Is my Sigma 100-600 C Lens Faulty

Orias wrote in post #18464147
...
- I do have a UV filter on the front (as with most of my lenses), not for any other reason other than protection from scratches etc....

AF issues that come and go with different lighting conditions?
This is the dictionary definition of symptoms of a UV filter.

Glad to see you got it working for you. I love mine,. it's an amazing lens!

For me being able to set a custom focus limiter distance is hugely useful. At an airshow I can set the limiter to 100m and be sure that as I pan on a low flying aircraft it simply will not try to refocus on anything really close to the flight line that might get in the way. Having an older body with fewer AF options makes this even more important to me. So yes the custom options are pretty useful.

I am trained as an engineer and so realise that if you you want to have lenses with super accurate AF systems, that always work when shooting a silly small DoF's you have two choices. First you can pay through the nose for a system that is built to tolerances so high that no calibration will ever be necessary, at least for some, probably quite short, designed life cycle. This by the way is the option where the nifty fifty starts at around $1000 and prices go up from there. I actually doubt that this level of engineering would always work.

The second option is to build to a high enough standard of tolerance that 90% of your customers are unlikely to have any issues, even when mixing different combinations of lens and body. For the other 10%, although given the numbers of cameras Canon sells, it's probably really less than 1% that have issues, you can either simply charge them a fee to calibrate the lens to the specific body, since both the camera and lens are likely well inside the respective tolerances neither would be classed as a warranty repair individually. Or you can provide a system on the camera or lens to allow the user to do their own calibration at no additional cost to them.

Given that my personal circumstance mean that I can barely afford to buy even nice secondhand kit, option one would be a non starter. I would think that even the 1% would baulk at having to pay upwards of $1000 for a simple 50mm f/1.8 prime, and $10000 for the body. Just to ensure that the AF system would be exact every time on every body/lens combination possible. Having a system to take care of the very few times that there are actually tolerance combinations that produce visible problems makes much more sense for highly critical customers.

Alan

CheshireCat wrote in post #18463898
Unacceptable. It seems the lens is front-focusing by quite a bit.

As discussed in other threads, I am totally against the Sigma “have naive users spend more money for a dock product to fix lens production issues” mentality.
My money is perfectly working, so lenses must be perfectly working out of the box. Other users will disagree.

Different lens, but similar problem:
https://www.the-digital-picture.com …News-Post.aspx?News=14462
Note that if the lens is tilted or decentered, the dock is useless but Sigma will be happy to keep your money.

The dock does quite a bit more than a "fix for focus" device.

a) It does substantially more than just AFMA, because you get 16 points of adjustments, not 1 or 2.
b) It allows you to customize your lens to a number of different settings, IS switches, and others.
c) It allows for DIY firmware updates to the lens where Sigma often enhances AF or other features of lenses.

I had this $50 dock included in a lens purchase from a forum member, but I have used it a few times now on Sigma lenses. Very handy! I almost sold it, but am glad I kept it.

Some folks like to waste their time and money buying different bodies or lenses, or sending them in to the manufacturer to "fix" things, when it takes so little effort to just adjust things at home. It takes less time to do the adjustments than it does to repackage a lens for a return to a store, or to the manufacturer. I like AFMA too so I can use older lenses, or 3rd party lenses. I am one of those folks that dabble and change everything I buy, so these types of "under the cover" functions are right up my alley.

I have adjusted my Sigma a bit using the dock, since I want all focal lengths as sharp as possible, something not done with the Canon AFMA. It is a good (but heavy and large) lens! Pair it with an APS-C and have a blast.

IMAGE LINK: https://photos.smugmug​.com …/X2/potnh-X2.jpg&lb=1&s=A

IMAGE LINK: https://photos.smugmug​.com …/X2/potng-X2.jpg&lb=1&s=A

BigAl007 wrote in post #18471804
I am trained as an engineer and so realise that if you you want to have lenses with super accurate AF systems, that always work when shooting a silly small DoF's you have two choices. First you can pay through the nose for a system that is built to tolerances so high that no calibration will ever be necessary, at least for some, probably quite short, designed life cycle. This by the way is the option where the nifty fifty starts at around $1000 and prices go up from there. I actually doubt that this level of engineering would always work.

As an engineer, you know that just one counterexample is enough to disprove your theory.

I might be a lucky guy, but none of my lenses require AFMA... I think my luck got boosted since when Canon perfectly calibrated my camera body and fixed 2 of my lenses which were defective out of the box and could not focus properly (they were a 135L and a 70-200/2.8L IS, both expensive pro lenses).

TeamSpeed wrote in post #18471815
The dock does quite a bit more than a "fix for focus" device.

a) It does substantially more than just AFMA, because you get 16 points of adjustments, not 1 or 2.
b) It allows you to customize your lens to a number of different settings, IS switches, and others.
c) It allows for DIY firmware updates to the lens where Sigma often enhances AF or other features of lenses.

a) “fix for focus” in 16 different points.
c) “fix for focus” and other malfunctions when a new camera body comes out and the lens does not work properly on it.

CheshireCat wrote in post #18471896
a) “fix for focus” in 16 different points.
c) “fix for focus” and other malfunctions when a new camera body comes out and the lens does not work properly on it.

Nope, c) is not a fix for focus (at least not exclusively). Sigma just enhanced the AF speed for example, in a firmware update. That wasn't a fix, it was an enhancement on an otherwise fine lens. They have addressed some OS issues as well, sound of the diaphragms, compatibility with TCs, etc.

No different than when Canon issues firmware to enhance functions (which has happened only 2 times) or fix things (countless times). How can one be fine with Canon including a "usb dock" inside their cameras to fix issues later, or enhance things, but then belittle Sigma when theirs is a separate dock that costs as much as Canon battery?

In any case, I am very happy that Sigma has provided a way to put a technician into my living room than having to send something off to Canon, which is what we STILL have to do when their lenses, bodies and TC don't work well together.

Now that I've got around to processing my way through some of the images I got with the Sigma 150-600 C, I am pretty happy. Here are a few examples:

IMAGE LINK: https://photos.smugmug​.com …L/IMG_7037-L.jpg&lb=1&s=A

IMAGE LINK: https://photos.smugmug​.com …L/IMG_6055-L.jpg&lb=1&s=A

IMAGE LINK: https://photos.smugmug​.com …L/IMG_6956-L.jpg&lb=1&s=A

IMAGE LINK: https://photos.smugmug​.com …/IMG_7060-XL.jpg&lb=1&s=A

IMAGE LINK: https://photos.smugmug​.com …/IMG_6220-XL.jpg&lb=1&s=A

TeamSpeed wrote in post #18471815
The dock does quite a bit more than a "fix for focus" device.

Some folks like to waste their time and money buying different bodies or lenses, or sending them in to the manufacturer to "fix" things, when it takes so little effort to just adjust things at home. It takes less time to do the adjustments than it does to repackage a lens for a return to a store, or to the manufacturer.

I might add, that the shipping and insurance for about two trips or two lenses about pays for the dock (currently $59! The only downside I encountered is does require Windows 7 or later (as best I recall).

"TeamSpeed", I love the images, especially the turtle!

CheshireCat wrote in post #18471892
As an engineer, you know that just one counterexample is enough to disprove your theory.

Actually, as a Six Sigma engineer, one counterexample would be considered a significant outlier and hence thrown away.