sequence frames with delay

Somewhere to ask questions about the best way to use SharpCap
Forum rules


If you have a problem or question, please check the FAQ to see if it already has an answer : https://www.sharpcap.co.uk/sharpcap-faqs
donboy
Posts: 256
Joined: Sat Mar 25, 2017 1:57 am

sequence frames with delay

#1

Post by donboy »

Robin,

I would like to run a set number of frames and have a fixed delay in between downloaded captures. I tried using the settings provided and I couldn't get it to work.

Example:

Exposure - 60sec
Total frames to capture - 25
Delay between captured frames - 15sec

So how would I go about doing this?

Don

P.S. is it possible in the future that the Output Format could be saved in the camera profile?
User avatar
admin
Site Admin
Posts: 13173
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: sequence frames with delay

#2

Post by admin »

Hi Don,

set the exposure you want and then setup the capture start dialog like this
Capture.PNG
Capture.PNG (47.08 KiB) Viewed 2329 times
That should do the trick.

I think the output format should be saved, but you need to uncheck 'Start Cameras with Auto output format' in the settings.

cheers,

Robin
donboy
Posts: 256
Joined: Sat Mar 25, 2017 1:57 am

Re: sequence frames with delay

#3

Post by donboy »

Robin,

I've tried what you suggested for sequencing with following:
60sec exposure
Sequence length 20
delay 10sec.
Output format .fits

What happens is the following:

Start the capture and immediately a frame is saved. Then the next exposure happens 60sec after the 1st and then the 3rd comes 60sec after the 2nd, etc. There really is no true delay in between exposures. Then sometimes after the delay count down another frame is saved. I can't get it to operate the same way twice. I really don't think this is working properly.

Don
User avatar
admin
Site Admin
Posts: 13173
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: sequence frames with delay

#4

Post by admin »

Ah, ok, I see. There is an interaction between this sequence functionality and the fact that frames are being captured all the time.

One feature introduced in 3.0 (I think) was that if you are using long exposures and capture a single frame (snapshot button or via the sequence), SharpCap will actually save the frame that has just finished if the camera settings are unchanged. This is good because it means you don't have to always wait to capture something and you can also save the frame that you can see on the screen (this applies for exposures of a few seconds or more).

This has an interesting interaction with the delay setup. Basically if it gets to the end of the delay and the frame that has finished most recently has not already been saved then that finished frame will be saved and the sequence will move onto the next step. It all depends on the relative lengths of the delay and the frame.

A better way to do this is to use the 'Frame Rate Limit' control to set a limit of (say) 1 frame per 2 minutes. Then just start capturing for 25 frames (no sequence, just set a limit of 25). Obviously this doesn't quite get your delay of exactly 15s, but it should be reliable.

A robust way to do what you are describing with a 15s delay will come along in SharpCap 3.2 where I am planning a still camera mode and a full sequencing tool.

cheers,

Robin
donboy
Posts: 256
Joined: Sat Mar 25, 2017 1:57 am

Re: sequence frames with delay

#5

Post by donboy »

Sorry didn't quite understand what to set.
User avatar
admin
Site Admin
Posts: 13173
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: sequence frames with delay

#6

Post by admin »

This control - basically it causes SharpCap to limit the rate at which it handles frames from the camera.
Capture.PNG
Capture.PNG (12.06 KiB) Viewed 2322 times
Robin
Paolino
Posts: 2
Joined: Mon Jul 18, 2022 10:11 am

Re: sequence frames with delay

#7

Post by Paolino »

Hello everyone and sorry if I'm not the right section of the forum. I am new to the forum and to using this nice software. I've already seen that the topic has already been covered, but in versions prior to the one I use. I wanted to know if it is possible to put a delay between one frame and another in order to allow the sensor of the ASI 385 mc to cool down. The sharpcap version is the latest available in July 2022. Thanks in advance for the help.
Paolino.
User avatar
admin
Site Admin
Posts: 13173
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: sequence frames with delay

#8

Post by admin »

Hi Paolino,

the approach shown here will not help you, since with this approach the camera continues running as usual (capturing frames all the time) and SharpCap simply throws the images away if they are arriving more often than the specified rate.

You can put the camera into still mode (see https://docs.sharpcap.co.uk/4.0/#Live%2 ... ill%20Mode) which means it will only take images on request, rather than all the time. That might be part of a solution. You can also try setting the exposure to a long value (say 10s) - that tends to reduce power consumption by a camera quite a lot when compared to capturing several frames per second.

cheers,

Robin
Paolino
Posts: 2
Joined: Mon Jul 18, 2022 10:11 am

Re: sequence frames with delay

#9

Post by Paolino »

Hi Robin and thanks for the quick reply.
I will do tests based on your advice to see if I can get the result. Unfortunately I bought an uncooled astronomical camera and the noise shows up! Thank you for your availability and see you soon!
Paolino
User avatar
Calamity_Jane
Posts: 25
Joined: Wed Oct 13, 2021 9:23 am

Re: Sequence frames with delay

#10

Post by Calamity_Jane »

Hi:

Have I understood this correctly?

If I want to capture a sequence of .ser files of Jupiter to make a movie of the rotation, moons etc., I could do the following to obtain a fairly steady 10 minutes between frames:

1. Capture for 1 minute
2. Set delay between frames to 9 minutes
3. Repeat 24 times

Should this then give me a 4-hour sequence with 10 minutes between frames?

Thanks,

Jane.
Post Reply