RWY-16
Topic Author
Posts: 103
Joined: Fri Dec 29, 2000 1:18 am

Teleconverter And Vignetting

Wed Aug 29, 2001 8:54 pm

Hi

My zoom lens 70-200/2.8 shows some vignetting with an aperture f 5.6. If I use a teleconverter, for example the x 2.0, how strong is the vignetting with the same aperture f 5.6? Is it the same or is it more or less?

What kind of experience did you make?

Thanks a lot in advance for your answers.

Andi
 
ckw
Posts: 4586
Joined: Fri Aug 27, 2010 12:26 am

RE: Teleconverter And Vignetting

Wed Aug 29, 2001 9:09 pm

I'm surprised at a 2.8 vignetting at f5.6 (two stops down!) normally vignetting is most apparent wide open and reduces on stopping down. If what you've stated is in fact the case, I'd consider getting the lens checked - what is the vignetting like at f4 or f8?

To answer you question, it is not unusual to find some vignetting with a teleconvertor, esp. with the lens wide open. Stopping down one or two stops usually avoids this, but in the case of your lens its hard to say.

Cheers,

Colin
Colin K. Work, Pixstel
 
jwenting
Posts: 9973
Joined: Mon Apr 23, 2001 10:12 pm

RE: Teleconverter And Vignetting

Wed Aug 29, 2001 9:22 pm

Is it really the lens or the scanner?
My scanner sometimes causes what looks like vignetting in the corners, even when scanning only part of the image. This is most visible when the center is bright white, leading me to believe it has to do with the exposure settings of the scanner.
I wish I were flying
 
da Fwog
Posts: 845
Joined: Thu Aug 19, 1999 5:25 am

RE: Teleconverter And Vignetting

Fri Aug 31, 2001 8:15 pm

I'd like to know what lens that is. I have the Sigma 70-200 F2.8EX & matched 2X converter, and my experience is that vignetting is negligible at ALL apertures with the lens on its own, and only really apparent wide-open at F5.6 using the converter.

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