0

'Nominal' continuous drive speed on the EOS-M is 4fps

I normally shoot Raw + Jpeg. In this mode, I get a burst of three frames at 1.25 fps, then it oscillates between about .7 and 1.25 fps.

If I switch to Raw only, things improve a bit; I get a burst of four frames at just over 4 fps, and then it settles down to about 1 or 1.1 fps.

Storage cards are Sandisk Extreme, 45 MB/s.

Two questions:

  • Am I right in thinking that Raw without Jpeg is the fastest mode for continuous drive?

  • Are there any other adjustments I could make to increase the continuous drive rate?

  • 1
    Depending on the final use of the image it might be sufficient to shoot a movie (60fps @ 720p and 30fps @ 1080p) and extract a frame in post. – Saaru Lindestøkke Mar 31 '14 at 19:13
2

Canon specifies that you can shoot up to 15 JPEG or 6 RAW images or 3 JPEG+RAW files continuously at 4.3 FPS. This is under ideal conditions with focus locked on the first frame.

Most importantly, this is measured with a sufficiently fast memory card. Since you are getting so many fewer shots, it is most likely that your card is too slow. You can get faster models which will improve the performance up to the specified maximum. This affects how fast the buffer is cleared but will not change the drive-speed which is pretty much set.

  • I've added an answer with a graph. It fits with your answer, except that I can't quite understand the discrepancy with their assertion of a 15-JPEG burst. – Brent.Longborough Apr 10 '15 at 12:02
4

I had the same problem with burst speed with my EOS M: JPEG only was slower than RAW only. The reason was in the menu: Lens aberration corretion -> Chromatic aberration -> if "enable" is set then JPEG slow down, when change to "disable" JPEG burst mode last much longer.

3

Shooting JPG only should be faster than RAW only. Although the camera has to process the JPG, the resulting file is much smaller and generally the memory card is the bottleneck, so smaller files transfer faster and get you a higher rate.

1

For what it's worth, I have just conducted a small experiment to try to confirm the effect of (RAW only) x (RAW + JPEG) x (JPEG only), and the effect of SD card speed.

Graph of results

I took six samples, each of ten shots. I extracted the 1/100 second timestamps from the EXIF data, and plotted the nine inter-frame intervals, shown in the graph, as follows:

UHS-1: RAW+JPEG (full size), with a Sandisk Extreme 16GB card rated at 45 MB/s, U-1 C-10

UHS-2 (the 2 is a typo in the graph): RAW+JPEG (full size), with a Sandisk Extreme Pro 16GB card rated at 95 MB/s, U-3 C-10

1080P: JPEG only, 1920x1080, with the UHS-3 card

720x480: JPEG only, 720x480 (the smallest possible), UHS-3

RAW: RAW only, UHS3

R-UHS-1: RAW only, with the UHS-1 card

Conclusions?

  1. There isn't a lot of difference between UHS-1 and UHS-3 SD cards -- none when JPEGs are involved, and a small difference in RAW-only once the buffer is full

  2. The only way to get close to Canon's figure of 4.3 fps is to shoot RAW-only, and even then only for a burst of about seven frames

  3. JPEG size doesn't appear to make much difference (JPEG only)

  4. The only thing that I don't understand is the peak of the second interval when shooting RAW+JPEG

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.