Talk:Teleconverter

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Hey, nice idea with showing those viewfinder images, I wouldn't have thought of that. I would like to point out two things though. Firstable it would be better if there was some larger object shown (a building maybe), so that you could compare its size on those photographs. The other problem is light. The 300mm tele has a rather high f-number, so with the converter its pretty dark (my first impression was it was too dark). And I still think we could use a picture of a teleconverter itself, but unfortunatelly i can't make one right now. Again thx Swn. --filu 29 June 2005 19:08 (UTC)

I am working on better versions, with a bigger "motive". The darknes of the teleconverter version is deliberate. I wanted to illustrate the loss of light.

I have uploaded an image of my teleconverter with the camera and lens mounted, but half tranparent. I can not really decide if it is usefull, or if I should just take a simple picture of the converter. --swn 29 June 2005 21:42 (UTC)

I thought that it was a bit too illustrative on the point of the loss of light, but perhaps with a bigger "motive" it won't be a problem. I think both pictures of a teleconverter might be useful (I like the semitransparent one though) --filu 30 June 2005 13:40 (UTC)

I have updated the viewfinder images, and uploaded one more image of the teleconverter. I think only one of these should be added to the article. --swn 3 July 2005 22:38 (UTC)

[edit] Dedicated teleconverter?

I'm not sure I understand correctly this sentence:

Dedicated teleconverters only work with a limited number of lenses, usually telephoto lenses made by the same manufacturer.

Does this mean that those dedicated teleconverters won't work with other equipment or that the quality of the picture is best when dedicated teleconverter is used with equipment from the same manufacturer? If it's the latter my guess is that the wording should be changed. --filu 17:28, 18 May 2006 (UTC)

Mostly the latter, but some teleconverters have front elements that protrude into barrel of the lens that's mounted to it. If the lens has rear elements that are too close to the back, the lens won't mount (and could be damaged in the attempt). So a manufacturer who produces such a teleconverter will usually indicate that it's only to be used with certain lenses that they produce, in order to prevent damage. (Every lens manufacturer persists in the fiction that they are the only company in the world that makes lenses, and will not dare to mention a competitor's products in their materials.) -- Coneslayer 19:25, 16 August 2007 (UTC)

[edit] Is this an extender?

So, is this what canon calls a tele extender ([1])? If so, I think there should be a link to this article from the disambig extender and a redirect from tele extender. I spent ages yesterday trying to find the article for extenders, and in the end was directed here by someone on the talk page of extension tube (which I mistakenly thought was what I was looking for). IronChris | (talk) 17:15, 9 December 2006 (UTC)

I went to google and it sais two things: 1. the term tele extender is used primarly for devices allowing you to attach your camera to a telescope through an eyepiece; 2. Canon uses the name tele extender to describe a teleconverter. If this is only one manufacturer that uses this term (I don't know, this is just what google suggests...) than a redirect is not needed in my opinion. --filu 16:50, 10 December 2006 (UTC)

[edit] DOF and effective F stop?

If a 2X teleconverter connected to, say a 105mm f/2.8 lens, the effective F stop is 2 stops smaller (f/5.6) but will the DOF at the level of a 210mm f/2.8 lens or a 210mm f/5.6 lens? --antilived^{T | C | G} 11:08, 20 January 2007 (UTC)