Customer Reviews 

Canon EF-12 ll extension tube.
2009-04-03This canon EF-12 ll extension tube is great,work exacthly as I expected. I also bought the canon EF 25ll extension at same time. I love them. Thanks.

Does the job
2009-02-03Considering it's just a spacer, it would be hard for this item to be exceptional. It enables super close-up photos; I'm happy with the results.

Great tube.... But
2008-12-17Great tube but wish I had bought the three tube kit from Kenko.
Wayne

Great Macro lens enhancer!!
2008-11-17Pros:
You can get much closer
Works with both EF-S and EF lenses
Auto focus still functions perfectly
Takes up very little room in your camera bag
Item looks about 3 times as large in photo using 17-40 Canon F/4 Lens
Cons:
A little tight to put on and take off of lens
Can no longer focus very far away let alone infinity
Review:
I purchased this Extension tube so I could take better Macro photos without having to purchase an expensive Macro lens. I've got so many lenses already.
I installed the tube between my Canon Rebel XTi and Canon 17-40 F/4 L lens and bang!!! Instant macro lens.
A photo I had taken without the tube of a penny using the Canon 17-40 zoomed to 40mm gave a so so image. Putting the tube on allowed me to focus so close the penny filled almost the entire view finder. Looking at the penny image taken with the tube you can see little details I never noticed before like each and ever step and little details like the little FG on the lower right corner on the back of the penny.
Verdict:
I highly recommend it's worth every penny!!!

As good as a Macro lens (almost)
2008-08-27Good product, does what it says it'll do. I was suprised how well it works.
Electronics Articles 
Camera basics: shutter-speed, aperture and ISO
In this article, I’ll introduce you to the basic elements that you can use to control exposure in your shooting. If you have a digital SLR, there will be a way to set all of these controls on your camera, but since they differ between manufacturers and models, you’ll need to refer to your camera’s manual to find out exactly how to change them.
All cameras, whether an ancient film camera, or a more modern digital, work in pretty much the same way. Photographs are taken by letting light fall onto a light-sensitive medium, which records the image. Traditionally, this has been film, but more recently, it tends to be a digital sensor. The more light that falls onto the film or sensor, the lighter the image.
Put simply, a camera consists of a light-tight box that stores a light-sensitive device (either a film or a digital sensor), a lens that magnifies and focuses the image onto that light-sensitive device through a hole in the box (called the aperture) , and a shutter that opens ...
Professional video camera
A Professional video camera (often called a Television camera even though the use has spread) is a high-end device for recording electronic moving images (as opposed to a movie camera, that records the images on film). Originally developed for use in television studios, they are now commonly used for corporate and educational videos, music videos, direct-to-video movies, etc.
There are two types of professional video cameras: High end portable, recording cameras (essentially, high-end camcorders) used for ENG and EFP image acquisition, and studio cameras which lack the recording capability of a camcorder, and are often fixed on studio pedestals. Portable professional cameras are generally much larger than consumer cameras and are designed to be carried on the shoulder.
Technology
It is common for professional cameras to split the incoming light into the three primary colors that humans are able to see, feeding each color into a separate pickup tube (in older cameras) or charge ...