Fixed focal length to used with teleconverter

I'm going to be purchasing two teleconverters, The Kenko Pro 300 AF 3x

AND 2x of the same (they're made by Tonika with hoya glass). I'd like

to know if anyone has used these with fixed focal length lenses

ranging between 50mm and 100mm. I've already seen the results from

some telephoto lenses used (which I was satisfied with), but I'm not

interested in telephoto lens info. I'd like to know how sharp, or not,

the images are compared to other teleconverters while using fixed

focal length. I won't even consider Canons versions since they say the

IS functionality is disabled. and Since I'll be using one of the

lenses with IS. I'm asking because I also want to get a decent (most

likely not "L" quality glass) prime for use with these teleconverters.

I'll be using them with 300D and Rebel 2000 cameras. Thanx in advance.

Canon's TCs don't disable IS. They simply won't work with most lenses that I can afford. Specifially, they only work with some of the longer L series lenses.

 

Also, the Canon TCs report to the camera the true effective maximum aperture with the lens and TC combined, so some combinations become lower than the camera's minimum requirements for autofocus to work. Most other manufacturers TCs just pass the lens' max aperture data straight through to the camera, so even if the combination is f/11 the camera will try to AF. With most cameras this doesn't work very well, but I can confirm that the DRebel/300D will AF quite well with lens/TC combinations down to f/8.

 

Also, Canon TCs will usually slow down the AF speed of most L telephoto lenses so that AF becomes more reliable. As far as I know, none of the third party TCs do that.

 

Finally, TCs are designed to work well with long lenses. They are not optimised for 50mm to 100mm lens lengths. Maybe someone else has some real world experience here. And a 3x TC is going to really be pushing the sharpness of any lens.

 

I sometimes use a Kenko 1.5x TC with a Canon 28-135, on a DRebel/300D and the results are pretty good considering it's only a decent lens to begin with. AF is still fast & acurate even in dim light.

Jim, <P>

 

I believe the comment comes from the fact that older Canon bodies disable IS when

they disable AF. Thus if the lenses maximum aperture (as correctly report by the

Canon TC) is not large enough for the camera to AF reliably then the camera will not

allow AF and on older bodies this disables IS.<P>

 

See <A HREF="http://eosdoc.com/manuals/notes/IScompat/">EOS Documentation

Project : Image Stabilizer and EOS Camera Body Compatibility</A><P>

 

I have an EOS 5 and it has this problem. <P>

 

Stephen, If you have an IS lens but not a telephoto chances are it is the 28-135 and

this lens cannot be used on a Canon TC. <P>

 

I am not sure whether you mean telephoto or zoom lenses.<P>

 

The obvious prime for use with these lenses which is not L quality is the 200/2.8. It

is the longest non-L prime telephoto. <P>

<p>The 200/2.8 <em>is</em> an L lens. The longest non-L prime is the 135/2.8 SF.</p>

 

<p>Yuor bodies are new and will have IS enabled even with a teleconverter, no matter how slow the combination may be. Only bodies from before approximately 1995 have the issue of disabling IS if the combination is reported to be slower than f/5.6.</p>

 

<p>Even the best 2x teleconverters cause image degradation - turning a top-notch lens into a good but not specatular lens. A 3x TC would be worse. I can't speak for the quality of these two TCs but I suspect you'll be disappointed with the results.</p>

 

<p>You are looking for primes between 50 and 100. You will be "using one of the lenses with IS" but there are no lenses with IS which match your criteria. And there's a huge difference between the two ends of your range of focal lengths when adding the TCs - one gives you 50, 100, and 150; the other gives you 100, 200, and 300.</p>

 

<p>It sounds like you're putting the cart before the horse. What I think you ought to do is to establish what focal lengths you need, and then determine what equipment to use to get you there - not determine what some of the equipment will be and then wonder what the next bit should be and never even discuss what the goal is. If you need nothing longer than 150, for example, then a 100mm lens plus a 3x TC will do you very little good - and the 135/2.8 SF is probably going to give you better results than a 50 with a 3x or an 85 with a 2x.</p>

You are right. I was working from memory and thought the 200/2.8 was a non-L

lens. It is not. <P>

 

This together with the Canon 300/4L represent the best value in the Canon telephoto

range in my opinion. The 200 has the advantage of being black rather than eye

catching and attention attracting white.<P>

 

The reason that the 200 is less well known (obviously by me - the red ring really is

kind of obvious) is that the focal length is covered by the very popular 70-200/2.8L

and 70-200/4L. The 200/2.8 has better resistance to flare and is much easier to

carry than the 70-200/2.8L. I tried one of those in the local Jessops and found it

cumbersome.<P>

 

There is a review of two TCs at <A HREF="http://www.seittipaja.fi/data/Pontification/

b_Photography/de_TC_vs_TC/a_Converter_vs_Converter.html">Petteri's

Pontifications</A> and the lens used for the test was the 200/2.8L.

heh...to coin a phrase "I'm shooting for the moon baby!" I'm thinking the 200 lens mentioned, and I wanted to try\experiment with a bit lesser lenses. What the heck, if it doesn't work out I'll sell 'em. No harm, no foul.