Archive for March, 2010
This is probably my best photography of Mars even though it does not exhibit the side of mars with the most features. The seeing was great for my location (Alpo seeing 6/10). Mars was quite high in the sky. The conditions were as good as for the shot I took in November. Orographic clouds over Olympus Mons can be seen, and as well as albedo features such as Phlegra Montes, Phlegethon Catena and Amazonis Planitia. Picture taken at roughly f/d 40 using a 2.5x Siebert optics barlow with DMK B&K Camera – about 1,500 rgb frames – each frane between 1/10 and 1/15 sec of exposure.
For those who are wondering why it is possible to capture (when the seeing is great…) details that are at or sometime far below Dawe’s limit – look at the excellent article from Damien Peach on this topic, explaining why Dawe’s limit is not really applicable to extended objects (planetary disk) with high contrast features.
Between two rainfalls – I was able to take this picture of Saturn with my Maksutov Cassegrain 7″ at focal plane f/d 15 with my DMK B&W camera. This is a composite picture from about 1100 RGB frames.
Notice from left to right two of Saturn’s satellites: Rhea (mag 9.9) and Tethys (mag 10.3). Cassini’s division is guessed but not very obvious since the rings have a low inclination. – The C ring is hinted on the left and right portion of the disk. Disk diameter is 19″.
Saturn is more challenging to image because of its low surface magnitude. On the Red channel I had to shot at a speed as low as 1/9 sec by image. Just finishing up shooting the blue channel, and clouds came over! Next time I’ll try to image at f/d 22 using a 1/5x barlow to bring more details.
Transparency: 2/6 (Full moon)
Shot on 2/28/2010 at 1.10am PST