SharpCap - free Astro Webcam Capture Software

[rwg]

@calan,

ah, right, understood on #3 now - makes sense - I will put that on the todo list.

If you look on the http://www.sharpcap.co.uk website or in the Help->About screen in the program you will find a paypal donation link

cheers,

Robin

[calan]

Thanks Robin.

Is there a way to temporarily disconnect the camera without losing all the loaded settings, dark frame, etc?

As mentioned earlier, I sometimes need to temporarily use the camera for something else... but when I reconnect in SC I have to reload the profile, readjust image controls, load dark frame, etc.

Or...  a way to simply ignore the camera completely (Pause?) may work too. I just know that nothing plays nice for me when two apps are trying to read/control the camera at once.

[rwg]

Hi Calan,

I think your best best would be to get everything set up the way you want and then create a capture profile to save all those settings. Then you can set that profile as default which means it gets loaded every time you open the camera. I think that should work with things like dark frame too (if not, let me know and I will fix).

cheers,

Robin

[calan]

Robin,

I do use saved profiles for various target types, camera gain, and exposure (and set one as a default). But, I typically readjust image controls once the profile is loaded, depending on the seeing, target, moon glow, etc. If I saved profiles for every situation, there would be thousands of them.

Also, the dark frame selection doesn't get saved with my profiles.

Thanks

[larryh]

Robin, here's a couple more examples taken last night.  These are raw frames from video.  Sharpcap seemed to be finding a reasonable number of stars, usually more than 10, but could not solve.

http://nova.astrometry.net/status/1202593

http://nova.astrometry.net/status/1202595

 

[rwg]

Hi Larry,

Thanks for the further examples - I have had a look at your previous sample frames and I am still having trouble working out *why* they aren't solving, let alone fixing the problem! I think that it's actually a combination of a number of reasons including hot pixels and possibly too tight limits on how closely a pattern of stars has to be matched before SharpCap accepts it as a match. I'm thinking of making some pretty big changes to the way that the plate solving is done as what I have now is evolved from the code I wrote to align frames for live stacking - that works really well when the frames are almost the same just rotated or offset a bit. It doesn't seem to work so well at finding a match when there are big differences like hot pixels or a big difference in the area covered.

cheers,

Robin

[bendavidson]

Hi Robin, thanks for the programme and support.

I've installed Sharpcap 2.8 and managed to get it to connect to my ASI1600MC.  I can change settings and switch on and off the cooler from Sharpcap, but when trying to capture stills the computer freezes.  Earlier when connecting via a USB hub the status bar looked like it was capturing, but  only the capture settings file saved and not the actual image.  The freezing issue occurs when I plug the AZI1600 direct into my Windows 7 PC.  After several tries the PC is now freezing as soon as I try to select the camera.

Anything obvious I can try to fix this?

Cheers, 

Ben

[rwg]

Hi Ben,

are you really using 2.8? 2.9 would be a better bet for the 1600 cameras as it has an updated version of the ZWO SDK which should give better support for those cameras.

cheers,

Robin

[bendavidson]

Hi Robin,

Am using 2.8.2378 -  would that still be the issue?

Will download 2.9 and test...

[bendavidson]

17 hours ago, rwg said:

Hi Ben,

are you really using 2.8? 2.9 would be a better bet for the 1600 cameras as it has an updated version of the ZWO SDK which should give better support for those cameras.

cheers,

Robin

I've downloaded and installed the latest 2.9 version.

The bug is still there - if I use a USB powered hub nothing is captured (or at least nothing is saved); if I plug the USB cable straight from my camera to the PC, Windows freezes as it appears to be saving the captured image and I have to do a hard reboot.

Any ideas?

 

[calan]

Is there a way to use Live Stack and have it automatically save each frame that is successfully stacked while viewing on the screen?

Probably obvious, but I can't figure it out. I thought I was doing that when after live-stacking 50 exposures or so, I would hit Save and choose "16 bit stack"... but it appears that I only got a single image for each object ... all night.  

[rwg]

@calan

Currently Live Stacking only saves the final stacked output - there's no option to save individual frames. That idea is already in the todo list, just hasn't had a chance to happen yet.

@bendavidson

Ok, let's check a few things - are you using a USB2 or USB3 connection? Do you see correct images if you are not capturing (ie if you are just watching the camera output on screen)? How long a USB cable are you using? (USB3 gets sulky when the length gets past about 3.5m or so). Are you using the camera via the direct SDK support in SharpCap or via the ASCOM or Webcam driver (last two not recommended). Are you using RGB24 mode or RAW8 mode (RAW8 recommended).

cheers,

Robin

[calan]

50 minutes ago, rwg said:

@calan

Currently Live Stacking only saves the final stacked output - there's no option to save individual frames. That idea is already in the todo list, just hasn't had a chance to happen yet.

cheers,

Robin

That would be a REALLY nice feature. Would bridge the gap between EAA and astrophotography, without having to treat them as separate tasks. After a frame is successfully stacked (which would automatically increase the quality of the saved images based on the live stack filtering), just dump it to disk as a fits file, etc.

[calan]

Tried the polar alignment routine for the first time last night and it is AWESOME. So easy to do, and my unguided LXD75 was staying on target for 20 minutes worth of exposures with hardly any drift at all.

Very nicely done sir!

[bendavidson]

23 hours ago, rwg said:

 

@bendavidson

Ok, let's check a few things - are you using a USB2 or USB3 connection? Do you see correct images if you are not capturing (ie if you are just watching the camera output on screen)? How long a USB cable are you using? (USB3 gets sulky when the length gets past about 3.5m or so). Are you using the camera via the direct SDK support in SharpCap or via the ASCOM or Webcam driver (last two not recommended). Are you using RGB24 mode or RAW8 mode (RAW8 recommended).

cheers,

Robin

I'm using USB3 connection from the camera to the hub, and USB3 from the hub to the PC.

The camera output on the screen looks ok - it refreshes at the interval set (or at least it does now that I'm using SharpCap 2.9), and the hot pixels change from image to image and there are more of them the longer the exposure.  (Cloudless night tonight so will test against the sky later!)

USB cables are both 2m.

I'm using the top menu option (Manufacturers sdk I think).

Using RGB24 mode, the default.

 

 

[bendavidson]

Just switched to Raw8 mode and all is now working fine apparently - images are saving to the hard drive. Via the USB hub.

No idea why that made a difference, but it did.

Thank you :-)

[rwg]

@bendavidson

RAW8 is only one byte per pixel, RGB24 is 3 bytes per pixel - this is particularly important for the high resolution of these cameras - a RAW8 frame is about 16 megabytes, an RGB one is 48. The RGB frame doesn't actually store any more data, it's just in a less efficient format.

Glad to hear that you are in business though!

cheers,

Robin

 

[Stub Mandrel]

Could you give a three-sentence explanation of the polar alignment function and how to use it! Can I use it with a system with no connection between mount and computer?

[rwg]

Hi Neil,

yes, you can use it with no computer connection.

1) You use SharpCap to take at least two images of the sky near the pole. You rotate the mount around 90 degrees in RA between the two images

2) SharpCap works out two points from the images a) the point about which they appear to rotate and  b ) the position of the celestial pole (plate solving the images)

3) If the two are in the same place then you are perfectly polar aligned. If not, SharpCap will guide you through the adjustments needed to correct the misalignment.

It seems to work best with a guiding style camera (ZWO 120, QHY5LII, Altair GPCAM) in a finder-guider (~200mm FL).

A bit more than 3 sentences, but I hope it conveys the idea.

Robin

[Stub Mandrel]

Thanks Robin!

I will try that once I have a guide cam!

[calan]

6 hours ago, rwg said:

It seems to work best with a guiding style camera (ZWO 120, QHY5LII, Altair GPCAM) in a finder-guider (~200mm FL).

FWIW, I just put my ASI224MC in the 60mm finder scope and tweaked the exposure and gain until I saw about 8-10 stars, and it worked great.

[calan]

I tried to control my scope from SC last night, and it says that the driver doesn't support movement (nudge) commands... but it does. I can move the scope manually in other ASCOM programs as well as the POTH handset control.

I'm using the POTH hub, connected to the Meade Classic 200 & Autostar ASCOM combined driver. The driver name is:

"Meade LX200 Classic and Autostar #494, #495, and #497 (combined telescope/focuser, 5.0.4)" 

[bendavidson]

17 hours ago, rwg said:

@bendavidson

RAW8 is only one byte per pixel, RGB24 is 3 bytes per pixel - this is particularly important for the high resolution of these cameras - a RAW8 frame is about 16 megabytes, an RGB one is 48. The RGB frame doesn't actually store any more data, it's just in a less efficient format.

Glad to hear that you are in business though!

cheers,

Robin

 

Hi Robin,

Tryng to stack last night's images today, I find there's no colour data and when zooming in there's a criss-cross pattern of squares.  Is this because the subs saved in png format?  I have tried to set the default as FITS but it seems to switch back to png...

Any ideas?

Thanks...

[rwg]

@bendavidson

You need to tell your stacking software (DeepSkyStacker?) to debayer the frames to turn the mono image with the grid effect into a proper colour image. DeepSkyStacker can be told to do this with FITS input images (look in the Raw/FITS settings). With PNG frames you might need to pre-process them in PIPP into colour frames.

@calan

Can you grab a screenshot of the message? The wording seems to indicate that it's not coming from the SharpCap code. It may be that the Meade driver isn't supporting the way that SharpCap tries to move the mount (the MoveAxis command). Calling ASCOM a standard is a bit of a joke as there are usually 3 ways to do anything and some manufacturers support option A, some option B and some option C. Lots of them also get things subtly wrong, just for fun. Grrr

Robin

[calan]

Suggestion...

It would be really nice to be able to include an overlay on snapshot images saved from the live stack dialog, that shows various info (system date/time, camera, object name, exposure, gain, stack count, and user notes). Similar to the way Miloslick does it, like this:

Bonus points for configurable font, color, transparency, and location of the text.