topic 750D delay on continuously long exposure shooting in EOS DSLR & Mirrorless Cameras

750D delay on continuously long exposure shooting

WimVanCraen — Wed, 19 Feb 2020 22:50:17 GMT

I have a 750D where I:

Have exposure time on 10"
f8.0
ISO 100
shoot RAW
set manual focus
don't want to see the picture afterwards (is turned off)
set noise compensations OFF
set it to continuous shooting
disable lens corrections
use a Sandisk Extreme PRO SD card - 32 GB - 95 MB/s transfer - SD HC I - class 10

(I think those are the important ones, let me know if you need more)

So, I want to take pictures continuously with a longer exposure time: 10" exposure - done - take another image with 10" - ...

But what I experience is that between ending picture a and starting taking picture b, there is a delay of 1-2s. And I don't want it. It should immidiatly start taking the next picture.

I've tried many things already. Directly on the Canon, use a remote controle, use apps (Andriod & PC), put it in capturing JPEG, reformat the SD card, ... Nothing is fixing the issue.

FW is up to date.

Anyone who has a clue how I could fix this?

If you have questions or suggestions, please put them here in the topic.

-----------------

For your information: I need this for making star trail photos: Link to google images

Re: 750D delay on continuously long exposure shooting

kvbarkley — Thu, 20 Feb 2020 16:30:09 GMT

I forget the actual setting, but you may have dark frame noise compensation turned on.

Re: 750D delay on continuously long exposure shooting

WimVanCraen — Thu, 20 Feb 2020 18:33:03 GMT

Both "Long exposure noise reduction" and "High ISO speed noise reduction"

Ow, and the "anti-flicker shoot." also

See menu below, but all are OFF

Re: 750D delay on continuously long exposure shooting

jrhoffman75 — Thu, 20 Feb 2020 20:39:45 GMT

The icon for High ISO speed NR does not indicate OFF.

Re: 750D delay on continuously long exposure shooting

WimVanCraen — Fri, 21 Feb 2020 11:32:18 GMT

@jrhoffman75 Do you mean in my image?

If yes: yes indeed, but that is just a internet image 🙂 on my camera it is OFF

Re: 750D delay on continuously long exposure shooting

Waddizzle — Fri, 21 Feb 2020 18:07:34 GMT

”But what I experience is that between ending picture a and starting taking picture b, there is a delay of 1-2s.”

A delay of 1-2 seconds is not very much at all. Does the memory card LED light up after each capture? It should.

If you are in continuous shooting mode, how are triggering the shutter? Are you using Live View mode? Shutter lockup?

Re: 750D delay on continuously long exposure shooting

WimVanCraen — Mon, 24 Feb 2020 06:39:04 GMT

1s is too much it you want to take star trail pictures.

Yes, the LED is lit the whole time.

I'm trigger the shutter with my remote controller, who is continuously triggering the camera. So the input of the remote control is triggered the whole time, and because of the "continuous shooting", the picture is taking continuously

No live view mode.

No shutter lockup

As for example, I've did some lightpainting taking 2 images of 10". Moving the light in a smooth way, still not too fast.

Adding the 2 images (Ps - "Lightnen" layers), it's resulting in this image below.

You see clearly the interruption in the light in the middle

Re: 750D delay on continuously long exposure shooting

Waddizzle — Mon, 24 Feb 2020 10:50:37 GMT

"Yes, the LED is lit the whole time."

There is nothing wrong with your camera. Every DSLR camera body does what you are experiencing. You need to revise your expectations downward. That is my advice.

Re: 750D delay on continuously long exposure shooting

WimVanCraen — Mon, 24 Feb 2020 11:45:06 GMT

"There is nothing wrong with your camera. Every DSLR camera body does what you are experiencing. You need to revise your expectations downward. That is my advice."

I've seen Nikon cameras where this wasn't an issue. There was no delay there...

Re: 750D delay on continuously long exposure shooting

Waddizzle — Mon, 24 Feb 2020 18:15:11 GMT

@WimVanCraen wrote:
"There is nothing wrong with your camera. Every DSLR camera body does what you are experiencing. You need to revise your expectations downward. That is my advice."

I've seen Nikon cameras where this wasn't an issue. There was no delay there...

What model Nikon?

I have serious doubts about your claim. Every DSLR made does it. It is called mirror slap. Your camera cannot move the mirror faster than 5 cycles per second, which is the frame rate

But, your issue is with the camera is writing to the card for an extended period of time between frames.

Re: 750D delay on continuously long exposure shooting

jrhoffman75 — Mon, 24 Feb 2020 19:45:06 GMT

I tried an experiment with my Canon 1D X. It has a 12 frame per second potential frame rate. If I set the time to 10 seconds there was a definite pause between shots. Yet, at 1/1000 of a second it fires like a machine gun.

Why would you shoot teo 10 second light painting shots rather than one 20 second shot?

When I’ve shot star trails I expose for twenty seconds, pause 1 second then shoot again, repeating for twenty shots and blend using a star stacking program. I use a remote controller.

Re: 750D delay on continuously long exposure shooting

Waddizzle — Mon, 24 Feb 2020 20:08:15 GMT

“I tried an experiment with my Canon 1D X. It has a 12 per second potential frame rate. If I set the time to 10 seconds there was a definite pause between shots. Yet, at 1/1000 of a second it fires like a machine gun.“

If you were shooting RAW, then maybe it is building the JPEG preview image during that pause.

Re: 750D delay on continuously long exposure shooting

jrhoffman75 — Mon, 24 Feb 2020 21:30:35 GMT

@Waddizzle wrote:
“I tried an experiment with my Canon 1D X. It has a 12 per second potential frame rate. If I set the time to 10 seconds there was a definite pause between shots. Yet, at 1/1000 of a second it fires like a machine gun.“

If you were shooting RAW, then maybe it is building the JPEG preview image during that pause.

Possibly - since OP is shooting RAW same might be happening with his camera.

Re: 750D delay on continuously long exposure shooting

Waddizzle — Mon, 24 Feb 2020 22:51:18 GMT

@WimVanCraen wrote:
"There is nothing wrong with your camera. Every DSLR camera body does what you are experiencing. You need to revise your expectations downward. That is my advice."

I've seen Nikon cameras where this wasn't an issue. There was no delay there...

Here is a recent thread with links that show you how a mirror works, and why your Nikon claim is demonstrably false. There is a link in the first post to video that shows how a mirror and the shutter work together.

https://community.usa.canon.com/t5/General-Camera-Discussion/You-wanna-see-mirror-slap/td-p/289409

This is how a DSLR works, and how it differs from a mirrorless camera. If you watched the video, then you saw how the mirror would open, then shutter would expose the image sensor, and finally the mirror would drop back down. When do you think the image data gets sampled?

The image data in DSLR gets sampled AFTER the mirror drops back in place.

The data has been captured by the camera, and the camera can read the data line by line, row by row, or whatever. The point is that the image sensor is no longer exposed to light when it is being read, which means the data is STATIC, and not changing.

A mirrorless camera has no mirror, to block off the light.from reaching the shutter and the image sensor. Mirrorless cameras must read the image data VERY quickly when in continuous shooting mode, while the shutter is closed. The image data is not static, and is constantly changing. This can be a problem when subjects are moving within the frame.

Sampling dynamic image data can result in "rollling shutter" effects on moving subjects This effect is readily apparent with video shot from a moving vehicle. All of the light poles will look bent.

Back to the mirror in a DSLR. What this means is that DSLRs, all DSLRs will always have a slight pause between frames. This is a fact, without exception. Why the pause is apparently longer with slower shutter speeds is a good question. But, it is a normal behavior of all DSLRs.

Re: 750D delay on continuously long exposure shooting

WimVanCraen — Tue, 25 Feb 2020 11:58:20 GMT

Feedback from the canon support desk:

"Thank you for contacting Canon.

Hereby we can inform you that how the EOS 750d works, where you describe that it is 1 to 2 sec. takes before a new recording is made is not a defect of the EOS 750D. This is because the sensor data is stored during this time. And so it is not possible to immediately start a new recording. We see this as normal for the moment. Once the sensor data (data) has been saved, a new recording can only be made.

If you have any further questions, you can contact us by replying to this message.

Kind regards,

Saraah

Canon Services & Support"

Case closed. Unfortunately
Thanks for the replies here

Re: 750D delay on continuously long exposure shooting

WimVanCraen — Tue, 25 Feb 2020 15:51:54 GMT

"Why would you shoot teo 10 second light painting shots rather than one 20 second shot?

When I’ve shot star trails I expose for twenty seconds, pause 1 second then shoot again, repeating for twenty shots and blend using a star stacking program. I use a remote controller."

For your information: I use the 10" to prevent the light pollution here in Belgium 🙂 If you go higher, more and more light coming from the light pollution is captered