Canon R8 - Single shot versus Servo

[mmbrombe]

I recently upgraded from Fuji APS-C to a Canon R8 mostly due to the improved autofocus. The difference is truly staggering, I am consistently amazed at the R8 autofocus speed and reliability, regardless of the subject. With such a great AF system (especially in Servo AF), I am just wondering what would be the reason for using single shot versus servo AF. Sure, common knowledge is "single shot for static objects", but is there any downside to leaving the camera  permanently in servo AF? Even for "static" objects, I could see servo AF being more reliable by accounting for any small motions from the camera/photographer. Perhaps a hit in battery life, but other than that I can't see a good reason for using single shot when continuous AF is so powerful on the R8. Thanks for any advice from those with more experience in the Canon system.

[shadowsports]

Greetings,

I think most of us are single point or spot AF shooters.  This ensures the camera focuses on exactly what you are telling it to.  While the AF systems on newer body's are very advanced, sometimes the camera will shift focus to something it sees and deems you are wanting to track.  You have your other options (aperture, shutter speed and ISO) to choose from that affects depth of field, freeze / motion blur and controlling the light capturing sensitivity you want in an image. Servo AF is best for action shots. I'd still use single point AF for subjects which are primarily stationary.

[deebatman316]

For static subjects One Shot is the better choice instead of Servo AF. Servo AF doesn't have any focus lock so the camera will take pictures even if they're NOT in focus. Also in low light or contrast situations the AF Assist Beam WILL NOT be PROJECTED by the camera or speedlite. Most AF Assist Beam related problems are related to the camera AF system being set to Servo AF. Servo AF (formerly AI Servo) from the very beginning of the EOS system has NEVER allowed AF Assist Beam Projection. Whether that be Intermittent Flash Firing, LED or "IR/ Infrared" (the old red grid pattern projected by a speedlite, not really IR).

[Waddizzle]

One of the basic differences between One Shot AF and Servo AF is when the exposure gets locked in.  When you use One Shot AF, the exposures is locked when focus is locked.  This can be useful for focus and recompose shooting.

Servo AF locks exposure when the shutter is fired.  This is most useful for action photography.

[Tronhard]

In my experience, leaving the camera on servo, but decoupling focus from the shutter button works well.  In that case your focus is, by default, assigned to the AF button on the camera back.

So for static objects you prod the AF button and it will hold lock, but if you keep it held down, it will track. There is a You Tube video from Canon Australia on this if you do a search.

I personally prefer single point focus for precision.

[mmbrombe]

Thanks everybody for your detailed responses, much appreciated. This forum is a great resource!