Extension Tubes

[karmakvisser]

I have a question about extention tubes. I want to do some more macro work but haven't saved up enough to get the 105 macro lens that I want. A craigslist came up recently for a Nikon AF Extension Tube Set -- Kenko It includes all 3 sizes, 12,20 and 36. The price appears to be around 169. The poster is willing to take 100 bucks for all 3. I've seen some reviews where there was concern about the plastic construction but they seem to hold up. Does anyone have experience with this product or am I better off looking for a superior set although more expensive. Here is a product description: Kenko DG Teleplus Extension Tube Set Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance. Getting closer has the effect of magnifying your subject (making it appear larger in the viewfinder and in your pictures). They are exceptionally useful for macro photography, enabling you to convert almost any lens into a macro lens at a fraction of the cost while maintaining its original optical quality. The DG extension tubes have no optics. They are mounted in between the camera body and lens to create more distance between the lens and film plane. By moving the lens father away from the film or CCD sensor in the camera, the lens is forced to focus much closer than normal. The greater the length of the extension tube, the closer the lens can focus. The KENKO DG AUTO EXTENSION TUBE SET contains three tubes of different length, a 12 mm, 20 mm, and 36 mm, which can be used individually or in any combination to obtain the desired magnification. Kenko also makes a DG UNITUBE 12 mm or 25 mm which can be purchased individually. Kenko's Auto Focus extension tubes are designed with all the circuitry and mechanical coupling to maintain auto focus and TTL auto exposure with most Canon, Nikon, and Minolta lenses given there is enough light to activate the cameras AF system properly. Please Note; 1. When using extension tubes the lens will not focus to infinity. The focus range will be greatly limited to a very close focusing distance. 2. There is light fall off when using any extension tube, sometimes the equivalent of 3 f-stops of light is lost when using multiple extension tubes together. This light lost can affect the camera's ability to auto focus. Manual focusing is recommended should the lens begin to "hunt" (not lock onto the subject). 3. Nikon "D" information is not transmitted because the lens is focusing closer than its programmed to focus. 4. Kenko Auto Extension Tubes are not auto focus compatible with Nikon AF-s (Silent Wave) lenses, manual focusing is required with these lenses."

This ad is not displayed to registered and logged-in members. Register your free account today and become a member on 6SpeedOnline!

[karmakvisser]

It seems that the Kenko rings work a bit better then the Nikon steel versions with the exception of the flexing. It seems that the flexing is mostly controlible if not disconcerting. However, the ability to meter seems to give the Kenko's an advantage. I saw some very impressive macro photography using this technique.

Here is a post I found on Nikonians.

The Kenko rings do allow autofocus, but this is not so useful in macro photography.

The Kenko rings allow metering with a D50 and CPU lenses, which to many users is more important than AF. The Nikon rings don't. You can still use the Nikon rings with lenses that have an aperture ring, but you must expose manually by trial-and-error and by checking the histogram in test shots. Metering with the Nikon rings (with some limitations) is possible only with the D200, D2 series and probably some older models like the D1 series.

If you have the older Micro Nikkor 105mm without VR and with an aperture ring, you can use the Nikon PK-11, PK-12, PK-13 and PN-11 extension rings (with manual exposure on a D50).

If you have the Micro Nikkor 105mm VR, you cannot use the Nikon extension rings and must use the Kenko ones, regardless of metering and AF, and of which camera body you have.

The bodies of the Kenko rings are made of plastic (like their teleconverters), which makes them flex a little unter stress (especially when you use all three rings stacked together). With heavy lenses, flexing may be enough to cause intermittent electrical contact between the body and lens.

The Nikon rings are all-metal and built to closer tolerances, so they are much stiffer. They have neither electrical contacts nor mechanic AF transmission, but they do have the AI aperture ring couplings (except for very old pre-AI rings like the M series) and the lever to control the diaphragm during exposure.

The Nikon PN-11 has a built-in collar with tripod socket, so it can carry heavy lenses and balance the weight well.

[NFRs2000NYC]

Kenko for sure. You would have to be a sucker to pay hundreds of dollars for what is basically a spacer. I use kenko tubes with my 70-200 F2.8 and my 150mm macro (both heavy lenses) and have no problems...AF works fine as well. Sure they will flex if you only hold the body, but you shouldn't shoot macro like that anyway. Furthermore, you really need to manual focus when you are shooting macro. Got mine on ebay for $125ish.

[karmakvisser]

Originally Posted by NFRs2000NYC

Kenko for sure. You would have to be a sucker to pay hundreds of dollars for what is basically a spacer. I use kenko tubes with my 70-200 F2.8 and my 150mm macro (both heavy lenses) and have no problems...AF works fine as well. Sure they will flex if you only hold the body, but you shouldn't shoot macro like that anyway. Furthermore, you really need to manual focus when you are shooting macro. Got mine on ebay for $125ish.

Thanks for the feedback. I picked up the set of 3 for $100 bucks yesterday. The tubes my my 80to200 look like a massive lens! Here are a couple of practice shots. You have to get real close which kind of freaked my cat out. I can't wait to get to some nature shots.








regards

ken