Talk:Telephoto lens

Telephoto / Zoom

I have placed a request on zoom lens to merge into this article. There is duplication between this article and zoom lens. I think the two articles should be combined. I think a zoom lens should be a subcategory of telephoto lens, as the distinction is basically a zoom lens has a varying focal length. The issues as to what a focal length is, what an angle of view is, and how these things are related are common to both. Furthermore, the artistic aspects of using a telephoto and zoom to me seem to be the same. Bottom line, there is information in the zoom article that relates to telephoto and vice versa. --Lenehey 22:32, August 22, 2005 (UTC)

NO ! It's a common confusion. A telephoto is not a zoom. And the artistic aspects of using a telephoto and zoom aren't the same especialy if we extend the topic to the use of zoom in movies and video. There's a (very incomplete BTW) article about photographic lenses another, another about wide-angle lenses, another about normal lenses, another about zoom lenses and I think it should stay like this. Ericd 21:40, 23 August 2005 (UTC)

Correction

There seems to be a little bit of confusion in this article. It starts by saying that a telephoto lens is any lens with a focal length significantly longer than the focal length of a normal lens but then saying that a telephoto lens must include a telephoto group.

I think the article needs clarifying. Specifically, I think these points need to be made:

1. A lens with a focal length significantly longer than the focal length of a normal lens is a long lens.

2. A telephoto lens is an optical design that has the property of allowing the lens to be physically shorter than the focal length would suggest. A telephoto lens need not be a long lens but generally is.

3. The term telephoto is commonly misused to describe any long lens.

Stephen Short 20:10, 14 April 2006 (UTC)

The page, in general is very confused between lenses that are telephoto and lenses that are just long. The introduction says that a tele lens must have a telephoto group but everything from the Effects section onwards applies equally well to any long lens, telephoto or not. Would it not be better to split this article into two pages, one for 'long lens' (talking about what a long lens is, what effects they have and when they're used) and one for 'telephoto lens' (explaining that it's a common long lens design)?

Dricherby 12:59, 4 May 2007 (UTC)

Clear definition

This article could use a sentence or two before where it currently starts or a bit of rewording. It would be more helpful to include a short (if somewhat imprecise) definition of what a telephoto lens is. To someone just coming in, the first paragraph's focus on what isn't telephoto will probably not be entirely helpful. —Preceding unsigned comment added by 63.227.66.222 (talk • contribs)

AMEN BROTHER! All I wanted to know was what it did, not how it did it in excruciating technical detail. One simple sentence, then you can get to the technobabble. Scottanon (talk) 21:50, 1 April 2009 (UTC)

I agree, the lede lacks a basic defintion. Just one sentence that states, "Telephoto lenses are typically used for..." or "Photographers prefer telephoto lenses when..." would be very helpful. Bms4880 (talk) 22:20, 9 March 2011 (UTC)

Argumentative wording about long vs telephoto

I'm copying this here since the anonymous user making recent changes is at a new IP address and I didn't want it being lost on some random anonymous talk page.

About your (anonymous) edits - While what you are stating is fact, your wording is argumentative. Wikipedia is about informing people, not talking down to them or showing them that you're "right". Very good, you know that a telephoto lens must technically have a "telephoto group" of lenses in it. The article already stated that, no need to make it so prominent. I assume most modern long-focal-length lenses are telephoto anyway, simply for practical reasons. So there's little need to "correct" people in the introduction. --Imroy 19:12, 2 September 2006 (UTC)

Instead of complaining about it, why didn't you try to contribute something better, rather than just revert the factually incorrect version. The entry didn't even mention the telephoto group until half way through, and then only in passing, leaving the reader with the impression that any long focus lens is a telephoto lens, unless he read far enough and made the conection. It needs to be prominent, because that is the essential feature of the telephoto lens. 86.134.123.38 13:00, 3 September 2006 (UTC)

If you must know, I did start editing your contribution, moving the "correction" to the second paragraph and also breaking the article up into sections. But I ditched it because I was tired at the time. I'll have another look at it soon and see what I can do. And if you look at the diff[1], you'll see that I did not simply revert your previous edits, I did try to incorporate some of your contribution. --Imroy 14:18, 3 September 2006 (UTC)

Fair comment. I had assumed you had simply reverted it, because that is what the change description said. 86.134.123.38 15:09, 3 September 2006 (UTC)

It would help to clarify how to measure

How to demonstrate that a particular lens is physically shorter than its focal length would help, it may even clarify the potential confusion about Catadioptric design.

For example you don't measure from the front to the lens mount, the lens mount may be any distance from the focal point (large format, bellows mounted lenses are obvious examples). The Angénieux retrofocus article explains retrofocus clearly so it should be easy to explain telephoto clearly too.

Bill burk (talk) 04:06, 19 May 2014 (UTC)

It may even help to describe Wide Angle designs

Like telephoto designs are used to make a lens physically shorter, wide angle lenses are sometimes designed to make the lens physically longer than their focal length. 35mm SLR cameras need the lens farther from the film plane to make room for the mirror box. I think telling both stories in the same article could help people grasp the concept, and it could be defined in terms of light path distortion to solve specific problems.

While Catadioptric lens designs don't distort the path, they fold it. Bill burk (talk) 04:06, 19 May 2014 (UTC)

Non-Telephoto Catadioptrics?

However, lenses incorporating mirrors are not necessarily of telephoto design. Is there any particular citation to prove this statment? (other than people saying that there are some?) 69.72.7.119 04:01, 12 October 2006 (UTC)

There are some medium focal length mirror 'lenses' around where the focal length is around twice the pysical length of the assembly (and I have one sitting in front of me - it's a 500mm mirror and it's 265mm long (excluding mount)). This is characteristic of a Schmidt design and obviously does not require any telephoto elements to achieve this (though I have no intention of dismantling this one to check). This could be achieved with just 2 mirrors and nothing else, but there are some refractive surfaces in the glass elements which are undoubtedly to correct abberations from the mirrors. Many older short (relatively) focal length (mirror) 'lenses' fall into this category, but virtually all modern 500mm lenses are of refractive design. Much longer focal length mirrors do have telephoto elements in them to keep them a respectable size.

I B Wright 09:54, 12 October 2006 (UTC)

The Schmidt and the Maksutov optical system (see Catadioptrics) both uses a convex secondary mirror to bounce the light through the primary. That convex secondary is the "telephoto group"--- it extends the light cone beyond the focal legth of the primary "mirror". I have not seen any Catadioptric lenses that are not Schmidts or Maksutovs. If there is a non-telephoto lens out there it would probably be a "flat secondary" Schmidt... which could exist although i have never seen one... but I think the original statment would need a citation of such a beast. Mr Floating IP 69.72.7.207 13:35, 12 October 2006 (UTC)

Thumbnail focus

Why do some of the thumbnail images appear to be out-of-focus? Does that happen during the reduction? I don't know too much about digital manipulation. 66.57.225.77 04:00, 29 October 2006 (UTC)

Long lenses

The opening paragraph of this article specifficaly excludes "Long Lenses". Why does Long lens redirect here? If something is not included in a definition should not be redirected and maybe even have its own article?69.72.7.39 16:23, 9 January 2007 (UTC)

The term "long lens" is almost always used to mean "long-focal-length lens". Most long lenses are telephoto lenses. Furthermore, while the formal definition of telephoto excludes lenses that aren't shortened by a telephoto optical design, the informal use covers ALL long lenses. Dicklyon 19:33, 9 January 2007 (UTC)

Without a Doubt...

This is one of the most uninformed articles written on Wikipedia, through and through. Factual inconsistencies, falsehoods and random made-up BS. This article doesn't even deserve to be panned for its grammatical butchering because the content is so awful. Evil Prince 01:14, 15 October 2007 (UTC)

Picture caption not correct?

The photo shows a Beroflex 500/8 lens and the captions state it is not a telephoto lens. I own this lens and it is definitely constructed as a telephoto lens according to the description in the article. It is also less than 500mm long. It is rather long compared to modern lenses, but still a telephoto construction. —Preceding unsigned comment added by 89.56.141.46 (talk) 22:09, 14 June 2008 (UTC)

In any case what would be the point of illustrating an article on telephoto lenses with a picture of a lens that isn't a telephoto? 83.104.249.240 (talk) 03:41, 25 February 2009 (UTC)

Article cleanup

Cleaned up article for style, WP:MOSBEGIN, WP:JARGON, and general referencing. Some images did not seem to fit WP:IMAGE per: not being informative, or even readable at thumbnail. Also moved some material off to Long focus lens since reference, article content, and most editors on this page point to the telephoto being a specific construction/sub-type of a long focus lens. The prose style is still a little teach-ie. The added paragraphs on Alexander McKay look to be trivia since they have no reference as to if what he did was notable in any way, i.e a historic first? a well published pathfinder?, etc. Fountains of Bryn Mawr (talk) 20:50, 9 December 2010 (UTC)

Animals

Is there no mention of this type of lens in animals?--91.104.230.118 (talk) 20:59, 22 January 2011 (UTC)

No.  Velella  ^{Velella Talk}   22:17, 22 January 2011 (UTC)

Alexander McKay photos of the Vjestnik

Would be really interesting to see them – I guess there are no digital scans available. What was the focal length of his constructions? Paul Pot (talk) 23:30, 7 July 2012 (UTC)