Talk:Canon TS-E 24mm lens

NEW TS-E AF

24 TS-E II, Autofocus, Canon claims that it does have autofocus... http://canon.com.au/products/cameras_lenses_accessories/tse_lenses/tse24F35l2.aspx And the 17TS-E... I do agree it might be weird, but canon says it does.... 203.161.68.28 (talk) 07:44, 23 February 2009 (UTC)[reply]

This is a wrong, nowhere else is this claimed. Canon Australia messed up. These types of lenses have no use for AF, you just don't use them that way. Nebrot (talk) 09:24, 23 February 2009 (UTC)[reply]

Further to this, the Canon USA website says it's a manual focus lens. Nebrot is right - Canon Australia messed up. (If they didn't, I definitely want one.) 121.44.222.68 (talk) 07:32, 1 March 2009 (UTC)[reply]

I versus II specs

I added the model II specs to the infobox where the differ from the original TS-E 24mm, but wonder if it should be split into two separate tables like the Canon EF 70-200mm lens (which have five variants now). -- Autopilot (talk) 01:37, 8 January 2010 (UTC)[reply]

Leaning Towers

The towers in the example photo are leaning back (to the left) by about 20 degrees. The flagpoles are also leaning back by the same amount. This does not seem like a good example of "correction". Kwenchin (talk) 14:11, 2 March 2010 (UTC)[reply]

Very true. It looks like the camera wasn't level when the shot was taken. If you have a better example, feel free to upload it... Bobby Tables (talk) 15:38, 2 March 2010 (UTC)[reply]

Degrees of Freedom TS-E 24mm II (also applies to TS-E 17mm)

It says there are three degrees of freedom.

These new lenses have four degrees of freedom. (tilt, rotation of tilt, shift, rotation of shift)

(ps I haven't found a source for this) Kwenchin (talk) 10:08, 3 March 2010 (UTC)[reply]

I'm not entirely sure if that's true. Rotation of tilt and rotation of shift are the same degree of freedom - rotation. The old TS-E lenses don't rotate freely, and as such they only have two degrees of freedom, whereas the new ones have three. Just because rotation has no effect without any tilt or shift doesn't mean it can't be used :) Bobby Tables (talk) 17:41, 3 March 2010 (UTC)[reply]

The rotations are in different axes so count as two.
Are you saying that the statement "The TS-E24mm f/3.5L provides three degrees of freedom" is incorrect and should say "two"?

Kwenchin (talk) 21:44, 3 March 2010 (UTC)[reply]

I wonder whether “degrees of freedom” really adds any useful information. If it's felt important, though (and Sidney Ray uses the term in the Camera Movements chapter of The Manual of Photography, 9th ed., 163–66), the correct number is largely a subjective call, and depends more on what's actually allowed rather than how it's achieved. For a typical monorail camera, he shows 11 degrees of freedom:

Front focusing
Front rise and fall
Front cross (lateral shift)
Front tilt
Front swing
Rear focusing
Rear rise and fall
Rear cross (lateral shift)
Rear tilt
Rear swing
Rotating back (allowing changing between portrait and landscape orientation)

The TS-E 24 mm f/3.5L II, in effect, provides all of the front movements, so if Ray's criteria guide, the answer is probably five, including focusing (which, if you think about it, is fairly important ...). But again, I'm not sure whether this informs or confuses. What's important is that the shifts and tilts are independent, even if they aren't set in quite the same manner as on a view camera. JeffConrad (talk) 04:44, 5 April 2010 (UTC)[reply]

I changed this article to indicate four degrees of freedom for consistency with the other three TS-E articles; this doesn't necessarily mean that I think it's the final answer. As I've said, I'm not sure it really adds much more than technobabble for the average reader. JeffConrad (talk) 01:10, 6 April 2010 (UTC)[reply]

Edits of 5 April 2010

Looks like I saved the changes before adding a comment ...

Much of the edit is minor copy editing, including typographical changes for conformance to the WP:MOS, especially spaces before units. I also tried to make it clear that the article refers to the Series II version, though the image and specs are for the original version. I changed the link to Tilt-shift lens in case that is ever moved to an article that's actually about tilt/shift lenses.

A few technical points:

The description of shift is a bit sparse; a description could be expanded to one like that in the Perspective control lens article. It also could be described as “pointing” the camera without moving the back, as Howard Bond describes it.
Perspective is controlled by the camera back, so it can't be controlled by shifting the lens. Rear tilt and swing can be emulated by tilting the camera and shifting the lens to provide the desired framing. This could be mentioned, but it seemed superfluous and possibly confusing. I also think there's an advantage to not saying too much here (or in similar articles about other TS lenses) because the descriptions should be consistent, and every separate instance is something additional to maintain.
Tilt rotates the plane of focus away from parallel to the image plane; the DoF when the lens is tilted is wedge shaped. There probably are other ways to say it, but I don't think any are as succinct. And many descriptions I've seen simply aren't correct.

JeffConrad (talk) 04:18, 5 April 2010 (UTC)[reply]

I've made a few other minor changes, including adding a brief description of what the rotation does. In listing the special features, I changed “perspective correction” to “perspective control”, consistent with similar changes to Perspective control lens and Perspective control. The mention of perspective control is somewhat of a misnomer, because as I mentioned, the lens doesn't really control perspective. Both perspective control and Scheimpflug principle seen a bit ponderous to me; I think simply saying tilt and shift would be much simpler as well as more accurate.

Companion changes to other TS-E articles

I've made (more or less) companion changes to the articles on the other TS-E lenses. I've left the descriptions of degrees of freedom as they are, but I think this should be given some thought, because I find inclusion of rotation confusing, especially for the 45 mm and 90 mm lenses. One clever fellow asked if this meant unscrewing the lens so that it falls off, and even inserted his observations into the text of the Tilt-shift photography article. While that was just plain silly, I wonder if the current description isn't confusing.

Some of the infoboxes contain contradictions, such as the 24 mm and 90 mm lenses indicating that they aren't macro capable yet including macro as applications.

The article on the 17 mm lens is the only one that mentions the lack of autofocus; is it necessary to do so? If so, it would seem to be appropriate to mention it for the other lenses as well. None of the articles mentions automatic aperture control; it's been provided for every EF lens that I'm aware of, and it's now provided on the Nikon PC-E lenses, so perhaps it's taken for granted (and most readers have probably never used a lens without it). Nonetheless, some of the third-party lenses, such as the Hartbelei Super-Rotators, still don't provide it. JeffConrad (talk) 06:37, 5 April 2010 (UTC)[reply]

I've made a few changes to this and the other TS-E articles in attempt to better describe what the lenses do, and to make the descriptions consistent. See if these changes work.

I added mention of the lack of autofocus to all articles; though this may be obvious to those who have used TS lenses, it may not be to the average reader. If nothing else, it affords a less-awkward way of mentioning the EF mount (apologies for the seemingly endless attempts).

There's obviously a lot of repeated material; I'm not sure it's possible to avoid this and still give a decent description of the lens functions. It does strike me that much of the material would make at least a decent stub for a real article on tilt/shift lenses; some material from the article Perspective control lens could be included, with perhaps some additional discussion of tilt. Thoughts? JeffConrad (talk) 01:21, 6 April 2010 (UTC)[reply]