EOS 90D Autofocus Issues with EF 100-400mm L IS II USM

[canon_eos_90D]

I recently bought a Canon EOS 90D body.

Unfortunately I'm encountering focus issues when using the body with the Canon 100-400mm L IS II lens.

When I'm trying to focus (using OVF) on an object (like a race car for instance) that's coming towards to me, the camera/lens won't focus.

The settings on my camera are: Autofocus > AI Servo, shutterspeed: 1/1000 - 1/2000. Normally those shutterspeeds should deliver me a sharp picture. But that's not the case.

When I attach the lens to a Canon 6D or 5D Mark IV I don't have any problems at all; the focus issues don't happen with those two bodies.

I know when a subject moves closer to or further away of the camera, the sensor can have some difficulties in focussing. But with the fast shutter speeds I should get sharp images, which is not happening with the 90D body.

Anyone an idea how I can solve this issue?

[Waddizzle]

Have you tested it using a tripod to photograph stationary objects, preferably at varying distances?  If not, try it.

[Waddizzle]

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@canon_eos_90D wrote:

I know when a subject moves closer to or further away of the camera, the sensor can have some difficulties in focussing. But with the fast shutter speeds I should get sharp images, which is not happening with the 90D body.

Anyone an idea how I can solve this issue?

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Your conclusion is simply not true.  A fast shutter speed does NOT correct auto focusing issues.  

[canon_eos_90D]

I know - but with every other camera and compareble lens it works without these issues!
I only want to say that the chance of getting a sharper image may be greater by using a shutter speed to freeze te action.

[canon_eos_90D]

When the cars are coming to me, they vary in distance...
Using a tripod at motorsports isn't that handy (it ain't wildlife photography...).
The lens and body were mounted on a monopod. We experimented with and without the monopod.

Same results... 😞

[shadowsports]

Greetings,

I can't speak to the 90D specifically, I have a 6D2.

However, I had a similar issue earlier this year at a indoor go-kart event.  This was the first time I ever saw my camera struggle.  I would think AI-Servo would be your best bet coupled with a  fast shutter speed.  Outside on a sunny day f11 or higher should yield sharp photos.  A freeze frame of the action with relatively sharp focus fore and aft of your subject.

**EDIT..  knowing now you were on a mono-pod

My question would be...  were you using IS?  If so, which mode?

See pages 8, 9 and 10

ef100-400f45-56lisiiusm-im-e.pdf (c-wss.com)

[canon_eos_90D]

Hello Shadowsports

We've tried AI Servo and AI Focus, but the results stayed the same...

Thanks for the PDF regarding the lens. I'm going to read it thoroughly... but with the settings 1-2-3 we've also been playing...

Strange that the lens works faultless on the 6D and 5DIV...

[jrhoffman75]

Do you have a filter on the lens?

Some posters have reported problems that are resolved by removing the filter.

[ebiggs1]

This is worth repeating, "A fast shutter speed does NOT correct auto focusing issues."  In fact it may make it more difficult for the camera. IMHO, I would never use Ai-focus. Ai-servo can be of some help but it will fire even if focus is not achieved. Result, blurry photos! You might want to just use the reliable standard One shot and just the center focus point.

BTW, "Do you have a filter on the lens?"  If so remove it. The 100-400mm doesn't do well with filters even good filters. 

[Waddizzle]

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@canon_eos_90D wrote:

I know when a subject moves closer to or further away of the camera, the sensor can have some difficulties in focussing. But with the fast shutter speeds I should get sharp images, which is not happening with the 90D body.

Anyone an idea how I can solve this issue?

---

Your conclusion is simply not true.  A fast shutter speed does NOT correct auto focusing issues.

Oh, yeah.  That part about fast shutter speeds being able to correct focusing distance issues is not true, either.  Can you post a sample photo of your issue.  Please include the SXIF data, exposure settings, camera AF mode and AF point settings, etc.

Until you do that, I am forced to assume that your issue is operator error, and lack of experience and expertise.

[Waddizzle]

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@canon_eos_90D wrote:

I know when a subject moves closer to or further away of the camera, the sensor can have some difficulties in focussing. But with the fast shutter speeds I should get sharp images, which is not happening with the 90D body.

Anyone an idea how I can solve this issue?

---

Your conclusion is simply not true.  A fast shutter speed does NOT correct auto focusing issues.

Oh, yeah.  That part about fast shutter speeds being able to correct focusing distance issues is not true, either.  Can you post a sample photo of your issue.  Please include the SXIF data, exposure settings, camera AF mode and AF point settings, etc.

Until you do that, I am forced to assume that your issue is operator error, and lack of experience and expertise.