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using 2x1 tele converter

by finkel13 / May 4, 2009 1:22 AM PDT

Does anyone have experience using 2x1 tele converters? I'm considering using one to extend my Canon 75-300mm lens that I use with my Digital Rebel.

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I wouldn't
by kalel33-20416052469708587370302374692233 / May 4, 2009 1:35 AM PDT

A 2x teleconverter will degrade the image quality of the photo, which would be bad for the 75-300 because it's already the worst telephoto zoom lens made by Canon, by quite a ways. Also, if you add a teleconverter and the largest aperture is above F5.6 then the Camera loses autofocus. Since your lens is F5.6 to begin with then adding any teleconverter will lose autofocus.

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by finkel13 / May 4, 2009 1:42 AM PDT
In reply to: I wouldn't

I was wondering about what would happen to the autofocus, but have heard conflicting answers. I tried a Sigma 1.4x converter in a photo store and the autofocus seemed to work fine. Why us the 75-300 lens so bad in your opinion?

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It's not just my opinion
by kalel33-20416052469708587370302374692233 / May 4, 2009 2:32 AM PDT
In reply to: Thanks

A 1.4x teleconverter would only drop you're aperture by one stop, but if you zoom to 300mm(where largest aperture is F5.6)it turns into F8 which you would lose auto focus. You lose two stops with a 2x.

Read these threads on the 75-300, there's a reason it's so cheap.

Here is a ton of consumer reviews on the lens, it received 5.6 out of 10. The 55-250IS and 70-300IS are much better than the 75-300.

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Also, here's a professional review site
by kalel33-20416052469708587370302374692233 / May 4, 2009 2:47 AM PDT
In reply to: Thanks
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Re: canon lens
by finkel13 / May 4, 2009 9:09 AM PDT

I have the Canon EF 75-300mm f/4-5.6 IS USM

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Optically they're the same lens, only missing IS
by kalel33-20416052469708587370302374692233 / May 4, 2009 9:14 AM PDT
In reply to: Re: canon lens

The 75-300 was the first to get IS back in the mid '90s, and even the IS is not near as efficient as the current IS lens.

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