Advise about Teleconverters needed...

[Gus00]

I have a limited budget and I'm looking at a 2x Teleconverter to use with my Canon 70-300 lens. I know there are some pros and cons to go along with T'converters but I don't know much else.

I have my eye on a 2x AF 7 Element unit.

Looking forward to your thoughts.

Gus

[Cadwell]

All teleconvertors degrade the image somewhat. With a good 1.4x TC you barely notice it. With a good 2x TC it's plain to see.

Basically, a 2x TC will turn a good lens into an average one and a an average lens into a poor one.

I presume you are not talking about using a Canon or Sigma EX TC? because neither of those are compatible with that lens.

It is extremely unlikely that you will retain autofocus with that lens and a teleconvertor. If you do, then the autofocus will not be reliable

[Belmondo]

I have both the 1.4X and 2X Canon TCs, and I rarely use them but find them useful under certain circumstances. Most people would prefer to have a lens that covers a desired focal range, but that isn't always feasible. A TC is at best a compromise.

I should mention, however, that the Canon TCs will only work with the L telephoto lenses, but in fact work very well, especially the 1.4X. The 2.0X TC, besides slowing the lens down by two full f-stops, also degrades the image optically more noticeably than the 1.4X IMHO.

[DC]

I have a 1.4 attached to my 500 lens permenantly. Almost unnoticeable in terms of quality loss. 2x is still pretty good too. I've even stacked both and got acceptable results. With a converter attached you have to stop down at least one stop from wide open, and with 2x preferably 2 stops.

On an F4 lens, you're looking at F8 with 1.4 and F11/16 with a 2x.

To answer the original question, I would not recommend the use of 2x converter with that particular lens. I'm assuming it's a 4.5-5.6 lens? which means wide open at the long end you'll be at f11, you need to stop down at least 1 stop which means f16, and preferably one more - f22. Assuming there is actually enough light to focus (manually) and keep the shutter speed fast enough, you'll be disappointed with the results.

I understand your frustration though, I have been there. Save your money and get a 300F4L, used if you have to. Then add a Canon 1.4x. It's the combo I have on my backup camera, and it gives superb results.

Just my input for what it's worth to you...

[CyberDyneSystems]

The POLL did not have the option I would vote for.. so I added it.

Essentially Teleconverters ARE a "gift from heaven" .. but given your intended use.. you would be just as well off with a telescope and duct tape. :?


T-Cons are only a gift from heaven when you use matching T-cons with recmended lenses.

Trying to get a third party t-con to work with a low budget zoom will not result in a quality images. The 70-300mm will give very very poor results with a T-con...

[lime]

Here's a link about using TC's, with samples.
http://www.bobatkins.com/photography/tutorials/tc3.html

[Transfix]

I use my Canon 1.4x Type II TC all the time on a 300 2.8 L IS.

Not all TCs will be compatible with the Canon L lenses. The Older Tamron converters on a Canon will crop the corners. If it's a Canon lens, I'd stick with a Canon TC. Type II especially.

With the 1.3 crop factor and a 1.4 tc, i havn't needed the 2x tc often. The last time I used it was the Big 12 baseball tournemant shooting outfielders.

Sample shots with both a 1.4 and 2x TC. http://gallery.mikestrong.net/list.php?exhibition=24