Nikon AFS Extension tubes

[Erik Lund]

The new lenses with floating elements are often troubled with extension tubes since you are using them outside their designed distance. You get a sharp center but often the image just breaks up.

Some years ago I converted a TC-20E by removing the glass leaving just an extension tube, it can be used with the old unit focusing designs like: Micro Nikkor 55mm f/3.5, 105mm f/4 and similar and the New Noct-Nikkor actually does well with extension as well, although a shorter TC-14E would be preferable to use as donor.

The TC-20E Extension tube design does also perform quite bad with 200mm f/2.0 and 300mm f/2.8 since their optical design rely heavily on Internal Focusing.

Please note that it will also not work with the new E-Type lenses they have electronic aperture stop down.

Generally the old advise to use a TC for close up work still goes;

the old TC-14 and TC-201 work often better than an extension tube on the old Micro Nikkors.

Again the new 58mm 1.4 has shown some initial good performance with TC14E, 17E and 20E-III, I need to try it out some more...

BTW link to PN11 DIY modification
http://damien.douxchamps.net/photo/pn11/

[Øivind Tøien]

>The TC-20E Extension tube design ...>Please note that it will also not work with the new E-Type lenses they have electronic aperture stop down.

I thought the advantage of rebuilding a TCxx-E to an extension ring is allowing feed though of the electrical connections?

I believe that for instance TC14-E II is listed as compatible with 300 f/4 PF, and my understanding is the the difference between I and II versions is just exterior cosmetics?  The only thing I could foresee is that set aperture will not be correct as the electronics will compensate as for a TC.

[Intrepid]

Erik, purely out of academic curiosity, are there no extension tubes with all the electrical contacts available?  For the Sony E mount, for example, there are extension tubes with full compatibility.

[Erik Lund]

>The TC-20E Extension tube design ...>Please note that it will also not work with the new E-Type lenses they have electronic aperture stop down.

I thought the advantage of rebuilding a TCxx-E to an extension ring is allowing feed though of the electrical connections?

I believe that for instance TC14-E II is listed as compatible with 300 f/4 PF, and my understanding is the the difference between I and II versions is just exterior cosmetics?  The only thing I could foresee is that set aperture will not be correct as the electronics will compensate as for a TC.

Correct it is listed as compatible, I will have to check why I couldn't get the 300mm PF to work with my TC-20E mark I...

[Erik Lund]

Erik, purely out of academic curiosity, are there no extension tubes with all the electrical contacts available?  For the Sony E mount, for example, there are extension tubes with full compatibility.

Only very cheaply made plastic extension tubes are available with contacts, and their internal baffle size is rather small compared to the Nikon TC's so not usable on large rear element lenses...

[Intrepid]

This may be of interest:  http://www.venuslens.net/product/xpro-macro-tube/

[Bjørn Rørslett]

Yes, even at the suggest price $169 might be cheaper than ripping apart TCs ....

Remains to be seen if build and workmanship are commensurate with the price, though. I might have to get one of these items.

Looking again at the product shots at their web site, I'm a little worried about the narrow inner diametre. Some lenses might create vignetting when attached to this tube. Only practical field testing will disclose any weaknesses.

[Erik Lund]

Except there is hardly any hole through it,,, 

But for some applications it will be fine

BTW the TC20-E has a rear opening of 34.55mm

[Asle F]

The internal baffle size looked very small. And it is much longer than, at least I, usually use for extension tubes. My most used tubes are K1 and PK-11a.

[armando_m]

This may be of interest:  http://www.venuslens.net/product/xpro-macro-tube/

Michale Erlewine published a short review (or warning) of the lens, the conclusion is that he returned it
he had 2 complains, hard to focus precisely due to a very short focus throw , and not very sharp

[Michael Erlewine]

What I wanted to convey on the Venus 60mm macro lens is that this is an interesting idea, but obviously one that was not well-thought out. Why would a macro lens that goes to 2x not have a focus throw that would allow us to smoothly focus, instead of (as it is) vainly try to find focus. The exact focus point rolls by so fast that it is useless. You would have to put it on a rail.

And it is nowhere near well corrected. About the only value was that it went to 2x without fiddling with extension and all that we are discussing here. When I look at the lenses I already have to do this right (industrial lenses), of course, I sent it right back and had to shake my head as to why I ever expected anything better.
 
As for the Venus  X-Pro Vari-Length Auto Extension Tube (for Nikon), that is a lot of extension, 55mm (2.165 inches) to 71mm (2.79 inches) in one piece. I feel that to use this extension tube we have to know a little about macro photography above 1:1, and that takes some learning. I thought about getting it until I realized I don’t shoot macro above 1:1… much.  Both of these seem like interesting ideas that I probably would never use. But it may interest some of you folks for the reasons you mentioned.

[Intrepid]

This may be of interest:  http://www.venuslens.net/product/xpro-macro-tube/

Michale Erlewine published a short review (or warning) of the lens, the conclusion is that he returned it
he had 2 complains, hard to focus precisely due to a very short focus throw , and not very sharp

Armando, I do not see any connection whatsoever. Oh well.

[Intrepid]

Except there is hardly any hole through it,,, 

But for some applications it will be fine

BTW the TC20-E has a rear opening of 34.55mm

Agree.  Have you looked Vivitar S1 Macro focusing TCs?  It might also have the same opening dia.

[armando_m]

This may be of interest:  http://www.venuslens.net/product/xpro-macro-tube/

Michale Erlewine published a short review (or warning) of the lens, the conclusion is that he returned it
he had 2 complains, hard to focus precisely due to a very short focus throw , and not very sharp

Armando, I do not see any connection whatsoever. Oh well.

sorry got confused by the  "venus" brand, and did not click on you link before replying 

[Intrepid]

No worries, Armando.  It was scary as it was just like me!