Canon 5D Mark III User Manual (en)

 Setting the Image-Recording Quality
With Custom Controls, you can assign the image-recording quality to 
the <B> button or depth-of-field preview button so you can switch to 
it momentarily. If you assign [One-touch image quality setting] to the 
<B> button or depth-of-field preview button, you can quickly switch 
to the desired image-recording quality and shoot.
For details, see Custom Controls (p.321).
The maximum burst is displayed on the 
bottom right in the viewfinder.
If the maximum burst for continuous 
shooting is 99 or higher, “99” will be 
One-touch Image Quality Setting
Maximum Burst During Continuous Shooting
If [51: Record func+card/folder sel.] is set to [Rec. separately], you 
cannot switch to the One-touch image quality setting.
The maximum burst is displayed even when a card is not inserted in the 
camera. Make sure that a card is inserted before taking a picture.
If the viewfinder displays “99” for the maximum burst, it means the 
maximum burst is 99 or higher. If the maximum burst decreases to 98 or 
lower and the internal buffer memory becomes full, “buSY” will be 
displayed in the viewfinder and on the LCD panel. Shooting will then be 
disabled temporarily. If you stop continuous shooting, the maximum burst 
will increase. After all the captured images are written to the card, the 
maximum burst will be as listed on page 121.
The maximum burst indicator in the viewfinder will not change even 
when you use a UDMA CF card. However, the maximum burst shown in 
parentheses on page 121 will apply.