#141  
Old 28-05-2016, 12:03 AM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,346
Well i managed to get some images tonight, nothing that is ready to share but making progress. No issues with the camera but the support systems are driving me crazy. SG Pro is a learning curve for me, and coming from the dslr/BYEOS world it is very different. I have got focusing working fine now, but initally just worked with luminance through an open filter wheel spot as that easier than doing it through a narrowband filter. Did some test subs on the Lagoon Nebula, with no filters, just to see if the gain setting and sub lengths were right. Shot several different exposure lengths, 30, 60, 90, 120, 180 secs in luminance, to check the histogram and clipping. Shot some more in Ha to compare the histogram, and moving it right off the bias side does take some time. I probably have the camera setting wrong. I was initially using unity gain setting, and tried Jon Ristas suggestion of optimal gain at 60. The images are displayed on the screen after down loading but then when i tried to go into the file to have a look at the images there was nothing there. I have no idea why it is not saving images in the designated Light file. Update, just found out i have to right click on the temporary image to save it, hope there is away to save a sequence of images without having to save each one like that. Any suggestions on that? Is it a limitation of the trial version? It is supposed to be a full working version.
SGPro froze on me once for some reason, but that has been reported on CN as well, some sort of memory issues that ZWO is discussing with the SGPro people.
I may try APT the next session.
Hope someone else gets one of these cameras soon.

Last edited by glend; 28-05-2016 at 03:46 AM.
Reply With Quote
  #142  
Old 28-05-2016, 06:54 AM
Shiraz's Avatar
Shiraz (Ray)
Registered User

Shiraz is offline
 
Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,787
It will be a lot different to a DSLR, but when you get it going, SGpro does it all very nicely. It has the ability to focus through a broadband filter and then switch back to narrowband, which makes it easy with parfocal filters. If it is working, I guess that you must be able to see stars in the images, so the camera is working. You will be on a huge learning curve if you are beginning to use a new camera, filter based imaging and SGpro all at the same time!! SGpro by itself has a daunting collection of options, many of which only make sense after you have been using it a while, so some simpler software that only does image capture would be a good idea while you check out the camera. FWIW, I intend to use Nebulosity while getting the camera sorted because I know it well and it is the most stable software I have. I also occasionally use FITSliberator for checking FITS files if anything has gone wrong - it is a nice tool for viewing files.

Are you quite sure that there is nothing saved in the files?. the sky data will be pretty close to zero (which I understand defaults to 21 for this camera/software) for short subs, especially if you are using a low gain setting and on a linear display you will see a totally black background with a few stars and hot pixels. You will need to use a huge amount of screen stretch (eg with the sliders in SGpro) to see anything dim. You don't normally have to right click on an image to get it to save properly - when running the sequence it will flash a status display down the bottom of the screen that says "downloading" and then "saving file" (or something like that).

It will all work, but it is worrying that SGpro froze - it generally seems to be stable and reliable. Do you have the latest ASCOM driver for the camera?

Last edited by Shiraz; 28-05-2016 at 07:40 AM.
Reply With Quote
  #143  
Old 28-05-2016, 07:47 AM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 15,472
I agree with Ray. Learning 3 different things at once is not ideal in my experience. I try to limit the change I am working on to one at a time. Otherwise it can be frustrating and take the fun out of it.

Greg.
Reply With Quote
  #144  
Old 28-05-2016, 07:49 AM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,346
Thanks for that response Ray. I am sure there is nothing in the SGP files. I went into the subfolders that it created for Darks and Lights, and it is creating subfolders in those by date but there is noting inside the sub folders. I had shot a bunch of darks and only looked at them initially while they were on the sequence capture screen and it never occurred to me that they were not being saved, until I checked the files last night. I can see the sequencer working and yes I can see the download taking place on the bar at the bottom, but it does not save after that.
Re your other question, yes it certainly is working and I can clearly see my target object in the sequence temp display, even down to the gas cloud detail in the Lagoon both in Luminance and Ha. It was when I tired to open one in Photoshop that I discovered nothing in the destination file.
I have downloaded the SGPro Manual pdf (all 200 pages of it) and will be going through that today.
Yes I have the correct (and current) driver for the camera. Re the freeze, maybe that was the incorrect term, it goes into a "Not Responding" mode, and I suspect it maybe due to filter wheel start up routine. It only requried a restart once. I will try to raise a question on the ZWO forum about it but Sam has previously said SGPro had a memory management issue, so perhaps he will just refer me to them. Time will tell. Now that I am getting familiar with SGPro, I don't really want to try another one, if I can just solve the 'save' issue. I do miss the ability to review images in great detail on a Liveview screen.
Reply With Quote
  #145  
Old 28-05-2016, 08:13 AM
Atmos's Avatar
Atmos (Colin)
Ultimate Noob

Atmos is offline
 
Join Date: Aug 2011
Location: Melbourne
Posts: 6,329
Might seem a bit silly (its happened to me so I am talking from experience ) but are you sure that it hasn't saved the images somewhere else? I'd suggest searching for "Frame 1" and seeing if anything pops up somewhere.

And with the Filter Wheel, I depending on which driver you are using it does hold up the software (like it has frozen) until the filter wheel has finished doing it twice rotation thing. The normal driver does it, just means that it resets after every connection. The RS232 driver doesn't, just connects and assumes that it is on filter position 1 even when it isn't. After the first move to another position it finds itself but it doesn't pause SGP upon connection.
Reply With Quote
  #146  
Old 28-05-2016, 08:23 AM
Shiraz's Avatar
Shiraz (Ray)
Registered User

Shiraz is offline
 
Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,787
that's a good point - maybe try running it with a camera simulator and see where the files end up.
Reply With Quote
  #147  
Old 28-05-2016, 08:33 AM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,346
Doh!

It's my fault, I did not realise that to open an image you have to go to the little folder icon on the tool bar. When I do that I can see my Darks and Light captured images all there. I've just looked through them and I might put up a few jpgs here later to illustrate the various exposures and what they picked up (in luminance and Ha).

I have also just upgrade my ASCOM to Platform 6.2 and the latest release of the ASI1600 driver V1.0.2.5, I had been using V1.0.2.4

I feel like I am making some progress. I will do some daytime testing just to make sure the new ASCOM, drivers, and devices are playing nice, but I am encouraged. Images soon.
Reply With Quote
  #148  
Old 28-05-2016, 09:16 AM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,346
First Image

Of course SGP only produces FITs files, so I have had to go through Fits Liberator before going to Photoshop to get this image. Not sure I want to do that all the time.

So this first image is pretty rough, but as a first attempt with this new equipment and software I am ok with it. It is a single sub of 180" shot at Unity Gain setting (I think), with sensor at -25C. Histogram is way over to the left. No darks, bias, or flats applied, this is just a single sub. No processing in Photoshop other than conversion to jpg for upload to Astrobin:

Detail page here:
http://www.astrobin.com/full/250497/None/

Full size here:
http://www.astrobin.com/full/250497/None/


Last edited by glend; 28-05-2016 at 09:41 AM.
Reply With Quote
  #149  
Old 28-05-2016, 09:20 AM
Atmos's Avatar
Atmos (Colin)
Ultimate Noob

Atmos is offline
 
Join Date: Aug 2011
Location: Melbourne
Posts: 6,329
This has just had a histogram stretch of the above data.
Attached Thumbnails
Click for full-size image (Lagoon.jpg)
190.1 KB63 views
Reply With Quote
  #150  
Old 28-05-2016, 09:35 AM
Shiraz's Avatar
Shiraz (Ray)
Registered User

Shiraz is offline
 
Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,787
woohoo

hmm, that would qualify as pretty convincing - 3 minutes eh?

but where is all the CMOS noise!!!! What trick have you used to hide it???
Reply With Quote
  #151  
Old 28-05-2016, 09:40 AM
codemonkey's Avatar
codemonkey (Lee)
Registered User

codemonkey is offline
 
Join Date: Jul 2013
Location: Kilcoy, QLD
Posts: 1,761
Nice first light Glen! By the way, it's normal for the histogram to be over to the left with these sorts of cameras. If it's not, you've overexposed it.

How do you feel about PixInsight?
Reply With Quote
  #152  
Old 28-05-2016, 09:43 AM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,346
Here is the 60 second test sub (single frame) no stacking, but this one I have stretched. The histogram looks much better.
This is just 60" folks:

http://www.astrobin.com/250499/

Full size here:

http://www.astrobin.com/full/250499/None/
Attached Thumbnails
Click for full-size image (Lagoon Nebula 60sec 1x1 Lum Single Frame Stretched Small.jpg)
196.7 KB33 views
Reply With Quote
  #153  
Old 28-05-2016, 09:49 AM
Shiraz's Avatar
Shiraz (Ray)
Registered User

Shiraz is offline
 
Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,787
Quote:
Originally Posted by glend View Post
Here is the 60 second test sub (single frame) no stacking, but this one I have stretched. The histogram looks much better.
This is just 60" folks:

http://www.astrobin.com/250499/

Full size here:

http://www.astrobin.com/full/250499/None/
no sign of any fixed pattern noise, "amp glow" or overload streaks on the bright stars - cool.

Last edited by Shiraz; 28-05-2016 at 10:32 AM.
Reply With Quote
  #154  
Old 28-05-2016, 10:07 AM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,346
And finally here is the 30" single frame that has been stretched.

http://www.astrobin.com/full/250500/None/

I am thinking the short 30" subs are enough given the way they stretch, and the clipping is not there (see the Astrobin histogram on the detail page here:
http://www.astrobin.com/250500/
).

So a stack of these 30" subs will be my next effort I think. PS: remember the moon was up when these were shot.
Reply With Quote
  #155  
Old 28-05-2016, 10:10 AM
codemonkey's Avatar
codemonkey (Lee)
Registered User

codemonkey is offline
 
Join Date: Jul 2013
Location: Kilcoy, QLD
Posts: 1,761
So... anyone wanna buy a SX-674?
Reply With Quote
  #156  
Old 28-05-2016, 10:31 AM
Atmos's Avatar
Atmos (Colin)
Ultimate Noob

Atmos is offline
 
Join Date: Aug 2011
Location: Melbourne
Posts: 6,329
For 30" all of the brighter stars look very bloated, I do wonder if this has anything to do with the settings that you mentioned you were a bit unsure with.

To get them correct I found following a QHY How To quite useful.
You can do it inside which is handy, you basically start with everything at 0 (Gain and Offset which I assume are the two you can change).

Point the camera at a wall that is reasonably evenly illuminated. Start with fast exposures (0.001) and double the exposure time each frame looking at the average ADU, what you are looking for is when the average ADU stops getting higher (looking for saturation).

Then using that exposure (where it just reaches saturation) you increase the gain until that levels out at 65535 ADU.
To deal with the offset, start taking bias frames and slowly increase the offset until the bias level is 500-1000 ADU.
Reply With Quote
  #157  
Old 28-05-2016, 10:50 AM
Shiraz's Avatar
Shiraz (Ray)
Registered User

Shiraz is offline
 
Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,787
Colin, I think that the 1600 has split amplification (and an on-chip DSP keeping watch?) - it does not behave much like a raw CCD.

ZWO/Panasonic? have already done the calibration (I guess controlled by on-chip registers) and you can dial up any allowable mixture of read noise, dynamic range etc. as per the graphs. And you can control the exposure - should be an interesting optimisation problem. The offset defaults to 21 ADU? in most software.
Attached Thumbnails
Click for full-size image (zwo.jpg)
82.2 KB47 views

Last edited by Shiraz; 28-05-2016 at 05:25 PM.
Reply With Quote
  #158  
Old 28-05-2016, 11:06 AM
Atmos's Avatar
Atmos (Colin)
Ultimate Noob

Atmos is offline
 
Join Date: Aug 2011
Location: Melbourne
Posts: 6,329
Quote:
Originally Posted by Shiraz View Post
I think that the 1600 has split amplification and an on-chip DSP keeping watch Colin - it does not behave much like a raw CCD.

ZWO/Panasonic? have already done the calibration (I guess controlled by on-chip registers) and you can dial up any allowable mixture of read noise, dynamic range etc. as per the graphs. And you can control the exposure - should be an interesting optimisation problem. The offset defaults to 21 ADU? in most software.
I assumed that was Glen was referring to may have been similar to what I needed to do with my QHY9&22 which is set the gain and offset as they don't.

Looks different
Reply With Quote
  #159  
Old 28-05-2016, 11:39 AM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,346
The camera has three standard pick list gain & offset settings to choose from: high dynamic range, unity, and lowest noise. I can't be sure but i think i was using Unity, which happens to have a gain of 139 as shown on the graph below. In addition you can slide the bars to choose your own settings. Jon Rista (CN) seems to think he is going to do everything at a gain setting of 60.

I have to say all the ADU comments below go right over my head.
I beieve, in time, as more cameras get into imagers hands, the settings issues will resolve themselves through user feedback. I am not seeking perfection right now, just to produce some reasonable images with this big change in approach is enough for me for now.

As it is clearing up here i am starting to consider narrowband for tonight. The beauty of this camera is that you can probably do enough data acquistion in a few hours to build a nice narrowband image. What used to take me three nights with my mono dslr is only going to take a couple of hours now, imho.

Looking at the exposure charts on CN it looks like anything above 20" will give good data. That might be true for LRGB but i expect narrowband to take much longer. However, i did do one Ha image last night at 60", it was out of focus because i forgot to refocus, but showed me enough to think maybe that could be a reasonable sub length to start at, something impossible with most cameras.
Reply With Quote
  #160  
Old 28-05-2016, 11:49 AM
Shiraz's Avatar
Shiraz (Ray)
Registered User

Shiraz is offline
 
Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,787
gain 60 looks to me like a good choice to start with - full 12 bit dynamic range and still a very low read noise. It is going to be exciting to push things into the gain300 region though...
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 04:36 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
OzScopes Authorised Dealer
Advertisement
Lunatico Astronomical
Advertisement
Bintel
Advertisement
SkyWatcher Australia
Advertisement
Celestron Australia
Advertisement
Meade Australia
Advertisement
NexDome Observatories
Advertisement
Astronomy and Electronics Centre
Advertisement