Are they parfocal? Tokina 80-200 2.8 and Sigma 70-200 2.8

<p >I'm referring to theses lenses:<br />Tokina AT-X 828 AF Pro 80-200mm f/2.8 SD<br />Sigma 70-200mm F2.8 EX DG APO HSM (pre-marco, with aperture ring in Nikon mount)</p>

<p>For those of you who owns any of these lenses, can you tell me if they are parfocal?<br>

(Parfoal means: Once focus is set at the most telephoto setting, the focus holds even when you zoom out.)</p>

<p>Also, when you adjust focus manually on the lens, do you notice any image shift, especially when you change direction on the focus pulling? (I heard the Nikon 80-200 AF-D two-ring version does that. When you pull focus from close to far, then you pull from far to close, you see an image shift. That isn't acceptable for video shooting.)</p>

<p >thx</p>

<p > </p>

<p >Jack</p>

<p>All modern zoom lenses are parfocal to a certain extent, never perfectly. Autofocus fills the gap nicely. Some cine lenses (e.g., Fujinon) can be adjusted to optimize focus when zoomed, but at specific distances, not necessarily overall.</p>

<p>The Nikkor 80-200/2.8 AFS, 70-200/2.8 AFS VR and Canon "L" Cine lenses exhibit a little focus shift - not enough to affect composition, but requiring touchup. I doubt you can expect any better from third-party manufacturers.</p>

<p>I think that the Sigma 70-200mm you mentioned is newer than the Tokina, and therefore, many of these problems like parfocal have been improved.<br>

I was at a camera shop another day, and tried these lenses: Nikon AF-S 80-200mm f/2.8, Nikon 70-200mm f/2.8 VR, and Nikon 70-200mm f/2.8 VRII. I noticed that the parfocal problem improved over these 3 generations.<br>

I, however, have no experiences with Sigma telephoto, but I know that they are good alternatives to Nikon. If you want a third party telephoto lens, check out the Tamron 70-200mm f/2.8 and the ready-to-release Sigma 70-200mm f/2.8 OS HSM!</p>