Canon 90D with Sigma 70-200 overexposes all pictures taken through the viewfinder (live view ok!)

[philippelang]

Hi,

I'm the happy owner of a Canon 90D. I have just bought a Sigma 70-200 lense, and I noticed that all pictures taken through the viewfinder are overexposed, no matter what I do. If I want to have a picture that is close to reality, I have to compensate the exposition with -2/-3. Tha't's a lot, not just "fine-tuning". With the other lenses, I never had this problem: Sigma 18-35mm f1.8, Canon 50mm f1.8...

Is that Sigma firmware problem? 90D firmware problem?

[cn4873]

That sounds just like my issue. It had to be sent in for the update. I'm not sure what they do because it came back with the same FW. But they did inform me that they had a software fix for it. You can send them an email via the service ticket sight and they can let you know. Just look on the Sigma sight.

[mikeaff]

Just purchased a 90D to upgrade from my 80D and am having this exact problem with my Sigma 150-600 C.  Spoke with Sigma today and they verified everything that's already been posted about Sigma's non-user fix.  (you need to send the lens into Sigma for their in house update).  The guy I spoke with had some harsh things to say about the 90D metering, but he may just be talking Sigma's book.

The 90D seems to meter approximately the same as my 80D and 6Dii with Canon lenses, but I'm still seeing aboiut 1/2 stop overexposure with my 400mm 5.6. vs the other 2 bodies.  I'm getting about 2 stops overexpsure with the 90D and the Sigma.

I might just have a not too great copy of the 90D.

In any event, I've been really happy with the 80D, so the 90D is going back. (The Sigma 150-600 is my primary lens-birds and wildlife and I don't want to hassle with sending it in and hoping Sigma can fix my problem).  I'm just going to hang around a while longer with my 80D and 6DII, which both work perfectly with the Sigma lens, and then go mirrorless I guess.

[ebiggs1]

You might be too quick to condemn the 90D. The evaluative metering mode is the default for a 90D.   Evaluative means the camera uses certain algorithms to adjust the exposure.  This works well most of the time but it can be unpredictable with certain lenses and certain circumstances.  A BIF against a bright sky for instance. Try changing the metering mode.

[mikeaff]

Thanks. 

I did try different metering modes and had the same problem with the Sigma lens no matter which mode I used (1 to 2 stops overexposed).  I also had the same problem to a lesser degree with my Canon 400mm 5.6.  With that lens, I'm consistently about 1/2 tstop overexposed.

  Sigma also told me that this is not a problem that is consistent with every 90D. I really think it's largely my copy of the camera.

[philippelang]

Sigma is right: I have two 90D bodies, and only one of them has got this problem. I ended up sending the "faulty" body to Sigma with my 18-35 Art lens: they made some magic and now it works fine. I never remove that lens from this body, and use the other for all my other Sigma lenses.

[MoZoG]

Hi,

I had a same problem around in July of 2023. Sorry, english is not my mother language.

I bought my 90D in Aug 2022. 

I my case this issue happend with a Sigma 24-105 F4 art lens.

What I could figure out after a lot of discussion and service visit at in my local official Canon service is there firmware dependecies between the 90D fw and the Sigma objectives fw.

First part of the story is: I had to send the gear to the service after I purchased it, because there was a serious problem with its focus system (it was brand new). They repaired it. Before the service my 90D firmware version was 1.1.1 which can downloadable from the Canon official site. After the service it changed to 1.1.3 (small software upgrade, maybe the focus system problem solving, who knows the service communication is very poor)

I bought an used Sigma 24-105 F4 Art in June of 2023 and a Sigma USB dock. Before the purchase I checked the Sigma's site about the compatibility and there is a notice about the 90D, there is a firmware upgrade which released at 21.07.2020 version number Ver.2.01. and it solving this overexposure problem on the EOS 90D and EOS-1D X Mark III.

After the deaI I noticed the overexposured problem and I checked the Lens fw it was the lates (2.01). Important to know the Sigma Optimization pro software is only show the main and two sub version number of the firmware!

After a lot of service event and contacing Canon Hungary I could make a deal with the service to talk a service guy directly. Luckily the Canon and the Sigma service is the same company in Hungary. It is really a big luck.

He put the objective into his service docker (this is not the same like the consumer stuff what you can buy in the shops) and the Sigma service software said there is a new firmware for this lense where the main version (2.01) was the same, and there was 6 or 8 more digit in the sub version where 2 digit had a different number (means there is a  very little changing in the fiwmare. This firmware's release date 01/15/2023 (my birthday date:) )

Finally the problem solved.

Canon official answer : What you can experienced is a product limitation. (thanks)

My subjective conclusion: (yes, subjective because I know there is a lot of information which is hided from my eyes) even though there is apparently a contract between Canon and Sigma whereby Sigma can produce tools for the Canon EF bayonet, somehow the communication between the two companies regarding updates is not perfect.

Okay anybody could say: Buy Canon lens.

Why I buy Sigma lens instead of Canon lens first because the price, because in some cases (like focus calibration to the gear) is more versatile. 

So I can say the two company has almost the same responsibility to solve the problem.

Canon and Sigma could distribute more info about the firmwares and it's dependencies.

[Ralph57]

I solved the problem by selling my Canon 90D and will never buy another Sigma lens.

[shadowsports]

Greetings,

This is a 2 yr old thread and a well-documented issue.  Sigma released FW to address this behavior on several of their Art and Contemporary lenses.  Specifically, for the 90D and 1DX mkIII.  Example:

Ver.2.03

2020.08.20

• It has optimized the exposure during viewfinder shooting when used in combination with the EOS 90D and the EOS-1D X Mark III.
• It has fixed a rarely-occurring communication problem during Live View shooting when mounted on the EOS-1D X Mark III.

Its best to use Canon lenses with Canon body's.  (best results and user experience).  There is nothing wrong with the 90D or with Sigma glass.  The issue was identified and addressed 3 yrs ago.😀

[MoZoG]

Hello,

Yeah you are right, if you only read the Sigma site and don't exprerinece the same issue years later, it is definitely solved.

But how can happend after 2 year of this issue, I could faced the same problem, if all the firmware were up to date.

It happend because since 2020 there are two other firmware version released for this gear. V1.1.2, and V1.1.3. (you cannot dowload this from Canon site there is still the V1.1.1)

When the Sigma released the 2.01 fw for 24-105 F4 art the gears fw version was 1.1.1 (released 2019)

As I wrote seems there is several firmware sub version which cannot works well together.

I bought these combination because all the official sites said they are compatible and works well.

I read all the articles in this thread and others on the internet, and I see that some of people sent his stuff to the service and they do some magic.

Sorry but magic isn't be :D, I am from those people who wants to know things well and when I spent a lot of money for these things I want to know what I bought. Especially when I am planing a business with these things.

However I planned to buy other Canon and/or Sigma lens but now I have to recalculat my plans and seems my next body won't be the Canon. Becasue to figure out this issue I spent a really lot of time.

Because basically the Canon responsible to release the firmware changes and notes to his partners, in time I think. 

[MoZoG]

Yes,

This was one of the possible option in my mind, but actually I spent all my money for this to lift my business to the next level, and to sell the gear for lower price isn't an option actually.