Camera Controls Always Open Alongside the Capture Window - No Need to Open Dialogs

SharpCap

SharpCap is a fairly comprehensive webcam and Astronomy camera capture tool. It is primarily designed for astronomical use.
I wrote it because I got fed up with the awkward control over camera settings in programs like Amcap, Open Video Capture, etc.
The main goals were to be easy to use when observing, and to help avoid mistakes like capturing with the wrong resolution or camera settings, or overwriting an existing file accidentally.

Main Features

·  Camera controls always open alongside the capture window - no need to open dialogs

·  Can save and restore capture profiles, which store all the camera settings - once you have your camera set up perfectly to capture the moon, save the settings and restore them later

·  Can adjust camera settings during capture if necessary

·  Automatic file name generation for each new capture - no more overwritten captures

·  Camera settings written to file alongside every capture - no more trying to remember what settings you used.

·  Limit capture length by time or frames, or just take a single frame

·  Useful preview transforms - these preprocess each frame of the image when previewing:

·  Highlight over exposed areas

·  Image boost (increase gain to find faint things)

·  Focus score (measures image sharpness to help focusing)

·  Histogram

·  Frame Stacking

·  RGB align

·  Support for LX modified webcams

·  ASCOM Focuser support

·  ASCOM camera support

·  Night mode

·  Zoom the preview

·  Overlay a movable, rotatable reticule on the preview

·  Support for Basler cameras, including unique Basler LX mode support

·  Support for running a sequence of captures

Supported Cameras

·  Almost all webcams

·  Basler cameras that use the Basler Pylon drivers

·  Most cameras with an ASCOM driver

·  Special support for adjusting parameters of the SPC900 webcam in the settings panel

·  LX modified SPC900 cameras (serial or parallel)

·  ZWOptical cameras

Screenshots

Using SharpCap

There are some great video tutorials on using SharpCap for Astrophotography over on the Tutorials board at the astronomyshed.co.uk forum (Note that you need to be a forum member to access the Tutorials).

Getting SharpCap

Head on over to the Downloads page.

Feature Requests

Got an idea for a new feature? Let me know by posting here. You can also vote on features suggested by others.

Improve SharpCap!

SharpCap is open source and extensible - if you can code in a .NET language and want SharpCap to support a new device, you can probably have a go at adding support yourself.
In particular, the following items are modular and can be added to

·  Camera support

·  Focuser support

·  LX control support

Capturing Your Target

In the last postI went through the process of modifing your web cam and setting up your laptop with the programs necessary to use a webcam for astrophotography. In this post I will go through the set up and use of one of these programs, Sharpcap.

Sharpcap is the program of choice for capturing webcam video of your targets. This program allows you to easily change the key settings of your webcam. This is a good thing as each viewing session will require different settings based on the viewing conditions and target you are trying to capture.

Step 1

The first thing you need to do is identify the target you want to capture, the Moon and Jupiter would be to easy targets to work with as they are easily found in the sky. What I would recommend if try and find your target with a low mm eyepiece maybe a 6mm get it centered before swapping in the modified webcam.

Start up Sharpcap.

Depending on your scope specs you might want to attach a barlow as well. I found with my Skywatcher 150p i got better results when using a 2x barlow. Its up to you really, but give it a try with and without the barlow.

Step 2

For this tutorial I will use Jupiter as my target, So after lining up Jupiter in my 6mm eyepiece and then swappingit withmy modified webcam, we should see a view of it on screen in Sharpcap. If you do not, have a play with the focus on your telescope, I had this problem and it took me a while to realise my focus was way out. By playing with it the image came into view.

Spend some time here to try and get the focus as good as you can, this can be very difficult if it is a windy night or a lot of cloud as Jupiter will appear all wavey. One tip is to move to a star and focus on this then move back to Jupiter.

So now we should have a screen something like this.

As I mentioned earlier you should should spend some time getting as good as an image at this point, initally play with the focuser on your telescope, try to get aviewof the cloud bands, You will want to play with the settings on the right hand side of the screen as well, in particular the exposure.If you can see some of the moons of Jupiter in the image set the exposure so theyjust fall our out of the image.

Of course you can play this and sacrifice some detail on the planet to capture the moons its completely up to you.

Step 3

Once you are happy with the focus and exposure there are a few other settings you should look at. The Colour / Space Compression should be set to RGB24. Depending on your viewing conditions the frames per second should be ideally set to 10. Set the resolution as high as you can.

yyyyyy / Settings I used for this CaptureFrame Divisor=1
Resolution=1280×800
Frame Rate (fps)=10.00
Colour Space / Compression=RGB24
Pan=0
Tilt=-9
Zoom=10
Exposure=-9
Focus=9(Auto)
Brightness=118
Contrast=8
Saturation=55
Sharpness=50
WhiteBalance=4621
BacklightCompensation=0

Refocus if necessary.

Step 4

You are now ready to start your capture, Press the Start Capture button in the top left of the screen.

You will then get asked how long a capture you want, I usually try to get about 4 ins but anything over a minute will do the job.

Press Start Capture.

Sharpcap will start recording.

Step 5

When Sharpcap is finished you will have a video file on your desktop. This is the file we will import into our stacking program in the next post.

Below is the capture I got and the one I will be working with.

In the next post we will import this into Registax for stacking.

Using Registax

Stacking the Footage

Ok so from the last post we have captured our footage and are now ready to move this into Registax for stacking. What this program does is analyse the video, splits the video into frames, removes the frames that can’t be used and stacks the rest one on top of each other to produce a single image. There are a lot of options in Registax, the method I am going to show you may not be the best one, but it works for me. Experimentation is the key here. Luckily in Ireland there are plenty of cloudy nights, giving ample time to play with these settings.

Lets get Stacking

First let me remind you of the intial footage we got in our last post from Sharpcap.

Step 1.

Load the video into Registax.

Click Select and pick the video file you want to work with. Your screen should look something like this.

Before we get going on stacking I will try my best to explain the settings you need to go through at this stage.

Belowthe main areas you need to worry about are highlighted. Click on each section to get a more in depth descriptionof each function.

Number of Alignpoints, Show Aligndata, Intensity Selection, Minimum distance between, Set Alignpoints

Step 2

Now that we have our video loaded into Registax and our settings set as per the screen above, we need to Set the Alignpoints.

To this scroll through the video using the slide bar at the bottom until you find your best looking frame, then click the Set Alignpoints button. You should get a screen similar to the one below.

Notice that Registax has place red dots over the image, these are the points that Registax will use to align this frame with the other ones in the video.

Now click Align, Depending on the number of alignpoints and the size of the video this process can take a wee while.

But once it is complete it is onto step 3

Step 3

Once the Alignment is complete you will be presented with a screen similar to the one below.

You can see that there is an image with small circles and lines coming from their center. What you need to do now is scroll through your image until you find a frame that has as short as lines as possible.

Once you have found that you need to click on the Limit button. Registax will now run through all the frames in the video and remove the frames that don’t come up to scratch.

Step 4

When Registax is finished removing the frames you will be presented with a single image. This image is now the combination of all the good frames in your video stacked one on top of each other.

Don’t worry if it still looks poor, the real magic is about to begin.

The panel on the left is what we will be concentrating on now. These are the wavelets and moving the sliders and adjusting the denoise and sharpen levels of each slider bring different levels of detail.

The best thing to do is play with the them, the slider settings will be different for every image. Below are the settings i used for the particular video we are working on.

You can see now without doing anything else to the image some impressive detail is coming out, We can see a Moon, a shadow of that moon and the Great Red Spot as well as some detail in the cloud bands.

Step 5

We could leave the image here or move it into another processing program such as photoshop but i like to do one or two more things before going there.

Histogram

First click on the Histogram button on the panel on the right hand side of the screen.

This will open up a screen with a curve, don’t worry if youdon’tunderstand what a histogram is, I don’t.

But if you slide the Grey Arrow left and right you can quite dramatically alter the image, again experimentation is best here.

RGB Align

The next thing to do is click on the RGB Align button on the right hand side. You will be presented with a box which you can drag andre-sizeover the image of the planet.

Click the Estimate button and Registax will go and do some calculations. This process helps remove any colour around the edge of the planet.

Another thing to do is click on the Flip & Rotate button, this allows you to orientate the image the right way round.

Now we could do some more work in Photoshop if you like, but that is for another tutorial.

For now lets look at a before and after image.

Just a reminder of the equipment used here. The footage was taken using a modified Microsoft Lifecam attached to a 2x Barlow and using a Skywatcher 150p.

You can find the previous tutorials here

Getting Started – Webcam Astrophotography

Recording the Footage – Using Sharpcap

I hope you can see that by using some fairly simple and cheap equipment you can get some very acceptable images. I myself am still learning the processes to get as good an image as possible so if anyone has any advice or would like to add anything to these tutorials please let me know.

Registax Stacking
I've had a few messages from SharpCap users who have had difficulty in getting the AVI files they have captured to stack properly in Registax. Sadly, getting Registax to deal with a full range of different AVI compression methods is a bit of a black art, so here are some pointers to hopefully get you going...
1.  Try changing the colour space/compression setting. A vanilla install of Registax 6.1 on Windows XP will happily cope with an AVI in YUY2 format, but not MJPG for instance.
2.  Try converting your AVI to an 'old format AVI' using VirtualDub (http://www.virtualdub.org/download.html). Open your AVI and then use 'Save old format AVI' from the file menu. This won't help if your AVI looks wrong when loaded into VirtualDub
3.  Install the FFDShow codecs (http://ffdshow-tryout.sourceforge.net/download.php). Don't pick the stable beta 7 release which doesn't seem to have the config programs in the start menu, instead try the 'SVN 32 bit Generic' version. Just installing FFDShow seemed to fix MJPG for Registax6 for me.
4.  Configure FFDShow for VideoForWindows - you'll find the config program in Start->All Programs->ffdshow->VFW configuration. Once you've started it, select the 'Decoder' tab, click on 'codecs' at the top of the list under the tabs and scroll down to the format you are trying to get to work (ie MJPEG). Change the 'disabled' to 'libavcodec' and press OK.
I find that once I have FFDshow installed and working pretty much any AVI will open in Registax.
Having said all that, I don't actually use Registax myself - I find the UI pretty unintuitive and the workflow positively mindboggling. Instead I prefer AviStack (http://www.avistack.de/). AviStack also requires some tweaking to get it to read all AVI formats...
1.  Always download the 32 bit version of AviStack, even on a 64 bit windows box - otherwise the next trick will not work.
2.  Follow the instructions half way down the AviStack main web page to get and install KsGravi (http://www.rlkling.com/dlms.htm). This allows AviStack to access any file format that Video For Windows can handle. You need to copy the two files mentioned into the folder with AviStack2.exe (with the CD icon) in. Use the KsGravi_vs2008 version of the download if nothing changes having installed the first version.
3.  You need to install FFDShow and configure it for VFW as shown above for Registax.