SharpCap - free Astro Webcam Capture Software

[rwg]

@Demonperformer

A quick look suggests USB speed issues - You look like you are using a USB2 port but these cameras are much happier on USB3. If that isn't possible, try turning your Turbo USB setting down (a long way) or try putting it onto Auto. I think that you are dropping a vast majority of the captured frames due to USB issues which leaves everything else rather flaky.

cheers,

Robin

 

[rwg]

10 hours ago, bendavidson said:

One more question for now...

This stacked pic  was from a series of captures of the pinwheel galaxy - gain was too low and the moon was full, so poor quality pic generally, but there's something seriously wrong with the flats - any idea what is causing the banding?  I'm worried I've just got the wrong sort of light panel but hoping there's something in the SC settings I can adjust.  Flats were 1/500th of a second.

(Stacked pic without flats also attached)

Thanks.

Ben

 

Definitly looks like a processing issue as there is no sign of the stripes in the stack with no flats. Also the 3d look in the region of the dust donuts is very odd.

I think you might get more help in a processing thread as I haven't really got as much expertise to add in this field. What happens if you use your flat frame as both flat and light frame? In theory that should give you an even gray output I believe.

cheers,

Robin

[DonBoy]

ASI1600MC-Cool Win7

1. ver 2915 bin 4 crashing - did a send & quit - not an issue in 2895

2. With hardware binning there is no signal increase beyond what bin 2 yields with bin 3 or bin 4  

3. Mono bin only works with bin 4

Don

 

[Demonperformer]

17 hours ago, rwg said:

@Demonperformer

A quick look suggests USB speed issues - You look like you are using a USB2 port but these cameras are much happier on USB3. If that isn't possible, try turning your Turbo USB setting down (a long way) or try putting it onto Auto. I think that you are dropping a vast majority of the captured frames due to USB issues which leaves everything else rather flaky.

cheers,

Robin

 

Thanks for this, Robin.

I have now had a chance to action your suggestion and it has worked a treat: turbo USB reduced from 90-40 and (for good measure) I reduced the maximum frame rate to 1fps. Won't be good for planetary, but I will worry about that later (if at all). For DSO imaging, 1fps maximum should not produce any difficulties. Applying the same principle to APT, I have solved the problems I was having there as well - so doubly good advice.

Thanks.

[bendavidson]

Thanks from me too - will turn down turbo and see if I get less temperamental capture behaviour...

what's the lowest one should set it at?

[rwg]

Re. the Turbo USB - turn it all the way down, then gradually up until you start getting the dropped frame count increase. Then turn it down a bit and you should be good.

Setting the Maximum Frame rate to 1fps is not helpful in this case - that doesn't have any effect on SharpCap grabbing frames from the camera, it just makes any excess frames get thrown away.

cheers,

Robin

[Brent]

Hi Robin,

Firstly, thanks again for this great piece of software.

I have an issue which I have found an effective (if long winded) workaround for, but I thought I'd let you know about it anyway.

I have SharpCap 2.9 and have been testing the polar alignment routine with a 9x50 finder and a Philips SPC900 LX modified webcam.

I can set the exposure length correctly (I need to use about 12 seconds to resolve enough stars) and the screen displays each new exposure UNTIL I open the polar alignment window. The last image then stays on screen only until the next exposure completes, at which point just a frame which appears to be noise is displayed. I found that if I close the polar alignment window, new exposures resume being displayed correctly, and if I re-open the polar alignment window it will return to the step at which I closed it  and continue, using the last frame displayed (hope that makes sense!).

So, I can open and close the PA window and time it right to get through the routine but obviously don't have live on-screen updates on the final step. The routine is otherwise really fast and accurate I must say, well done, and thanks to you and @themos for this great innovation ?.

[rwg]

@Brent

I think I know what is going on here - both the LX module and the Polar align are fighting over the one place in the application where they can plug in and receive each frame as it arrives. I hadn't thought of that combination - I will have to look into it.

cheers,

Robin

[Brent]

Thanks Robin 

[bendavidson]

On 9/18/2016 at 21:16, rwg said:

Definitly looks like a processing issue as there is no sign of the stripes in the stack with no flats. Also the 3d look in the region of the dust donuts is very odd.

I think you might get more help in a processing thread as I haven't really got as much expertise to add in this field. What happens if you use your flat frame as both flat and light frame? In theory that should give you an even gray output I believe.

cheers,

Robin

Thanks Robin,

Looking at the screen grab and capture below, I think the issue is likely to be the type of light panel I'm using.

Would value any views but I don't think it's a SC issue...

 

 

Capture_0001.fits

[rwg]

Try using minimum gain and a longer exposure for your flats -  that effect looks awfully like the banding you get on some webcams under 50/60hz electric light, so I'm suspecting that your light panel varies in brightness over a short time period and maybe a longer exposure would help average that out.

cheers,

Robin

[bendavidson]

On 9/23/2016 at 08:39, rwg said:

Try using minimum gain and a longer exposure for your flats -  that effect looks awfully like the banding you get on some webcams under 50/60hz electric light, so I'm suspecting that your light panel varies in brightness over a short time period and maybe a longer exposure would help average that out.

cheers,

Robin

I thought that too, but until just now was under the misapprehension from the guide notes I've been using here that I needed to ensure the gain on flats was the same as on darks.  

I'll try lower gain, longer exposure and see if that works.

Thanks,

Ben

[bendavidson]

Nope - still didn't work - 1/125th second and still getting the stripes (turned the gain down low to get the histogram in the middle, but you can see the stripes around the vignette edges even with gain higher).  I surmise it's the type of light panel I bought.

[bendavidson]

On another subject, am I right in thinking that the settings in the 'image controls' panel make a difference to the image you see on the screen, but no difference to the captured image saved as a FITS file in my case?

[rwg]

Hmm those stripes definitely not looking good. I'd suggest testing an alternate illumination for flat frames just to check - something simple like cloudy or clear daytime sky, a piece of A4 paper with a torch shone at it or similar - just to make sure that you don't get lines with those. If you do get lines with any of those then it would point to the camera, if not then the finger is pointing squarely at your light panel.

Most of the controls in the panel on the right *DO* affect what gets saved in the FITS file - Exposure and gain are the most obvious examples, but gamma, white balance etc also do. The only things that affect the screen only are those in the 'Display Controls' section which allow you to tweak the gamma/brightness/contrast used for display without having any effect on the saved files.

cheers,

Robin

[bendavidson]

Re: light panel, tried morning twilight for flats and it was fine.  Must be the light panel, although it's been suggested it's the power source rather than the panel as such - will check that out before getting a different one.

Re: image controls - thanks; kicking myself!  Don't know where I got the from that they made no difference, but glad I know now and won't [removed word] up more captures by playing around mid-sequence!

[rwg]

Sounds like you are on the right track - good luck

Robin

[DonBoy]

Robin,

When using the ASI1600MC-Cool with latest SC the Brightness (offset) control ranges from 0 to 240 on two of my computers and on two other folks they only see a range of 0 to 60.  What should the correct  range be?

Don

[rwg]

@DonBoy

Looks like this is a deliberate change made by ZWO in their SDK - see http://astronomy-imaging-camera.com/software/change_ASISDK.txt

I'd expect to see a maximum brightness of 60 in any computer running the very latest (2.9.2929) version of SharpCap.

cheers,

Robin

[dist]

Hello together,

first of all excuse my writing mistakes but I have little practice in speaking English and additional I 'm new in this forum.

Last week I got a new QHY183c Coldmos Color camera
Recommended software for this camera is SharpCap 2.9 that runs on my Windows10 Computer.
After installing the necessary camera- and ASCOM Drivers for my QHY-4pinfilterwheel I got some error Messages.
In summary the content of these messages is that the filterwheel could not be found by the program although the camera works and the filterwheel is connected.
With the same configuration all is working well in MaximDL.

 

Who is able to give me a hint to solve the Problems.

Dietmar

[rwg]

Hi Dietmar,

if you are using the filterwheel connected via the camera then you do not need to select the filterwheel in the SharpCap hardware selection settings page - SharpCap will automatically detect the connected wheel and use it when you start using the camera. In fact you have to do it this way because while SharpCap is using the camera, it isn't possible for the QHY ASCOM driver to talk to the filter wheel.

Hopefully this will solve the issue - if not, please post a screenshot of the message you are getting.

thanks

Robin

[dist]

Hi Robin,

thanks for your prompt reply.

Unfortunately your proposal did not work properly.

I took a series of screenshots. They might be helpful for you to analyse the Problem.

Kind regards

Dietmar

 

 

[perdrix]

This is actually a request for help with the code of another application (PHD2).   SInce the 1607 anniversary edition of Windows 10 x64, PHD2 fails to get the list of valild video modes for my Lifecam Studio WDM webcam.  As a result, it fails to connect.

However it's clear that Sharpcap does succeed in getting this as it populates the Video Formats section of the control panel on the right.

Would you be prepared to share the code you use to get this information?  I'm OK if you prefer to do this offline (mailto:david.partridge@perdrix.co.uk)

Thanks lots

Dave

[rwg]

@perdrix

Yes, I've heard that Microsoft have done nasty things to webcams in the anniversary edition. I think they have somehow banned the MJPEG mode. It might be that you can workaround the issue by either installing or uninstalling the specific software for the Lifecam camera - the software changes the list of available modes and maybe the different list will help.

Anyway, if that's no good then it's - as you suggest - back to the PHD source and there you will discover that the webcam handling code is based on some sort of camera abstraction class from WxWidgets that was probably old when Windows 2000 was launched. It probably needs a significant re-write from scratch... Rather than share the SharpCap source, I can point you at the places that I used as references when developing it.

Firstly easy to understand but not directly usable in PHD (because it's .NET code ) - http://directshownet.sourceforge.net/  . The samples contain at least one program that will let you detect cameras and show video from it. I think they also have a sample showing how to use the samplegrabbercallback to grab frames from the video, which you'd need for PHD. The same concepts would apply in C++, but the COM code to call all the directshow interfaces is rather more cumbersome.

Second place to look - Amcap (https://msdn.microsoft.com/en-us/library/windows/desktop/dd373424(v=vs.85).aspx).  Amcap is actually a sample application written by Microsoft to show you how to use the Directshow APIs. It's all written in C/C++ and is pretty complete (it does much more than you need just to access a webcam, handling audio, analogue video devices and more). You can get the source by installing the windows SDK, although I have a feeling that it's not in the latest version so you might need to go back and get an older version.

Hope this helps!

Robin

 

@dist

Thanks for the screenshots - I'm going to test with my QHY174Cool and CFW2S which I hope is close enough to show the same problem.

cheers,

Robin

 

[DavM]

I have tried PA using Sharpcap a couple of times. I have a question regarding the "moving" of the RA axis. Can this be rotated by disengaging the clutch and rotating, with the mount turned off, or with the mount turned on and "slewing" with the Hand Set, or doesn't it matter which!

Thanks in advance for replies.

Dave