I spent all day yesterday preparing and doing, and this morning (Sunday) analysing my experiment on the Meade Deep Sky Imager pro. The results are a complete surprise to me and I hope can resolve some of the timing issues. So without further chat... lets get started... Attached is a .jpg image and a short movie clip. Goal - To understand the time line cycle of the Meade Deep Sky Imager pro (DSIpro) Camera when used to collect images for time sensitive applications, ie The Pluto Occultation. Equipment -DSIpro fitted with a Pentax 28mm lens controlled by DELL laptop PC. -KIWI OSD system consisting of PC164c video camera (NTSC), 6" monitor, KIWI OSD, GPS system to supply time standard, Canon Camcorder. -Subject, a 12volt 1.3AH battery fitted with a Red LED, mounted and swung on a string as a pendulum of 2.2metres length. Method Summary Setup the DSIpro camera and make 1 second exposures of a moving subject while at the same time video the activity with a time inserter equipment (KIWI OSD) and then correlate the two processes. Method Details 1) the laptop's clock was synced by use of the internet feature of "date & time" control panel. 2) the KIWI OSD system was setup and a GPS fix was obtained. 3) the video camera was pointed at the laptop screen that was showing the date & time control panel and it was found that the laptop was 0.140 seconds slow to UTC 4) the DSIpro was setup to record 1 second exposures, saving all RAW frames, in FITS format, with combine images unchecked. 5) Both the DSIpro and the video camera were pointed at the subject and the Battery/LED assembly swung repeatidly to gather many "one" second scans of the pendulum swing. 6) look through the one second scans, watching for a sequence that showed an obvious start and end. Pay attention to the preceeding, and following scans to ensure continuity. Make note of the time as written in "properties" for that particular file. 7) look through the videotape to find the corresponding section and note the KIWI OSD display. Analysis 1)The scan that best meets the requirements has the time listed in properties as 12:11:19am. This is converted to 14:11:19UT. The next scan is 14:11:21UT Both these scans are assembled into one image, labeled and is attached to this email. 2) A .mpg movie file also atteched, shows the battery/LED assembly in my hand, it is released to swing to the right, then to the left and my hand is removed from the scene just after the maximum to the left swing and the video ends just as the second right swing ends. 3) Analysis of the scans and the movie reveal... a) the 14:11:19UT scan starts at 14:11:17.653UT and the LED leaves a lighter trail to the right, pauses at the RH end of the swing and retraces the path thereby making the trail more solid where the image of the LED is double-up. b) the 14:11:19UT scan ends at 14:11:19.753UT. Take note of the smuge on the wood below the LED trail. The more solid section of the LED trail ends to the left of the smuge. c) the duration of the scan is 2 seconds even though I have set the software for a 1 second exposure! d) the 14:11:21UT scan swings to the left, pauses and swings to the right. My hand is shown very faintly as it is removed from the scene just after the left swing. Take note, the start of the swing seems to be BEFORE the end of the previous image as if is shown above the smuge. There seems to be overlap in the two images. Conclusions. The time given in the properties for the particular file is for the END of the exposure. The exposure time is 2 seconds. There is no dead time or image download time as it is all done on-the-fly There are some "shared photons" between images. maybe 2 or 3% the end.... thew!!! Comments welcome Regards DaveGault AUSTRALIA