SharpCap - free Astro Webcam Capture Software

[rwg]

Ok - the trick that would allow the histogram etc to work in capture is something that has been on my 'to do wishlist' for a while - it would also mean (I think) that you could switch from preview to capture without it having to stop the preview and refresh all the controls, which would be good. I'll try to get it done for 1.5 most likely.

As to the Toucam, sadly Philips seem to do nothing the standard way for their drivers - the Toucam isn't using the standard approach for controlling the gain or the non-standard way I have to control SPC

I don't think this is likely to get fixed, since even getting the SPC working was a real slog - your best bet is to try running wcctrl alongside SharpCap.

Robin

[valy]

Robin, SER are perfect for astro, but sometimes I want just an AVI for youtube for example. Now I use avistack to get TIFF, lightroom to bulk process and export to JPEG and Imagetoavi to make the AVI. Or sould I use a different capture tool?

Regarding FPS, in the TXT file (near the SER file), FPS is also 10 on auto mode, the same as in the text box ("Frame Rate (fps)=10"). I didn't pay atention to the status bar, next time I'll check.

Regards.

[rwg]

Ok, see where you are coming from. I probably will not get a chance to do AVI output before 1.4 - I'm reluctant to add any new features that I haven't started yet otherwise I'll never get it finished!

The frame rate thing is a bug which I will try to look into.

thanks,

Robin

[MorningMajor]

I've been trying to do a mosaic of the moon, but after about 20 x 1000 frame captures,(which went well) I noticed that sharpcap started dropping hundreds of frames - ie captured 200 and dropped 1200 - what causes this? I'm guessing it's a disk problem, whilst there still appears to be a reasonable amount of free space left, I'm wondering if it's disk fragmetation? - would this cause it?

[rwg]

Disk fragmentation is a possibility - if it can't write the frame data to disk fast enough it will start dropping frames. At the start of the capture you might get away with it as Windows will start keeping the data to be written in memory, but as the disk gets further and further behind it will eventually run out of memory for this and drop frames.

Another common reason for dropped frames is that the exposure is set too long - if you set (say) the exposure to 1/15s and the frame rate to 30fps, half your frames will be dropped simply because they can't be taken as the camera is still busy finishing the exposure of the previous frame!

Robin

[carastro]

I had my first go at Sharpcap a couple of nights ago. I could not find any captured files afterwards. (Where are they saved, I looked everywhere?).

However I think I set it to capture for too long as I put hours instead of minutes and ended up stopping the capture, would this have also stopped what had been imaged up to that point from being saved?

Have you got a simple "idiot guide" for this?

Carole

[MorningMajor]

Hi Carole

By clicking stop capture you shouldn't lose what has already been taken, so your file should be there somewhere - did you set where to store the file before you started the capture (File>Set Capture Folder). If you didn't do this, I'm not sure what sharpcap uses as a default folder I'm afraid.

Try doing a wildcard search for any AVI files type *.avi into the windows search box (assuming your using Windows of course)

[rwg]

If you haven't changed the capture folder setting, by default it will save capture stores on the desktop.

If that doesn't help then do another quick capture and look at the status bar bottom left after it finishes. The status will include the name of the file out saved the capture to. Your other missing captures will be in the same folder.

Robin

Sent from my GT-I9000 using Tapatalk

[astroimpulse]

I plan on using this for all my webcam stuff as I prefer it to everything else I've used.

I'm having a problem with codecs though.

At 1280 x 720 the MJPG gives me 30FPS but drops a load of frames.

But YUY2 will only give me 10FPS

I've read the HUFFYUV codec will give me the 30FPS I want without dropping (at 10FPS it doesn't drop unlike MJPG).

Does anyone know how to get SharpCap to regonise this after I've installed?

I've tried all the options and can't get it to go above 10FPS or give me a further YUY2 option.

I must be doing something wrong

[rwg]

So, sadly there's a lot of misinformation out there on the use of things like hufyuv with webcam capture. Compression codecs like huffyuv are only applied as the last stage of the chain between the camera and the disk - there's no way that using this sort of compression codec can change the achievable frame rate as that is (in the case of the lifecam) limited by the first stage - transfer from the camera to the PC.

The lifecam has two possible modes for transfer from the camera to the PC - MJPG and YUY2. MJPG allows much higher frame rates at full resolution, whereas YUY2 is limited to about 10fps as you've found out.

Now, the important thing to note is that the data arriving at the PC is in this compressed format in the first place - image data loss has already occurred at this point in either YUY2 or MPJG mode. The best thing to do is not to apply any separate compression filter when saving, as that could only lead to further image data loss. If you capture in MJPG, the saved AVI is the raw MJPG data from the camera, if you capture in YUY2 it's the YUY2 data. This obviously has the best performance too as there is no need for compression code to run.

This is why SharpCap deliberately doesn't offer any option to use compression codecs like HuffYUV - they can't offer any benefit except a (possible) reduction in avi output size at the cost of reduced image quality.

Hope that this explains things. As for dropped frames in MJPG - one thing to check is the exposure time - if this is set too long then the frame rate can't be maintained - you can't do 30fps at 1/15s exposures!

Robin

[astroimpulse]

Awesome explanation! Massive thanks

If you capture in MJPG, the saved AVI is the raw MJPG data from the camera, if you capture in YUY2 it's the YUY2 data. This obviously has the best performance too as there is no need for compression code to run.

Are you saying stick with MJPG (@30fps) in that sentence? Or is the second sentence referring to the latter part (YUY2 @ 10fps)?

It's the only part that isn't crystal clear to me in that awesome post

[rwg]

Sy,

depends on the seeing - YUY2 images should be better in theory than MJPG - less compression means less artifacts in the image. If the seeing is good then 10fps YUY2 will give you the best results. In poor seeing, you might do better by going to MJPG and 30fps.

Another possibility is to lower the capture resolution and then crank the zoom up to maximum. My testing indicates that with the Lifecam HD, doing this acts as a 'region of interest' crop on the full resolution picture with no noticeable quality loss. So you could do YUY2 at 800x480 at 20fps or similar if you are doing planetary work where the planet will fit into the cropped region.

I can see that I'm going to have to write a FAQ

cheers,

Robin

[astroimpulse]

Hmmmm, interesting

So effectively using the zoom would give me a similar resolution as using full HD would after I'd cropped it down to the area of interest? I guess the full HD could be pointless on planet shots where the planet only fills a small area. 95% space etc.

Interesting and makes sense.

Cheers Robin

[carastro]

Try doing a wildcard search for any AVI files type *.avi into the windows search box

Brilliant, found a whole load of them, guess where?

Program files\rwg\sharpcap

Would never have thought of looking in the programme folder.

Now, how to alter the destination for next time.

I also can't work out the capture timer as it just seems to keep going whatever I put in it, and then when I stop it the task bar is still rolling up loads of numbers.

Well I am getting the files, but just would like to make it work as it should.

Thanks

Carole

[MorningMajor]

I can see that I'm going to have to write a FAQ

Yes please!

[MorningMajor]

Now, how to alter the destination for next time.

Go to File>Set Capture Folder - then navigate to where you want to store them.

[rwg]

@Carole

no, I wouldn't have expected the files to go there either - hope you've managed to reset the destination as @MorningMajor suggested. I'll try to work out just why that is happening.

As to numbers in the status bar, it shows frame counts when previewing as well as capturing (so you can see if you are dropping frames before you start capturing for instance) which might be what you are seeing. Get the hang of things first using 'unlimited' capture mode and starting/stopping captures manually, then try the limited modes.

@Sy,

yes, the results _should_ be the same. I tested on a terrestrial target with both full HD resolution and a lower resolution zoomed to max and couldn't see any difference between the detail seen.

Robin

[malc-c]

I've flashed a SPC880 to a 900N, and just completed the SC1.5 mod using the three transistor method to give a serial connection. It all seems to work and I've used the Astronomy Shed video to set the LX mode... however can someone confirm how to use the amp on/off setting in SharpCap to enable / disable the amp.

[carastro]

Thanks Sim and Robin.

All Sorted. Capture file destination now changed, and I've even sorted the file capture timer. I had it set to unlimited

So looks like I'm set to go next time.

Carole

[rwg]

@Malcolm,

just set the Amp off control line (probably to DTR) - this will cause SharpCap to try to turn the amp off during each long exposure capture. You may need to check the 'invert' button too if the amp doesn't seem to be turning off properly - a few dark exposures should be enough to tell.

@Carole,

glad it's OK now. Checked the code today and found that the code that set the default folder to the desktop got lost somewhere - probably when I was chaning something else. I've put it back in for 1.4

cheers,

Robin

[rwg]

Right...

I finally got back to finishing off SharpCap 1.4 tonight and there is now a public beta build you can download and test. As it's a beta, it might well contain bugs - please test it indoors before risking an imaging session!

SharpCap 1.4.203 BETA Available - SharpCap

Here are the highlights...

* Long exposure support for Basler cameras

* Parallel port control support for LX modified webcams

* Automatic USB serial port selection for LX modified webcams - chooses highest numbered serial port.

* Frame progress bar shown for all cameras in LX mode to show how far through the current frame you are

* Single frame capture support for all supported cameras types

* Multiple output formats supported - SER, PNG, FITS for non-webcam cameras

* Experimental support for any camera with an ASCOM driver

* Improved capture file handling - formats that produce multiple files like PNG and FITS create a folder and save them into it

* Various bugfixes

enjoy,

Robin

[malc-c]

Robin

I have downloaded and installed the beta but get the attached error and then the app crashes

error.txt

[leenewtoastro]

installed and ui works fine here. strangely i installed to another directory to avoid messing up orgonal sharpcap but the install has uninstalled the original!

will test lx stuff tomoz (tuesday)

[malc-c]

Strange - un-installed original version and installed the beta again and still get the same error

[leenewtoastro]

Try another download malc. Properly extract to folder instead of straight double click install if you get me