What make a lens good for a particular application?

[adrian douglas]

Apart from the obvious, optics, AF, and lens speeds, what makes a

lens better for some applications than others? What makes an 85/1.4

better for portraits than a 50/1.4 for example?

[michael_hohner]

A 85mm lens is not necessarily "better" than a 50mm for portraits. For many portraits you like to shoot from a certain distance to achieve a pleasing perspective. When you now intend to make a head-and-shoulders portrait you need a certain field of view, and a focal length around 80mm provides that field of view. However, you can make a full-body portrait from about the same distance using a 50mm lens, or a group portrait with a wide-angle lens.

[steve_dunn2]

<p>Sometimes a particular focal length will be particularly good, or particularly bad, for a given type of photography. As the previous response said, lots of different focal lengths can be used for portraiture - depending on what your portrait is. Nature photography usually calls for a telephoto lens, but again, it depends on how big the animal is, how close you can safely get, whether you're shooting one animal or a group, etc. Landscapes are often taken with wide-angle lenses, to include a large expanse in the view - but there are also times when you want to isolate something, so you use a telephoto.</p>

 

<p>There are some other characteristics for various types of photography. One example might be architectural photography, in which you're usually taking pictures of buildings that have straight lines for corners and you expect them to render as straight lines in the picture. A lens with minimal distortion is required for this. Perspective correction (shift) lenses are also useful for this type of photography.</p>

[marbing]

Well, if you asked about 28mm vs 85mm for portraits then the answer would be easier to see. The wide angle lens would distort the portrait while the 85mm lens would take a more realistic portrait. As the focal lengths get closer to each other the differences become harder to see in the individual shots. If you took lenses such as 50mm-85mm-100mm-135mm then you end up with a range of focal lengths that are acceptable for portraits. With the 135mm lens, you end up standing farther back to get the shot so it wouldn't be great if you have to take a headshot in a closet and you would be standing at the other end of the room to get a full length shot. For those shots there are the other focal lengths.

 

I have the Zeiss 85/f1.4 as my main portrait lens but, if necessary, I use the others

[jim schwaiger]

In a word, PERSPECTIVE.

 

Taking a head shot of someone with a 28mm requires that you be very close, at 135mm, you have to be farther away which gives a very different perspective. Getting close causes faces to look distorted - the nose will appear too large, and the face will appear much wider than at "normal" viewing distances.

 

So,, different focal lengths require different distances to shoot the same subject which inherently gives a different perspective.

 

Note that this doesn't mean that you can't use a wide angle lens to make an effective portrait. It is simply more difficult to create a portrait image that works well with wide angle lens. Care must be taken to manage the distortions, or use them in a creative way.

[klix]

Agree with all of the above, but I believe the manufacturers perpetuate what the writers and magazines promote and come up with self-fulfilling prophecies.

 

So, in my experience (Nikon), while yes, in general, you can use just about any lens (within reason) for portraiture (as one example), the qualities that make a good portrait lens (bokeh, for one) seem to be designed and built into lenses in the 85-135mm range to begin with.