Problem focusing with Sigma Lenses w. LA-EA3 on A7R ii

[kenwind86]

I 've just received my LA-EA3 lens adaptor and tested my long waited Sigma A mount lenses but I 've been having trouble with the focusing.

 

Sigma 35mm f1.4 Art works perfectly with both phase detection mode and contrast AF mode.

 

Sigma 50mm f1.4 Art cannot focus at all, it jumps between closest focal point and 4 feet.

 

Sigma 70-200mm f2.8 DG seems to be able to set a focal point but is out of focus.

 

Does anyone has any of the problems? What would be the problem? The lenses or the camera?

 

Would a firmware update on the camera or the lens fix those issues?

 

Please help!~

[Wesley]

I 've just received my LA-EA3 lens adaptor and tested my long waited Sigma A mount lenses but I 've been having trouble with the focusing.

 

Sigma 35mm f1.4 Art works perfectly with both phase detection mode and contrast AF mode.

 

Sigma 50mm f1.4 Art cannot focus at all, it jumps between closest focal point and 4 feet.

 

Sigma 70-200mm f2.8 DG seems to be able to set a focal point but is out of focus.

 

Does anyone has any of the problems? What would be the problem? The lenses or the camera?

 

Would a firmware update on the camera or the lens fix those issues?

 

Please help!~

 

Your testing with the 35mm and 50mm Art is inline with what I've read. The previous 50mm DG works. Cannot comment on the 70-200.

 

Some lenses just work well, some don't.

[kenwind86]

Should have done more research before getting the lenses. I had Sigma lens on my Canon before and never had to deal with this kind of problems. Should have bought Sigma with Canon mount and get the Metabones instead.

 

Ended up getting the LA-EA4 to work on the 50mm and 80-200mm, though not as fast as LA-EA3 with the 35mm, at least it does the job and let me be able to use the lenses.

[ahshing]

Just tried

 

Sigma 50/1.4 HSM = works

Sigma 85/1.4 HSM = works

Sigma 35/1.4 Art = works

Sigma 50/1.4 Art = Not works

Sigma 70-200/2.8 OS HSM = works

[jackdevant]

I had exactly the same thing. Sigma 50 mm Art does not focus on A7rII, using mirror-less adapter.

 

Other lens tested worked very well:

 

24-70 mm f2.8 ZA

70-200 mm f 2.8 GII

300 mm f2.8 G

 

A-mount lens focused, but some advanced modes were disabled, like extended spot.

[alba63]

The topic isn't exactly fresh anymore, so do any of you have further experiences?

I have the A7r II, and plan to get a Sigma 85mm 1,4 as a portrait lens.  I have the choice to get an EF mount lens with my Metabones IV adapter, or the Sony a-mount lens with the EA3 adapter. My biggest concern is whether I have to expect front/ back- focus problems. I haven't yet understood whether this issue is SLR- typical, or also occurs on the PDAF- sensors in the a7 line.

 

If anybody has experiences with Sigma + A7 (II series) cameras, I'd be thankful for any useful info.

 

Bernie

[Wally The Confused]

I do not know if this helps or not, but, I have the A7 II and an old Minolta MD   85mm F 1.7.  ( 1973 )

Using a  metal tube adapter, and   turning the  top control, to  Aperture, then going into the menu & selecting  " Manual Focus "

Works very well, but  is, initially    fiddly.

Good Luck.

 

PS, I wanted to try the Tamron 15 - 30, on my A 7 II, but on checking, I found that  they were a really bad combination. so I forgot  about that.

[michelb]

The topic isn't exactly fresh anymore, so do any of you have further experiences?

I have the A7r II, and plan to get a Sigma 85mm 1,4 as a portrait lens.  I have the choice to get an EF mount lens with my Metabones IV adapter, or the Sony a-mount lens with the EA3 adapter. My biggest concern is whether I have to expect front/ back- focus problems. I haven't yet understood whether this issue is SLR- typical, or also occurs on the PDAF- sensors in the a7 line.

 

If anybody has experiences with Sigma + A7 (II series) cameras, I'd be thankful for any useful info.

 

Bernie

The Sony A-Mount 85mm F1.4 lens has no SSM so it won't AF with LA-EA3. The 85 F 2.8 will since it has a SAM motor but i wonder at what kind of speed.

 

I am hoping Sony will release a new model ( LA-EA 3.5 ???) that would lose the mirror and AF modules of the LA-EA4 but gain the AF motor to allow AF with screw-drive AF lenses.

 

All attempts with Sigma lenses will be hit and miss since Sigma uses reverse engineering to avoid paying Sony royalties on lens communications protocols. A sigma lens that works today may stop working after a camera FW update or new camera model. Eventually same could happen with your Metabones.

 

Front / Back focus issues should only happen with mirror equipped adapters or cameras since the AF sensor modules are actually hidden and separate from the imaging sensor of the cameras. LA-EA2 and LA-EA4 have the mirrors and the separate AF modules hidden

[MarkMitro]

I've recently bought a Sony A7 iii, also bought an LAEA3 so I can use my Sigma Art lenses. Got the same issue with the 50mm. Manual focus is great (obviously) but in auto focus mode, it's jumping back and forth. No solution to this yet?

 

It's awkward that the 35mm art lens is working flawlessly. 

 

thanks

[Dave Wilkins]

On 9/26/2015 at 2:15 PM, kenwind86 said:

Should have done more research before getting the lenses. I had Sigma lens on my Canon before and never had to deal with this kind of problems. Should have bought Sigma with Canon mount and get the Metabones instead.

 

Ended up getting the LA-EA4 to work on the 50mm and 80-200mm, though not as fast as LA-EA3 with the 35mm, at least it does the job and let me be able to use the lenses.

Usually you have the lenses from the A series first, so your comment is not very helpful

[m20003293]

I have issues with the combination of A7R-II, LA-EA3 and the following lenses:

SAL70-200G (F2.8 lens) and SAL70-400G (F5.6 lens)

These lenses will focus occasionally, but also stop focusing suddenly. De-attaching and re-attaching the LA-EA3 to the camera body resolves the problem, but it happens each 2 or 3 shots so making it useless. 

With the Sigma 50 F1.4DG this never happens, so I was thinking about bad electrical connections but clearly it is not always the case.

Sometimes I also have the same issues with my SAL1735Z and SAL2475Z lenses (1st not 2nd version Sony Zeiss with SSM).

Maybe the tension of such large lenses on such a small body causes the bad contacts. Anyway my camera and LA-EA3 are both brand new so I don't expect any problems in that area.

I retested everything with LA-EA4 and never experienced same issues here. But I don't like this, I was hoping to get rid of any front- and backfocusing and with LA-EA4 it's not solved.(The thing is.. the A7R -II has such an incredible resolution that front- back focus on a lens shows a different value depending on focal length. So instead of just one value you really want to insert a correction table depending on the focal length. Canon has such settings, it would really help Sony also included them - it's just software anyway)

Edited April 9, 2020 by m20003293
typo and added information