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SharpCap - free Astro Webcam Capture Software

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Thanks very much for the clarification, Robin. I will probably use RAW16 just to help capture more detail. I've only had problems detecting enough stars in a couple of fields, e.g M51 and M81 using my SW Mak102 (@ f/6) with the ASI224. I found that at 300 gain I needed 20sec exposures rather than 10 sec exposures for enough stars to register, whereas 10sec had worked for other fields. Also found that at 350 gain, and a slightly wider field (lower f/ratio), I could get stacking to work with only 7sec exposures. So I think, as you say, it is really a question of the combination of gain, exposure time and field size for finding enough stars for live stacking to work. One last question - Does background skyglow have any impact on the effectiveness of the star detection algorithm? I have pretty bad sky glow as I live very deep in a white zone, but I'm guessing that this is probably not a factor. Thanks again for your help. 

Errol

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Hi,

the star detection algorithm works with a default threshold of 50 (out of 255) - ie nothing dimmer than that is considered a star. Currently, there's no way to tweak that form the UI. If you use the polar alignment feature which also uses star detection then it re-tries with a threshold of 25 if it fails to find enough stars the first time through.

As I say, send me a frame or two and I can add them to my test frames and see what tweaks might help to bring the stars out more easily.

cheers,

Robin

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Hi Robin,

I have only saved the resulting stacks (using the saved as viewed option in LiveStack) as .png files, so I don't have any individual frames that I assume you are looking for. What I can do  the next time I am out with the camera is collect some individual captures before stacking, and indicate which ones failed to stack once I turn on live stacking. I will PM you a couple of test frames for different objects (one that stacks, one that doesn't) - should be fun to play with :happy7:. Thanks.

 

Regards,

Errol

 

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I just learned about this software. The polar align feature looks very promising and i would like to test it with my ASI 120MM attached to my 9x50 finderscope. Problem is that 2.9 beta versions install correctly on my machine but do not start at all. I see window for brief second and after that nothing happens. I tried to start with ctrl key pressed but this do not help. I also do not see any dmp file on my desktop or in the installation folder. My laptop have core i7 cpu at 2.4ghz, 16GB ram and nvidia 770m videocard. All drivers are updated. Interesting is that the latest stable version - 2.8 starts correctly. Please help me to make 2.9 beta to work so that i can test this polar align procedure. :)

 

Edit: Just to add that my OS is windows 10 64 bit

Edited by neptun

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Hi Robin,

I had several 'freezes' in a short session last night, resulting in having to go the ctrl-alt-delete route and start again.

This is 2.7.2135 under W8, with MS Lifecam. Basically, it keeps capturing, but does not respond to any clicks on any buttons. In order to change settings, I have to crash out of the program.

One issue is that only way to  move the exposure slider is to click auto, then click it again. Once the slider has been moved and you go to another function, it locks in place and you have to go in and out of auto to move it.

Minor issue - it always starts up at minimum resolution, 50%, so a little tiny box at top left! Could you calculate the biggest size of max resolution (typically full-HD at 75% for me) as the default as this is the one that makes target finding easiest.

I managed to get several runs - but then the laptop went flat :-(

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1 hour ago, neptun said:

I just learned about this software. The polar align feature looks very promising and i would like to test it with my ASI 120MM attached to my 9x50 finderscope. Problem is that 2.9 beta versions install correctly on my machine but do not start at all. I see window for brief second and after that nothing happens. I tried to start with ctrl key pressed but this do not help. I also do not see any dmp file on my desktop or in the installation folder. My laptop have core i7 cpu at 2.4ghz, 16GB ram and nvidia 770m videocard. All drivers are updated. Interesting is that the latest stable version - 2.8 starts correctly. Please help me to make 2.9 beta to work so that i can test this polar align procedure. :)

 

Edit: Just to add that my OS is windows 10 64 bit

Hi Neptun,

the first thing to try is to look at the folder where SharpCap saves its log files - maybe some info is getting into the log file that will help sort out the problem even if the program shuts down very quickly. Get a windows explorer window and put

%LOCALAPPDATA%\SharpCap\logs

into the location box and press return - that should open the SharpCap log file folder and you'll probably see lots of log files. It might be easiest to delete them all, then run SharpCap 2.9 and see if a new file appears and what is in it if it does appear - please send me the full content of any log file created by 2.9 or let me know if nothing is appearing and we'll move on to stage 2...

cheers,

Robin

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1 hour ago, Stub Mandrel said:

Hi Robin,

I had several 'freezes' in a short session last night, resulting in having to go the ctrl-alt-delete route and start again.

This is 2.7.2135 under W8, with MS Lifecam. Basically, it keeps capturing, but does not respond to any clicks on any buttons. In order to change settings, I have to crash out of the program.

 

Hi Neil,

There has been an issue in some versions where the controls become unresponsive if they overlap the preview area (basically there is a hidden window above the preview area to handle the reticule drawing and movement and that was covering the controls and stealing the mouse input). I'd fixed it once a long time ago and then the code got lost somehow and I had to fix it again recently. It sounds very like the problem you are having...

So, if you stick with 2.7 you could try reducing the zoom to ensure that the preview area isn't extending under the controls. Or (hint, hint) you could upgrade to 2.8 where that issue is fixed (and where I'd want to be fixing the problem if it turns out not to be that issue).

cheers,

Robin

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Hi Robin,

Sharpcap (I have an old version) sometimes gives me the chance to upgrade, but when I choose to do so, the box comes up saying downloading, but nothing happens and after about 5 minutes I give up.  Any ideas.  I am running a Vista laptop 32bit (my trusty workhorse). 

Carole

 

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I've upgraded to 28.

I was only trying to avoid beta versions as they always run out just before I get a clear night :-)

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Hi Carole,

I'd suggest just downloading and installing the latest version from http://www.sharpcap.co.uk/sharpcap/downloads

You can install different versions side-by-side on the same machine (ie 2.7, 2.8, 2.9) so you can try out the new version without removing the existing version. Windows XP and Vista are still supported in 2.8 and work with the most recent builds of 2.9, but I'm not promising anything for the final release of 2.9 - if something comes up that means no more XP/Vista compatibility then I'm afraid I'm going to wave goodbye to them!

cheers,

Robin

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Hello Robin,

 

I had what appeared to be a more productive evening + early morning yesterday, using the latest version I captured plenty of Saturn, Mars and Jupiter. Transferring the Saturn and Mars to my laptop alone is taking about five or six hours... I have been able to get enough processed to see good results on saturn (for a webcam) and a recognisable if very pallid Mars.

I only had one freeze in a far longer session - it was when recording with the Video controls window open over the view. I couldn't get anything to respond to a click. Otherwise seamless operation. the way the screen jumps between a sequence of captures is disconcerting, but possibly useful as it draws attention to what's happening.

One query - captured video look far brighter on my laptop than on the PC. The difference appears too great to be down to monitor gamma. any idea what could cause this?

One problem (related to the above) the histogram window opens but doesn't show anything, same problem in V27. I used to use this every time I set up a run with earlier versions (same W8 toshiba laptop of mediocre performance).

I found it opened cameras with a more sensible image size.

 

Mars_try_1.jpg

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7 hours ago, Stub Mandrel said:

One query - captured video look far brighter on my laptop than on the PC. The difference appears too great to be down to monitor gamma. any idea what could cause this?

One problem (related to the above) the histogram window opens but doesn't show anything, same problem in V27. I used to use this every time I set up a run with earlier versions (same W8 toshiba laptop of mediocre performance).

Hi Neil,

not sure about the video looking brighter - are you comparing like with like (ie playing back the video on both the PC and the laptop in the same program like PIPP?)

I've seen the empty histogram issue too, but haven't managed to pin down what is causing it yet. It happened on my obsy PC when I was trying to grab Jupiter the other evening but when I'd come inside with a mental note to fix it I couldn't make it break. Most frustrating! If you happen to notice any pattern to it working/not working I'd love to know...

cheers,

Robin

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17 hours ago, rwg said:

Hi Neil,

not sure about the video looking brighter - are you comparing like with like (ie playing back the video on both the PC and the laptop in the same program like PIPP?)

I've seen the empty histogram issue too, but haven't managed to pin down what is causing it yet. It happened on my obsy PC when I was trying to grab Jupiter the other evening but when I'd come inside with a mental note to fix it I couldn't make it break. Most frustrating! If you happen to notice any pattern to it working/not working I'd love to know...

cheers,

Robin

Just playing it in Media player compared to 'live view' in sharpcap. I notice that sometimes changes in brightness do not apply themselves to the display immediately, sometimes the brightness suddenly changes if you open the dialogue and click a slider especially if exposure has been changed. Is there an issue with changes in the main display (along the right) controls not always applying, especially exposure? I may have reduced brightness and it affected the save and not the display?

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Hello sorry for cutting in, but  didnt really know if i should start a new topic,if so i will remove.

My question is can a dslr be used in Sharpcap.

 

Paul

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@paul mc c - no, SharpCap doesn't work with DSLR - I'd recommend looking into a DSLR focused application like APT.

@Stub Mandrel - there are 3 controls on the right - 'Display Brightness', 'Display Contrast' and 'Display Gamma' that  just affect the view in SharpCap, not the saved file. Is it possible that you'd adjusted any of these to brighten or darken the image?

cheers,

Robin

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38 minutes ago, rwg said:

- there are 3 controls on the right - 'Display Brightness', 'Display Contrast' and 'Display Gamma' that  just affect the view in SharpCap, not the saved file. Is it possible that you'd adjusted any of these to brighten or darken the image?

As Betelgeuse said to Procyon... "You cannot be Sirius!"

Actually those controls don't show when using teh Lifecam - I get camera control (exposure) and video Proc Amp (saturation & contrast) plus a button to get the Video capture filter - no display controls. They show up with the 'test camera'

P.S. - that test 'high speed camera' could be bad for epileptics.

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Ah, with a webcam, SharpCap has much less control - it basically tells the Microsoft DirectShow component to get on with it (ie display on screen and/or save to file). Actually all webcam capture programs basically do the same thing, which was what made it funny when someone would declare on this (or another) forum that 'AmCap is definitely sharper than WxAstroCapture' or similar...

The high speed test camera is something I keep meaning to find time to improve - I want to put an image of Jupiter with random noise and fake seeing wobbles on there... One day :)

cheers,

Robin

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13 hours ago, rwg said:

Ah, with a webcam, SharpCap has much less control - it basically tells the Microsoft DirectShow component to get on with it (ie display on screen and/or save to file). Actually all webcam capture programs basically do the same thing, which was what made it funny when someone would declare on this (or another) forum that 'AmCap is definitely sharper than WxAstroCapture' or similar...

 

Thanks, but for the avoidance of confusion what I see on the screen SHOULD therefore be what I see on the recording?

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On 23/04/2016 at 19:40, paul mc c said:

Hello sorry for cutting in, but  didnt really know if i should start a new topic,if so i will remove.

My question is can a dslr be used in Sharpcap.

 

Paul

There's a piece  of software called ExtraWebcam that turns the LiveView stream of a Canon EOS camera into a virtual webcam stream and SharpCap will play along with that (I tested it this year).

 

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@Stub Mandrel Hehe, I'm confused too.

With a camera like a ZWO or QHY camera, SharpCap is in full control of capture and display, so I *know* that what goes in the AVI/SER file is the same as what you see and the same as what comes out of the camera.

With a webcam, SharpCap has less control. It just tells the Windows 'DirectShow' video component to capture from camera X, show it here on the screen and save it to blah.avi. DirectShow does all the hard work. I've never seen a problem like the one you are describing with different brightnesses, but I can't rule it out entirely since it isn't my code that is doing the hard work. I suspect that what is in the AVI file is what is coming off the camera and that one of the playback views (either in SharpCap or when watching the AVI) is being tweaked by something - graphics drivers settings, other DirectShow software installed, magic pixies (just joking), etc.

cheers,

Robin

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I have to say I am very pleased with sharpcap even though I don't use it for astro I use a celestron microscope cam for microscopy and it works a treat much better than anything else out their in my mind.

Alan

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I need to experiment, but decent evenings/early mornings are hard to find when you can take advantage of them :-(

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Hello Robin,

Not sure if this is Windows update or Sharpcap... but there seems to be a correlation between MSVCP120.DLL going missing and Sharpcap updates installing another version of visual C++ redistributable. This crocks my GIS system and with QGIS being a 348 Mb install to fix the issue every time...

Could it be Sharpcap casuing this?

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Hi Neil,

I expect so, sadly :(

As far as I can tell, SharpCap is doing the right thing when it installs - it installs the latest version of the visual studio C++ redist unconditionally on every install as this seems to be the recommended approach. This should leave everything alone if you already have the latest version and install/update if not.

I suppose that there are two possibilities -

1) your GIS program depends on a specific version of the runtime (naughty) and gets upset when it is updated

2) SharpCap's install is doing something evil and unexpected and is actually removing the runtime rather than installing it.

Any evidence either way?

cheers,

Robin

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Well it installed a 2013 X64 version - presumably Sharpcap install the X86 one?

At least now I have teh latest version of QGIS!

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