Is my Sigma 100-600 C Lens Faulty

Hi guys,

I recently picked up a Sigma 100-600mm Contemporary lens in a pretty good deal. Seeing as I mostly photograph wildlife, I thought this would be a good option for me with double the reach of my existing lens. However, I have been trying in vain to get any sort of sharp image out of it on my 70D.
I have done a number of shots, and have been comparing to to my Canon 70-300L, and it doesn't even come close. I don't expect it to be better, but I have yet to see one usable shot .. it almost looks like all images have motion blur, even when tripod mounted at 1/1000s.

Here is what I see at 600mm, the aerial was about 50m away, the crane about 500m away. I also can't seem to get a sharp image using the viewfinder at 10x zoom. Something that I don't have an issue with on the Canon 70-300L

Is it possible that I got a dodgy unit?

Cheers

Turn IS off on the tripod maybe?

How do your hand held shots look?

Very best,

Hey there,

IS was off on the Tripod on all shots. At 1/1000s the shots look pretty much the same as with the tripod. Generally blurry and soft at 600mm. But I also tried at 500 and 300, and it's really not much better at all.
Here is a comparison of my Canon 70-300L @ 300mm vs. the Sigma 100-600 @ 300mm.

Both are Tripod mounted, F8, IS Off, Remote Shutter Realease. And in both cases I was focusing on the "0" on the ruler. As you can see, the Canon is much sharper and the Sigma just looks like motion blur when there was really no chance of that!

It's gotta be faulty then. It looks like the stabilization is on and actively correcting when it shouldn't be.

Very best,

Orias wrote in post #18463861
Hi guys,

I recently picked up a Sigma 100-600mm Contemporary lens in a pretty good deal.

Did you mean 150-600mm? Does this mean you picked it up used? If so, I wonder if the previous owner had used a dock and configured the lens to their specific body, and now you are attempting to use it with totally incorrect settings. That lens is generally known to be fairly sharp.

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.

Sorry, yes ... I did mean 150-600

And it's brand new, not 2nd hand, so there shouldn't be any issues with previous users' configurations. I actually already had the Sigma dock, so I know that all of the settings are default, and the Firmware is already updated to the most recent version.
It's looking more and more likely that I might have got a bad one

Thanks for the feedback so far, much appreciated.
Cheers

What do you have the second from the top switch set to?

The Sigma is a bit softer at 600mm, but especially on my 5D3, have been pretty impressed with its sharpness for the money (don't use long telephoto as much, so this lens was my top choice for its performance and weight). It works great out of the box, and seems compatible with my Canon bodies, so have never felt the need to get the Sigma dock. Is the distance limiter set to Full, and have you tried the two different Custom modes? The lens might have a default C1:speed, C2:accurate focus. If any of those settings make a difference, then that may reveal where the fault lies.

Jethr0 wrote in post #18463915
What do you have the second from the top switch set to?

I've got that set to FULL at the moment

In terms of the Custom Settings, right now they are both at the defaults out of the box, but I have that set to "OFF" for these tests. I just did a couple of shots on the dogs with a flash, handheld at 1/250. The first one was at 150mm and it's nice and sharp, so very happy with that. The 2nd one was at 600mm (but I was only about 3m away), and it's not too bad really. Not 100% on the focus, but salvageable in editing I think.

The lens definitely works better with the light from a flash, but it still doesn't explain why my crane/aerial shots are so fuzzy, when they were tripod mounted and there was enough light to get 1/1000s at F8. There's every chance that this could be user error, but I am pretty experienced with my Canon 70-300L, so maybe the Sigma is just a lot less forgiving

Orias wrote in post #18463900
Sorry, yes ... I did mean 150-600

And it's brand new, not 2nd hand, so there shouldn't be any issues with previous users' configurations. I actually already had the Sigma dock, so I know that all of the settings are default, and the Firmware is already updated to the most recent version.
It's looking more and more likely that I might have got a bad one

Since you have the dock, have you tweaked it for your specific camera body?

The problem with this is that it's very hard to see if it's front or back focusing. I don't have enough space to test it properly at 600mm (need about 30m or so), and when I do try and test it, pretty much the whole image appears as out of focus, like the original measuring stick one I posted above.

It seems like it's sharper around the 6 or 7 on the marker, which would seem to indicate that it's front focusing, but this is over a distance of 10m, so it's not really an accurate representation of the focus at 600mm where I need about 30m

Cheers

Maybe the crane was moving slightly in the wind?

Mine is sharp everywhere (IMO). Maybe exchange it?

Jethr0 wrote in post #18463962
Maybe the crane was moving slightly in the wind?

Definitely no wind out here today, I'm stuck out in Madrid and it's generally warm and mild today
I'll take the lens to the zoo tomorrow and see what happens. I'll get a few hundred shots with it at least, which will allow me to make a more informed decision.

I'll definitely take the Canon 70-300L too, so it's not a total waste of a day if the Sigma turns out to be faulty!

Orias wrote in post #18463966
Definitely no wind out here today, I'm stuck out in Madrid and it's generally warm and mild today
I'll take the lens to the zoo tomorrow and see what happens. I'll get a few hundred shots with it at least, which will allow me to make a more informed decision.

I'll definitely take the Canon 70-300L too, so it's not a total waste of a day if the Sigma turns out to be faulty!

Those of us who own the 70-300L are generally happy with it...and often compare future long lenses to the results we got with our 70-300L. I ended up getting a 100-400Lii... much more expensive than your Sigma... and I love it.

I still can't bring myself to sell the 70-300L. They aren't worth all that much these days, so I am keeping mine. I'm trying to get my wife to use it.

Anyway, sorry for thinking in font. I'd take your Sigma back. It sure looks like there is an issue with it. I guess you'll know better after your zoo trip.