Question about adding extender on 70-200

[bham]

I am looking to purchase maybe the 1.4x or 2x and was wondering if they can be used together? I know this maybe a dumb question.

[sirsloop]

There are no dumb questions, only dumb answers :wink

You could theoretically use a 1.x4 and a 2.0x together, but the resulting loss of auto-focus and loss in image quality would not make it practical. Most lenses aren't all that practical to use with a 2.0x, IMHO including the 70-200/2.8L. I absolutely love this lens, and it works fantastic with a 1.4x... but a 2.0x is kinda ho-hum. You do get 400mm out of the thing, but the price in image quality is high. :uhoh

[bham]

There are no dumb questions, only dumb answers :wink

You could theoretically use a 1.x4 and a 2.0x together, but the resulting loss of auto-focus and loss in image quality would not make it practical. Most lenses aren't all that practical to use with a 2.0x, IMHO including the 70-200/2.8L. I absolutely love this lens, and it works fantastic with a 1.4x... but a 2.0x is kinda ho-hum. You do get 400mm out of the thing, but the price in image quality is high. :uhoh

Thanks that is some good feedback.

What is ho-hum with using it with the 2.0?

[luke_church]

Thanks that is some good feedback.

What is ho-hum with using it with the 2.0?

http://danks.netfirms.com/TCtest.htm

Based on this review, it seems unclear whether the optical quality of the 2.0 is better than the 1.4x and software upsampling.

[ziggy53]

Thanks that is some good feedback.

What is ho-hum with using it with the 2.0?
Rear-mounted telextenders are pretty amazing pieces of glass, but there is only so much they can do. Mating to zoom lenses is extremely difficult to do properly. Remember that all lenses are designed to focus at the image plane, either onto the film plane or onto the imaging chip. Inserting an additional optical complication in between doesn't always improve the situation (like almost never).

Even the 1.4x telextender induces some optical distortion and loss of sharpness, but the 2x is really designed just for long telephoto primes.

Even if the 2x were perfect, it would be magnifying any defects of the host lens by (surprise) 2x.

Adding a 1.4x on top isn't going to improve the situation, plus you would drop 3 stops of light transmission. Suddenly that wonderful f2.8L is now an f8 with poorer properties than many consumer lenses.

[bham]

So Ideally the 1.4x or 2x should be used on a fixed length lens such as the Canon 300L 4 IS or 300L 2.8?

Then its just cheaply adding reach and you are giving up f-stops.

I didn't know that they were designed mainly for the fixed length lenses. I learn something here at least once a day, if not more frequently.

[ziggy53]

Here are the compatibility charts:

http://www.bhphotovideo.com/FrameWork/charts/canon1_4xExtender.html
http://www.bhphotovideo.com/FrameWork/charts/canon2xExtender.html

Note the exceptions and addendums.

[bham]

Here are the compatibility charts:

http://www.bhphotovideo.com/FrameWork/charts/canon1_4xExtender.html
http://www.bhphotovideo.com/FrameWork/charts/canon2xExtender.html

Note the exceptions and addendums.

Yes I had seen that before.

[Doug G.]

I am looking to purchase maybe the 1.4x or 2x and was wondering if they can be used together? I know this maybe a dumb question.

I've owned the Canon 70-200 f/4L in both the non-IS and IS versions. They both produce REMARKABLE and fully professional quality results with the Canon 1.4x converter. I would expect the f/2.8L lenses to do the same. Yes, theoretically the converters MAY perform slightly better with non-zoom lenses, but don't be mislead. Thousands of pros use the 1.4x with their 70-200 L lenses with complete confidence.

On the other hand, 2x converters are not quite as satisfactory optically and are more difficult to use. I think it's better to buy a longer lens. As far as combining teleconverters, not a good idea.

Also, mixing a Brand 'C' converter with a Brand 'S' lens can yield unpredictable results. Stick with one quality brand.

[claudermilk]

I wouldn't stack TCs on a 70-200. I wouldn't even use a single TC, particularly the 2x, on a 70-200 unless conditions were optimal. There was a thread recently with some good examples of a 70-200 + TC (I think 1.4) under optimal conditions showing that the combo can work well. However, if you start getting into low light, the 70-200 + TC combo falls apart alarmingly. I tried, and gave up on it; I preached against the combo entriely until seeing those examples.

The TCs work best on long primes like the 300mm, 400mm, etc.

That said, I am considering adding a Canon 1.4x TC to my bag for some longer shots with my 70-200/2.8. I now have a year pass to the SD Zoo & WAP, so plan on lots of "wildlife" shooting this year and that 200mm is already a bit short.

[dogwood]

There's a good article on this topic in the current issue of Photography Monthly (a UK mag that's widely available in the USA).

They found the third party teleconvertors were both cheaper and optically better than some of the Canon or Nikon teleconvertors. They do recommend using them at f/8 and above, however.

I've personally had decent luck with a 2x Canon on a 70-200-- but will admit my results are a little softer than I'd get with just a 70-200.

[Doug G.]

There are no dumb questions, only dumb answers :wink

You could theoretically use a 1.x4 and a 2.0x together, but the resulting loss of auto-focus and loss in image quality would not make it practical. Most lenses aren't all that practical to use with a 2.0x, IMHO including the 70-200/2.8L. I absolutely love this lens, and it works fantastic with a 1.4x... but a 2.0x is kinda ho-hum. You do get 400mm out of the thing, but the price in image quality is high. :uhoh

Sirsloop,

I agree with every word you said in paragraph 2, and your comment about "dumb answers" in paragraph 1 also seems to be right on the mark.

[GJMPhoto]

I have the 70-200L IS 2.8 and I do use the 2x II converter from time to time. In those situations where I need a 400 mm lens, the converter is just fine. At 5.6, but Image Stablized, the lens produces excellent results. Even enlarged, the 'softness' is not bad at all.

I'm thrilled with the combination...I'm carrying enough weight that having a 400mm 5.6 for no additional weight is WELL worth it.

[claudermilk]

There's a good article on this topic in the current issue of Photography Monthly (a UK mag that's widely available in the USA).

They found the third party teleconvertors were both cheaper and optically better than some of the Canon or Nikon teleconvertors. They do recommend using them at f/8 and above, however.

I've personally had decent luck with a 2x Canon on a 70-200-- but will admit my results are a little softer than I'd get with just a 70-200.

OK, so which 3rd party converters did they like better?