Venus visibility conditions are getting better every day. The brightness of the planet is so high that under favorable conditions it can be found with the naked eye during the day. The angular size at the time of the capturing was 16.72 “, the angular distance from the Sun was 42 degrees. It is interesting that the distance from the Earth to Venus was exactly 1 astronomical unit (150,000,000 km).
Details of Venus’s cloud cover are best obtained when shooting with a light filter that transmits only ultraviolet light. There are special filters for shooting Venus (for example, Baader U-Venus), but they are very expensive. As a budget solution, I decided to use a bunch of ZWB2 filters with a diameter of 20.5 mm and a NPZ SZS-22 1.25″.
ZWB2 transmits ultraviolet radiation with a maximum at 365 nm. I bought it without a rim – an inexpensive 1.25″ filter perfectly fit as a housing. The disadvantage of the ZWB2 filter is that it also transmits infrared radiation, to which the camera is also sensitive. To reducing it, a second filter is used – the NPZ SZS-22. Читать далее (Read more) > > >
In the evening of January 20, 2020, I decided to open the capturing season on Venus. The angular size of the planet at the time of the capturing was 14.36″. The telescope previously cooled for several hours on the backyard. For capturing I used both a color camera (for getting RGB images) and monochrome (for IR and near UV). I knew that details in the atmosphere of Venus could also appear with RGB capturing, but I did not think so clearly.
Venus, January 20, 2020, 17:02.
-telescope Celestron NexStar 8 SE
-Barlow lens cell NPZ 2x
-atmospheric dispersion corrector ZWO ADC
-filter ZWO IR-cut
-camera ZWO 183MC (7 мс, gain 102, 138 fps, 2 minutes)
Stacking of 1500 frames from 16686 in Autostakkert, wavelets in Registax 6.
Location: Russia, Anapa, backyard.
The source video and the addition result (stack) can be downloaded here.
During processing, I used single-point alignment, since when setting several points, artifacts appear on the image. Processing video of Jupiter (manual)
In addition, strange stripes appeared in the blue channel, similar to Newton’s rings. To eliminate them, I used the Image Analyzer, namely the frequency domain filter. With the eraser, you can remove the area responsible for the stripes in the image. Yes, while the other part of the image will be distorted, but you can make a collage from the original and processed image and get rid of the displayed defects. Читать далее (Read more) > > >