Hello all,

I am getting a significant vignette with my Nikon 70-200 mounted to the Mk3 via a Novoflex adapter.

I shot a quick test and uploaded it here (http://www.youtube.com/watch?v=T_Q39j-c2Ck&feature=youtu.be). Surely this isn't normal.

Is it a result of the adapter maybe?

I would think that it is your adapter. I have shot many Nikkor primes through a Fotodiox adapter and have never experienced vignetting on my 5D3.

That's frustrating since it's the priciest adapter I could find.

I specifically need this one because the lens has no aperture control ring and this Novoflex adapter has a sliding knob to enable aperture control.

I haven't noticed vignetting on other lenses but maybe I just need to pay closer attention.

Why would the use of the adapter result in vignetting?

If this is the Fotodiox (http://fotodioxpro.com/index.php/fotodiox-lens-mount-adapter-nikon-g-d-type-lens-to-canon-eos-camera-fits-fits-canon-eos-1d-1ds-mark-ii-iii-iv-1dc-1dx-d30-d60-10d-20d-20da-30d-40d-50d-60d-60da-5d-mark-ii-mark-iii-7d-rebel-xt-xti-xsi-t1-t1i-t2i-t3-t3i-t4-t4i-c300-c500.html) you're referring to I might pick one up. It's about 90% cheaper than the Novoflex one so hopefully it's a success. Though they look identical so I don't know how one could produce vignetting while the other wouldn't...

I tested one that I got from eBay for $40 that looks just like the Fotodiox one, with a white aperture ring, but it ogt stuck to my lens and wouldn't come off! So I promised not to try any more cheap ones.

If you're using Nikkor G lenses (Ken Rockwell jokingly says this means "Gelded"), then perhaps the adapter is adding some additional flange depth, resulting in the vignetting.

While I have no doubts that the Nikkor is a fine lens, you're also giving up IS and autofocus over a Canon counterpart. The later is obviously only helpful for stills but the former is helpful for both stills and video. Speaking of fine lenses, the EF 70-200mm/f2.8L IS MkII is perhaps THE finest lens made in this range and will have BOTH features and NO vignetting.

But that's probably not what you wanted to hear.

FWIW, my Fotodiox adapter does not do aperture control, as I only have old MF Nikkor primes. Which is awesome glass... but focus backward to Canon's, so I always have to ask myself, "Canon or Nikkor." So... their days are numbered.

You're right, that isn't what I wanted to hear. But it's what I've been expecting as the most logical solution.

Though I may just buy a second hand version one of that lens rather than a $2,000 newly released one.

Are the advantages of the new release that great over the previous one? They're both 2.8 with USM and IS.

The Mk II is quite a bit sharper at both ends wide-open. Here's a good review of the new lens and the reviewer references the old one and new improvements:
Canon EF 70-200mm f/2.8 L IS II USM Lens Review (http://www.the-digital-picture.com/Reviews/Canon-EF-70-200mm-f-2.8-L-IS-II-USM-Lens-Review.aspx)

You can see actual ISO 12233 chart of each lens and move back and forth by mouse-hover here:
Canon EF 70-200mm f/2.8 L IS II USM Lens Image Quality (http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&FLI=3&API=0&LensComp=103&FLIComp=4&APIComp=0&Camera=453&CameraComp=453&Sample=0&SampleComp=0)

For my own use, I bought the EF 70-200mm/f4L IS instead, and saved a lot of $ and weight (I paid US$950 used for mine). The tradeoff obviously is that extra stop loss. So it's not a great choice for indoor sports of getting super-shallow DOF, but it's a tack-sharp lens for the $.

I've considered getting the f/4 as well. But I'm so used to shooting with my Nikon 2.8s that going f/4 may frustrate me considerably. The fact of the matter is that 70-200 almost always comes out at a wedding reception where I'm stuck at the other end of a dark room from the couple making their speeches or something like that so the 2.8 would be better. But maybe the ISO on the Mk3 would make up for it...

The ISOs with the 5D3 are about 1.5 to 2 stops better than the 5D2. And miles better than crop-sensor Canons. But sometimes there's no beating fast glass and most weddings lit like caves. If there's a lens rental house close-by, it might make sense to rent an f4 and f2.8 and replicate some of your shooting environments... for just a few dozen dollars a day you'd see the trade-offs first hand.