Sigma Video on their lenses adapted to the RF mount

[Tronhard]

Anyone following this site for any length of time will be aware of the controversy among some about the performance of Sigma lenses, and in particular the 150-600 Contemporary, working (or not) on the R-series bodies.

This has led to calls for Canon to modify their cameras to accommodate the perceived issues with third-party lenses.  As I have had to respond ad nauseam, no OEM camera maker takes any responsibility for 3rd party equipment attached to their bodies - be it Nikon, Canon or any other, whether it be lenses or flashes.

Well, about six months ago, SIGMA released the following video on using their current EF lenses on the R-series bodies. 

What is significant to me is their strong statement that their lenses perform well on the R-series  bodies - so obviously they see no issue to be fixed.  While I have faith that Sigma and Tamron are working on RF native lenses and will hopefully be able to release them in the foreseeable future, this video lends weight to the argument that it is more likely that it is how the cameras are set up, or operated. 

I observe that the bodies I have seen most people claim flawless operation are the full-frame bodies, for which the Sigma lenses were designed. Most issues seemed to happen with the APS-C R7 tracking system, which has also had issues reported with Canon EF legacy glass and even RF glass, so I wonder if the focusing system of that unit is worthy of consideration as a factor?  I don't have one so I am only speculating.

Another variable might be the firmware version of the Sigma lenses and their customization settings. There may also be issues with technique - using a tripod vs hand-held.  Finally (tongue in cheek) I observe that that presenter from Sigma is shooting gannets, where I have taken a lot of my shots of the same moving birds without any issue, so maybe someone will suggest that it's all about the subject! 🙂

[ctitanic]

Got it, Sony a7r III had something like that. I hate it.

[Waddizzle]

Great post!

I have also noticed AF performance issues when I used the 150-600 “C” with my 7D2.  I’ve noticed similar issues with my son’s 80D.  The images are a little soft, and tracking is often hit or miss.  I can not think of any logical reason why sensor size should make a difference.  But observations suggest that it can make a big difference.

I have not experienced either issue with full frame sensors, including the APS-H 1D Mark IV.  The 6D2 has the same AF system as the 80D.  The [angle] of view through the AF points on the 80D and the 6D2 are arguably identical.  Yet, the 6D2 captures tack sharp images, as well as my 6D.

[Tronhard]

While I am very pleased that Sigma released the video, what would be very helpful is if they gave a reference to a dive into the settings they used to get results and a strong statement about the rigorous methodology they used to back up their statements.  I truly appreciate the strength of the statement from Sigma, but if the idea is to get people shooting reliably with the Sigma lenses and protect both their own and Canon's good names, it deserves a more technical explanation.

[Waddizzle]

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@Tronhard wrote:

While I am very pleased that Sigma released the video, what would be very helpful is if they gave a reference to a dive into the settings they used to get results and a strong statement about the rigorous methodology they used to back up their statements.  I truly appreciate the strength of the statement from Sigma, but if the idea is to get people shooting reliably with the Sigma lenses and protect both their own and Canon's good names, it deserves a more technical explanation.

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I think the video is a crime against the truth.  There are real issues with Sigma lenses and Canon camera bodies.  They’re not new.  Sigma discontinued their “APO” lenses for good reason.

The Sigma OS and the Canon AF systems tend to get into a tug-of-war under the right conditions.  I had the 150-500mm APO.  It was a great lens until you started tracking a moving subject.  You would get a loud THUNK out of the lens.  The subject would roll upward out of view, like an old TV set, and everything would go blurry and OOF.  I finally figured out the cure.  I would leave OS turned off.  

I sold it and bought the 150-600 “C”.  It could use the Sigma Dock.  The THUNK issue was cured.  But focus seemed slower.  Making AFMA adjustments revealed the AF motors tended to over/under shoot the mark.  This last led to frequent AF hunting, especially when OS was turned on.  The fix was simple.  Leave OS turned off.

Sigma released a major firmware update to the AF in 2017(?).  They claimed to fixed the hunting, the under/over shoot issue, and increased AF speed by 40%.  I’m not going to question their claims.  

One firmware download later, and I had a different lens.  The lens focused much faster, and seemed to always nail focus.  This was also about when Sigma launched their Global series of lenses, which could also use the Sigma Dock.

But, the Sigma Global series had their own brand new set of issues when used with Canon DSLR bodies.  You could get these large, grey concentric rings in your images.  This problem was caused by a Noise Reduction setting in the camera, which Sigma fixed with a firmware update to all of their lenses compatible with the Sigma Dock.

Introduce the EOS 90D, R, and RP and the concentric ring issue returned.  These bodies had improved DPAF sensors, although Canon did not advertise them as being a next generation in DPAF sensor technology.  Once again a lens firmware update was released to fix the issue.

Some users of Canon MILC bodies seem to have discovered “focus pulsing”.  It looks like a high speed version of the focus hunting that I have seen in Sigma lenses in the past.  Adjust your settings and it goes away.

[Tronhard]

To me the setup of the lenses is critical.  I found no issues on my own lenses when using the R5, R6 and R6II units - apart from the rare occasion when it could not find ANY focus, but that was essentially because I was shooting through screening objects, like trees - so I don't think that is a fair criticism for me to make.

The most issues seem to be with the R7, which has a very high pixel density at 32MP in an APS-C sensor, so that is equivalent to the pixel density of an 81MP FF sensor, which is pretty massive.  The R7 used a dumbed-down version of the R3 sensor, which is 23MP FF, so there could well be issues to do with that.  Finally, as we seem to agree, how the focus is configured and used is going to have a major impact on the success.  The  videos I saw seemed to indicate that the Sigma 150-600c was on a tripod with OIS active.  I shoot hand-held with OIS and have no issues, so I wonder if that is significant.

[Waddizzle]

Trevor,

I am surprised and not surprised to hear the R7 seems to have issues with the Sigma 150-600mm.  As I noted earlier, my 7D2 could not perform as well with the lens as my full frame bodies, or even the APS-H 1D4.  The 7D2 was fine for One Shot AF, but not as stellar when it came to tracking in AI Servo mode.  Turing off the Sigma OS seemed to make the biggest improvement, which is true for both FF and APS-C bodies.

I am not saying APS-C bodies and the Sigma 150-600mm don’t play well together.  They just did play as well together as with my full frame bodies, 6D, 6D2, and now the R6 Mark II.  The latter is a great body with all my Canon L glass, especially the EF 135mm f/2 USM.