MY SLR EQUIPMENT COMPOSITION IS AS FOLLOWS, CANON EOS 5 BODY, 50MM F.1.4 USM, 28-105 USM AND 75-300 USM IS. I'M PLANNING TO BY A KENKO AF TELEPLUS TC 2X OR 1.4X. HAS ANYBODY EXPERIENCED IT OR CAN GIVE ME ANY INFORMATION REGARDING IF IT IS POSSIBLE TO HAVE FULL AF LINKAGE WITH THIS KENKO TC AND MY EOS 5 BODY AND LENSES?? PLEASE, I WILL ALSO VERY MUCH WELLCOME ANY OTHERS SUGGESTIONS OR RECOMENDATIONS.

TAHNK YOU VERY MUCH.

CHARLES.

-- charles garr (cfgar@hotmail.com), October 28, 1999

Answers

My only comment is that you are unlikely to get very good optical performance with 3rd party TCs (especially 2x) on these lenses. The system will try to AF, but will often fail with lenses slower than f4 (with the 1.4x) of f2.8 (with the 2x).

The good news is the Tamron TCs are cheap.

Also, using ALL UPPER CASE makes it hard to read your post. Please use normal (lower case) text.

-- Bob Atkins (bobatkins@hotmail.com), October 28, 1999.

Check carefully. EOS converters won't do on the 70-300 as they have a front element that pokes forward and makes them impossible to fit. Check 3rd party carefully that they don't touch rear element. I tried a 12mm tube then converter, but in most cases it stopped autofocus with 1.4x as it pushes effective Fstop past f8.

-- Lawrie Weston (westonl@melbpc.org.au), November 17, 1999.

Lawrie:

Coming back to our mail exchange, I inform you that finally I've got my KENKO TC 1.5x. And, last weekend I tested it, this way:

a) From my office 16th. floor. All shots focused at a 40 stories building, 100-150m away, same floor, same window. Sunday morning fair skies, the building facing the sun. b) Film, Fuji superia reala 100. 36 pictures, 1-21 at 9-9:30 am and 22-36 at 11-11:30 am c) Lens and focal length, all with and without TC * 50mm f/1.4 (50) * 28-105 USM (28-50-70-105) * 75-300 USM IS (75-135-300) d) All pictures taken Av at f/8 (best quality and standarization of the test).

Comments:

1.- Autofocus worked perfectly well with three lenses in all focal lengths. I worked mainly with eye control, but also shot several frames focused with central spot. All did excellent. 2.- Special mention deserves the 75-300 IS. I tested mainly with IS on, and always worked well. I also checked with IS off and without AF, just M, also worked ok. Also I tested it (of course with TC) inside the office with less light and worked pretty well. But best functioning was with full day light, I was worried specially at 300mm, because specifications mentioned that manual focus is necesary if maximum aperture is f/4 or darker, just the case of 300mmm. But anyway the 75-300 USM IS, is not a fast lens, several times it got confused and I have to insist to take the picture in focus. 3.- I made prints, contact sheet, and also 4x6. 4.- I checked all of them with two lupes one KENKO 6x and one PEAK 22x. 5.- No doubt the best of all 50mm f/1.4, with TC also was very good, sharp. 6.- The other two lenses are not the same quality, but the difference among photos shot with or without TC, is not easy to discover. 7.- For example, the comparison of 300mm with and without TC. With the lupe 6x was ok, not easy to find diferences or distorsions, but with Peak 22x I could see that a window in the edge (corner of the print) had two very narrow lines of red and green colours, and this colours in the picture taken with TC suffered an inversion (one in the place of the other) imposible to see without the 22x. In any case sharpness was practically the same, of course not very sharp indeed. 8.- I found out that the metering system of my EOS 5, compensates the TC, it knows the TC is there. All pictures with TC, were shot with compensation +1 and just following the EOS 5 reading (without compensation). It is easy to see that those C.+1 are overexposed. 9.- The comparison with focal length of three lenses allows me to say (like Bob Atkins) that KENKO 1.5x in fact is a 1.4x (no doubt). 10.- In general results are pretty good, the zooms I owned of course have important limitations, specially 75-300, but the KENKO 1.4x perfomed very well, lets say matching the lens (even the 50mm f/1.4) I am very happy with my investment.

Coming Next:

I am thinking that the Canon 200mm f/2.8L USM might be a very good investment and also should work perfectly well with TC 1.4x and TC 2x. I realized that I will enjoy having a faster lens, with a faster autofocus. This 200mm seems to be light, L quality, black, and not excevelly expensive like others L category.

I hope this information could be of some help also for you and many others interested in third parties TC.

Any comments or recomendations are wellcome. Thanks,

Regards,

Carlos

>From: westonl@melbpc.org.au >To: cfgar@hotmail.com >Subject: Response to TELECONVERTERS FOR EF LENSES AND EOS 5. >Date: Wed, 17 Nov 1999 20:56:37 GMT > >Lawrie Weston (westonl@melbpc.org.au) responded to a message you left >in the Canon EOS FAQ forum bboard: > >Subject: Response to TELECONVERTERS FOR EF LENSES AND EOS 5. > >Check carefully. EOS converters won't do on the 70-300 as they have a >front element that pokes forward and makes them impossible to fit. >Check 3rd party carefully that they don't touch rear element. >I tried a 12mm tube then converter, but in most cases it stopped >autofocus with 1.4x as it pushes effective Fstop past f8. > >-----------------

-- carlos garcia (cfgar@hotmail.com), December 07, 1999.