Webcam Imaging. Part 1 Equipment. Overview. Principles. Mono Chips. Colour Chips

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1 Webcam Imaging Part 1 Equipment Overview Principles of webcam imaging Choosing your webcam Other equipment Software Principles Poor man s adaptive optics Freeze the seeing by capturing very short exposures Capture large number of frames Discard distorted frames Stack frames to create an average image Image processing to sharpen image Bright objects Planets, Moon, Sun, Spacecraft Choosing your webcam Good light sensitivity (<1 lux) Fast frame capture rate Good dynamic range Ideally CCD chip, not CMOS Low/no image compression Fast connection Colour Chips Can be used on all subjects Lower resolution than the equivalent mono chip No colour filters and shorter processing Low Hassle Mono Chips Greater sensitivity > lower gain and/or greater magnification Higher resolution than the equivalent colour chip All that is needed for most lunar imaging Luminance layer with RGB from colour webcam For full colour need to buy set of colour filters + wheel/slider ( 200+) RGB AVI takes 3+ x longer to capture and 4+ x longer to process 1

2 Chip sizes 640 x 480 (webcams), 1024 x 768, 1280 x 960 or 1616 x 1232 Small chips have faster frame rates and higher sensitivity (due to larger pixels) Larger chips cover larger area of sky, but slower frame rates + lower sensitivity Planets Large chip size not important as optics/seeing limit resolution more often than chip size Moon/Sun Larger chip = fewer captures to cover a large area Frame rate and compression USB 1.1 Low frame rate > low compression + low gain, but seeing not frozen + long capture times High frame rate > high compression + high gain, but seeing frozen + short capture times Frame rate and compression USB 2/ Firewire/GigE USB 2/USB3/Firewire/GigE = no compression Firewire - need for extra cables of laptops GigE Works over network cabling Larger chips > more data to send > lower frame rates 640 x 480 = max. 60 fps 1024 x 768 = max. 30 fps 1280 x 960 = max. 15 fps Cameras Microsoft Cinema HD LifeCam Xbox Live Vision CMOS Chip x 480 colour Max 30 fps (USB 2.0) Requires destructive modifications Remove 4 x LEDs + glue on adaptor EBay Meade Lunar and Planetary Imager (LPI) Bundle = cam + adaptor + software 640 x 380 CMOS chip 30 (discontinued( discontinued) 2

3 Philips Toucam Philips Toucam Pro II/SPC 900NC Sony ICX098BQ colour chip Chip x 480 colour Max 10 fps (USB 1.1) Discontinued (+ 60 for optional B&W modification) Screw-in adaptor ( 10-20) 20) QHY5v or t a.k.a. Orion Starshoot Planetary Imager Mono/colour CMOS Chip (v) x 480 Mono CMOS Chip x 1536 Max 55 fps (752 x 480) USB Celestron Neximage Celestron Neximage (discontinued)) = Toucam Cam + adaptor + software (outdated) Celestron Neximage x 1944 colour CMOS chip 50 fps (640 x480 mode) 299 Atik Atik 1- HS2 webcam Chip x 480 Monochrome, air cooled, long exposure, RAW mode Max 60 fps (320 x 240 mode) USB 1.1 Discontinued Imaging Source DMK (mono) or DBK (colour) series Models based on ICX098BQ and ICX618ALA series imaging chips Chip x 480 to 1280 x 960 Max 60 fps (640 x 480 models) USB 2 or Firewire or GigE models 275 to 480 Avoid DFK variant with built-in in IR cut filter Lumenera Lumenera SkyNyx (colour or mono) Chip x 494 to 1616 x 1216 Max 60 fps (659 x 494 models) USB 2 12 bit images $1000 to $2700 (+ duty and VAT) Chip now a bit out of date 3

4 Point Grey Flea 3 Sony ICX618ALA chip Chip x 480 to 2080 x 1552 Max 150 fps (640 x 480 models) USB 3.0, Firewire (800) standard or GigE Vision 16 bit images 540 to 1,600 Basler Ace/Scout Sony ICX618ALA chip Chip x 480 Max 120 fps GigE Vision 12 bit images 520 Problem with circular artefacts and noise caused by overheating Sony ICX242 chip Atik Titan Mono x 494 USB 2.0 Max 15 fps 16 bit images 465 Includes Guide port and active cooling multi-purpose camera QHY IMG0H Sony ICX618ALA chip 640 x 480 colour or mono versions 14 bit/8 bit output Max. 50/30 fps 379 Includes Guide port and active cooling multi-purpose camera Tweaking your Philips Webcam Toucam modifications Factory Settings Optimised non RAW RAW mode B/W Chip 4

5 Toucam firmware upgrades Astrobond WcRmac software Optimised colour mode RAW mode Factory Settings RAW mode Optimised non RAW Toucam RAW mode RAW mode outputs data in black and white Software converts this into colour data Most capture programs only display live RAW image in b&w Programs such as Sharpcap and QCFocus will display live RAW image in low- resolution colour Need to debayer AVI before processing (option built in to Registax software) More difficult to judge focus and exposure in RAW mode Toucam Mono chip Replace Sony ICX098BQ colour chip with Sony ICX098BL 60 for B&W modification Toucam - LX modification Normal Toucam Pro limited to no more than 1/5 th sec exposure Add components and re-wire inside to allow for long exposures Good for up to 30 secs,, longer with air cooling Uses separate Parallel port wire for LX control Parallel port to USB converter Connecting your webcam Remove lens Screw in adaptor Fit any filters/barlow lenses Put it in eyepiece socket on telescope Barlows and Focal Reducers Connect between webcam and telescope 2 x Barlows essential for planets Up to 4 x Barlows can be useful Focal Reducers useful for whole Sun or Moon 5

6 Filters (colour camera) IR cut filter improves sharpness and colour balance Filters (mono camera) Beating the seeing filters for imaging of Moon and Luminance imaging of planets Poor seeing > IR pass filter Moderate seeing > red + IR cut Good seeing > green + IR cut UV pass filter (or #47 violet) for imaging Venus Green + IR cut for imaging the Sun RGB filters = colour + IR cut Filters wheel or slider Computer USB lead between computer and webcam >5 m = active lead Imaging session can take up over 4GB of Hard disk space Lots of hard disk space Plenty of memory and fast hard disc Image Capture Software Proprietary software with Camera Sharpcap (free) WXAstrocapture (free) Cratelets (free) K3CCDTools 3 (free demo) WcCtrl (free) FireCapture (for mono high speed video) Al s reticle (free) 6