500mm 4.5L with 2X adapter problem

[EugeneK]

Has anyone had a problem with the Canon 500mm 4.5L with 2x Canon adapter not working with a D60? The focus does not work - manual or otherwise. The 1.4x works fine and the 2X works with my 300mm 4L IS. This combo worked on my old A2, in fact I used to stack both 1.4x and 2x together (with extension ring).
Is this a problem with the D60 in general or maybe my D60? I don't use this combo generally, epecially with the 1.6 factor of the camera, but the few times I tried it it didn't work. Does it work on a 10D?
-Eugene

[CyberDyneSystems]

This is "normal"

You need a quick "teleconverter" primer :)

the AF in Canon SLRs will only function if the lens attached meets the SLRs requirmenets for a minimum aperture.

With the D60, and all other Canon SLRs except the 1 series and EOS 3 that minimum requirement is f/5.6

In other words, a lens or lens/Teleconverter combo with a maximum aperture of less than f/5.6 will NOT autofocus on the camera. The AF just needs that much light to function.

By putting a 2X on your 500mm f/4.5 you have stopped down the largest possible opening to f/9

No Canon SLR can AF at a max aperure of f/9.

A 1.4X T-con with that lens will result in a max aperute of f/6.3... still too small for AF on a D60.. but it will AF on a "1" series.

Hope this helps

[Scottes]

Manual Focus should still work. Doesn't that lens have a focus ring? That should work whether a camera is attached or not.

[robertwgross]

CDS, your text about autofocus is nice, but Eugene said that his rig did not focus at all, manual or otherwise.

---Bob Gross---

[CyberDyneSystems]

:shock:

I somehow missed the word "manual" in there?

In which case the only thing that I cpould imagine preventing focus is that you are too close to the subject. Otherwise I'm at a loss.

[Scottes]

Yeah, I'm kinda confused by this, too. The Canon TCs (all TCs?) don't affect minimum focus distance, but that's a good thought CDS.

I guess a definition of "does not work" is in order. Eugene, exactly what happens with and without the TC?

[PaulB]

When it was a current lens Canon did not recommend using the 500/4.5L with Extenders at all - although I know people who do use it with the 1.4x.
Even with the 1.4x it won't AF (in theory) with the D60 as has been pointed out previously.
Other than that I can't think why it won't focus at all though.

[PaulB]

Just had chance to properly check - Canon said that Extenders 1.4x and 2x could only be used for manual focus; no camera body specified, so no AF even with the 1 series bodies (officially).