1.4x or 2x Teleconverter?

<p>Hi All,</p>

<p>I have a 40D and a 24-105 f/4 L, and I'm shopping for a longer telephoto zoom. I've pretty much decided on the Canon 70-200 IS f/4 L and was thinking of buying a Canon teleconverter too. The 1.4x seems to be the popular choice, but I would probably prefer the longer reach of the 2x. Is there a reason not to buy the 2x for this lens? I'm aware I would lose two stops instead of one, and I have all but the center autofocus point turned off anyway. Suggestions?</p>

<p>Many thanks,</p>

<p>Dave </p>

<p>With the 2x you will lose auto-focus on that body.</p>

<p>The 1.4x is much better than the 2X. I shoot the 70-200 f2.8 zoom and the 1.4x is pretty good on this lens. The 2X is fairly poor - at least on a full frame body.</p>

<p>I have both, and the 2X stays on the shelf. Too much light loss and way too much sharpness loss. I really like my 70-200 f4 - it's very sharp and it handles the 1.4 quite well. On the other hand, some folks don't like the f4 as much as the 2.8. You might want to heft both on your camera before making a final decision. </p>

<p>f/4 and 2X will not AF on 40D.</p>

<p>I've found the 2X to be not very useful, even on quality glass. The comparison is photoshop cropping, and I find that I am better off using the 1.4 and cropping later compared to using the 2X (that's on a 70-200 2.8, which, if anything, should be better for the 2X compared to your glass).</p>

<p>Dave</p>

<p>I have the 70-200 f4 IS and the 1.4 Extender which I use on a 5D2. You really can't tell much difference with the 1.4 Extender on, its that good, even at 100% zoom of 21 megapixels. In a standard size print, you couldn't tell. As others mentioned above, there are downsides to the 2X.</p>

<p>i have the outfit you're looking at. excellent. f4 IS version of that zoom is one of the best zooms made. with the canon 1.4 tc (version II) it's a very usable rig. sharpness loss is not an issue -- i'm sure there must be some but can't object to the results i've gotten.<br>

i've never used a 2x converter but everyone says they're too much of a compromise. the 1.4x adds a lot of reach with almost no added weight to lug around. highly recommend.<br>

here's a 100% crop of a shot with 40D, canon 70-200 f4 IS with canon 1.4 tc II at 280mm:<br>

http://www.photo.net/photo/7923572&size=lg</p>

<p>and the original:<br>

http://www.photo.net/photo/7923571&size=lg</p>

<p>Thanks, guys. Excellent advice.</p>

<p>The reason to not buying the 2x is image quality, you'll have the reach, but you won't like the quality.</p>

<p>And here's another satisfied user of the 70~200/4L IS with the Extender 1.4x. Works fine on the 5DII and on the 50D. I did some tests a while back using a 40D body, and these showed that, with the lens set at its long end, the lens with the Extender 1.4x (II, but it doesn't make any difference) revealed detail not visible with the lens alone, but the lens with the Extender 2x II did not reveal any more detail than the lens with the Extender 1.4x. So it is worth using the Extender 1.4x, but rather than use the Extender 2x II, with the loss of a stop and the loss of AF on all but 1-series bodies, you might as well crop from a lens + Extender 1.4x image. That test on the 40D is probably good for the 5DII as well, because the pixel density is much the same, but it may be worth re-testing on the 50D.</p>

<p>Dave<br>

I have used a 2x extender with the 1.2 70-200m and the 100-400 Canon lenses. I have used both combinations with a 20D and 5DmII.<br>

The photo experience was shooting a documentary of an Eagle Nest rearing a single chick. Over 4 months.<br>

The 2X extender and the 70-200 provided excellent detail, sharpness, and versatility. There was no focus problem.<br>

With the 100-400, I lost auto focus. At max zoom (800mm) there was degradation in the both sharpness and clarity. Even with F22, the depth of field was not good and manual focus was damn near impossible, especially given the subject.<br>

While I have a good essay of the rearing of an Eagle Chick, the throw-away percentage of blurry, out of focus, poor depth of field was immense.<br>

I would NOT use a 2x extender for similar assignments in the future. A fixed-focus 400mm or 800mm lens would be better suited to the subject and circumstances. I would consider using a 1.4 extender with the 100-400mm lens as I don't believe I would lose autofocus or image sharpness. Oh, I can't afford the fixed focus lenses, which is why I was cheating using an extender.<br>

I have "heard" that Canon is developing a 2x extender that retains autofocus. It would have to improve the optics as well before I would consider an upgrade.<br>

Stick with the 2X on the 70-200mm lens. You'll get decent results. I took the combination to Africa and was satisfied with the results.</p>

<p>Larry Clement<br>

Dunedin, FL</p>

<p>Soryy - I mean the 2.8 70-200mm Canon L lens</p>

<p>I have the 70-200 F4 IS L on a 50D. I am looking at an extender.<br>

What I would like to see is SOOTC samples of the exact same image, same time of day, same aperture, taken with and without the extender. Then a 100% crop of the extender shot, and a 140% crop of the non-extender shot (or 100% and 200% if it's a 2X)<br>

Perhaps centre and edge, so a brick wall in good sun is probably as good a target as anything. Something with even and fine detail, in which the subject is not the reason for the shot.<br>

I have looked and looked for these, with no luck. I have seen all sorts of efforts, such as moon shots etc, but always one will be black and white and high contrast (usually the <em>extender</em> one!) or a different zoom, so you have no idea of what processing has been done ... (I actually consider moon shots to be a poor example, because you are shooting through 300Km of increasingly dirty air).......pictures of a few stones taken in an aquarium ....non-cropped (or unknown cropped) 800px shots of deer and swans. All lovely, but but of little use for comparison.<br>

If anyone can oblige a careful few shots, I know <em>I </em> for one would be extremely grateful, and I am sure it would help others.<br>

I have to be honest. Considering the loss of F-stop(s) and obviously the cost, I wonder if there is any<em> real</em> advantage in using an extender, rather than a simple extra crop. The 70-200 is an amazing piece of glass, and AFAICs the limit to cropping is my camera's sensor! So the proof of the pudding would be great!</p>

<p>Nick</p>

<p>so many opinions, so little real data</p>

<p>1.4x Teleconverter: small and light, provides excellent IQ but slow AF slightly, the shots look a little "soft" <br>

2x Teleconverter: 2 stops down and some loss of image quality <br /> </p>