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When you add the Tele Conversion Lens to a camera such as the A80,
what does that do to the speed (if that's the right word) of the lens?

Thanks,

Bill Cherepy
Grayson, GA

Bill.

Generally adding conversion lenses reduces the amount of light entering the
camera.
The A80 will just adjust evertthing as necessary (e.g. a bigger F number or
slower speed).

A rough guess is that it will halve the amount of light

Cheers
TAJ Simmons
microsoft powerpoint mvp

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"Bill Cherepy" <> wrote in message
news:...
> When you add the Tele Conversion Lens to a camera such as the A80,
> what does that do to the speed (if that's the right word) of the lens?
>
> Thanks,
>
> Bill Cherepy
> Grayson, GA

On Fri, 24 Oct 2003 20:39:28 GMT, Bill Cherepy <>
wrote:

>When you add the Tele Conversion Lens to a camera such as the A80,
>what does that do to the speed (if that's the right word) of the lens?
>
>Thanks,
>
>Bill Cherepy
>Grayson, GA

Rear convertors increase the minimum f/# by the focal length
multiplier. Thus a 2X teleconvertor turns an f/4 lens into an
f/8---two stops loss in the maximum light gathering power.

I had assumed that a front convertor would have the same rule, but--in
another thread---someone said that this is not the case. While I have
no first hand knowledge, it seems that a teleconvertor 9or wide angle
convertor) would be difficult to implement without some increase in
f/#

Off to see if any mfg sites address this...

-Mark

*****************************************
digital photos, more and better computers,
and never enough time to do the projects.
Private e-mail: Just say no to No

On Fri, 24 Oct 2003 20:39:28 GMT, Bill Cherepy <>
wrote:

>When you add the Tele Conversion Lens to a camera such as the A80,
>what does that do to the speed (if that's the right word) of the lens?
>
>Thanks,
>
>Bill Cherepy
>Grayson, GA

PS--

found nothing on Canon site, but--for the Nikon 5700, they claim that
the f/# is preserved for both the tele and wide-angle adapters.

-Mark

*****************************************
digital photos, more and better computers,
and never enough time to do the projects.
Private e-mail: Just say no to No