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Detailed analysis on CCD, Lens, and Camera selection for the BigBOSS Fiber View Camera system. Market search, specs comparison, cost analysis. Recommendations for prototype camera setup.
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Drawing Number:BigBOSS-43 Rev:v1 BigBOSS FVC CCD and Lens Review Drawn by: C. Baltay Cognizant Engineer/Scientist: C. Baltay Date: 2012-03-27
BigBOSS FVC Technical Note4 CCD, Lens, and Camera Review Technical Note
CCD Selection • Carried out a market search on available CCD detectors for the Fiber View Camera • Looked for devices 40 mm across or larger to keep demagnification at around 25 or less • Looked for pixel size < 10 microns • Looked for 50 megapixels or more • Readout time ~1 sec • Monochrome sensors • Found four possible devices
CCD Choice Considered 4 Frontside Illuminated, Monochrome Sensors C. Baltay, Talk B2.4,Dec 6 2011
CCD Detailed Specs C. Baltay, Talk B2.4,Dec 6 2011
Comments on CCD Choice • Detailed specs of all four choices are acceptable • 6μ vs 9μ pixels are similar in precision, 9μ somewhat preferred • Price strongly favors Kodak CCD, especially when we consider whole camera cost
Lens Selection • Given a CCD around 40 mm across and a 1 meter dia focal plane, need a demagnification of around 25. • Given the 8900 mm distance of the FVC from the focal plane implies a lens with a focal length of around 400 mm • Detailed ray trace studies including the corrector optics showed that 400 mm focal length is right • Need resolution of about 100 lines/mm • After looking at a large variety of available lenses picked five lenses that could be suitable
Comments on Lens Choice • Canon vs Schneider or Rodenstock • Words of wisdom from large format CCD and camera gurus: the Canon lenses are designed for 35 mm film or full frame digital SLR’s, for large format work need wider field of view lenses like Hasselblad, Schneider or Rodenstock • However 35 mm or full frame format is 24x36 mm, 43 mm diagonal. We have with the Kodak CCD a 36 mm diameter image, or a 5o field of view, so Canon camera lenses are fine. • The Canon camera lenses have better resolution then the large field of view lenses, and are available with larger apertures.
Comments on Lenses • Canon 400 mm f/5.6 or f/2.8 ? • Cost is considerably higher for the faster lens ($11,499 vs $1339) • But the f/2.8 has a 4 times larger aperture area, requiring ¼ as many photons out of the fibers to give the same no of photons on the CCD, making life easier for the fiber illuminating system near the spectrometer end of the fibers. • Is this worth the extra 10K$ ? • Or, we could go for the cheaper lens for the prototype, and get the faster lens for the real camera if we need the larger aperture. C. Baltay, Talk B2.4,Dec 6 2011
Camera Selection • Did extensive market research on available cameras • Looked for cameras that can accommodate monochrome CCD’s that we are interested in ( this ruled out Hasselblad and similar cameras which are available with color only) • Looked for cameras with built in electronics that allowed a 1 sec readout time • Looked for compact, easy to mount camera body • Looked for cameras with control and readout software available • Found six possible candidates
Electronics and Package Choice * Prices include the CCD
Electronics Package Features C. Baltay, Talk B2.4,Dec 6 2011
Recommendations • Best choices are: • Kodak KAF 50100 CCD • Canon 400 mm f/5.6 lens • FLI Proline PL50100 Camera • Cost estimate of the prototype camera: f/5.6 lens FLI camera including the CCD $ 21,045 Canon 400 mm lens 1,339 Miscellaneous, contingency 3,000 Total for prototype camera $ 25,384 C. Baltay, Talk B2.4,Dec 6 2011