Which extender is best

[GuyF]

I've got a Canon extender and only added advantage I'd add is that it reports accurate focal length information in the EXIF.

That's the older dg version, the newer dgx version reports correct exif. There's always a lot of confusion about the different Kenko genrations, just get the latest one :-p

Strangely, my 3 year old DG version gives me correct EXIF info. l just checked an image and it reports the lens as " EF70-200mm f/2.8L IS II USM +2.0x", focal length as 380mm and max aperture as 5.7.

Is this only because it's a version II lens?

Hmmm, I'm quite sure my 70-200 f4 IS reports the correct EXIF with either Kenko TC. Certainly my 300mm does. Only with the two stacked do things go off tangent - EXIF only reported for lens plus TC directly attached to it and ignores the one at the body end.

[Marsu42]

Strangely, my 3 year old DG version gives me correct EXIF info. l just checked an image and it reports the lens as " EF70-200mm f/2.8L IS II USM +2.0x", focal length as 380mm and max aperture as 5.7. Is this only because it's a version II lens?

As I wrote, the Kenko confusion is growing :-p ... obviously the older "dg" tries to emulate the Canon one by adding +2.0x to the lens info, the newer dgx only modifies the focal length, at least with my 70-300L + 1.4x ... maybe to get around the disabled f8 af.

[ahsanford]

My personal experience is limited here, but my thoughts are:

1) Don't buy an extender for just the lenses you have today.  Think about what will be in your bag down the road, and with that in mind, get the most compatible tool you can.

2) I own a 2x III and only have one lens (the great 70-200 F/2.8L IS II) that I use it on.  Though it's somewhat less sharp than the native glass, you know the argument -- less weight/size to carry, less risk to smuggle into events that you shouldn't bring large glass to (read: sporting events), less heavy/expensive glass not getting used, and far less cost.  For me, as an enthusiast (i.e. not a pro), this is an easy decision for the aforementioned reasons, and I love my extender as a result.

3) AF speed with an extender does suffer a bit, so sports may be problematic depending on what you shoot.  I've shot baseball with it very well, but I've only been framed on pitchers or batters (which are easy targets) -- hockey, basketball, etc. would likely be a nightmare with one.

4) If you are a pixel peeper, let Bryan Carnathan show you the way...

http://www.the-digital-picture.com/Reviews/Canon-Extender-EF-2x-III-Review.aspx

As always, the good Mr. Carnathan has nice mouseover comparisons of the different extenders.  Look about 40% of the way down the page for the sharpness comparison.

Also, he has controlled lab shots with/without extenders here:
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&Sample=0&FLI=3&API=3&LensComp=687&CameraComp=453&SampleComp=0&FLIComp=7&APIComp=2

Feel free to noodle with apertures and extenders (just change focal length, the 1.4 or 2.0 should be obvious based on seeing 280 or 400 on a 70-200 lens).  Then mouseover left to right on the graphic to see each.  Super useful!

Just my two bits.

- A

[bklein61]

MARSU42,  I have similar setup.  I have the 50D and the 70-300L.  I have been tryng to decide on using the 70-300L with the Kenko for wildlife or purchase the 400mm 5.6.  Although I am not sure if there is any noticable difference in IQ using the Kenko extender versus the 4005.6 L by itself.

Any thoughts

[ahsanford]

MARSU42,  I have similar setup.  I have the 50D and the 70-300L.  I have been tryng to decide on using the 70-300L with the Kenko for wildlife or purchase the 400mm 5.6.  Although I am not sure if there is any noticable difference in IQ using the Kenko extender versus the 4005.6 L by itself.

Any thoughts

I've not shot those, but an L prime (even a modestly priced one like the 400 5.6) without an extender should significantly outperform a zoom with an extender, right?

Using that same tool I referred to, comparing almost exactly what you are referring to:
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=738&Camera=453&Sample=0&FLI=5&API=1&LensComp=278&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=2

Disclaimer:  I don't know what apertures you shoot, and these comparison are only on FF bodies. 

Despite the disclaimer, my original guess appears to be in line with the sample shots -- even fully open, the 400 prime seems clearly sharper than the 1.4x F/8 70-300L.  Stopping down the 400 prime to the equivalent 'fully open' F/8 of the 1.4x + zoom aperture improves upon this slightly in the corners.

That said [with a fair shrug and hands going up in the air] sharpness isn't everything.  What you shoot and what you care about is your business.  Telling someone else what they should want in a lens is like telling someone how to raise their kids.   

- A

[Marsu42]

MARSU42,  I have similar setup.  I have the 50D and the 70-300L.  I have been tryng to decide on using the 70-300L with the Kenko for wildlife or purchase the 400mm 5.6.  Although I am not sure if there is any noticable difference in IQ using the Kenko extender versus the 4005.6 L by itself.

I've not shot those, but an L prime (even a modestly priced one like the 400 5.6) without an extender should significantly outperform a zoom with an extender, right?

Right. I think the 70-300L rates as "very good" (maybe not "excellent" like the more expensive/heavier/larger 70-200L or even the "stellar" 200L), and with the extender it is just "good". The 400/5.6L should not only be significantly sharper, but the af @f8 with the extender does hunt sometimes if only using one af point on my 60d - so for that reason alone it's better to get the prime. The tc solution for the zoom is just convenience and some shots.

[ahsanford]

MARSU42,  I have similar setup.  I have the 50D and the 70-300L.  I have been tryng to decide on using the 70-300L with the Kenko for wildlife or purchase the 400mm 5.6.  Although I am not sure if there is any noticable difference in IQ using the Kenko extender versus the 4005.6 L by itself.

I've not shot those, but an L prime (even a modestly priced one like the 400 5.6) without an extender should significantly outperform a zoom with an extender, right?

Right. I think the 70-300L rates as "very good" (maybe not "excellent" like the more expensive/heavier/larger 70-200L or even the "stellar" 200L), and with the extender it is just "good". The 400/5.6L should not only be significantly sharper, but the af @f8 with the extender does hunt sometimes if only using one af point on my 60d - so for that reason alone it's better to get the prime. The tc solution for the zoom is just convenience and some shots.

Excellent point. 

'Effective' fully open apertures with extenders not only slow AF in general due to a smaller effective aperture (as I said before), but as Marsu42 aptly points out, that smaller aperture also greatly limits what AF points you can use.  Depending on your body + lens + extender choice, your AF will hunt longer before locking on.

[mrsfotografie]

FWIW I have the 1.4 Canon TC II that I use with my 70-200 F/2.8 IS II. Interestingly this combination is supposedly sharper on an APS-C body than the same lens with the new Mk III 1.4 TC, which I'm ready to believe 

http://www.the-digital-picture.com/Reviews/Canon-EF-70-200mm-f-2.8-L-IS-II-USM-Lens-Review.aspx

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687

[ahsanford]

FWIW I have the 1.4 Canon TC II that I use with my 70-200 F/2.8 IS II. Interestingly this combination is supposedly sharper on an APS-C body than the same lens with the new Mk III 1.4 TC, which I'm ready to believe 

http://www.the-digital-picture.com/Reviews/Canon-EF-70-200mm-f-2.8-L-IS-II-USM-Lens-Review.aspx

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687

I believe Carnathan only has 1-3 copies of each lens, whereas a rental shop like LR has (in some cases) a dozen copies or so.  I wonder if there is significant copy to copy variation with Canon Mk III extenders...

(Paging Roger Cicala!)

- A

[johnf3f]

Ok, so I am look at the samples  from cyberphoto.se, and the Sigma 2x converter looks considerably sharper than the Canon 2x III both at f/5.6 and especially at f/8. Do my eyes deceive me?

I tried the Sigma 2x vs the Canon Mk2 and found the Canon noticeably better in colour and contrast though pretty similar in sharpness. I later traded The Canon Mk2 2x to get the Mk3. Basically My Canon Mk2 2x was staying at home as I felt cropping was better (remember I found the Sigma significantly inferior to the Canon Mk2) in other words it was a waste of money giving mediocre results on my 300 & 600mm lenses. The Mk3 2x however is enough better to make it worthwhile (it is VERY good on F2.8 primes) to use and carry around. Though very expensive the 2 x Mk3 is significantly better than the Mk2 which was significantly better than the Sigma. Though the Sigma wins hands down on price!

[RC]

At least for Canon TCs, make sure they are compatible with your lens and the lens you plan to buy.  Also keep in mind that for some lens/TC combos, you will lose AF functionality.

[Fotofanten]

Ok, so I am look at the samples  from cyberphoto.se, and the Sigma 2x converter looks considerably sharper than the Canon 2x III both at f/5.6 and especially at f/8. Do my eyes deceive me?

I tried the Sigma 2x vs the Canon Mk2 and found the Canon noticeably better in colour and contrast though pretty similar in sharpness. I later traded The Canon Mk2 2x to get the Mk3. Basically My Canon Mk2 2x was staying at home as I felt cropping was better (remember I found the Sigma significantly inferior to the Canon Mk2) in other words it was a waste of money giving mediocre results on my 300 & 600mm lenses. The Mk3 2x however is enough better to make it worthwhile (it is VERY good on F2.8 primes) to use and carry around. Though very expensive the 2 x Mk3 is significantly better than the Mk2 which was significantly better than the Sigma. Though the Sigma wins hands down on price!

Wow, thank you for that insightful post! Much appreciated

[natureshots]

I've owned the kenko dgx set, tamron 2x and sigma 2x and I've used the canon.
At 1.4x the kenko is pretty much indistinguishable from the canon mkIII. The kenko works with any lens and the canon with very few lenses. Get the kenko unless you have one of the new mkII canon supertelephoto primes which I'm taking a wild guess is a no.
At 2x the Canon mkIII is substantially better. Kenko comes next, then the canon mkII, then the Tamron and then the sigma which produces mud (and also broke on me in 6 months although it was used/abused very heavily). Make sure your lens can accept the canon 2x if you want the best and can swing the extra $200 for the canon. Also be prepared to make some compromises with the 2x even with the canon. If the light is great and you have good technique you can even get some surprisingly good results with stacked Kenkos. Its less than ideal but I was pretty surprised. If your technique is not so great than you will not be able to stack TCs.

[East Wind Photography]

The 70-200 2.8l II is a very fine lens.  Stick with the canon TCs.  I've used both the 1.4 and the 2x TCs with that lens and the 1.4 loss is negligible.  With the 2x the loss is slight but worth the cost vsa 400mm prime.

The reason I suggest using the canon TCs is that the III version tc's are matched for use with version II lenses.  Using a 3rd party TC will give you slower AF speed and likely lower IQ.  I don't think you will be happy with anything else.  They are more expensive but if you are looking for a matched TC performance my advice would be to stick with the canon TCs. Budget for both the 1.4 and the 2x because you will end up getting both and that's the best choice for expanding the capability of the 70-200 2.8L II lens.

At this moment I will probably only be using it on my 70-200 f/2.8L IS II USM.
Well since Canon doubled their prices, it's not interesting anymore to stick to that.
The Kenko ones on the other hand are much cheaper! And if they deliver the same results, I can do the math...

In my country (Netherlands) I get these TC's for these prices (converted to USD):
Canon EF 1.4x III Extender for 607,00 USD
Kenko PRO 300 DGX 1.4x for 290,00 USD

Canon EF 2.0x III Extender for 619,00 USD
Kenko PRO 300 DGX 2.0x for 315,00 USD

In both cases it would save me 300+ USD if I would buy the Kenko TC's....

[bycostello]

canon for canon stuff every time...