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

[arabicsnus]

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

[March411]

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

[ctitanic]

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.

[March411]

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

[ebiggs1]

Well said.😊 Gold star for you  today.

[kapalabhati]

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:

1. 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"
2. 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
3. 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! 📸

[March411]

@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!

[ebiggs1]

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

Yes it is absolutely a great lens.