How fast can the camera trigger?

I have my Canon SX-260 working properly on AUX1 (pin 54), but it does not seem to trigger as fast as I would like.
When testing it using “Trigger Camera NOW” in MP, the fastest it will trigger is 4.5 seconds even when using a fast USB connection. When flying it is programmed to trigger every 2.6 seconds based on GPS position and speed of aircraft, but it seems to skip many pictures and comes back with about half the number it should have.
Has anyone else seen this issue? I don’t think it is in the camera because if I set the camera to self-timed picture taking, it can manage less than 2 seconds per image.
Is there some latency in Pixhawk which limits the speed of camera triggering?

And as an addendum to my earlier post, how do I see the camera trigger points in the Dataflash log? The instructions say that there is a group called CAM, but it does not show in my Dataflash.

Also, my log bitmask has a bit to record CAM (4096) which is set, but I cannot find the CAM records.

Camera trigger time usually depends on the camera settings, especially if you have auto anything turned on.

Auto focus seems to be the slowest.
What about shutter, ISO?
We have manual settings with auto ISO being the only auto mode turned on.
Sony Alpha 6000 achieves 1 sec pictures, but always keep it to a minimum of 1.5 sec.

The easiest test is to just take the camera outside and start taking pictures quickly just using the shutter button and see how quickly it reacts.
Once you have it turned for a few hundred shots a second apart and you experience delays then you will need to look deeper into your connection and triggering system.

Can you post one of your logs?

The camera will take pictures at a rate of 2 seconds per image when in self-timed mode using CHDK, so the storage time, focusing time, etc. seem to be fast enough. But when triggering from Pixhawk it takes 4.5 seconds.

Here is the log file. It is a bit long because I was recording all the time even when unarmed. But the last flight starting at line number 1627916 is the one with the photographs taken. If you can show me how to see when they were taken, I would appreciate it. I cannot find any reference to camera in the log.

The fastest rate you can trigger a camera is 5Hz (10Hz update rate, and you have to pull the pin low before you can trigger it again). However as @mboland said it’s the camera that limits your capture rate.

It’s not uncommon to have different methods of triggering the camera (CHDK vs external trigger) to have very different timing characteristics. (Certain cameras suffer if auto review is enabled).

You didn’t link your log here, but I’d recommend checking your CAM_DURATION. While 5Hz is the fastest you can trigger the camera, you would have to have a CAM_DURATION of 1, while a duration of 10 will hold it for 1 second, which limits your capture rate.

Thank you for that input. I uploaded the dataflash .bin file using the “upload” icon on this page and it said “saved”, but like you I did not see it appear. Maybe uploading a file is a bit more involved than just using the “upload” icon.

However, I agree that I do suspect the camera, and will focus my efforts on debugging that. The tlog file shows the camera taking pictures at the proper places.

Can anyone answer my question - why does the camera trigger event not show up in the dataflash log? Or if it does show up, what is the event name that I am looking for there?

That is where I could get the exact timing of the Pixhawk trigger.

I assume you are referring to the TRIG message? That is only emitted if you have CAM_FEEDBACK setup. Otherwise we only emit CAM messages. If feedback is enabled TRIG is where you said to take a photo, CAM is when you got the feedback event that the photo had happened. Without feedback CAM is where you said to take the photo (and hopefully not far off from where it was actually taken)

It would really help if you could get that data flash file to upload so we can see your parameters and setup as well as the log itself.

There is a limit on file size for direct uploads here, so maybe try to .zip it or use Google drive or Dropbox.

The file is nearly 60 MBytes so I put it in my Dropbox. Here is the link

Sorry it is so long - I had it set on continuous recording even when not armed. The flight with the camera shots is at the end of the log starting at line 1627800.

Thank you WickedShell for your input. I filtered on CAM (found it at the very end of the filter options) and bingo! there are all the camera commands. They are providing the output triggers every 2.4 seconds, which is about right. Now I can see where the problem lies and address it…

That is exactly what I was looking for. I was stumped because CAM is not one of the options for plotting shown at the right of the window (AHR2, ARSP, ATT, BARO, …etc)

Thanks again for your help.

APM Planner has very good graphing tools, and simply clicking in the MSG Type field and typing CAM jumps to the first entry, and typing CA after that jumps to the next, etc.

The entries are there as you saw.

Your camera trigger times seem to be default of 1 (1/10th of a second). Is that long enough to trigger your camera?

I am assuming you have been through the camera configuration settings

I am still learning all the features of the graphing tools. When you say "clicking in the MSG Type field and typing CAM " are you referring to the list of sorting items on the right hand side? I checked the MSG / Message box, but where to I type CAM? Or are you referring to the Filter capability?

Yes, 1/10 second is enough time to trigger, and I have been through the camera configuration settings.

I found the problem - the CHDK seems to easily revert to storing the RAW image as well as the JPG image. Unless I carefully check it and turn it off if it has reverted, then it takes 4.5 seconds to store each image. If I store the JPG only it takes 1.5 seconds. Big difference.

Thank you for your support.

I was referring to the spreadsheet view of your data.

The second column is ‘MSG Type’
click on any cell in that column
type CAM
It will jump to the first CAM message
Type CAM again , or just CA is quicker as there are no other messages that start with CA, and it will jump to the next CAM message.

Mike, What program are you using to look at this spreadsheet? My screenshot from Mission Planner “Review a Log File” looks nothing like this. I attach a screenshot of the same line number:

I can open it in Excel, but then I do not get any of the first two columns.

Your program looks more useful than the one I am using.

I am using APM Planner for most logging analysis as it has a very good layout and control.
Mission Planner is stronger in other areas.

I came here when I saw you were using CHDK. I wanted to mention that using CHDK to shoot RAW/DNG will slow down the shot rate by several seconds. It looks like you found that out on your own!

CHDK has what I consider a nasty “feature”. There is a camera button sequence “short cut” that will enable RAW shooting without going into the CHDK menus to do so. Many people accidentally trip over this sequence while using their cameras normally and only discover this after their SD card fills up quickly or their fastest shot rate slows down.

You can enable an onscreen “icon” that will tell you via your camera’s LCD that it is enabled but not many people figure that out ahead of time.

Good news though! The latest development version of CHDK has that “short cut” disabled by default. You have to turn it on with the CHDK menu if you want it active. The development version of CHDK is always very stable - I can’t remember them ever releasing an update that did not function correctly.