Extender for Sigma 150-600 Sport w/Canon 7D2

Is there an extender that will function between the 7D2 and sigma 150-600...and how's the image quality. I don't mind being limited to a single AF point, and I realize there will be loss of f-stop.

Yup:

https://www.sigmaphoto​.com/teleconverter-tc-1401

Kenko pro 300 if you can even find one any more. I used that very often with the 7D2.

TeamSpeed wrote in post #19114911
Kenko pro 300 if you can even find one any more. I used that very often with the 7D2.

...and you used it between a Sigma 150-600 Sport lens and 7D2?

Lens firmware matters.

7D2 and 150-600 Sport with EF 1.4TCIII worked when the Sport was released.
Sigma then did firmware update and the EF 1.4TCIII no longer worked.
EF 1.4TCII worked before and after update.

No longer worked means you cannot take a photo, "lens communication error" or similar message is displayed.

This was my experience a few years ago. I don't know how many firmware updates have been released since.

Don't assume this was intentional action by Sigma. The 500 f4 Sport did not work with EF1.4TCIII on release but after later firmware update it did. EF1.4TCII worked before and after. Again, further updates have been released.

I found it was not worthwhile to use 1.4TC on 150-600 Sport and 7D2.
It was worthwhile on 1D4 if you can tolerate the AF performance drop.
ie, with 1D4 and cooperative static subject the image quality was good. Otherwise better off cropping a bare lens shot.
7D2 image quality with 1.4TC was not worthwhile.

Larry Johnson wrote in post #19114881
Is there an extender that will function between the 7D2 and sigma 150-600...and how's the image quality. I don't mind being limited to a single AF point, and I realize there will be loss of f-stop.

f/9 AF is going to be very marginal on the 7D2, unless you use live view. It will only work well with bright light and good contrast, and simple depth structure, and will be slow.

If you use a non-reporting converter (or a taped one) AF will be faster, and more AF points may be available, but faster AF sometimes becomes AF that overshoots, and hunts back and forth, or "locks" at the wrong position. You also lose correct EXIF reporting; your files will have no indication of the actual focal length and f-number.

If mirror-less is in your future, the newer ones can AF combos that would be dead in the water on a DSLR. With my R5, it will AF my Sigma 100-400/5-6.3 accurately at 1120/18, and even somewhat quickly if the lens is almost in focus from the last shot (you can identify the subject in the viewfinder before it is in focus). If I tape the converter closest to the camera to hide it, it focuses faster and often hits target, but may jump off of focus more easily or shoot past it occasionally.

Choderboy wrote in post #19147895
Lens firmware matters.

7D2 and 150-600 Sport with EF 1.4TCIII worked when the Sport was released.
Sigma then did firmware update and the EF 1.4TCIII no longer worked.
EF 1.4TCII worked before and after update.

No longer worked means you cannot take a photo, "lens communication error" or similar message is displayed.

It's time for converters with a USB port, and multi-position switches for custom TC modes and simple non-reporting. You could enter your own hunt speeds, and max full drive speeds, optimized for your lens and AF system. It could have body-side TC pins to see a TC behind it, for correct EXIF info, if you want it. Any switch position could use a different firmware.

TCs are such an integral part of focal-length-limited photography, but somehow they don't get designed with flexibility in mind.

It is becoming more apparent to people using modern mirror-less cameras that much of the impression that that many people have had that "cropping is better than TCs" is more a result of poor AF than of additional optical problems with TCs. Perfectly focused optics with a TC (and with sufficient stability) give more subject detail, even with sub-perfect main optics and TCs that might reduce global contrast a tad, or have slight halos around fine details. You can hide most of that in post, if you need to, but you can't pull out real details that were never captured, because they happened inside of big pixels (and yes, I think that even 7D2 and even 90D pixels are large, for the best optics).

Larry Johnson wrote in post #19145546
...and you used it between a Sigma 150-600 Sport lens and 7D2?

I had the contemporary version but yes, on the 7D2 and 5D3. In good light, AF was snappy and locked on, and the results were quite good.

TeamSpeed wrote in post #19114911
Kenko pro 300 if you can even find one any more. I used that very often with the 7D2.

DG or DGX? The older DG has better compatibility with recent cameras, as the DGX (at least with the earliest firmware) crash cameras like the 7D2, 90D, and R5, in my experience.

The old ones back from around 2008 or so, I never saw good reviews on their newer ones so I stayed away. I sold them when I got my MKIII Canon TCs and wish I hadn't.

John Sheehy wrote in post #19147909
It's time for converters with a USB port, and multi-position switches for custom TC modes and simple non-reporting. You could enter your own hunt speeds, and max full drive speeds, optimized for your lens and AF system. It could have body-side TC pins to see a TC behind it, for correct EXIF info, if you want it. Any switch position could use a different firmware.

That may work if you know how to program proportional–integral–​derivative controllers (PID controllers or three-term controller) because you want the focus to move quickly with minimal overshoot. The parameters for this will vary with different lenses, so you would need different setting s for different lenses made by the same manufacturer. Lenses made by other manufacturers would have different settings for their lenses of a given focal length. As teleconverters (TC) are simply a fixed lens with some electronics to pass information (either analog or digital), there isn't much incentive for the TC vendors other than Canon to do all that. Canon has optimized their TCs to work with their lenses and cameras.

I have had my combos hunt a few times here and there, but hardly ever have had them overshoot the target and stop OOF. The hunting is more annoying because a lens like the 150-600 with a TC takes a bit of time to rack back and forth.

The 1.4x Kenko, Sigma lens, and 7D2 did pretty well together when I had these (I no longer have any of these now).

Choderboy wrote in post #19147895
Lens firmware matters.

7D2 and 150-600 Sport with EF 1.4TCIII worked when the Sport was released.
Sigma then did firmware update and the EF 1.4TCIII no longer worked.
EF 1.4TCII worked before and after update.

No longer worked means you cannot take a photo, "lens communication error" or similar message is displayed.

This was my experience a few years ago. I don't know how many firmware updates have been released since.

Don't assume this was intentional action by Sigma. The 500 f4 Sport did not work with EF1.4TCIII on release but after later firmware update it did. EF1.4TCII worked before and after. Again, further updates have been released.

I found it was not worthwhile to use 1.4TC on 150-600 Sport and 7D2.
It was worthwhile on 1D4 if you can tolerate the AF performance drop.
ie, with 1D4 and cooperative static subject the image quality was good. Otherwise better off cropping a bare lens shot.
7D2 image quality with 1.4TC was not worthwhile.

Thanks for all the replies and discussion. Are you referring to the canon converter when you mention EF 1.4TCII.
I own the canon 1.4 III converter and I'm well aware it doesn't work. I also just bought a kenko 1.4xpro300 and it also doesn't work; i.e. won't let me take a photo.
Maybe I should just get a pro body and even longer lens. Can't get closer to my subjects because of their in the water and boats aren't allowed.

Larry Johnson wrote in post #19150648
Thanks for all the replies and discussion. Are you referring to the canon converter when you mention EF 1.4TCII.
I own the canon 1.4 III converter and I'm well aware it doesn't work. I also just bought a kenko 1.4xpro300 and it also doesn't work; i.e. won't let me take a photo.
Maybe I should just get a pro body and even longer lens. Can't get closer to my subjects because of their in the water and boats aren't allowed.

Kenko "DGX" converters are designed to hijack the lens-body communication instead of just reporting themselves to the lens. They are magical on the older cameras that they are compatible with, like my 7D and 6D , but crash most recent cameras, like my 7D2, 90D, and R5. The older "DG" ones work by protocol, and are far more versatile, working with pretty much all lenses, with no protrusions in the front.

The DG TCs don't tell the lens to AF at a greater speed, though, with certain lenses and bodies as allowed when using a Canon vIII TC, and need to be taped (and lose their proper EXIF info) to allow faster AF speed. It would be nice to have a 3rd-party TC that didn't tell the AF to slow down, but still reported the correct f-number and focal length in the EXIF.

There are several kenko versions of their TC for Canon. Which specifically did you buy? Can you take a pic of the product or box it came in?