Anyone tried this? I'm drooling over the idea of that much range.
http://www.tamron.com/lenses/prod/18250_diII.asp
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Tamron 18-250mm Aspherical Lens
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- Posts: 175
Re: Tamron 18-250mm Aspherical Lens
Thu Oct 18, 2007 3:53 pm
khtaylor wrote:Anyone tried this? I'm drooling over the idea of that much range.
http://www.tamron.com/lenses/prod/18250_diII.asp
F6.3 on the long end is mighty slow. That won't even AF on any Canon crop cameras.
Canon 5D, EOS 3, 400D w/ 35 MM F/1.4L, 50 MM F1.8 II, 85 MM F1.2 L II, 100 MM F2.8 Macro, 200 MM F2.8 L, 300 MM F4L IS, 16-35 F2.8 L II, 24-105 F4 L IS
- Posts: 3780
Thu Oct 18, 2007 5:20 pm
ewhalen wrote:
While this is quoted by Canon, it's not necessarily always the case. An example I can personally attest to is the Canon 100-300 f/5.6L when used with a teleconverter (The Kenko 1.4X) which costs 1 stop of light. While in low light conditions it tends to hunt, in reasonable light it's fine. So, it's just a matter of knowing it's limitations, and when to use the TC or crop instead.
The reasons Canon says a lens over f/5.6 doesn't focus is due to the dependency of contrast to bring a subject into focus. As light levels drop, so will contrast. But this is somewhat dependent on the quality of optics used. This is where I've found problems with zooms with such range. An example we've seen in the past were the earlier Sigma 28-300's, which I personally owned and had problems with. The results after using it for awhile, was the dreaded "err 99". Even after re-chipping, the lens only worked for a short time, and I soon found myself replacing it. Since then, the newer models have been redesigned to avoid this problem, but it's always possible this can become a problem again when new model bodies are released.
Tamron, Sigma and other "after-market" lens makers usually aren't paying Canon and other makers for rights to produce lenses using their mounts. So, if Canon decides to incorporate something into their firmware which is dependent on different forms of communication with their lenses, it might fail when the proper information isn't transferred. Also, as a general rule, zooms using such wide range aren't as sharp as lenses using lesser range. However, this doesn't mean it's not acceptable, it's dependent on the expectations of the person using it. This, of course, is something each person must decide for themselves.
Rather than risking your money on opinions (which are different for each of us), I'd suggest reading reviews, and viewing test shots since only you can decide what your actual needs/expectations for the lens will be. If for example, you find yourself shooting primarily under less than perfect conditions, you might want to avoid this type lens. If you have other lenses which offer faster f/stops you can use for those times, it might be a nice addition to your bag. I can understand the "want" for a good "all around" lens for a day out, but I wouldn't want to depend on such a lens as my only choice. Hopefully someone owns this lens, and can offer some specifics with photos taken with it. And you might check the camera database for example shots, here: http://www.pbase.com/cameras/tamron/af_ ... _di_ii_ld_
Also beware when looking at shots to view the exif. Remember it's a good rule to keep the shutter speed around double (due to crop factor) of the mm lens used. If a shot looks overly soft, it might be the person used a low ISO at 250mm using 1/50th second which causes the problem, instead of poor optic quality. Others might use over-sharpening, or be better at bringing out the best. So, knowing the settings can help you decide.
Good luck, and keep us posted.
F6.3 on the long end is mighty slow. That won't even AF on any Canon crop cameras.
While this is quoted by Canon, it's not necessarily always the case. An example I can personally attest to is the Canon 100-300 f/5.6L when used with a teleconverter (The Kenko 1.4X) which costs 1 stop of light. While in low light conditions it tends to hunt, in reasonable light it's fine. So, it's just a matter of knowing it's limitations, and when to use the TC or crop instead.
The reasons Canon says a lens over f/5.6 doesn't focus is due to the dependency of contrast to bring a subject into focus. As light levels drop, so will contrast. But this is somewhat dependent on the quality of optics used. This is where I've found problems with zooms with such range. An example we've seen in the past were the earlier Sigma 28-300's, which I personally owned and had problems with. The results after using it for awhile, was the dreaded "err 99". Even after re-chipping, the lens only worked for a short time, and I soon found myself replacing it. Since then, the newer models have been redesigned to avoid this problem, but it's always possible this can become a problem again when new model bodies are released.
Tamron, Sigma and other "after-market" lens makers usually aren't paying Canon and other makers for rights to produce lenses using their mounts. So, if Canon decides to incorporate something into their firmware which is dependent on different forms of communication with their lenses, it might fail when the proper information isn't transferred. Also, as a general rule, zooms using such wide range aren't as sharp as lenses using lesser range. However, this doesn't mean it's not acceptable, it's dependent on the expectations of the person using it. This, of course, is something each person must decide for themselves.
Rather than risking your money on opinions (which are different for each of us), I'd suggest reading reviews, and viewing test shots since only you can decide what your actual needs/expectations for the lens will be. If for example, you find yourself shooting primarily under less than perfect conditions, you might want to avoid this type lens. If you have other lenses which offer faster f/stops you can use for those times, it might be a nice addition to your bag. I can understand the "want" for a good "all around" lens for a day out, but I wouldn't want to depend on such a lens as my only choice. Hopefully someone owns this lens, and can offer some specifics with photos taken with it. And you might check the camera database for example shots, here: http://www.pbase.com/cameras/tamron/af_ ... _di_ii_ld_
Also beware when looking at shots to view the exif. Remember it's a good rule to keep the shutter speed around double (due to crop factor) of the mm lens used. If a shot looks overly soft, it might be the person used a low ISO at 250mm using 1/50th second which causes the problem, instead of poor optic quality. Others might use over-sharpening, or be better at bringing out the best. So, knowing the settings can help you decide.
Good luck, and keep us posted.
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