Sigma 85 1.4, hunts a lot, and rumbles a lot !

[slick2000]

Just took this new lens, but I'm thinking I got a lemon.
The AF should be very fast, ok, maybe it is, but it hunts, rapidly, MANY times before locking the subject, the curious thing is that the lens rumbles, literally, a lot, when hunting for the AF lock, shaking a bit the whole camera.

Did some test and at 1.7 and 2.0 it does NOT focus properly at the subject, from the LCD the subject looks correctly in focus, but checking the picture shows way off focus

I've uploaded some bad and a couple good

http://img839.imageshack.us/g/dsc7356o.jpg/

the "best" example is this one:


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[Domdog31]

Looks like your using a D90 which unfortunately does not have an AF Fine tune functionality so if you need to dial in a value to fix a misalignment you can't...

In terms of AF there are way more variables to consider than just the lens - (AF-S, AF-C? Auto-Area, Single Point, Dynamic?) Focusing through Liveview or the VF? Are you in adequate light?

I find most errors are user errors but thats not to say you have a lens that doesnt work well with your camera.

Too often we think the lens is the culprit when in fact its a combination of the two (body and lens) in fact this lens you have may be perfect on my D3s...

So a few considerations:

1. Exchange the lens for a new one (or better yet try multiple ones on the camera at the store if you can)

2. Sell the D90 and buy a camera that has AF fine tune (D300, D7000 etc...)

3. Send the body and camera to Sigma to calibrate for you...(your best option IMO)

Good Luck!

 

[slick2000]

unfortunately the reseller doesn't have any other Sigma 85 to test

I test lenses on a regular basis (a couple every week), and for the very first time I found a lens that is "inconsistent", that hunts a lot for locking the subject, and focusing is a gamble.
The visibile pic in my post had the focus at center point.

BTW, AFS, single point (wide), viewfinder (the D90 LV focus is a joke...), the strange thing is that at 1.4 looks easier to manage that at smaller apertures.
I need a feedback from a Siggy user regarding the "rumble rumble, shake shake", during focusing

 

[HenryVIII]

Could you get a video of your lens trying to focus? That may help other Sigma 85 users to see if they have similar issues.

 

[daveja]

Sounds like a defective lens or camera. My Sigma 85 is quiet and accurate on my D700.

http://www.pbase.com/daveja/image/134795879/original

Subscribe to see EXIF info for this image (if available)

 

[ariel777]

I just tested mine on the D90 and have no problems. It locks instantly on the AF subject, and is silent. It's as sharp, if not sharper than, any other lens that I have (other than perhaps the 150 and 300). It seems that you may have a copy that is defective.

 

[mematsu]

I need a feedback from a Siggy user regarding the "rumble rumble, shake shake", during focusing

Sigma's HSM is not as smooth as Nikon's AF-S but "rumble rumble, shake shake" sounds a bit excessive.

 

[JR Magat]

I had this experience with a copy of the Sigma 50 and 85... i described it as the lens seemed to "ram" into focus... or like you stated, rumbles

I sent the Sigma 50 in for service and it was fixed & returned back in about 3 weeks. It performed better. The Sigma 85 was returned.

So, i would suggest you either send it into Sigma for calibration (under warranty) or return it and buy another... the Sig85 looks so good (with a good copy) that I picked up another one to compare against my 85D. This time I bought it used so I know what i'm getting - seller claims "no issues"

 

[static808]

i've had this issue with a previous copy of the sigma 50. even with center point, the af was very jittery, and in combination with the wicked torque of sigma's HSM, it led to a shaky and somewhat violent AF experience.:tongue: returned it and the replacement was perfect out of the box. my previous copy of the sigma 85 performed perfectly as well.

jr magat describes the HSM focusing quite well, as it "rams" into focus. it is faster than nikon's equivalent SWM (for the 50 and 85), but nikon's runs smoother and has much more subtlety to it. FWIW, this characteristic doesnt affect IQ, and the sigma 50 and 85 are both stellar optically.

 

[slick2000]

well, on next monday the reseller will have another copy, so I'll try the new one,
tomorrow I'll test a Nikon 85 1.4D .... too bad the Nikon is € 200 more ...

 

[avyoung]

I think you just have to get a different copy of the Siggy. Perhaps send camera/lens to sigma for calibration.

 

[slick2000]

ok got the Sigma replacement, this copy is PRRRRfect



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[TstarJ]

Wow very nice Nicola. Mine autofocuses correctly on the D700 and is very quite.

I'm glad you found a perfect copy it'll be a joy to use.

Jack