Hello Everyone, Would love your advice on this topic. Currently would like the ability to take nature shots. One of my Canon lens is 90-300mm. I find the cost of a good quality lens out of my range at the moment. But my teacher suggested Canon Extender Extender EF 2x II RRP $699.00 or Extender EF 1.4x II RRP $699.00 . Prices Australian Dollars. But the lens i have also thought of buying is alot more expensive EF 400mm f/5.6L USM RRP $2,699.00 . Would love your advice on this topic. Thankyou again for your wisdom and time. Chris:)

Jim is maybe the best person to answer this on a tech level. What I know though is. 1. That extenders arent compatible with all lenses, and some lenses will only work with the 1.4 or 2.0 respectively. 2. Tele converters may affect the optical quality with some lenses. 3. I think tele converters may cost you one stop of light!? Not sure. Also tele converters may only work with fast lenses (again not totally sure) Have you considered the 100-400mm L, I have used one but dont own one, lovely lens not sure how this lens compares to the price of the 400mm L

1. true...believe its mainly the EF L glass range? 2) As more glass = sub quality 3)1x4 will loose you 1 stop...2x =2 stops! Also to take into consideration is the f stop when using the ext! need a fast lens with the 2x...1x4 can get away with on 2.8 lens!...2x, pushing it imo!...ie, 2x on my EF 500 f4 makes it an f8!!!!....ok with a monopod and manual focusing! Much prefer the 1x4 if I need to!..many pple do!

1 x 4 ext on a 100-400 will make it: 140mm - 560mm! (40mm in every 100mm) loose about one stop!...but up the ISO to compensate:)

Ah cool I was sort of right about most of it! Not bad for someone thats never used a converter lol.

LostPatrol is right. Not all teleconverters are compatible with all lenses, mostly L telephotos. They will cause a slight loss of quality. From the Canon website: 1.4x teleconverter: This tele extender can be used with fixed focal length lenses 135mm and longer (except the 135mm f/2.8 Softfocus lens), and the EF 70-200 f/2.8L, 70-200 f/2.8L IS, 70-200 f/4.0L, and 100-400 f/4.5-5.6L IS zoom lenses. Effective aperture is reduced by one f-stop; autofocus is possible on any EOS camera when combined with a lens having an f/4 or faster maximum aperture. 2x: This extender has been re-designed optically and offers excellent performance with compatible EF lenses (same as the Extender EF 1.4x II). Features a new seven-element design, and same weather-resistant design and anti-reflection internal construction as the new EF 1.4x II. The EF 2x II doubles the focal length of any lens it's mounted to, and reduces its effective aperture by two stops. With the EF 2x II, AF is possible with any EOS body if the lens has an f/2.8 or faster maximum aperture, and compatible Image Stabilization lenses maintain the IS feature when used with any current EOS camera.

EF 100-400mm f/4.5-5.6L IS USM RRP $3,499.00 . So more expensive then the EF 400mm f/5.6L USM RRP 2,699.00 .These are in Australian dollars. The thing with the extenders is that quality is lost. Even though alot less the price i think i would be eventually disappointed with it:(. Another friend thinks that Sigma Lens might be the go. As yet i have tried to only stick to Canon brand. I use Canon EOS 20D. So to change brands will i loose quality? What is your view on cheaper brands? Are we paying for the brandname on certain lens or is the quality better? Thanks for your help Chris:)

Attached Link: Sigma reviews

I need to go on a course to understand all of this, but I'm sure it's sinking in on some level...

I agree with the advice given and the 1.4 is certainly a better bet for the lenses you are able to afford you will need as has been said an F4 L quality lens to be able to have autofocus working but the 1.4 converter can be made to work with a trick.. Canon disabled the function so more people would spend more on such lenses that exceed 400mm I would not agree that more glass = sub quality prime lenses dont need so much as there is no zoom factor to consider. But lenses with a greater zoom need the extra glass to compensate for the focal range each lens design will need to have that taken into consideration, but as a general rule of thumb the less glass the better, but unfortunately the lens has to then be big to allow enough light in the longer this is the bigger the lens.. My advice would be to go to a good dealer and check out the size and weight you will find a good 300mm prime good enough without an extender for most wildlife needs and then add the 1.4 and you can cope with most situtaions and not have the size and weight to worry about.. The 100-400 is quite big too but ask Nikki she manages superbly with hers.. There are also some Non Canon makes that are cheaper than L glass and produce excellent results but sad to say most of us who try them end up part exchanging them for the L glass

"Currently would like the ability to take nature shots." A brief glance at your gallery tells me that you are already doing that, and quite well I might add. But heed the advice of the experts that have already weighed in on this topic, their advice is sound. Sorry I can't help more.

Quote Dan: There are also some Non Canon makes that are cheaper than L glass and produce excellent results but sad to say most of us who try them end up part exchanging them for the L glass Would ya put a sub quality engine into a racing car :)