Search found 19 matches

by Furgus
Sat Mar 09, 2019 7:11 pm
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Hi, I wasn't really going to take this any further, as I am happy with how the system works (ie its reliable and accurate), but have found out a couple of bits of extra info: Firstly, when testing my usual laptop with my GPS server, I found that with an exposure time of 400ms or shorter, Sharpcap wa...
by Furgus
Fri Dec 28, 2018 9:52 pm
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Thanks Robin, I agree with you....I tried the exact same trial and it does indeed stamp as expected, on longer exposures (ie the time stamp represents the end of the exposure.) I have investigated several capture programs in this way....they do vary a bit. But....the anomaly, for me, comes at 'norma...
by Furgus
Fri Dec 28, 2018 12:18 pm
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Hi,

Had just one more thought on this,
Would there be any circumstances where SharpCap could allocate the timestamp of the previous frame (allocated when its exposure finished) to the new frame, just starting its exposure? (that too would fit what I'm seeing).

Thanks

And have a great 2019!
by Furgus
Mon Dec 10, 2018 11:12 am
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

A small clue, possibly, as to whats happening: I find that when using a USB 2 cable, both ASI224 and ASI174 cameras produce frames that have a 'late' timecode, (very roughly 1 frame duration late). When using USB 3 (which I always do).....the timestamps appear 'correct' nearly always (ie the timesta...
by Furgus
Sat Dec 08, 2018 5:24 pm
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Thanks Steve,
I'll have a look at Astro Flash timer.
by Furgus
Sat Dec 08, 2018 5:22 pm
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Thanks Dave, Yes, I've thought about how things might run more reliably....I do indeed turn off wifi and bluetooth before every session. I also change the priority (Task Manager, Details) in W10 to 'RealTime' for SharpCap (it defaults back to standard after a re-boot). W10 generally manages time bet...
by Furgus
Mon Dec 03, 2018 9:03 am
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Many Thanks Brian,

Will digest all of this and ask around. I like the idea of 'PWM' indicating the second.

Thanks again!
by Furgus
Sat Dec 01, 2018 11:42 pm
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Thanks Brian that sounds very interesting indeed! My initial thoughts on the feasibility....the 'whole second ' pulse would need to be marked, or different in some way, to the others....not sure if thats possible.....? Back to SharpCap.....I can say that since Robin's fix of the latest version...its...
by Furgus
Sat Dec 01, 2018 3:10 pm
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Thanks Robin and Brian for your thoughts. I wonder if a simple subtraction of the exposure duration is taken from the timestamp allocated at the end of the exposure? This would get you quite close. Certainly it fits in with my observation that the timestamp is virtually perfect when running the came...
by Furgus
Fri Nov 30, 2018 10:01 am
Forum: General Discussions
Topic: SharpCap Timestamp accuracy
Replies: 30
Views: 2617

Re: SharpCap Timestamp accuracy

Thankyou....it does makes sense.....but I wonder what exactly is happening because I think I'm seeing another effect. Enclosed a very short animation from my ZWOASI174 . This has a modification to record the output, via fibre optic, of a 1PPS LED from GPS. This is accurate to 100 nanoseconds. (It is...