04-26-2013 10:14 PM
Yes. That's why I mentioned setting the Tv to something high. Imagine if the camera set itself to Tv of 1 sec (exaggerate for making a point) then it can only take one frame per second or less... Also, the default setting might be having the noise filtering for high ISO turned on (check it on the camera). The high ISO filtering is very very slow...it will bring the camera burst speed to a crawl. When there is low light, there is higher ISO and thus more filtering.
04-27-2013 01:05 AM
Thanks. The high ISO filtering setting was what I was looking for. I was not aware of this automatic noise reducing feature. After finally finding it in the instruction book (page 254) I found this quote: "With setting 2, the maximum burst for continuous shooting will greatly decrease." This must have been disabled in the store's demo model, which is a good idea since they didn't have a memory card in the camera to show the quality of photos, but it does show off the faster burst rate. Good job sales team! =]
02-02-2014 05:05 PM
In my case, the camera is in manual mode, no high ISO reduction or LE noise reduction. Still, high burst mode is faster in good light conditions than low light.
A simple test:
>Set the camera in manual mode (even focus in lens to prevent autofocus)
>Set shutter speed to something higher than 1/250
>Disable high ISO reduction
>Disable LE noise reduction
>Set drive to Burst High
Cover the lens, press and hold shutter button. Notice the speed.
Now uncover the lens, point to something bright and do it again. The speed is clearly faster.
With live view, burst mode speed has no difference at all. Weird.
The question is, why that happen? Why the amount of light influences in burst speed?
02-03-2014 07:01 PM - edited 02-03-2014 10:02 PM
This only happens in very low light conditions. Similar to a dimly lit room in a house at night. Maybe a large room lit by one 60 watt bulb. By my own tests the lighting conditions where this fps reduction starts to appear is roughly equal to 1/100 f/2.8 at ISO 3200.
This slowed frame rate in low light is due to a new metering system called iFCL which was first introduced on the Canon 7D.
More info here: iFCL metering
To work with the iFCL metering sensor, cameras that use iFCL metering also feature a specific metering algorithm. These cameras always measure focus with all AF points, regardless of the selected AF mode. During the exposure reading the cameras look to see which points, in addition to the selected point, have achieved or almost achieved focus.
In Liveview the AF points are not being used and there is no low light slow down.
In addition to Liveview, another solution is to meter a brighter scene using Tv or Av and then press the * button for AE Lock. This stops the metering system and allows the camera to shoot at 7fps again. (the * button doesn't work in Manual mode so don't bother trying it in Manual)