just wondering. I should be receiving tomorrow (or gosh, in a few hours) a present and a T/C would allow me to expand the use without sacrificing autofocus. If you have used them, did you use the name brand one or Kenko, etc.? Did you like them?
I have used both the canon and the Sigma 1.4 teleconverter. And I cant tell the difference in quality. I have also heard that the Kenko model is very good as well. As far as the auto focusing is concerned, I think it depends on the lens you attach it to. My 1.4 teleconverter pretty much stays attached to my 300mm f4, this makes for a very good macro/birding combo.
Question... how drastic is the light loss when using a teleconvertor? And do you compensate before image capture or do you compensate in post? Just wondering. Thanks!
I personally don't notice the light fall off with the converter, maybe a bit when I use it with my 70-200mm lens, but its not noticeable with the 300mm lens.
i have a quantaray 2x TC that i got for $80. seems pretty good to me. light loss = 1 stop for 1.4's and 2 stops for 2's. the camera should automagically adjust because it uses TTL metering. remember, most of them don't work for apertures smaller than f4 though....dont know why, but the autofocus goes to pot after that.
i have the canon 1.4 & 2, both seem to work real good, i use the 1.4 the most, works real nice on 70-200 f4 L, usually makes the trip in the fly away set up for vacations iq seems to be right in there, so i do find it useful, also works on 400 5.6 gary
I have the Tamron 1.4x TC. Not liking it, the shaprness of the pictures went down quite drastically IMO. However, I've never tried other brands of TC so I don't know whether the problem lies with my particular TC or it's part of the side effect of a TC.
Just a comment on why TCs sometimes kill autofocus. The better TCs have some way to tell the camera that they're reducing the maximum aperture of the lens. This is specifically for Canon SLRs, I have no idea what happens with Nikon gear, but beyond I think F5.6 or something the camera won't try to focus. It figures there's not enough light and doesn't even try. The infamous "bigma" (Sigma 50-500) cheats at the long end because the real maximum aperture is actually smaller than the limit for Canon cameras. So it reports that it's wider than it actually is, so that Canon cameras will still focus. Some people do the same thing with teleconverters. I don't have one, but I've read about this. Apparently you can cover up two electrical contacts on the TC with tape, and then the camera doesn't even know the TC is there. So it won't know that the focal length is changed, or that the aperture is smaller, and will try to focus as it always does. It may not be able to if there's not enough light, but I think this often works. Also apparently the camera might slow down the autofocus process if the aperture is smaller, but not TOO small. The taping the contacts trick forces the camera to focus normally, which may work faster or may result in the lens having to hunt around to find the right focus point. And just to repeat what I've heard about the TCs.. I think the Canon TC (I'm speaking of the 1.4, the word is that 2x is too much and causes too much quality loss, in some cases worse than just interpolating the final image to blow it up) is supposed to be good, but it only works with L lenses. I mean it only fits on them, you just can't plug a normal lens on to it. And while I don't remember the specific model, I think that a Kenko TC was often said to be a good TC that costs a lot less and still looks nearly as good. I may be confusing that with Kenko extension tubes though, which are a totally different thing. This is based off of extensive reading of posts on the dpreview.com forums. I'm only going off of what others have said. I should probably get one, I'm in need of more reach and my 70-200F4L is supposed to respond to a 1.4 extension quite well. But I've just never done it.
hope this is still ot....i have been looking for some photos taken with teleconverters used with macro lenses..i think it was on the kenko site it mentioned they up the magnification but don't change something else(focus distance maybe don't really recall?) anyone have any photos of such they would want to post? or can you steer me in the direction( looked at photonet , pbase, fred miranda and didn't see them there)
Hi Kelly, forgot you told me about here til i stumbled across it in my old email..let the games begin ;D ;D ;D
I was pleased with the 1.4 on my 70-200/2.8 in December. I have a few pics that I haven't uploaded yet, but I probably will before my next trip.
good question, using a TC with a macro lens. i would imagine the light fall off would be the same but you should still get the increase of magnification to go along with it. i have never shot high mag. macro shots so i cannot attest to this, but i don't see why anything would change. i could be wrong with this but i don't know...
i wonder if any tc would mate with a macro, i just tried my canon 100 f2 macro to 1.4 tc, no go do any 3rd party tc mate to macros? gary
The Kenko and Tamron TCs don't have rear element issues, so they will mount on any EF lens. Not sure about EF-S though. But I really like that the Canon TCs will report lens info to EXIF in the secret file. DPP reports the lens exactly, including the TC.
