1Dx AI-Servo frame rate question

[Razor2012]

Thanks again. This was just confusing me as I try to understand as much as possible.

I´m a frequent reader of this forum, although I´m neither a pro nor an expert. This forum helps me a lot in learning and understanding. Thanks to everybody who is contributing and sharing his/her expertise to guys like me.

Apologize for another off topic post

No need for apologies, we are all here to learn.  It's not like you hijacked the thread or something.   

[Kevin Weinstein]

Hi Robert.  Yes, I am quite familiar with the 1D series.  Been on them since the 1Ds Mark II. 

I called Canon, and they are confused as well.  I even let them listen to the difference and the gentleman was a bit shocked.  We changed the custom setting to have a few different buttons lock focus in AI SERVO mode and no matter where we placed the focus lock button, the frames per second dropped considerably once the focus lock button was pressed.

I will keep you all posted!

KW

[Richard Lane]

Thanks for the update!  Keep us posted and good luck!

[Kevin Weinstein]

ooops.  Richard, not Robert.  Forgive me.   

[Richard Lane]

No  problem!

[Rex]

I have the same problem, on a 5DmkIII though.  I have back button focus instead of the shutter button.  When I'm not focusing in AI Servo it shoots around 3fps.  If I am focusing it shoots at the normal 6fps.  The 1st and 2nd image priority is set to focus.  If I change it to anything other then focus it might pause at the start but does shoot at the full 6fps when focusing and when not.
Its odd because it is slow when not focusing, but normal when it is and only in Ai-servo.

[MichaelLauer]

I've been playing around with some of the servo focus settings on the 1Dx.  I am using all 61 focus points and am using the focus priority setting.

My subject matter is gymnastics and the targets move a lot.  Still, I'm almost always getting the full 12fps.  I do experience a delay if the camera cannot get a focus lock.

For your situation, I'm wondering if you are using all of the focus points or if you are using a smaller selection.  The reason is that a smaller selection such as a single focal point may not be able to get the focus locked as easily.

[Richard Lane]

I have the same problem, on a 5DmkIII though.  I have back button focus instead of the shutter button.  When I'm not focusing in AI Servo it shoots around 3fps.  If I am focusing it shoots at the normal 6fps.  The 1st and 2nd image priority is set to focus.  If I change it to anything other then focus it might pause at the start but does shoot at the full 6fps when focusing and when not.
Its odd because it is slow when not focusing, but normal when it is and only in Ai-servo.

After further review and confirmation in the manual. I have deemed that this is a feature and not a problem with the 1DX or 5DIII. 

When you select 1st image "focus" priority and 2nd image "focus" priority the frame rate does slow down dramatically to ensure focus.

After further testing, "it appears to me that the 2nd image focus priority choice," has a greater impact on the shooting speed then the 1st image selection choice does.

"If I select 1st image focus priority, and 2nd image focus priority, the fps rate slows down."

"If I select 1st image release priority, and 2nd image focus priority, the fps rate slows down."

If I select 1st image focus priority, and 2nd image release priority then the the shooting speed is "fast."

* "So, it appears that the 2nd image focus priority choice slows the frame rate down more than the 1st image focus priority choice."

I have the default equal priority set for 1st and 2nd image and that seems to be working very well for me.

There is also another setting on the next menu: AF3:One Shot AF release priority, and I have that one set to "focus priority" which is also the default.

This One shot setting, coupled with the 2nd image focus priority choice, may further explain why some were getting different fps rates depending on which AF mode (One Shot vs. AI Servo) they were in.

Rich

[Rex]

That all makes sense, but one of the main reasons I use back button focus is so that I can choose to manual focus when ever I want.  Its annoying that if Im not using the AF I'm still being restricted to the 3fps.
I can just set the 1st and 2nd image priority to equal which is fine because its normally focused by the time I want to take the photo.
Anyway cheers for the info!

[Richard Lane]

I see your point, but since manual focus isn't that great for tracking fast subjects in AI servo, you might as well make the setting change to equal like you mentioned.

Or, if you want, you could still choose focus priority for 1st image,  and equal priority for 2nd image and it's still very fast, since it's the 2nd image that seems to be setting the fps and the 1st image sets a very slight initial delay, but since the 1DX is so fast at focusing I find the 1st image delay to be barely detectable.

The only reason I'm using equal for both is because I don't won't any delay for my action shots.

Cheers!