-----------------------------------

ratiubogdan

08 Noi 2011 01:43



-----------------------------------

Citisem si eu pe wikipedia ca nu prea se vede, dar pe un site unde se compara diferitele filtre, scrie asa despre Rosette:

NGC 2237-9 "ROSETTE NEBULA" (diffuse nebula in Monoceros). 
DEEP-SKY: (2) Some increase in contrast, but nebula is still more of a diffuse haze around the central star cluster with hints of irregularity. 
UHC: (5) Noticable increase in contrast, with more outer nebulosity visible and some irregular light and dark structure being visible. Nebula was visible when UHC was held up to unaided eye! 
OIII: (5) Higher contrast than with UHC, with more dark irregular detail throughout the region, but not quite as much nebulosity visible as in UHC. 
H-BETA: (1) Very faint glow around the star cluster, not much better than without a filter (but much dimmer). 
RECOMMENDATION FOR ROSETTE NEBULA: UHC/OIII (near tie). 

sursa: http://www.cloudynights.com/item.php?item_id=1520

Si daca omul zice ca se vede si cu ochiul liber, am incercat si eu cu un filtru UHC dar degeaba :)