At the telephoto end of the zoom range, does this converter preserve the original lens' f2.8 aperture and image quality?
1329593
This is a good quality lens. Yes you can preserve the original f2.8. As regards image quality I don't have a laboratory to measure such things but there certainly isn't the obvious problem with distortion or focus out near the edges that you see with cheaper lenses. I'm sorry I can't be more specific.
913377
I read somewhere it does NOT work. I would not recommend this combination anyway für quality reasons. It is a bad idea to use a converter for a wide-to.tele-zoom. Teleconverters are best for fast lenses (2.0...4.0) and longer focal lenghts (fixed or fast pro telezooms).
2207206
It just so happens that yesterday I tried the 2.0 on my 7D Mark II with the new 100-400 II lens and it lost its AF function. It works fine with the 1.4 extender, though.
322289
Lens no problem, don't know the size of the teleconverter, but likely the answer is yes to both flash an everything else. To be honest, I hardly use it as instead went wit ha backpack and one of these "sling" bags as felt it was a more practical way to carry the stuff around
1837117
It is not a "fixed" F/2.8. It is a "constant" F/2.8 which does not change when zoom from 24 to 70. It still has the smallest aperture of F/22 that you can use to gain all the DOF you want.
744851
I have tested the Canon 1.4x teleconverter and it works well. AF is also listed as possible even for the Canon 2x teleconverter. Listed here: http://www.bhphotovideo.com/FrameWork/charts/canon1_4xExtender.html http://www.bhphotovideo.com/FrameWork/charts/canon2xExtender.html Here is the list for the Kenko Pro 300 teleconverter which is a highly rated teleconverter and it is compatible with the the lens as well for both the 1.4 and 2.0: http://www.kenkoglobal.com/pdf/TELEPLUS_DGX_series_CompatibilityList.pdf. Obviously, things will be more challenging with a 2.0 teleconverter but not impossible. It will all depend on how steady you are with the camera(tripod), you ability to focus manually, and the amount of available light etc.
40905
Yes, you may, but..there's a caveat. First, remember that the threads on the lens of this camera were put there for adding filters to your shoot and those are light and thin. If the 2x teleconverter you have is long, you may find it produces vignetting at wide settings of the zoom. Next, if the teleconverter is heavy, it will put an unnecessary weight on the lens. I've found that using a 2x or higher teleconverter will usually produce fuzzy pictures when the zoom is extended, so caution, and remember those threads on the lens are delicate..... be gentle when placing or removing filters or your teleconverter on the cam. In all probability, you may not be happy with the results. Usually extenders are placed between the camera body and the lens, whereas in your case, the extender would obviously have to go on the end of the lens. Happy shooting.
552135
That's the same camera I have, and I use a Tamron 70-300 for my moon shooting. Sure, the 2x converter works, but remember that you won't have automatic focusing.
1357949
1. re focal length conversion--no.2. re light loss--I have not noted any--but, frankly, I am usually using any / all of my adapter with a fixed f-stop setting or with AE.
829592
No, they use a physically different mounting. There are Teleconverters on the used market that fit FD lenses, do a search on Amazon and ebay for one. If you are hoping to make a FD lens work with a EF mount, there are good converters from Ed Micka, but they are hand made and expensive. The commonly available ones degrade the image. Canon made a FD-EOS converter, they are scarce and price is out of this world.
2161906
No it won't, in fact the opposite. It increases the zoom and reduces the wide angle. With the converter installed you can really only use the camera at close to full zoom.
1673397
I used the 1.4X teleconverter with the Sigma 300 f. 2.8, for pentax. So I do not have experience on its use with the 18-250 Sigma lens. Any way I'm not very happy of it, there is huge decay in quality and in focus. I would not suggest to any friend of mine to buy it.
570267
This is an excellent teleconverter, I can make very good to excellent 11x 14 + prints without a problem. It will not with your lens, it works with the lens for a full frame camera.
1733719
I believe it is compatible with the exception of Autofocus whichever I think eases to work at f5.6 therefore because of losing 2 stops with the converter only lenses of f2.8 and larger (f1.8. f1.4 etc ) will have autofocus the lens you are asking about is compatible ( but you will have to focus manually). Check Nikons web site for compatabilty
1985600
I ordered Tamron 1.4x for my Nikon. I have not had any problems with the Teleconverter. But realize that I made sure it was for a Nikon not Canon.
1777785
This Teleconverter lens won't work out of range. This Teleconverter up to 400mm or less than 400mm.
102012
Sorry, there are no teleconverters for EF-S lenses available in the US that I'm aware of. I've heard rumors of EF-S compatible (Kenko?) teleconverters from Hong Kong but I still haven't been able to verify. Either way, its likely that a teleconverter with the 55-250 wouldn't be much, if any, better than simply cropping the image (might as well put the T1i's extra megapixels to good use). Plus a 1.4X teleconverter would add a stop and a 2X would add 2 stops putting your lens' aperture above f5.6, the minimum needed for auto-focus to function.