LiMovie – Light Measurement tool for Occultation observation used Video Recorder
- Program jest rzadko aktualizowany. Ostatnią wersją programu wydaje się być wersja 0.9.98.5, chociaż główna strona programu podaję ostatnią stabilną wersję jako 0.9.97.3h – autor Kazuhisa Miyashita
- Instrukcja obsługi pod adresem: http://www.asteroidoccultation.com/observations/LIMOVIE.doc (D. Herald -2006) – nie jest to pełna dokumentacja programu.
- LiMovie nie pokazuje pełnego okna w rozdzielczości 720 x 576 – należy przesunąć w dół kursorem
- Poradnik jak odczytać momenty zakryć w LiMovie: http://www.poyntsource.com/New/LunarOccTiming.htm
- Test poprawnego wyświetlania półobrazów w LiMovie: http://www.poyntsource.com/BREIT_IDEAS/LiMovie.htm
- If you have having trouble reading AVI files in LiMovie, make sure it is using DirectShow. To set this option in LiMovie, select the Option/”Update Setting Items” item from the main menu bar, then the File Reading pane, the click on Direct Show in the Rendering engine section.
PROBLEM ODCZYTYWANIA STEMPLA CZASU
- Program prawidłowo odczytuje stempel czasu z IOTA VTI, kiedy ustawionym separatorem dziesiętnym (ustawienia regionalne Windows) jest kropka a nie przecinek.
- Z IOTA Video Capture ver. 2.1 i stemplem czasu z Kiwi OSD oraz kamerą RunCam Night Eagle Astro i grabberem Star Tech SVID2USB23 nie dało się odczytać znaczników czasu programem LiMovie
- Dlaczego Limovie może odczytać stampla czasu ? – oto możliwe przyczyny:
– gamma reverse being on
– having the wrong time stamp checkbox option automatically selected by Limovie (no matter how many times I change the INI settings),
– having the field exposure threshold set to a value preventing time stamps from being read (spróbuj z ustawieniem wartości Treshold na 90…)
– having video dimensions being slightly different from what Limovie is used to (needing to use AVISynth to correct for which)
– recording the time stamps in front of the earthshine lunar darkside
– on occasion even with field order odd/even first being selected
– problem może być także przez videograbber
– złe ustawianie niebieskich prostokątów odczytujących stempel czasu – It can be found in the right hand panel under ‘More’, when you get the expanded menu, try clicking “IOTA VTI wide scan”. If that doesn’t help read your video, that, plus changing the threshold setting is the only way to modify the OCR reader.
- I was able to ‘fix’ a frame grabber output that had uselessly bad timestamp recognition to perfect recognition (as in no errors at all) by writing an AviSynth script that trimmed off a couple of scan lines. That trimming aligned the timestamp characters with the Limovie sample box and perfect OCR resulted.ROZDZIELACZ SYGNAŁU WIDEO ( Y- splitter)
- Jeśli chcesz rozdzielić sygnał video “Y-splitterem” (za wyjściem VTI), używaj takiego ze wzmacniaczem np https://www.shinybowusa.com/shop/product_info.php?products_id=170 – nie ma wtedy problemu z czytaniem stempla czasu
- The passive ‘Y’ splitter reduces the video signal voltage by about ½ which causes some (not necessarily all) frame grabbers to lose the bottom portion of the video brightness. The brighter parts of the video are captured, but at about ½ brightness compared to non-split videos. The less bright portions of the video (including the bottom half of occultations) are cut off making the event bottom look very flat and no noise.
- Czy z użyciem LiMovie można wykonywać fotometrię gwiazd tak jak programem Tangra ? –
- Limovie was originally written as a tool for measuring the brighnesses of stars, not specifically for occultation work.
- Video recordings of stars that are made for the purpose of measuring their brightnesses are often criticized on account of the 256-step brightness resolution of analog video systems. You needn’t worry about this, for it is not a limitation of the accuracy of the brighness measurement. With the frame rates that are usually used by video cameras, scintillation due to Earth’s atmosphere is the major source of noise, and often limits video signal-to-noise ratios to 4:1 or worse. The way to get a better S/N is to extend the duration of the recording — that is, average the brightness values in the csv file over a considerable length of the light curve. When you do this, you needn’t worry about the 256-step pixel-brightness resolution, because the brightness resolution is really 256 x Ap x N where Ap is the number of pixels in the measurement aperture, and N is the number of frames you are summing. The brightness resolution that is so obtained can be very high.
- If you are trying to make very accurate measurements, calibration of the video field becomes relatively important to enhance the accuracy of your measurement; while with occultation recordings, calibration is rarely helpful. Calibration can be accomplished by using AVIsynth
