Kenko Auto Extension Tube Set DG 12mm 20mm and 36mm Tubes for Canon EOS AF Digital and Film Cameras - AEXRUBEDGC

by Kenko

Product Details

• Item Weight: 8.8 ounces
• Shipping Weight: 9.1 ounces (View shipping rates and policies)
• ASIN: B000U8Y88M
• Item model number: KE-NAHDAFF
• Average Customer Review: 4.5 out of 5 stars  See all reviews (55 customer reviews)
• Date first available at Amazon.com: October 2, 2001

Product Description

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 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 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 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 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 of

Customer Reviews

Most Helpful Customer Reviews

503 of 505 people found the following review helpful:

5.0 out of 5 stars Great Tubes - But Know What You're Getting!, April 13, 2009

By 

Jeff Kraus (Orlando, FL USA) - See all my reviews
(TOP 1000 REVIEWER)    (VINE VOICE)    (REAL NAME)   

This review is from: Kenko Auto Extension Tube Set DG 12mm 20mm and 36mm Tubes for Canon EOS AF Digital and Film Cameras - AEXRUBEDGC (Accessory)

I've had these for a few years now. They're built really well, and in all this time they have developed absolutely no signs of wear.

Tubes are really pretty basic in construction. There are no glass elements, just mounts on each end and a pass-through for the lens data terminals. These are well-built, and as such they fulfill their intended purpose - that being that you now have an easy, less messy alternative to taping a cardboard toilet paper tube between your lens and camera body (and yes, you can do that if you want to go the low-tech route. Just make sure you seal the light leaks!) Any other issues are likely to be caused by a misunderstanding of the tube's purpose, not by the tube itself.

There seems to be a lot of confusion regarding extension tubes, based on some of the reviews I've read. While it would be difficult, without diagrams, to explain exactly how an extension tube works and the effect it has on focus distance and magnification, I can at least try to help with some of the problems people seem to be experiencing in these reviews.

1) There are two distinct versions of these tubes. On the 36mm tube, you will see either "for C/AF" or "for C/AFs". The ones that say "for C/AF" do not support the Canon EF-S mount. They support only the EF mount. If any of your lenses are EF-S, then you will need the ones that say "for C/AFs". Functionally, they are equivalent, but the "C/AFs" models can mount both types of lenses. As of now, it is impossible for me to tell which version is being sold here. I have to assume that they are selling the "C/AFs" model.

2) Extension tubes do not "magnify", technically. They increase the distance between the lens and the sensor. Imagine a projector sitting a foot from the wall, projecting an image on that wall. Using a pen, you outline the outer edge of that projected image on the wall. That's the outline of your "sensor". The image fills the "sensor". Now add more distance between the projector and the wall (that's what an extension tube does). It's the same image, but now it's projected onto a larger surface, flowing over the boundaries of the "sensor". So now the "sensor" only records the part of the image in the very center, just enlarged due to the added distance from the projector.

3) Moving the lens farther away from the sensor alters the usable focus distance for that lens. Don't take these numbers as truth (it's just an example), but a lens that normally focuses from 3ft to infinity might focus from 6 inches to 2 feet, once the extension tube is put on. How drastic the change is depends on the length of the tube and the focal length of the lens (See the next point).

4) The lens focal length has a huge impact on the focus range, but not necessarily in the direction you'd think. Longer lenses (like 200mm or 300mm) won't see as much difference in focal range with the smaller tubes. While there is a difference, you still won't be able to get close enough to really improve the magnification significantly. Wider lenses show a more drastic change. I have used my shortest tube (least "magnification") on my 17-40mm f/4L. Even though it's the shortest tube, when zoomed out to 17mm, the camera will actually only focus INSIDE THE LENS. Meaning even if I lay a dime on the glass of my lens, it's still not close enough to be in focus. That's why so many people like to use their tubes with a 50mm f/1.8. It's a nice medium-length lens that can allow really close focus while still being usable.

5) There's no such thing as a free lunch! Remember the projector reference in #2? Well, just like the tubes, the farther that projector gets from the wall, the darker the projection will be due to light falloff. Meaning you will lose light when you use tubes. The amount you lose increases exponentially with the added distance from the sensor. So in many cases you will need to mount on a tripod or use external lighting. Also, any imperfections in the lens (aberrations, fringing, etc) will be effectively "magnified" just as much as the image itself. And the lens resolution limits will also be made much more obvious since the sensor will be recording a smaller section of the overall image circle provided by the lens. However, it's important to note that the benefits usually will outweigh the drawbacks, especially when the tubes are used within reason (i.e. I wouldn't do resolution-critical photos with all three tubes stacked together).

Hopefully this information is useful to someone. If I said anything confusing or if you see any mistakes, please let me know and I'll be happy to make adjustments/corrections/clarifications as necessary. But as far as the product itself goes, these are excellent, solid extension tubes with a great fit, no light leaks, and a nice light weight.

54 of 54 people found the following review helpful:

4.0 out of 5 stars Short term: works great / Updated, May 30, 2008

By 

SEN - See all my reviews

Amazon Verified Purchase

Got this yesterday, tried it with a Canon EF 50mm f1.4 USM Medium Telephoto Lens for Canon SLR Cameras and Canon EOS 30D 8.2MP Digital SLR Camera (Body Only)... With the first two extension tubes, the results are amazing; with that setup you need to be about 4 cm (1.6" for you non metric people) from the subject; we're talking iris closeups here.

I thought about this for a long time because of the price, but it's well made, sturdy, lets you use autofocus if the lens allows it: I was unable to focus with a wide angle Canon 10-22, but that's just 'em laws of optical nature, and I need to fiddle a lot more with it.

Highly recommended if you feel drawn towards macro but don't feel like forking over lots of $$ for a macro lens; lighting is certainly an issue as you're very close to the subject, but may not warrant a macro flash like Canon MR-14EX Macro Ring Lite for 5D, 1Ds, 20D, 30D, G2, G3, G5, G6, Pro 1 & Rebel XT or Sigma Flash Macro Ring EM-140 DG for Canon SLR Cameras... And you will need to use a tripod.

Why not 5 stars? It's still a lot of money.

Update

These tubes have yet to let me down. I am now using them with a Canon EF 70-200mm f/4L USM Telephoto Zoom Lens for Canon SLR Cameras and no longer need to be as close to subjects as with the Canon EF 50mm f1.4 USM Standard & Medium Telephoto Lens for Canon SLR Cameras, which makes it much easier to get some light on the subject and even allows you to take macro shots hand held. The autofocus seems to work just as fast with these tubes as without.

33 of 36 people found the following review helpful:

4.0 out of 5 stars 50mm f1.8, December 24, 2006

By 

Tim P. Rudder - See all my reviews
(REAL NAME)   

Just like to point out the comment below about the tubes not working on a 50mm EF 1.8 are wrong. That comment almost made me not by them. I tried them in the store on my Canon EOS 400D and worked fine, as they do now after having bought them. If you buy them in a store make sure you get the right mount, there are different versions for Canon, Nikon and Minolta.