Computers for Astrophotography Use

Hi Tim,

I'm afraid I dont have a Canon - if it helps I can set up my Nikon and run it through the ASIAIR to compare times if you think it would help?

What I would suggest if it helps is (& sorry if its stuff you've already looked at)

• Which Canon model are we talking about (so can figure if its using USB 2 or USB 3 for data transfer)
• What is the make and model of the laptop you're using, how much free disk space does it have
• Do you have AntiVirus software loaded on the laptop and does it use Active Scanning (thats where it scans every file as its written to disk)

Nige

Hi Tim,

I connected by Nikon up to my 10 year old PC, which has a traditional Mechanical hard drive (not SSD), I controlled it with DigiCam software (as I couldn't find an ASCOM driver  to use SharpCap or FireCapture) . When I do this, saving the image to the PC hard disk I get sub-second transfer & save times.

I'm assuming that you don't have a delay between shots set in BackyardEOS (Sorry for asking the obvious)? 

If you're comfortable with techie stuff,  ou could look at the logfile and see where the delay is occurring.  the logfile should be at "My Pictures\BackyardTEMP\logs"

you should see something like


2020-05-22 11:04:18,825 [7] DEBUG - TAKE PICTURE ::: Shutter(MANUAL) Cable(CameraUSB) Av(1.8) Duration(20.0) Iso(1600) Quality(RAW) Mirror(0) SaveTo(PC)
2020-05-22 11:04:42,606 [5] DEBUG - NIKON EVENT --> OnDeviceOnImageReady(1,type[1]) fired
2020-05-22 11:04:59,204 [CameraTakePictureOnMessageRecieved] INFO  - Timespan 40.603


The key events are 

• Take a Picture
• Ready to download
• Image downloaded

In the above log file it took 17s to download a

The above is taken from a thread with a Nikon user with the same sort of issue
Delay - BackyardNIKON - O'Telescope (otelescope.com)


Or you could post a query on the O'Telescope website for Backyard EOS

Personally, I  doubt your transfer time would be improved by a new laptop (unless you're looking for an excuse to buy one ). Happy to chat about this further if you want at the next meeting

Hi Tim,

I've attached the log from DIGICAM and yes this is transfer of the image from the DSLR to the PC. Granted PC tend to be more powerful but mine is 10 year old Dell (i7 3Ghz with 8Gb RAM. I've attached an extract from the DigiCam Log to demonstrate - its taking 1s exposures with a 1s wait time between exposures. As you will see the time

Then in the interest of completeness, I hooked the Nikon DSLR to my ASIAIR pro, and run a series of image captures, the DSLR images (RAW) are being saved to the MicroSD card. This time I see a delay of 7 seconds (after the 1 sec exposure) to transfer the image to the ASIAIR and write it to its microSD card



So what does this all mean? The answer is I'm not sure or where to go next?

Perhaps you're suggestion of installing NINA and seeing what that gives you in terms of performance is a good idea, as is posting the question on the Backyard EOS web page. 

Let me know if you'd like to get together to try your camera on My ASIAIR or if you want to try with an SSD memory stick (I have a couple) or any combination to try and understand whats happening

Nige

Hi Nige, Hi Richard,

Thanks very much to you both for your messages.

Nige - I'm feeling somewhat guilty, as I didn't start out with the intention of inveigling anybody into doing so much. But I'm very grateful. Your results are quite useful. But I definitely owe you a return favour, or a large drink. Please remind me of that when an opportunity arises! I wasn't familiar with Digicam, but I've looked it up. It looks like a pretty good general purpose camera control program. I'm going to download it and give it a try, out of interest. I'm still rather flabbergasted by how quickly it does things, so I think I need to see it with my own eyes. Your second test, with the Asiair, provides very useful results from my point of view. The fact that you get a seven second turnaround time between shots confirms that my setup, with its 35 second turnaround time, is definitely below par. That's good, as it means I should be able to find a way to do much better. Thank you for all your help and experimentation. It's greatly appreciated. I think you should stop now. It's time for me to get my finger out and do some experiments of my own.

Richard. Many thanks for your thoughts. The fact that your Asiair "barely pauses between frames" adds to Nigel's evidence and further confirms that my setup is abnormally slow. With regard to the camera being disconnected from the laptop, it behaves quite "normally" in that state. With short exposures I can (of course) shoot several frames per second if I wish to. For longer exposures "long exposure noise reduction" might kick in - I think that's what you are talking about - but I have very definitely always had that switched off. I can for example shoot a series of long-exposure dark frames using camera and intervalometer, with the delay between frames being virtually non-existent. Guiding/dithering settling issues etc are of course a possible concern, but it's definitely not that (sorry!!). I'm very aware if/when anything like that is going on, and it's not the cause of the ever-present slow operation. Thanks for your thoughts and information. It's good to consider things and rule them out, which you have prompted me to do.

Separately I was talking on the phone with Nick T about something else. I took the opportunity to quiz him on the subject. We dug into the timing information contained in a series of dark frames on his computer, and ascertained that he gets a turnaround time of about 8 seconds between shots. He's using a quite powerful laptop, with an i7 CPU, running NINA, and an Atik camera with about 5.5Mpix. So although the kit is different, his timings are similar to yours Nige, and probably not out of line with yours Richard.

Time for me to do some experiments. I'm going to install and try NINA, and also try one or two other things, such as running without a USB hub in the system (although I don't believe the hub is the cause of any issues).

I'll get back to you with a full report (!!) once I'm done.

In the meantime, to complete the picture, if there is anybody out there who is using an i5-based laptop for their astrophotography, I would dearly love to know how well that works.

Thanks again.
All the best,
Tim

Hi Max,

Many thanks for doing those experiments. They add to the picture. Although I find that 120 second delay thing rather worrying!!

I've been doing my own experiments. The data transfer from camera to computer seems actually to take only about 5 seconds. The problem appears to be that the software then spends a lot of time "mucking about" before it gets around to asking the camera to start the next exposure. I tried a package called digiCamControl, which Nige pointed me to. That produces an intershot delay of about 5 seconds. As soon as the download has completed it tells the camera to start the next one, then after that it does the "mucking about" thing and about 25 seconds later the downloaded image appears on screen.

I've put NINA on my laptop today and got it all working. Mostly seems good, apart from the galling fact that it seems to be even slower than BackyardEOS. Like BYEOS it does a lot of messing around before it asks the camera to fire the shutter again.

Not sure what the answer is going to be!!

All the best,

Tim

Bit late to the discussion, but I have a fairly high spec (possibly over the top) set up and have no issues at all with acquisition and transfer times. 
In my dome I have my kit connected to an NUC mini PC; Win 11; 11th Gen Intel i5; 500Gb SSD main storage.
Camera is a ZWO ASI071MC OSC.
Image capture is via SGP.
To make things more complicated, the images I capture are written to a MS OneDrive folder on the SSD. This means that they are more or less instantaneously uploaded to the cloud via a WiFi connection (and subsequently downloaded to my "imaging" PC indoors). This does not appear to slow SGP image capture down at all.
I am also monitoring from indoors via a Remote Desktop connection to the dome NUC PC from my indoor PC.

In summary, I suspect the specs of the PC used for image capture are critical for performance. An older device with a standard HDD is likely to struggle.