topic Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01 in EOS DSLR & Mirrorless Cameras

EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

arabicsnus — Thu, 07 Nov 2024 16:24:46 GMT

Hello guys!

I upgraded my camera to the latest software (Canon R7 - FW 1.6).
Since then it does not recognise my lens (Sigma 120-300 2.8 sport).I used it the day before to shoot a football match. I have tried other lenses since then and it worked (Sigma 18-35 1.8, Sigma 50-100 1.8, Canon 18-55 kit lens). I have two very old cameras (Canon 400D, Canon 7D mark I) and I tried it on them too but the 120-300 lens worked perfectly. Has anyone experienced a similar phenomenon?

Best wishes, Gergő

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ctitanic — Wed, 06 Nov 2024 13:29:25 GMT

Err 01 is an error code that appears on Canon cameras when there is a communication issue between the camera and the lens. To fix this error, you can try cleaning the electrical contacts on the camera and lens with a clean, dry cloth.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ctitanic — Wed, 06 Nov 2024 13:32:36 GMT

Also, you are not the first one reporting issues between that lens and the R7.

https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/EOS-R7-won-t-recognize-Sigma-120-300mm-F2-8/td-p/509539

We concluded in that thread that the odds of finding a fix are minimal.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

March411 — Thu, 07 Nov 2024 13:33:04 GMT

Hey arabicsnus, welcome to the site.

If the lens worked prior to the firmware update you may want to go right to the source, Canon and save yourself some time and frustration. 800-385-2155 or 800-652-2666.

There was recently another thread regarding the same lens. A couple of us looked at a firmware update for the lens but did not see any documentation specific to R bodies in the update. Reaching out to Sigma might also be a good idea as they may be able to point you in the right direction. I have several Sigma lenses that customer support helped me resolve challenges when I moved to MILC. There is no guarantee, it is a older lens but worth making a couple calls to potentially save a good lens.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ebiggs1 — Thu, 07 Nov 2024 16:24:43 GMT

This is most likely not a camera issue but is a lens issue. Check to see if Sigma has a FW update for that lens. You will need the Sigma dock to do it.

"To fix this error, you can try cleaning the electrical contacts on the camera and lens with a clean, dry cloth."

Very unlikely as this rarely to never helps. The act of mounting and removing lenses generally is enough to keep both the lens and cameras contact working.

It wouldn't surprise me if Canon assisted or helped you with this but this isn't their problem. They don't make their cameras to work with off brand accessories or lenses. Sigma must make sure its lenses work with Canon cameras.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ctitanic — Fri, 08 Nov 2024 15:28:30 GMT

Sigma does not care about an old EF lens that was not designed to use R cameras and which market does not exist any more considering that Canon is not making any more EF cameras.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ebiggs1 — Fri, 08 Nov 2024 15:48:39 GMT

On the contrary on the Sigma web site.

SIGMA Global Vision (Art, Sports & Contemporary) lenses for Canon EF and Nikon F mounts are not only compatible with DSLR cameras, but mirrorless cameras as well, including Canon EOS R and Nikon Z bodies.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ctitanic — Fri, 08 Nov 2024 16:50:44 GMT

Check the compatibility list from Sigma. It list the R cameras but when you pick one of them and expand all you see are two lenses:

10-18mm F2.8 DC DN | Contemporary

18-50mm F2.8 DC DN | Contemporary

Those two are RF lenses soon to be released and if I do not mistaken they are RF-S lenses.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

March411 — Fri, 08 Nov 2024 17:00:02 GMT

Frank,

As I explained in the other thread regarding this lens Sigma has removed the EF compatibility chart when they reached an licensing agreement with Canon on the RF line.The results you received are exactly what you will see since the EF chart is no longer accessible.

When I spoke to tech and marketing at Sigma I attempted to explain that there are many people that still purchase and use EF on R bodies. They expressed that they would discuss it with the team and see if there was not a resolution. I think everyone understands that the current list is not a true reflection of compatibility with R bodies and the Sigma line.

Re: Canon R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ctitanic — Fri, 08 Nov 2024 20:09:54 GMT

And how that helps to the the question in this thread? Summarizing, Canon can't help with this issue and Sigma will not help either. This is the reality.

Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

March411 — Fri, 08 Nov 2024 20:36:54 GMT

That could not be further from the truth and if I used your logic I would have four Sigma lenses collecting dust.

In order to assist our membership in their attempts to resolve challenges, if we as a team cannot assist them we should suggest to them to contact Sigma and Canon support. You stating that neither can help is a guess at best since you haven't talked to either Sigma or Canon. I have, both groups make every effort to assist in resolving issues and Canon has clearly stated: “We will always seek to be supportive of our customers, and our staff may, on an ad-hoc basis, and purely on a case-by-case bases, and at their discretion, offer advice. It should be noted that Canon does not officially endorse or provide warranty to such advice that may be offered and any advice given does not reflect the official position of Canon as regards such advice.”

Seems like the polar opposite of can't/will not assist. Its a shame that we offer inaccurate information when there is a middle ground.

Canon Support: 800-385-2155 or 800-652-2666

Sigma Support: 15 Fleetwood Court, Ronkonkoma, NY 11779

Office: 9am-5pm, M-F ET

General: (631) 585-1144

Repairs: (631) 227-2036

Technical Support: (800) 896-6858

info@sigmaphoto.com

Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ctitanic — Fri, 08 Nov 2024 20:41:36 GMT

Yes, but if the issue is on Sigma side of the equation, the lens, there is nothing that Canon can do about it. And I have not talked to neither because I do not have that lens and the same problem but so far I have not seen anyone with that lens and camera coming here or any other forum claiming that they got a solution from either of the two companies.

Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

March411 — Fri, 08 Nov 2024 22:50:13 GMT

Well Frank I believe that the OP stated that it occurred with the recent Canon firmware, it's a fairly recent problem. It is concerning that because you have not heard of the problem or resolution that "We concluded in that thread that the odds of finding a fix are minimal." You concluded, others are suggesting that they contact the vendors since it appears that neither Sigma or Canon are aware of the issue. We have not not concluded, we are still curious and hopeful someone with this lens and problem will contact the suppliers.

I factually do not know if there is a fix, neither do you. Again, in stead of closing the door by saying it can't be resolved it may benefit everyone if we suggest someone contact either or both, then let us know if there is a resolution or no hope.

Difference is, some of us offer a possible path for solution for these members since it is a new challenge and don't simply close the door.

“The pessimist sees difficulty in every opportunity. The optimist sees opportunity in every difficulty.” —Winston Churchill

Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ebiggs1 — Sat, 09 Nov 2024 16:20:31 GMT

Well said.😊 Gold star for you today.

Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

kapalabhati — Fri, 06 Feb 2026 13:57:41 GMT

Hey there, i just made an account to post my experience over the last month.

I just solved this exact problem - my 120-300 f/2.8 Sports had the same issue (Err 01, no AF, no aperture, no IS on R7, but worked fine on R6 and RP).

The Good News: It's Fixable!

This is a known issue affecting certain older 120-300 Sports units, particularly those with pre-Toshiba CPU serial numbers. It's NOT a general R7 compatibility problem - it's a unit-specific communication error.

What I learned:

Sigma Japan personally tested the same combination and it worked fine
Multiple users worldwide have reported this (Germany, Korea, USA forums)
Sigma has a special firmware calibration that fixes it (NOT available via USB Dock)

What You Need To Do:

Contact Sigma support in your region with:
- Your lens serial number
- Symptom description (Err 01 on R7, works on other bodies)
- Mention this is a "known R7 communication issue affecting older production units"
Send it in for service:
- They'll apply the special firmware update
- Can't be done with USB Dock - requires service center equipment
- Takes about 1-2 weeks
Result:
- My lens came back working perfectly
- AF, aperture, IS - everything functions flawlessly now

Key Points:

✅This affects certain units (especially older serial numbers, there was a switch to Toshiba CPUs)
✅Sigma is aware and has the fix
✅Requires service center firmware calibration
✅After repair, works perfectly on R7

Don't give up on the lens - it's worth getting fixed. The 120-300 Sports is fantastic, especially on the R7 with the crop factor for wildlife!

Happy to answer questions about the process. Good luck! 📸

Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

March411 — Fri, 06 Feb 2026 13:43:16 GMT

@kapalabhati very much appreciated that you stopped by to post the solution. Hopefully @arabicsnus will check back to see how he or she can get his lens back into their rotation.

Personally, I will hold onto this so I can hopefully assist others in the future. Very cool of you to stop in just to assist!

Re: EOS R7 firmware 1.6 / Sigma 120-300 2.8 Sport / Err01

ebiggs1 — Fri, 06 Feb 2026 15:33:57 GMT

"The 120-300 Sports is fantastic, ..."

Yes it is absolutely a great lens.