I currently use the 1.4 II with my 7d and the 500mm and get tack sharp shots. I'm considering getting a 2x for when I need the occasional bit of extra reach. I have the 500mm f4 Is and not the new 500mm II, is there any advantage to getting the 2x III instead of the 2x II other than that it's newer. Also i've been very happy with the 1.4 resolution, is there much of a drop off with the 2x. Thanks Capt Don

I also use the 500mm Mk I on the 7D. Since I photograph small birds I often need extra reach beyond the 1.4X TC. My preference is to stack 1.4X TCs. You can switch quicker in the field. (Either take a TC off or add a TC quicker than removing a TC and mounting another TC) For the second TC I use a nonreporting Tamron or Kenko TC. This way I maintain AF using an outer focus point. Yes, it does work!

Everything I read several years ago stated that you got better IQ from stacked 1.4's than you would from the 2x II. Now, from all reports the 2X III has much better IQ than the 2X II. I am staying with the stacked 1.4's because I can maintain AF which I could not do with the 2x III.

Now, if the 7D II will focus at f8 as the new firmware for the 5D III does I may have to rethink my choice.

I don't think there is much difference between mk II and mk III IQ. Most difference is at the extremities with centre sharpness very close. The mk III supposedly offer some AF advantage with the mk II superteles. The 500 mk I + 2x mk II/III still has excellent IQ IMO although I've never tried it on the 7D, only 1D II and 1D III.

As bobsofpa says, you can stack another 1.4x TC with your current 1.4x but it'll need to be a third party TC and I would recommend the Kenko Pro 300 DGX. I have the DG version and it worked very well stacked with my Canon, but the newer DGX version apparently allows AF @ f/8 on 5D III.

Pixel Perfect wrote:
I don't think there is much difference between mk II and mk III IQ. Most difference is at the extremities with centre sharpness very close.

Agreed. The 1.4x and 2x Mk III both provide sharper edges and corners, but they're all very good in the central region.

Pixel Perfect wrote:
... I would recommend the Kenko Pro 300 DGX. I have the DG version and it worked very well stacked with my Canon...

Same here. The Kenko Pro 300 DG is every bit as good as the Canon EF 1.4x Mk I and II Extenders, and usually it's a lot less expensive.

If you buy a Kenko and want to save a ton of money don't get it from the likes of B&H etc, go to ebay and buy it from one of the reputable HK or Taiwan powersellers.

I would bet you will get a fair amount of "drop off" with the 2x unless you are rock solid on a tripod or using high shutter speeds.

How about a bump for some more dialogue from guys that have used the Canon 2x II

capt don wrote:
How about a bump for some more dialogue from guys that have used the Canon 2x II

Just do a Topic Search on this forum for " 2x " and you will come up with all sorts of comments.

capt don wrote:
How about a bump for some more dialogue from guys that have used the Canon 2x II

Here's a few old images from the 1D II + 500 + 2x II wide open

I've used my 500/4 with a variety of Canon bodies and with a variety of 1.4x and 2x converters, and I've never been a big fan of using this lens with a 2x.

While I've had some very good results using the 500/4 and a 2x with relatively static subjects, my satisfaction with the results has diminished quickly if I'm trying to shoot moving subjects. Further, image quality degradation is significantly greater with a 2x than it is with a 1.4x. That image quality degradation doesn't show up to be as big when using a low pixel density camera, such as a 1D Mark II, but, I've found that the loss in image quality manifests itself to a much greater extent with a high pixel density camera like the 7D. With that higher pixel density, any image imperfections, such as those caused by even minor camera shake or subject movement, are magnified to a much greater extent than they would be with a low pixel density camera like the 1D Mark II. Thus, I'm less inclined to be happy with the results using a 2x with a 7D than I would be using it with an older camera with lower pixel density.

Additionally, using a 500/4 with a 2x on the 7D gives you the field of view of a 1600 mm lens on a full frame camera. I find that, with that field of view, I feel like I'm looking through a soda straw, and I have a much more difficult time picking up the subject initially and tracking any movement of the subject. Further, in any situation where a field of view that is that narrow might be appropriate, the distance between the camera and the subject is likely to be great enough that atmospheric imperfections are going to further degrade the image. Thus, I have no interest in even trying to shoot subjects at those distances.

With regard to the version II and version III extenders, I know that I am in the minority here, but I consider my purchase of the version III extenders to have been money not well spent. While I have no doubt that those who have done comparison testing have found (very minor) image quality differences, in real world usage, I have found not even the smallest level of difference that will show up in a print. To me, the only significant difference is a slightly beefed up mount on the version III extenders, and that improved mount might lead to better long term performance of the converter.

Les

x2

Further, image quality degradation is significantly greater with a 2x than it is with a 1.4x.

Although the Canon 2X degrades the image more than does the Canon 1.4X, the IQ with the 2X is more than satisfactory, as demonstrated by Pixel Perfect's images shown above.

atmospheric imperfections are going to further degrade the image.

As far as atmospheric disturbance is concerned, it will depend entirely on your shooting conditions, and the problem is not limited to those times you will want to use the 2X. I've encountered it often when using the 1.4X while shooting across water.

camera shake

If you pay attention to your technique (and have a good tripod), this should not be a problem.

Having said all that, I'm intrigued by the suggestions to try stacking 1.4X extenders in order to retain phase-based AF on the 7D. If that gives IQ roughly equivalent to the Canon 2X, it sounds like the preferred approach.

John

capt don wrote:
{snip}
Also i've been very happy with the 1.4 resolution, is there much of a drop off with the 2x. Thanks Capt Don

On the 7D and 500 f4 IS, captured detail on a per frame basis improves from a 1.4x II to a 2x II. To my taste, the IQ of a 7D + 500 + 2x II is still decent. AF via LV contrast detect is also more convenient than plain, old MF.



Oriental Honeybuzzard (Pernis ptilorhynchus philippensis)
Shooting Info - Canon 7D + EF 500 f4 IS + 2x TC II, 1000 mm, f/10, ISO 400, 1/250 sec, 475B/516 support, manual exposure in available light, uncropped full frame resized to 1500x1000.