# Teardown: Canon EF 400mm f/2.8L IS III



## Canon Rumors Guy (Dec 18, 2018)

> Lensrentals.com has done something I’ve never seen before, and that’s tearing down a working Canon super telephoto lens. In this case, it’s the brand new EF 400mm f/2.8L IS III, the world’s lightest 400mm f/2.8 lens.
> An interesting bit of information that Roger and Aaron did get from the teardown, is that the EF 400mm f/2.8L IS III uses the same focusing motor as the RF 50mm f/1.2L.
> This is a great teardown and not for the faint of gear heart.
> *From Lensrentals.com:*
> Some things we were already aware of or assuming. The lens elements are moved towards the mount side of the lens. There are lots of optical adjustments like all Canon lenses. Despite being far lighter, it’s still very solidly built with a very strong frame, tons of big screws holding everything together, and no weak joints that we can see. It’s what we expected; Canon’s been building super telephotos for a long...



Continue reading...


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## YuengLinger (Dec 19, 2018)

So great to see and learn so much from these tear-downs. Thank you!


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## Chaitanya (Dec 19, 2018)

That AF motor in RF 50mm f1.2 is looking impressive.


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## Ozarker (Dec 19, 2018)

Hmmmm.... so more than white paint. That won't make the cynics happy.


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## ethanz (Dec 19, 2018)

CanonFanBoy said:


> Hmmmm.... so more than white paint. That won't make the cynics happy.



The 70-200 was just white paint, I think we all knew this 400 was something altogether new.


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## ethanz (Dec 19, 2018)

"Also, this will give the Sony fanpeople a full week to bash the Canon lens, because that does seem to be what they live for." 

I love Roger's wit.


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## Ozarker (Dec 19, 2018)

ethanz said:


> The 70-200 was just white paint, I think we all knew this 400 was something altogether new.


Not really. One just has to go back to the Auguat 2016 thread (CR3) and read the "lipstick on a pig" comments and "EF's last gasp" and etc.


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## Jack Douglas (Dec 19, 2018)

**Sonyfanism:* The haunting fear that someone, somewhere, may be happy with other equipment. Roger Cicala, 2018


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## YuengLinger (Dec 19, 2018)

CanonFanBoy said:


> Not really. One just has to go back to the Auguat 2016 thread (CR3) and read the "lipstick on a pig" comments and "EF's last gasp" and etc.


If EF is depending on sales of $12,000 USD Big Whites modified to work better with RF, then EF is up in some pretty thin air.


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## LDS (Dec 19, 2018)

I just wonder that Canon builds those lenses in dust-controlled environments with technicians wearing gloves, masks and other protective apparel.... LensRentals chooses a very different approach... or do they change it when reassembling them?


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## Graphic.Artifacts (Dec 19, 2018)

I was kind of hoping Roger would find some evidence that these lenses could be factory "upgraded" to RF mount/electronics in the future. Sounds like the internal components share a lot of RF design but they will always require EF to RF adapters. I guess they'll be a separate RF version at some point.


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## dolina (Dec 20, 2018)

Sony introducing a 400 accelerated Canon's release of a new lens. Congratulations to all sports photogs who are scheduled to get this one. You will not be disappointed.


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## acekings (Dec 20, 2018)

how much it will cost? 400 accelerated Canon's I was waiting for this.


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## Del Paso (Dec 20, 2018)

Just waiting for the Sony 400mm disassembly, will it fall apart like their 70-200 F 2,8?


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## RogerCicala (Dec 20, 2018)

LDS said:


> I just wonder that Canon builds those lenses in dust-controlled environments with technicians wearing gloves, masks and other protective apparel.... LensRentals chooses a very different approach... or do they change it when reassembling them?



And yet, they all have dust in them when we get them.  Every lens does, it's just whether you have a strong enough light to see it. Also we aren't working in a large factory with machines milling things, etc. While not a clean room, we have pretty good dust scrubbers where we work. 

But yes, to some degree we change tactics during reassembly. We can be cavalier during disassembly: the pieces are all going to sit on a table for a while so they will all have dust on them when reassembly starts. The main reason that reassembly takes longer is every piece is cleaned as it's reinserted. It's not unusual, too, for Aaron to do a bit of disassembly during reassembly because he finds he missed a piece of dust or a smear on an element. 

As a TMI aside, this is part of the reason I can no longer do the disassemblies myself. As I've gotten old my close vision isn't good enough to find the small bits of dust that Aaron sees easily. Bifocal jokes may start now. 

Roger


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## padam (Dec 20, 2018)

Graphic.Artifacts said:


> I was kind of hoping Roger would find some evidence that these lenses could be factory "upgraded" to RF mount/electronics in the future. Sounds like the internal components share a lot of RF design but they will always require EF to RF adapters. I guess they'll be a separate RF version at some point.


When they do RF-mount superteles, they will be completely different lenses (possibly DO lenses to cut down weight - increase price - even further, different interface, control ring, different aperture mechanism, etc.) but that's another 7 years when it might become somewhat feasible for the agencies to switch cameras and lenses. But in the meantime they might also launch more compact ones that are more similar to what they had considered for the EF-mount in the past.


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## magarity (Dec 20, 2018)

I like these teardown articles but I have to wonder, doesn't Canon have a "factory trained repair tech" program? The LR people always seem to be having to guess how things come apart when it seems like they should be able to go learn how to do it from Canon.


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## Del Paso (Dec 20, 2018)

magarity said:


> I like these teardown articles but I have to wonder, doesn't Canon have a "factory trained repair tech" program? The LR people always seem to be having to guess how things come apart when it seems like they should be able to go learn how to do it from Canon.


What if Canon prefers to do the repairs themselves ($$$$$) ?
Lens Rental is , obviously, a rental, not an official repair facility. They must be busy enough with their own stuff, without being asked to repair customer's warranty damages.


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## Don Haines (Dec 20, 2018)

dolina said:


> Sony introducing a 400 accelerated Canon's release of a new lens. Congratulations to all sports photogs who are scheduled to get this one. You will not be disappointed.


It true! When Sony introduced their Lens, canon decided to grow the fluorite crystals faster


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## Graphic.Artifacts (Dec 20, 2018)

Read a post on another forum that Canon may be growing Sony's flourite crystals as well since they don't have internal capacity for flourite. Similar design, similar release date. Could be true. It always seems to me that these camera companies get along much better than their respective fans.


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## ethanz (Dec 20, 2018)

Graphic.Artifacts said:


> Read a post on another forum that Canon may be growing Sony's flourite crystals as well since they don't have internal capacity for flourite. Similar design, similar release date. Could be true. It always seems to me that these camera companies get along much better than their respective fans.



I get along with Nikonites and Sony (only know one) people just fine, as long as they don't take my ribbing them seriously


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## RogerCicala (Dec 24, 2018)

magarity said:


> I like these teardown articles but I have to wonder, doesn't Canon have a "factory trained repair tech" program? The LR people always seem to be having to guess how things come apart when it seems like they should be able to go learn how to do it from Canon.



They do, if you want to pay a lot of money (way into 6 figures), accept both outside repairs and warranty repairs, which we do not want to do, and sign complete nondisclosure agreements. So pay a fortune, invest another fortune to enter a tough business I don't want to be in, and never write another word about Canon. I'd rather learn it myself.


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## ethanz (Dec 24, 2018)

RogerCicala said:


> They do, if you want to pay a lot of money (way into 6 figures), accept both outside repairs and warranty repairs, which we do not want to do, and sign complete nondisclosure agreements. So pay a fortune, invest another fortune to enter a tough business I don't want to be in, and never write another word about Canon. I'd rather learn it myself.



And I think you guys are smart and adventurous enough to learn it quite well yourselves.


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## Hesbehindyou (Dec 26, 2018)

Del Paso said:


> What if Canon prefers to do the repairs themselves ($$$$$) ?
> Lens Rental is , obviously, a rental, not an official repair facility. They must be busy enough with their own stuff, without being asked to repair customer's warranty damages.



Would be an obvious sideline - repair other peoples' stuff and rent them lenses while they're in for repair.

Given that they've already got the trained staff it'd be easy to start, as long as they limited the lenses they repaired to ones they stocked.


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## koenkooi (Dec 26, 2018)

Hesbehindyou said:


> Would be an obvious sideline - repair other peoples' stuff and rent them lenses while they're in for repair.
> 
> Given that they've already got the trained staff it'd be easy to start, as long as they limited the lenses they repaired to ones they stocked.



That assumes there's both enough trained staff and enough downtime currently to take on extra work. ISTR RogerCicala mentioning that the lens testing department alone had a huge backlog already.


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