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 Post subject: Microsoft LifeCam Cinema webcam (HD)
PostPosted: Fri Nov 09, 2012 3:36 pm 
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It must be 10 years since I gave up webcaming (when Keith became too good!) but below are a few notes on my initial tests with this newish HD webcam.

Software - Taking

I tried both WxAstroCapture and SharpCap using the 1280x720 HD resolution. Both are similar and have the essential histogram display for checking over/under exposure. I settled on SharpCap as it offered the promise of 30 frames per second (fps) using the MJPG codec. This codec and frame rate did not appear as an option with WxAstroCapture. SharpCap was a bit flakey and liable to crash but I decided to go with it. I didn't achieve 30fps with Jupiter on my laptop - 20fps was the fastest possible for no dropped frames. In further tests my Quad Core desktop could indeed capture 30fps so it appears that maximum frame rate is down to the PC. However, 20fps is an improvemnt and means 3000 to 4000 frames can be captured before Jupiter's rotation becomes apparent. The MJPG avi files produced are much much smaller than those saved under the YUY2 codec. I took a selection of both to compare. Quality looked similar - these are lossy compressions so neither is perfect.

Software - Processing

Registax6 had no issues with opening either type of avi file - YUY2 and MJPG. I could not persuade AviStack2 to read the MJPG files - "Codec not supported" message. This was despite following instructions to load the krsgravi DLL/DLM which is supposed to fix this. There is also a note that it can read any codec that Windows Media Player can play (the latter played them both) but no go for me in Avistack2. So Registax6 it is for processing.

Registax6 is starting to become somewhat bloated and suffers from overkill in my opinion. Where is the simplicity of earlier versions? I used it for the multipont alignment. Watch out for dust spots on the chip - flat fields would solve this but as yet I have not sorted out how Registax would use flats.

Taking

I used a Celestron C8 Celestar - a classic from the past! No GOTO and simple spur driven RA drive. From the first tests, if Polar alignment is good (not easy with the Wedgepod - you have to kick the legs to adjust) then having no electric DEC drive is not a problem. What is definitely needed is a focus motor.

With the small 3um pixels of the Omnivision chip a focal length of around 4 metres is sufficient. Rather than a barlow lens I use a 2x teleconverter bought on ebay for £2.56. It was a Japanese clone but even these are 4 element and on-axis images are good.

More details on my webpage:
http://www.deep-sky.co.uk/imaging/webcam/lifecam.htm


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 Post subject: Re: Microsoft LifeCam Cinema webcam (HD)
PostPosted: Sun Nov 11, 2012 7:16 pm 
Glad it's not just me that dipped my toe into the HD webcam waters Dave, I only used mine on the moon, but struggled with some of he settings, I'll have to peck your head about the settings you used in astro capture if you don't mind.
Cheers
Andy


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 Post subject: Re: Microsoft LifeCam Cinema webcam (HD)
PostPosted: Sun Nov 11, 2012 7:53 pm 
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Andy,
For the settings, I used a very scientific approach - set everything to the middle.
Exposure set manually looking at the histogram (I think around -7)
WhiteBalance - auto seems to get it near enough
Sharpness 25
Saturation 88
Contrast 5
Brightness 143.

You can save your parameters along with the resolution (1280x720), frame rate 20fps and compression MJPG.

There are probably better settings but I was happy just to get an image first time out.


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 Post subject: Re: Microsoft LifeCam Cinema webcam (HD)
PostPosted: Mon Nov 12, 2012 1:38 pm 
thanks for that Dave,
I'll have to dig around sharpcap next time im out with the intent of a bit of planet capture.
Cheers
Andy


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 Post subject: Re: Microsoft LifeCam Cinema webcam (HD)
PostPosted: Sun Dec 02, 2012 4:56 pm 
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Peter,
The cinema version is the one that is small enough to fit inside an old eyepiece or barlow lens tube. It has more than enough pixels for the planets. Details of the conversion steps are given here:
http://ghonis2.ho8.com/lifecam/lifecam1.html

The only snag I have found is that for extended objects such as the Moon it needs extra processing. It seems to have an in built flat-field to conteract the dificiencies of the lens supplied by Microsoft. This means when we take the lens off it produces reverse vignetting at both left and right edges. To conteract this then flat-fields are necessay for extended objects (not planets). I guess all Microsoft webcams will have this "feature". More details here:
http://www.deep-sky.co.uk/imaging/webcam/lifecam.htm
For the planets it is great value and if I wanted to take the Moon I would use a DSLR instead.

The frames per second is down to your PC rather than limited by USB2. My 2 year old laptop manages 20fps. The higher resolution lifecam studio might well be slower as it is downloading a lot more pixels.


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 Post subject: Re: Microsoft LifeCam Cinema webcam (HD)
PostPosted: Mon Dec 03, 2012 12:06 pm 
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Phil,
That adapter looks a better job than mine. My camera is secured in with blu-tack. Getting the chip square on was a problem - I used a small set-square across the end to check it was at right angles to the 1.25inch tube.


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 Post subject: Re: Microsoft LifeCam Cinema webcam (HD)
PostPosted: Wed Dec 05, 2012 1:52 pm 
sorry for my tardiness in picking this up - i bought the bigger of the 2 models. I also had the same billet adaptor as Phil & Billy Bones.
The main difference between the 2 models (when fitting to the billet adaptor) was that in the guide (ghonis) the unit used had the usb lead for the camera going straight into the back of the unit.
Mine didnt. This meant that i had to get a little bit creative to get the stripped down unit into the billet adaptor. This is where the gary honis website left me in the wind as the instructions intimated that i wouldnt get the upper & lower components to fit - but i did lol.

I wouldnt say it was difficult, but its been so long ago that i cant say it was easy either. If memory serves, i had some mojito's in my toolkit that helped stoke up the bravado before effectively destroying a £50+ webcam.

The most difficult bit was not touching the chip - which i failed to achieve...

Cheers
Andy


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