Are lens extenders any good?

Snapper · 11-21-2008, 05:15 AM

I seem to have built up more Canon fit lenses than I need, so I'm thinking of selling some off and just buying one decent lens. I already have 24-70mm covered, but I want to get rid of a Canon 28-135mm, a 75-300mm and Centon 500mm reflector, and maybe replace them with Canon 70-200mm f/4L.

I'm not a fan of long lenses, but I do need something long for photographing cricket for my club's website. So I was thinking of getting a Canon 2x extender so I can have a 400m in effect.

Question is, once you put a 2x extender on the lens, what kind of drop in quality will you get? Or should I look at getting a single non-Canon lens (like a Sigma 120-400mm f/4.5-5.6). I would need good quality up to 200mm for doing the occasional wedding though.

2F/2F · 11-21-2008, 05:22 AM

I have not used the EF doubler, but the 1.4x on the 70-200 f/4 is very decent. Not tack sharp, but OK. I used this combo quite a lot when shooting sports for the paper.

Pinholemaster · 11-21-2008, 06:18 AM

Don't know Canon's extenders, but the Nikon x1.4 extender is excellent but their x2.0 is crap. I only own a x1.4 extender because to the quality fall-off issues.

Ian Grant · 11-21-2008, 07:07 AM

It's fair to say that most are brilliant, the best are designed to be used with specific lenses.

The greater the extension the more compromises and the larger the drop in quality, x3 were once available but the majority were x2 with a smaller number of x1.4 mainly from the major camera/lens manufacturers.

One major problem is they work best with the lens fitted stopped down, but because they cut light transmission that often means you need to work at wider apertures if your shooting sports events so it's a Catch 22 situation.

They can be useful though, and may make the difference between getting a decent image or none at all, many sports photographers use the 300mm f2.8 Canon lens and the x1.4 or x2 converters but this is an optimal combinations. Converters are not as good with Zoom lenses.

For optimum quality a decent lens is always going to be better than using a converter. I've used a good 2x converter to shoot Cricket & Rugby in the past and while the images are acceptable there is a drop in quality.

Ian

Fotoguy20d · 11-21-2008, 07:13 AM

I've been using the Canon 1.4x II TC with my Canon 70-200 f2.8L IS for quite some time. Not as sharp as the lens alone (and certainly not as sharp as the 300mm f4L) but better than acceptable, and contrast is good. I bought a 2X II TC from KEH around 6 months ago and I'm disappointed in it - poor sharpness and contrast. So, if you need to get to 400mm, not the way to go. If you're interested, I'm planning on selling my Canon 300mm f4L (non-IS) to afford to upgrade my 28-135IS to a 24-105L.

Dan

Jeff Kubach · 11-21-2008, 08:32 AM

I have a Canon 2x extender for my Canon FD system. It seems to be OK from what I can see. I don't use a whole lot but I like it.

Jeff

Excalibur2 · 11-21-2008, 01:16 PM

Well like for like, I've yet to find a cheap MF zoom that can equal a MF prime.....so an extender on a zoom is going to make things worse......so it depends on what results are acceptable to you...my "foto care" huh! 2X extender is rubbish on a Tokina 80-200mm (erm well any pic is better than none I suppose), now my vivitar 70-150 with matching 2X extender, made by Kiron, is acceptable at 300mm..and saves me buying a 300mm prime.

A hand held shot at 300mm, not much depth of field though from about 25 yards away:-

Bob King · 11-22-2008, 03:34 AM

Any extender will degrade image quality to some degree. I have the Canon 1.4x which I use on my 70-200 f/2.8 IS L and I find the results quite acceptable. I believe it works better with L primes such as the 300 f/2.8. I have used the 2x (not mine) and the results were somewhat disappointing, and that seems to be the consensus among users. So, if you can manage the 70-200 f/4 with a 1.4x then do it - the results will be quite OK. But not the 2x. Of course the f/4 will become f/5.6 with the 1.4x. If you use a 2x on the 70-200 f/4 then its maximum aperture will become f/8 and you will lose AF unless you have a 1 series body.

If you do get the 70-200 then you will be pleased with it. Sigmas, Tamrons and others would have a hard time matching it.

Cheers, Bob

Christopher Walrath · 11-22-2008, 02:23 PM

I had a tele-extender (2X) for my Minolta/MD lens system a couple of years back. I had light fall off issues, up to a full stop with certain apertures and focal length combinations. I don't have the data anymore. However you do lose some light, but as long as you're metering TTL that's negligible.

DOI is another problem. The tele-extender spreads out the light reaching the film surface thus enlarging the circles of confusion and in turn reducing Distinctiveness of Image.

Snapper · 11-24-2008, 03:44 AM

Hmmm. So that's a 'no' then. I really need at least 400mm, so maybe a 2x on a 70-200mm is not the way to go. I'll have to look at a non-Canon lens then.