Extension ring for 70-200mm VR - glassless with apeture ring.

[eajames]

Wouldn't it be nice to see Nikon or a third-party manufacturer make a PN-11

length extension ring with a built in aperture ring (an "anti-G" device)? What

a great piece of gear that would be - close focusing the 70-200mm VR on a

D200, or an FM3a!

 

Is there such a device out there?

 

What are your experiences using the 70-200mm VR with an extension ring?

[mark_chappell]

If I had that lens, I'd much prefer to use a Canon 500D closeup lens than an extension tube,

if I wanted closer focus. With tubes, you lose some light and there will be focus shifts when

you zoom. Not the case with the 500D. The out-of-production Nikon 6T is another good

closeup lens.

[erik_loza]

I don't know if the 70-200mm is like the 80-200mm AF-S in this regard, but if it is, near-focus is where this leans is at its weakest. I left the 105mm at home during one of the Mexico trips thinking that my (then) new 80-200mm would be a viable substitute when used with the the 27mm tube or the 500D. Not until I got back did I discover that image quality was pretty miserable and I regretted not bring the Micro.

 

With the exception of he 70-180mm, it has been my experience that zooms, regardless of how good they are in other respects, just aren't optimized for close-up use. Long primes, however, love the tube. I use the PK-13 on my 300mm all the time.

[anthony_bez]

Kenko sell a AF enabled set of extention rings......http://www.thkphoto.com/products/kenko/index.html

[frank_skomial]

And the same Kenko shows how sharp distant mountains can be photographed with those tubes:

 

http://www.thkphoto.com/products/kenko/slrc-04.html

[Ed_Ingold]

Frank,

 

If you add extension tubes, the lens will no longer focus to infinity. How, then, are photos of mountains a legitimate example of their use?

 

Perhaps you forgot to add a "smiley" to the end of your post ;-)

 

The Kenko tubes give autofocus with standard AF lenses but not AFS lenses. Nor does this address the absense of an aperture ring on the 70-200 VR.

 

Canon makes a 77mm closeup auxillary lens with a dual element (achromat), which would be the best of the choice for closeups with this lens.

[briany]

Edward, Frank is well aware. http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00K8HA I like to give them the benefit of the doubt - they're not careless / scammers, the mountains are a poster on the wall... My Kenko tubes from about 4 years ago definitely autofocus with AFS lenses, but I've heard that the newer ones don't. I have no idea why. There are some other posts on here about this. Either version should retain metering though (of course on a D200, but also on a D70).

 

Eric, I would think (though I don't know) that putting the effective aperture that close to the sensor, rather than near the optical center of the lens, could have negative consequences, such as vignetting. To address the last part of your question, I've actually had pretty good luck with 70-200 stopped down a few stops and Kenko tubes.

[eajames]

I'd like to thank everyone for their contributions. I am leaning toward the Canon filter but I will first need to do the calculations to determine what the lens focal length range will become when the filter is added. I carry a 55mm 2.8 AIS Micro and was hoping to compliment that lens with a long macro lens - something to replace my 180mm AIS on a PN-11 (a very nice combo).

 

Brian: I believe that you are correct about the vignetting, but this "anti-G" tube that I'm imagining would not have aperture blades, but would transduce the position of the mechanical aperture ring to an electronic signal and relay that info to the lenses native aperture. Just a pipe dream, I suppose.

[alex_lofquist]

I have used the Kenko Uniplus 25(25mm) tube on my F5 and 70-200 f/2.8 VR.

All the functions work, including VR. At closest focus and at 200mm FL setting, the horizontal field of view (35mm format) is 115mm, and the working distance is 27". The reproduction ratio is 0.31X, or about 1/3 life size.

[eajames]

I've decided to go with the Canon 500D diopter. I couldn't find my copy of John Shaw's Close-Ups in Nature but I found my answer here:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003ug4

[yuri_sopko]

Bought the triple set last week online: Kenko "Automatic Extension Tube Set DG." And, they do focus with my Sigma 150/2.8 HSM no problem. However, they are of poor construction so I don't trust them.

 

eb