42mm on 35mm "full frame".
---- Wide angle lens: lens with a focal length significantly wider than a "normal" lens.
---- Telephoto lens: lens with a focal length significantly longer than a "normal" lens. In older books and discussions, roughly pre-WWII, the common term was "long focus" and "telephoto" was limited to its techinical definition (see below).
---- Standard lens: lens that comes packaged with the camera body. This is now an archaic term having been replaced in the common jargon with "kit lens". In the pre-zoom SLR era when the default lens was a prime, the common focal length was about 20-25% longer than "normal".

2. Optical design:
----- A technical term that refers to the placement of the exit node relative to the physical position of the actual lens elements. In a telephoto design, the exit node it very far forward of the physical center of the lens. Telephoto designs allow the lens to be very compact, relative to its focal length, compared to other more conventional designs.

Pugs · Dec 11, 2009

MrRamonG said:
Thanks for the replies, but this leads to another question. Is a zoom lens, 18mm-135mm, a partial telephoto lens?

I've been kicking these questions around but I haven't been able to secure a straightforward consistent answer.

When someone says, you need to get a telephoto lens, i want to know what they are talking about. And if someone says, don't bother with a telephoto just stick with a zoom, what does that mean?

I think sometimes people spout off statements just to sound like they know what they are talking about.

An 18-135mm lens is a zoom lens that covers a range of focal lengths from wide angle, to standard, to telephoto.

Zoom means that it has a variable focal length and you can zoom in or zoom out from one focal length to another. It means absolutely NOTHING in terms of whether it is wide, standard, telephoto, or covers all three.

Someone who tells you "don't bother with a telephoto just stick with a zoom" really doesn't know their terminology and likely doesn't know squat about lenses. The performance you're going to get from a prime (prime means non-zoom, it is one focal length and one focal length only) lens is generally going to be better than you can get with a zoom lens that covers the same focal length.

Plato · Dec 11, 2009

Pugs said:
A lens is a telephoto when the focal length is longer than a standard lens. And no, not all zooms are telephoto.

A standard lens reproduces an angle of view that is similar to what the naked eye sees. This is generally considered to be right around the 50mm mark, plus or minus 10-ish millimeters or so.

A wide-angle is any focal length below that and telephoto is any focal length above that.

If I'm wrong, someone please correct me so that I can learn, but this is what my understanding has been for the last twenty years or so...

Actually, a "long" lens is a lens with a focal length longer than that of a standard lens. In the 35mm film world, a "normal" lens was generally accepted to be anywhere from 45mm to 55mm. There is less agreement in the digital SLR world. A "telephoto" lens is a long lens with a focal length that exceeds its physical length.

Pugs · Dec 11, 2009

Plato said:
Pugs said:

A lens is a telephoto when the focal length is longer than a standard lens. And no, not all zooms are telephoto.

A standard lens reproduces an angle of view that is similar to what the naked eye sees. This is generally considered to be right around the 50mm mark, plus or minus 10-ish millimeters or so.

A wide-angle is any focal length below that and telephoto is any focal length above that.

If I'm wrong, someone please correct me so that I can learn, but this is what my understanding has been for the last twenty years or so...

Click to expand...

Actually, a "long" lens is a lens with a focal length longer than that of a standard lens. In the 35mm film world, a "normal" lens was generally accepted to be anywhere from 45mm to 55mm. There is less agreement in the digital SLR world. A "telephoto" lens is a long lens with a focal length that exceeds its physical length.

Thank you for the clarification!

KmH · Dec 11, 2009

Here's how Nikon breaks them down on their web site:

Wide-Angle

Standard

Telephoto

Super Telephoto

Wide-Angle Zoom

Standard Zoom

High Power Zoom

Close-Up

djacobox372 · Dec 12, 2009

On an APC size sensor even a 50mm lens can be considered a telephoto.

Basically anything that enlarges the subject beyond what you see with your naked eye is a telephoto, just as anything that gives a wider view then "normal" is a wide angle.

"Normal" varies. On 35mm film, or FX sensors it's 50mm... on digital apc crop sensors it's 35mm, on a medium format camera it's 80-90mm, on a large format camera it can be 135mm or larger.