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View Full Version here: : Double Cluster in Perseus : ngc864-889


Pierre
22-09-2007, 01:01 AM
Hello all,

here is the double cluster in Perseus imaged during the last "Nuit de l'Astronomie" in a local site "Champ du Feu" (alt 1100m), the 15th of last september
- Addition of 18x120s; préprocessing based with with offset (median of 9), "optimised dark" (median de 9), no flat.
- Imager: eos350d raw mode; 400iso.
- Astrographe: Takahashi Epsilon 160mm/f3.3
- Mount : em200Temma2jr

Processing with Iris 5.51: logarithm, color and saturation.

The focus was made with measuring the diffraction spikes generated with with a brighting star. Perhaps not the best method, although it helps :D:D...

The mid size is here (1 Mo):
http://astrosurf.com/pierre/Ciel_profond/e160/damas-400iso-raw-arith-18x120s-iod-black-log-coul-ech.jpg

See the full size is here (5.5 Mo) , the one that i prefer :
http://astrosurf.com/pierre/Ciel_profond/e160/damas-400iso-raw-arith-18x120s-iod-black-log-coul.jpg

Clear skies.
Pierre.

Garyh
22-09-2007, 07:56 AM
Wow...very sharp Pierre!
Lovely field of view around the clusters
Well done!

Pierre
22-09-2007, 04:03 PM
Hi Garyh,

thanks ;). We had a very good night with no foolish dancing stars as we can regularly see in my country. the sharpness is also due to the sampling rate which is not far from undersampling.

This Epsilon astrograph needs also a fine focus to reveal good pictures (focus stroke = 25µm ~ 0.0025 inch)

Ric
23-09-2007, 01:08 AM
A lovely image Pierre and very sharp.

A fine effort

davidpretorius
23-09-2007, 08:26 AM
lovely pierre, well done

Alchemy
23-09-2007, 09:09 AM
Nice shot

i plugged in double cluster to my planetarium program and it said ..not visible from my location. a shame!!