spectro-aras.com

CX Dra yesterday :

Comparaison with the 18/05 - 23/05 :


EM Cep :

To: Etienne,

Nice results!.......I'm usually too scared of going beyond 900 sec sub-exposures in the city, but when i go to my dark sky site I may try a 1200 sub exposure
with the LhiresIII and 1800 l/mm grating.

James

Hello James,
I think you must try long exposure, it's possible that near Ha there is not many lights ? Try for know if it's possible.
Try 300s, 600s, 900s, 1200s and make comparaison of the SNR, it's important ton make long time. you have a big diameter optique ?