Rho Ophiuchus


Optics: Canon 135 mm f:2 L lens, Canon 200 mm f:2.8 L, Canon 400 f5.6 L. Camera: Modified Baader Canon 350D (Halpha pass filter - see here) at ISO800.
Mount: Takashi EM200. Processing : Iris software. Observatory: Pic du Midi (altitude 2860 meters, french Pyrénées).

Rho Ophiuchus complex
The red bright star is Antares (Alpha Sco)
Comparison of the 135 mm and 200 mm images (full frame reduced by a factor four)
135 mm lens images: Stack of 14 x 180 seconds exposures at f/2.0 (full aperture). July 23, 2006
200 mm lens images: Stack of 9 x 300 seconds at f/2.8 (full aperture). July 25, 2006

The 135 mm lens images @ f/2.0
Scale reduced by a factor two relative to the original.

The 200 mm lens images @ F/2.8.
Original size reduced by a factor two.

The 200 mm lens images @ F/2.8.
Boost of the contrast.


Download the full-frame 200 mm images at the original size (7.3 Mb)

The 400 mm lens images @ F/5.6.
Stack of 28 x 120 seconds exposures at ISO800. Original size reduced by a factor 4. July 27, 2006

Crop at the original scale of the 400 mm lens images around the star HD147889 and the nebula IC4603.
Note the improvement of the resolution compared to the 135 mm and 200 mm images. Some IRAS source are visible (red stars).


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