Severe Inconsistent Focusing Problem

[jameszhan]

I bought this lens with great excitement because the samples I have seen are fantastic, and most of the reviews I saw were highly positive.

But too bad it wasn't able to focus properly on my Canon 80D.

Because you say "get the USB dock," let me tell you that I did, and it simply could not solve the problem because the focusing issues are inconsistent. For example, at 50mm, one shot is back focused, and the next shot is front focused.

Returning this lens is a huge sorrow to me because the build quality is insane, and also the sharpness is insane (when I got it to focus). Just hope Sigma will make sure their lenses are better calibrated in the future.

 

[Darek_bab]

Hi Jameszhan,

I have a similar issues with my SIGMA 150-600 C. I am going back and forth with calibration process using USB dock. This is the third time where I am recalibrating my focus. When I'm done with calibration and go out to take shots I'm getting different results. Pictures are out of focus and or blurry. I'm wonder if it is me? The way i handle this lense? Even when I try taking pictures with 1/2000 secs I get pictures out of focus. I just can't figure it out.

It's not just you. You can't use the dock to fix all the focusing problems. You can only fix consistent focusing problems, such as all photos are front focused or all photos are back focused. If the lens sometimes back focuses and sometimes front focuses, you either have to send it to Sigma's service center to get it calibrate or get another copy to test out. I heard sample variation is pretty drastic with Sigma.

Also what camera body are you using? Newer camera bodies tend to have more problems with lenses that came out before the bodies did.

--
-_- is the face I make when people assume I'm a newbie because I have an APS-C camera.
Photography is my art, my craft. View my works in my gallery!

I have D7100 (Nikon). I was so frustrated to the point where I'm ready to sell this boy. I'm not big of a fan to use third party lenses, just because possibilities of not to be full compatible wit the bodies. The only option I have, if going Nikon, is 200-500mm for about $1400, it's a big difference.

 

[crazygold]

If I told you it's the body and not the lens would you bother to believe that?
On my D500 it's totally constant, on my 7100 it wasn't,others have said the 7100 AF is wonky(with any lense) and I am in agreement. I needed two bodies so I solved the issue with another 500,happy camper now.

 

[Darek_bab]

If I told you it's the body and not the lens would you bother to believe that?
On my D500 it's totally constant, on my 7100 it wasn't,others have said the 7100 AF is wonky(with any lense) and I am in agreement. I needed two bodies so I solved the issue with another 500,happy camper now.

You're right ... I had it in my mind ... but I wasn't allow it to accept it ...

Thanks for your thoughts ...

 

[DigitalDon59]

I experienced inconsistent focussing on my Canon 80D as well with the 45 point automatic selection AF. When I switched the setting to Large zone AF the results improved. This is a heavy lens to be carrying around all day. But it is slowly winning back my trust for photo shoots.

 

[jameszhan]

I experienced inconsistent focussing on my Canon 80D as well with the 45 point automatic selection AF. When I switched the setting to Large zone AF the results improved. This is a heavy lens to be carrying around all day. But it is slowly winning back my trust for photo shoots.

Good to hear you found a trick. Unfortunately I do a lot of portrait work so I need to use single AF point to nail focus on the eye.

--
-_- is the face I make when people assume I'm a newbie because I have an APS-C camera.
Photography is my art, my craft. View my works in my gallery!

 

[Darek_bab]

Just for the heck I removed UV filter and was shocked !!!! The quality of the pictures are much better along with the focusing, especially where the background is bright. I guess I got low end uv filter. I must paid around $65, but I guess I should go for $150.

So that 'bad boy' is staying with me and without the uv filter

Should of could of would of ....

D

 

[jameszhan]

Just for the heck I removed UV filter and was shocked !!!! The quality of the pictures are much better along with the focusing, especially where the background is bright. I guess I got low end uv filter. I must paid around $65, but I guess I should go for $150.

So that 'bad boy' is staying with me and without the uv filter

Should of could of would of ....

D

UV filter is quite useless other than protecting the front glass element, but you should always keep the lens hood on while shooting anyways, which gives you very adequate protection already. Even with an expensive filter, it will still degrade the image quality a little bit. As proven in this video:

 

[Darek_bab]

Just for the heck I removed UV filter and was shocked !!!! The quality of the pictures are much better along with the focusing, especially where the background is bright. I guess I got low end uv filter. I must paid around $65, but I guess I should go for $150.

So that 'bad boy' is staying with me and without the uv filter

Should of could of would of ....

D

UV filter is quite useless other than protecting the front glass element, but you should always keep the lens hood on while shooting anyways, which gives you very adequate protection already. Even with an expensive filter, it will still degrade the image quality a little bit. As proven in this video:

 

[Rajat Sarkar]

I had the same issue with sigma art 50 mm, f1.4... @ 1.5 m to infinite distance. what i noticed that the issue disappears when focusing, using live view. I then tried back button focusing and got far consistent focusing compare the "half pressed focusing". My guess - it is the sigma-canon software interface.. something that canon doesn't like to share with anyone on how the lens behave with camera body. while on back button focusing- exposure metering is separated from auto focus and its far more accurate. please try and give your feed back as I may be wrong.