Poorly constructed, not worth meager price savings
Written: Mar 20 '05 (Updated Mar 29 '05)
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Product Rating:
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Pros: Cheap. Compatible with EF-S lenses.
Cons: Plastic mount on camera side looks alarmingly breakable. Electrical contacts not reliable.
The Bottom Line: Although these tubes may get the job done, the Kenko tubes are better constructed, and cost only slightly more. However, they require modification for EF-S.
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| tcchou71's Full Review: Prooptic Auto Extension Tube Set F/eos |
Why you want extension tubes
If you've never tried macro photography, extension tubes are a quick and inexpensive way to find out just how much you're missing. They reduce the minimum focus distance of any lens, so you can put your lens VERY close to your subject and get incredibly magnified photos showing details you never even knew existed; flowers with individual grains of pollen, alien-looking insects that fill an entire page, ridges on fingerprints, lichen on tree branches, and much more. Extension tubes can open up whole new worlds at very low cost, if you get a well-made brand, which alas, Pro-Optic isn't. (More about this in a moment).
Extension tubes won't replace dedicated macro lenses, which are optimized (e.g. with a flat focal plane) specifically for close focusing. With a tube, you'll also lose the ability to focus at infinity, whereas many macro lenses (but not all) will allow focusing to infinity. But tubes are so cheap, portable, and versatile that these limitations are acceptable for someone wanting a taste of macro photography without lugging around an extra lens.
A rule of thumb is that to get true macro magnification (1:1 ratio of sensor image to actual size), you need a total extension tube length almost as long as the focal length of the lens you attach it to. So a longer base lens will need more tubes stacked together to achieve the same magnification as a shorter lens. However, this disadvantage is offset by the greater working distance afforded by longer focal-length lenses. A longer working distance is useful because with short lenses (below 35mm or so), the subject is so close that the lens may block much of the ambient light. I usually use extension tubes on lenses with focal lengths at least 50mm. However, it is also advisable not to carry this too far - as with any other lens, handholdability gets harder at longer focal lengths.
Although tubes lack optical elements, they will still magnify imperfections in your base lens, because the image is spread over a larger area. And as with all macro photography, the depth of field becomes extremely thin, requiring the use of rather small apertures. For flowers, bugs, plants, etc., I usually use at least f11, and preferably closer to f16.
Why you don't want the Pro-Optic tubes
Currently, the Pro-Optic tubes are $40 cheaper than similar tubes by Kenko, a brand known mainly for their respectable budget teleconverters (this makes sense if you think of extension tubes as teleconverters without lenses). Because extension tubes have no optics, I balked at paying more, and took a chance on the cheap ones.
Like the Kenko set, the Pro-optic set consists of 3 stackable tubes. The lengths are 13mm, 21mm, and 31mm, similar to the Kenko tubes. With all three tubes stacked together, you get an extender of 65mm.
I was pleasantly surprised to see that the Pro-optic tubes work fine with Canon's new EF-S lenses (these are the lenses designed exclusively for the digital sensors on the Canon Rebel 300D, 350D, and the 20D). The tubes exhibit the special EF-S alignment mark, and are fully compatible with EF-S rear protruding elements.
But overall, these tubes look and act cheap. Although they fit reasonably tightly when attached to lens and camera, the mounts on the camera side are entirely plastic, and look alarmingly breakable. The entire weight of the lens/camera joint rests on three plastic lips about a millimeter thick. Although they have not broken yet, I think they would if the joint was ever put under stress from a heavy lens. If this happened, the camera and lens would separate, possibly with disastrous results.
Another problem is the unreliable contacts that transmit information between the camera and lens. They are simply metal rods that run through the entire length of the tube, unlike the spring-loaded contacts in most teleconverters and better quality extension tubes. They also lack the gold-plating that most other tubes use to resist oxidation. The makers of these tubes really cut corners here, and it shows. It is not uncommon for me to mount the extension tube on my lens and camera, only to find that the camera does not recognize the lens at all, and acts as if it is not even there. Removing and remounting the tube usually restores the connection, but it is inconvenient and I have missed several shots this way. At least one other reviewer has reported a more severe version of this problem with this product for a different camera mount (http://www.epinions.com/content_97045352068).
Given the high cost of good cameras/lenses, it's silly to join them with cheap tubes that have unreliable contacts and flimsy plastic mounts. Although these tubes will do the job for me, with a little coaxing, I would recommend paying the $40 extra for the Kenko tubes and their sturdier construction. The only exception may be if you need compatibility with EF-S lenses, which is not yet supported with the Kenko tubes. However, if you are handy with tools, you can enlarge the plastic rim of the Kenko's center opening - this makes them EF-S compatible, and in my opinion, is a better option than the Pro-Optic tubes.
Recommended:
No
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Epinions.com ID:
tcchou71
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 - Top 1000 |
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Member: Elephant Seal
Location: Baltimore, MD
Reviews written: 53
Trusted by: 3 members
About Me:
I'm a behavioral neuroscientist/psychologist. The giant animal in the photo is an elephant seal.
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