Today in Paris i was blessed with a nice sunny weather...with a very white milky sky....
but still i've been able to get the best image ever with my technique!!!
I modified my spectro-coronagraph : I took away the Lyot stop and put an Iris diaphragm against the collimator. Indeed after several trials during numerous session I realised I could fairly get the same results and the benefit of having a much lighter and shorter instrument.
So I made several trials with all my diffraction gratings from 2400 to 600 lines/mm... and guess what :
my hypothesis is verified : the less dispersion and the best definition it gets. Its because a point from the object ( a prominence ) becomes a ligne in a spectroscope. The width of the "line" depends on the dispersion. The h alpha line is about 1A "large". So the more dispersive is the spectroscope and the wider the "line" tends to be and then my image isnt made of points anymore when I use high dispersion.
Judge by yourself :
- 2400 tmm.jpg (393.74 KiB) Viewed 834 times
- 1800 tmm.jpg (433.83 KiB) Viewed 834 times
- 1200 tmm.jpg (157.05 KiB) Viewed 834 times
- 600 tmm_++++.jpg (190.83 KiB) Viewed 834 times
- 600 tmm_2 b_20230518_130632.861_UT.jpg (373.47 KiB) Viewed 834 times
Chris
