topic Slow Write on Canon 70D in EOS DSLR & Mirrorless Cameras

Slow Write on Canon 70D

khaslag — Thu, 13 Aug 2020 17:25:04 GMT

I recently tried to capture a set of astroimages at 15 sec. intervals over a period of 1.5 hrs (using an intervalorometer). I should have captured nearly 560 images. But when I downloaded the images to Bridge there were only 210. Looking at the Bridge information there is an additional 18 sec between the Date Created date/time and the Modified date/time. This 18 sec. per image accounts for the difference between the expected number and the actual number. But where does it come from and how can I account for it in the Intervalorometer settings.

Canon 70D

SDXC-I 64GB SD card

ISO 1600

~25MB per image

Re: Slow Write on Canon 70D

jrhoffman75 — Thu, 13 Aug 2020 18:10:32 GMT

Welcome to the forum khaslag.

What intervalomter were you using?

What were the camera and intervalomtere settings?

Re: Slow Write on Canon 70D

khaslag — Fri, 14 Aug 2020 19:12:33 GMT

Intervalorometer was a Phottix Taimi digital timer and remote

Delay = 0

Long = 15 (sec.)

Intvl = 1 sec.

N1=1

Repeat=99

N2 not set

Re: Slow Write on Canon 70D

khaslag — Sat, 15 Aug 2020 17:36:44 GMT

Also: Camera settings

ISO 1600

Exp=15 sec.

Manual Mode

Manual focus

RAW

LENR=Off

HISO Speed NR = Off

Re: Slow Write on Canon 70D

jrhoffman75 — Sat, 15 Aug 2020 17:45:59 GMT

Doubke check the instructions for the intervalometer. For my three Canon cameras the camera needs to be in Bulb mode when using an intervalometer.

Re: Slow Write on Canon 70D

khaslag — Sun, 30 Aug 2020 19:26:15 GMT

I took the timer out of the equation and just shot 30" in Manual Mode. The same results - it took 30 sec. to write a 30MB image to the card. I tried variations in ISO, shutter speed etc. and it appears it takes the same amount of time to write to the card as the image size (i.e. 1MB/s write speed!). Not a problem with faster shutter speeds but can be impactful for multiple long exposure astroimaging like skyscapes or meteor capture.

Re: Slow Write on Canon 70D

jrhoffman75 — Sun, 30 Aug 2020 20:16:01 GMT

Do you have any in-camera processing activated?

Re: Slow Write on Canon 70D

Waddizzle — Sun, 30 Aug 2020 20:52:31 GMT

@khaslag wrote:
I took the timer out of the equation and just shot 30" in Manual Mode. The same results - it took 30 sec. to write a 30MB image to the card. I tried variations in ISO, shutter speed etc. and it appears it takes the same amount of time to write to the card as the image size (i.e. 1MB/s write speed!). Not a problem with faster shutter speeds but can be impactful for multiple long exposure astroimaging like skyscapes or meteor capture.

John is correct about using Bulb mode. What brand of card are you using? It sounds like it could use a reformatting.

Re: Slow Write on Canon 70D

jrhoffman75 — Sun, 30 Aug 2020 21:50:20 GMT

As suggested try reformatting card in camera.

If that doesn't work try a new card. The 70D should be writing much faster than you are seeing.

Re: Slow Write on Canon 70D

khaslag — Sun, 30 Aug 2020 23:19:08 GMT

Tried reformatting the card and that solved the problem. I'll probably purchase a new one as added insurance. Thanks for all the help - really appreciate it.