Canon issues firmware update to fix front-focusing issues for RF 70–200mm F2.8 lenses

There are only 2 cameras that can take this lens. If they are struggling now, boy are they in for a big surprise when they have 10 cameras to test.

There really is no excuse since this is at minimum focus distance fully extended.

Anyone with a telephoto knows this is the first thing they try to shoot, since they are probably mounting the lens indoors and you are buying a telephoto for its reach.

It was replicated by regular uses and not a lens specialists which means Canon dropped the ball.

@ Chriswy - are you another person apologizing for Canon? Please don't blame marketing on this now.

Straight from Canon's own website.

https://www.usa.canon.com/internet/portal/us/home/products/details/lenses/ef/telephoto-zoom/rf-70-200mm-f2-8-l-is-usm

Minimum Focusing Distance of 2.3 ft./0.7m

With a minimum focusing distance of 2.3 ft./0.7m, and a maximum magnification of .23x, the RF 70-200mm F2.8 L IS USM lens excels in a variety of shooting situations. Whether closing in on the details of an object or capturing an unforgettable moment during a wedding ceremony, the RF 70-200mm F2.8 L IS USM lens provides incredible versatility with just the turn of the zoom ring.

Yeah you are probably right.

Thank you for not replying by banging on about white paint and thermal efficiency and all that hokum. I don't think many of us are shooting in death valley at high noon anytime soon, so a black lens is just fine. Anything else is attention seeking. ;)

I don't mind the white lens body so much. With the black bands it makes for a pretty cool stripped effect IMO. The white hood, on the other hand, now that is one obnoxiously ugly and horribly conspicuous lump of a thing. First thing I would do if I were to buy this lens would be to look for a more discreet alternative.

I could care less what color it is. A big lens is a big lens and people will still look regardless of the color of the lens.

Good in the snow though...🤣🤣

How many images were lost? The focus error was seemingly small and probably was not seen but only the most discriminating.
I am not trivializing the issue but suggesting perspective.
No one died.

So.... QC expert?

Compared to the others canon has way better QC. People noticed an issue, reported it and they promised an update and it is out in 2 weeks? I would say that this is small. It was a software thing, not hardware. Most QC is hardware related. QC is also not perfect, they won't necessarily test every single lens for every single situation. So I have a feeling that close focus test is not something they do extensively let alone for every lens. So unless every lens shows this issue it is easily and understandably missed.

As for shots missed. I think the majority of people didn't by this lens to shoot predominantly close focus subjects.

Who is that?
There are many professional lenses which extend externally.

Professionals aren't concerned about dirt ingestion. These types of discussions are typically with enthusiast amateurs or internet bloggers.

Considering dirt, let me tell you some experience. I have the old 100-400 push pull zoom which has less dust inside than my 85mm f/1.8 despite having used the tele lens way more often. The difference is, the old 100-400 has sealings while the prime lens doesn't have. The 85mm also has a few quite large particles inside of which I think how the hell did they get in there. So extending designs doesn't mean it will certainly attract dust inside however I like internal zooming more because the length will always be the same which comes handy if you take photos through glass (zoos, car windows or any other window)

Yes. This is why you should only but Sony products. I learned that by watching YouTube.

Roger Cicala did a teardown of this extremely well-made lens, and on the dust topic said, "let’s get the extending barrel discussion out of the way. Some of you HATE extending barrel lenses. That’s cool; don’t get one. Some of you like to call them dust pumps. That’s cool, too, although it’s incorrect. (We take care of over 20,000 lenses. The most common ‘dusters’ among current lenses all happen to be primes that don’t zoom at all.)....And a new thing we hadn’t seen before. The ports under the filter ring are covered with a breathable filter. This would let air pass through as needed but would filter out dust particles. Nicely done.....Will it prevent the lens from getting dust inside? Of course not; every lens gets dust inside. But it’s helpful...."

My takeaway from that is that there is no reason to avoid this lens due to dust ingestion, unless you are simply biased and make decisions based on false premises.

Yes, and Roger Cicala is someone who definately has experience and knowledge. More than any average youtuber who thinks that likes are worth more than IQ.

Who on earth is JCristina??????

<someone who posts on the internet> said something critical about <product of a brand I do not like>

So, guilty as charged: who needs evidence or rational argument any more?

@dlb41 Maybe read the comments on that video. Many people are correcting him.

There is a lensrentals article where they explain that for the most part primes then to have more dust in them than zooms.

So the argument of dirt ingestion because a lens telescopes is something that we intuitively feel is worse than a non telescoping lens, but the statistics don't back that up.

Anyway... don't take my word for it.
https://www.lensrentals.com/blog/2011/08/the-apocalypse-of-lens-dust/

I'm sorry but it reminds me of Ken Rockbuster argument:

https://www.lensrentals.com/blog/2012/03/hammerforum-com/

@fmian

I know... think it would be troubling though funny if there really was a forum for hammers where people talked like this.

It's a firmware UPDATE

A firmware update to fix an issue.

Its a ”update of a phenomen” 😀

@blackcoffee17: and I guess you never developed a product.

I developed product and software too. Not product with firmware. But I know that software without bugs does not exists and there are cases when the best testing will not reveal some issues because they only manifest if very specific situations.

The only problem in this case is, that this very "phenomen" can be discovered at a test what I perform each time I buy a lens. Nothing scientific, just taking some photos near and far and checking if focus is ok.
So Canon either
- known, that this will happen, but they underestimated the variance and the amunt of possible front focus
- skipped testing production samples completely

You choose which is better...

This "issue" is really easy to detect and should be evident even during spezification of the lens.
Of course nothing is perfect and I don't think there was a lot of harm done ;-). But the leading lens manufacturer not doing basic testing of one of their top lenses ... that's a shame.

Sony would "fix" this with a new lens or body instead of firmware...

I'm pretty sure Sony would fix this right away too; No need to start a flame war here.

Well, Sony "fixed" the 24 70 GM focus shift issue by forcing every Sony camera body to focus stopped down, making focus accuracy on Sony cameras taking a huge dump when focusing stop down in low light.

@GrapeJam: It's not just Sony thing, in AF-S mode all cameras open for focusing, and then stop it down to take the shot. If the lens has focus shift, that can be a problem when using AF stopped down, on any camera. In AF-C mode the camera won't stop down though, which I use almost always. For studio work with still subjects you should use MF anyway.
https://www.lensrentals.com/blog/2010/10/how-to-shoot-with-wide-aperture-lenses/ Scroll down to "Focus Shift".

"In AF-C mode the camera won't stop down though, which I use almost always"

My A7III certainly stopped down in AF C.

Sorry, I might not have expressed it right... what I meant, is that in AF-C, the camera will focus at the aperture setting you chose, down to f/8. I realise though that it might depend on the camera model as well as on the lens. However, this being the case, it should eliminate the issue of focus shift, since it will focus at the aperture you shoot.

It also makes focus accuracy taking a dump and focus hunting in low light wgen you stop down because the sensor's starved of light.

Then you can either shoot in AF-S or not stop down... There is not much reason for stopping down in low light anyway. ;-)

Except when you use flash or strobes, which alot of people do in wedding.

Imagine having to stop down to get both the bride and groom in focus while they were walking toward the stage in pitch black hall, or when they are on the dance floor.

Well in such situations, if you absolutely need to stop down in low light, I would use AF-S and just hit the shutter button, which will cause it to focus and shoot almost instantly. Given the increased DOF, it would proabably still be in focus even if the subject moved slightly between hitting the shutter and the actual exposure.

However, in the beginning you were complaining about a "24 70 GM focus shift issue", which seems to be unrelated to what you're talking about now. In fact, focus shift could only be a concern if a camera focuses wide open and then stops the lens down... about which you are complaining now that your Sony doesn't do in APS-C mode.

"However, in the beginning you were complaining about a "24 70 GM focus shift issue", which s seems to be unrelated to what you're talking about now"

The 24 70 GM focus shift issue was what caused Sony to make all Sony cameras focus stopped down, so yes, even now the 24 70 GM also focus stopped down.

Well, the focus error always occurred you just noticed it less when stopped down. Which isn't really an acceptable solution otherwise you could just shoot with a less sharp lens to begin with

I think "eyes in focus" or "ring shot" still want more DoF with a lens set to 200mm, as the blur will come in quickly...

You cant be trying to defend a focusing defect on a lens are you Dr Jon?

A lens that doesnt focus properly is garbage. Its like buying a toaster that doesnt toast bread on one side.

Quality control is horrid enough as it is. I have never gotten a good copy first try. Always have to return it twice or 4 times before getting one that focuses mostly properly and is not de-centered.

Panther fan: “Well, the focus error always occurred you just noticed it less when stopped down.”

Not sure about that. I suspect the lens has a load of spherical aberration at 200 mm and high magnification. At infinity it’s likely fine.

Spherical aberration used to be ‘over-corrected’ at infinity, with the expectation the lens would be stopped down there, so that at closer distances where the lens was used wide open the under-correction was not as bad.

Since testers now scrutinise the frame wide open at infinity, that approach has its limits in today’s market. Perhaps designers use less over-correction at infinity in response, so there’s worse under-correction at close distances. Bokeh considerations also apply.

Spherical aberration causes a frontward focus shift if the lens opens up for full-aperture shots. I wish an owner would confirm if the RF stops down in bright light for live view and focusing. Look closely. Please don’t say it doesn’t happen just because you haven’t noticed.

There are still some things that can go wrong.

Focus shift during stop down which you didn't calculate for
Not making a focus confirmation wiggle
Simply calculating the wrong focus adjustment your lens needs to make

Seems like Canon did the last one. The 70-200 RF is also Canons first lens with two focus groups. So it's new territory for them and things like this can happen.

Not if the lens focuses with two seperate groups and two seperate af motors (which have to work perfectly together, a slight error in calculation could cause shifts which need to be adjusted) or if you have focus shift from the aperture (as example, the sigma 500 f/4 is known for a stronger shift when stopped down).

@Samuel Dilworth
But your explanation doesn't make sense since the camera misses focus at the same aperture it uses for focus.

It is a combination of "not doing final focus confirmation" and just calculating the wrong distance both elements need to be moved

The two focus groups are controlled by the same motor and mechanism.