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Old Jun 3, 2003, 10:39 AM   #1
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Default Teleconverters and canon 10d

I have a canon 10d with a few consumer lenses. In using a canon EF 75-300mm, f/4-5.6 IS usm, I am satisfied with what I am getting. Then I decided that I would like a little more zoom power. I can't afford too much. So I tried a cheap 2x converter. Horrible. The salesman said that I wouldn't get any better results out of the Canon 1.4x or the 2x. Any advice would be appreciated. :?:
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Old Jun 3, 2003, 7:10 PM   #2
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How was it bad? In what ways? Which brand? Even the best teleconverter ever made will have these problems:
  1. Raise the smallest f-stop by 1 for a 1.4x and by 2 for a 2x.
  2. Increase any deficiencies in your lenses. If your lens has imperfections, the teleconverter will magnify them. It is, after all, magnifying the light which goes through the lens.
But not all TCs are created equal. Bad TCs can also increase flare, produce a color shifts and Chromatic Aborations. Some of this is caused by bad coatings on the glass (if they have any at all.)

Most people say that the Canon TCs are the best for their cameras, but that the Kenko are very good. Specifically this link:
http://www.adorama.com/catalog.tpl?o...;sku=KN14XPEOS
Their 2x at this link:
http://www.adorama.com/catalog.tpl?o...p;sku=KN2XPEOS
Is also nice. But the loss of light with the 2x seems like it would require really ideal lighting to be reasonable, or a really fast lens to begin with. Make sure that the TC will work with the lenses you have. I have heard that the Canon TC doesn't work with all of their lenses, I don't know if the Kenko has similar problems. They are almost exactly 1/2 the price of the Canon.

BTW, the links I gave you are for Adorama. I wouldn't buy there, as I've heard some bad things their post-sale customer treatment. I only use their site because its the best site I've found for searching for gear.
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Old Jun 3, 2003, 7:59 PM   #3
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Default eleconverters and canon 10d

Thanks for the reply eric. I bought my camera and lenses from Adorama. No complants. I was taking a picture of a nesting Bald Eagle. Pretty far away. On an uncropped 8x10 picture, the Eagle was about 1/8 of an inch. I cropped about 80% and got a picture with which I could live . Then I thought it would be nice to get a little closer, zoom-wise. So I tried a Ritz Camera Quadaray 2x for about $85. I couldn't zoom in and get a sharp picture. Plus no EF. I thought it was because it was a cheap lens. Then the sales person at Ritz said that getting a Canon for $300-$400 would't give me any better results. Therefore, should I try the Canon 1.4x or 2x. If they didn't work any better, I would hate the hassle of trying to return it. I can't, at the moment, afford more then $300-$400. Maybe I should just wait until I can afford something else?
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Old Jun 3, 2003, 9:09 PM   #4
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Depending on the lens, you won't loose AF with the 1.4x TC. If you are using a f4 lens, you will be fine (but the 2x TC will not have AF.) If you are using an F5.6 (like I am) you will loose AF no matter what TC you get (strickly speaking this is a lie, see below.)

Actually, let me change my story. I know that the consumer grade DSLR's (10D, D60, D30) will loose AF above F5.6. I don't know if that is true with the 1D or 1Ds. They do have better AF system, but I don't know if it's better in this specific way (works at higher f-stop.)

Quadaray isn't the best TC. They won't have as good coatings on the lens as Canon or Kenko, so I'd expect lens flare and maybe worse. If I didn't buy the Canon (and I'm starting to wish I didn't) I'd get the Kenko at about $170. After using my 1.4x Canon TC today, I don't think I'll use it as often as I hoped to. You can trick the AF to work above F5.6 on the 100-400L (which I have) but it was very hit and miss... basically didn't seem worth it when I can probably crop and upsize with acceptable (to me) results.

If you were happy with cropping 80%, then the Kenko will be good enough. If you slip over to dpreview.com and search their forums you'll see that people like it... and there are some very serious people there. A Pro friend of mine also uses it and likes it (that is how I got tipped off to it origionally.) But please *make sure* it works with the lenses you have. I know the Canon TCs don't work with all of the Canon lenses, maybe the Kenko's TC is the same.

As to my comment about Adorama. I read posts from several people who were annoyed by some upselling pressure on a callback about an order problem. Others complained that they gave them a hard time on returns. I've never heard such problems from B&H, which has (every time I've checked) the same prices. It should be noted that I've never bought anything from either of these stores.

If you want to learn the trick for enabling AF on the 100-400 (which is f5.6 at 400) with a TC, check out this link.
http://www.fredmiranda.com/TipsPage/
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Old Jun 4, 2003, 7:41 AM   #5
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Most 1.4x and 2x will work with any lens (provided the element do not stick too far back like on some wide angle!). The best ones are the one matched to their lenses. Canon has theirs matched to their 'L' series as well as other brands like Sigma with their EX without introducing too much softness.

Theses TC is a trade-off I believe to carrying a pair of heavy lenses. It's the main reason why people opted for constant f2.8 on the long tele! Now I'm not a long tele user so can somebody come up with a 0.625x I'll buy it anytime with the corresponding wider aperture (without blowing up the lens), that'll be something! :lol: :lol: :lol: BTW the other benefit of a large aperture is a bright viewfinder. Can you still see that well with a 2x on an f4.5? You can stop the lens down to increase sharpness, but at least the wider aperture help in the composing part!

I don't have any problem with Adorama yet (since I've not returned any thing), but then I haven't bought any big ticket item from them either. As for filters they are pretty reasonable and their shippings are extremely fast: 3 days UPS orders usually show up the next day, so I guess they didn't have time to call back! :P
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Old Jun 4, 2003, 8:57 AM   #6
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NHL

The problem (as I've read it) are as you say. The physical design of the Canon TCs mean they can not be connected to some of their lenses becuase some part of the lens sticks out and gets in the way. You can damage the lens if you try to do it.

I'm sure that Canon has this listed somewhere on their site, but I don't know where (yet!)

Eric
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Old Jul 2, 2003, 3:11 PM   #7
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Quote:
The salesman said that I wouldn't get any better results out of the Canon 1.4x or the 2x. Any advice would be appreciated
The salesman is wrong. The Canon 1.4x II and 2X tele converters will only work with Canon "L" lenses which have moisture/dust seals and are shaped differently than non-"L" mounts. Other than this restriction, the only significant loss with the 1.4x II is one stop of light. The Canon 2X will soften the image a healthy amount, and I've stopped using mine entirely, but I definitely use the 1.4x and see no image quality loss with it.

Kenko make a good 1.4x which can be used with any Canon lens and will also not compromise quality appreciably. Cheap tele converters are not worth bothering with, but high quality ones are a definite help.

On the issue of being able to autofocus. The Canon prosumer models (D30/D60/10D) are all designed to reliably autofocus at F5.6. The way this works is no matter what your aperture setting (such as F8, F22, etc.) the camera will use F5.6 or better (lower number) to autofocus, then after the autofocus has been accomplished, the camera sets the aperture required for the shot.

The D30 and D60 will really not autofocus unless the lens is F5.6 or better rated. There are electronic signals sent from the lens to the camera body which "inform" the camera of the lenses capabilities. With the 10D it is possible to "fool" these signals by placing transparent tape over three of the pins on the teleconverter. What this does is make the camera think it's still connected to a lens which it can use to autofocus with at F5.6 or better. The 10 D will reliably autofocus with "some" Canon "L" lenses like the 100-400IS at F8 or very close to F8. By this I mean that if you tape the pins on the 1.4x teleconverter, the 10D will go ahead and "try" to autofocus. Unless you are zoomed all the way to 400mm, it will reliably autofocus every time. At 400mm (lens focal length not including 1.4x tele) it will "try" and will succeed about half the time, but if you slide back just a few mm, it will autofocus and you can then extend to 400mm and get the shot.

The Canon Pro models (EOS-1D/EOS-1DS) will autofocus reliably at F8 and sometimes even at F11 with or without the tape on the teleconverter.

For those who want to try the tape, simply mount the teleconverter on the camera. Then hold the camera with the lens facing you and inspect the pins on the teleconverter. There are three pins on a small "bumped" up area on your right as you look into the teleconverter lens. Forget these three. Place clear Scotch tape over the last three pins on the "left" side (opposite side from the pins on the bumped up area). and then mount the lens. You can simply leave the tape in place.

Below is a 1:1 crop from a recent shot with my 100-400L IS and 1.4x tele converter taken at F8 - ISO 400 - 1/60th at about 560mm.

Lin

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Old Jul 2, 2003, 9:37 PM   #8
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Lin

Good to see you posting again, it's been awhile!

Kennrb

Here is a link which describes the pin-taping trick Lin is talking about. It also has a link to a picture of what to do, so it's fairly easy to do.

http://www.fredmiranda.com/TipsPage/

Eric
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Old Jul 3, 2003, 11:38 AM   #9
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Does someone use the Soligor 1.7x converter? AF works with this converter.

babelfish-translation:

in that nature photo is a report over the 1,7x soligor extender. the tester was very inspired and obvious is also closes af dazzles 5,6 off missing (probably not all information of the objective passed on).
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