Steve Conard Willow Oak Observatory, Gamber, MD International Occultation Timing Association (IOTA) Oct 20, 2012

Bruce, Russ, and I had originally hoped to do a thorough comparison of several video and digital interface cameras that could used for IOTAs observations Due to personal time limitations and weather, we didnt accomplish what we had intended It became a much a less controlled test, with fewer cameras, than we had originally intended View it as a quick comparison of several common cameras as typically used in real-world conditions

Data collection was not as well controlled as I had hoped Intended to have a parallel telescope recording the same field at the same time Did not take the time to fully learn to use the Flea cameraresulting in only 8-bit data collected The data have not rigorously been analyzed, and may contain errors More data is available to be analyzed when time permits

C-14 on CGE mount Focal reducer used to set f/number at about 4.0 In roll-off observatory Video data through IOTA-VTI to Canon ZR- 65 recorder Flea data through Firewire to desktop PC

Control was a Stellacam EX (my SN 01) Other video cameras Stellacam EX (SN 02) Watec 902 Ultimate (SN 01 and 02) PC164C-EX2 Firewire camera Flea 3 FL3-FW-03S3M-C All arrays are ½ format except the PC164C- EX2 which is 1/3

Used same field for each camera Eplison Lyra (Double Double) selected to have easy reference, and was fairly high in the sky Reference camera used before and after to look for changes Tried to pick nights with good transparency and no visible clouds Tangra used for data analysis Used auto aperture selection Picked up to 6 stars for comparison

Weather clear, reasonable transparancy Tangra apertures left to automatic selection Collected data with Stellacam EX 1 at 1 and 2 fields integration Collected data all other cameras Varied gain on one Watec Used 1 and 2 fields on the second Stellacam EX Collected data with Stellacam EX 1 at 1 and 2 fields integration Only minor difference in signal before/after with Stellacam EX 1

Stellacam EX SN 2Stellacam EX SN 1 Before

Watec 902 Ultimate SN 1Watec 902 Ultimate SN 2

PC164C-EX2Stellacam EX SN 1 After

PC164C-EX2 may give the best combination of SNR and signal level Significantly better at all but the brightest targets, where SNR may fold over (may not be the best choice for a bright asteroid over a fainter star) It also may have other issues that werent investigated here Watec 902 Ultimate and Stellacam EXs are very similar Watec can produce almost as much signal as the PC164C-EX2 when the gain is very high

Weather clear, reasonable transparancy Tangra apertures left to automatic selection Collected data with Stellacam EX 1 at 1 and 2 fields integration Collected data with Flea 3 Maxed out the gain at 24 dB Maximized exposure time at a 30 Hz readout rate Important: Flea was used in 8 bit mode Collected data with Stellacam EX 1 at 1 and 2 fields integration Only minor difference in signal before/after with Stellacam EX 1

Stellacam EX 2 FieldsFlea 3

Stellacam has much larger signal level This may not be true with Flea at 12-bits Roughly the same SNR for fainter targets, possible advantage to Flea for brighter ones

Weather clear, reasonable transparancy (same time as video comparison above) Collected data with Stellacam EX 1 at 32 fields integration Collected data Flea at Hz, max exposure Gain at 24 dB Flea at 8 bits Collected data with Stellacam EX 1 at 32 fields integration Only minor difference in signal before/after with Stellacam for the fainter targetsthe bright ones showed more change for some reason

Stellacam EX 2 FieldsFlea 3

Stellacam has much larger signal level This may not be true with Flea at 12-bits Roughly the same SNR for fainter targets, Stellacam showing saturation on brighter ones