first attempt with 600lpmm open slit

[highfnum]

sky condition not ideal but did it anyway
open slit

Capture 2023-06-09T16_11_26vsha600pds.jpg (81.19 KiB) Viewed 1013 times

[highfnum]

reference filter shot
earlier in day

Capture 2023-06-09T12_02_16apo80qrkpds.jpg (255.02 KiB) Viewed 1012 times

[rsfoto]

Hi,

Nice results

[ChrisHalpha2017]

Very good

WHat are your impressions ? have you tried in the same time with the other grating in your spectroscope to see the diferences ?

I wonder if your collimator is really well set ? I mean with the slit PRECISELY at the focus of the collimating lens. I say that because I've added a focuser to my collimator and adjusted precisely the focus and the images are sharper.

There is an issue I nerver mentionned before but it has its importance :

You can have the sharp image of the spectral lines but the prominences image will remain blurry : that happens when your slit isnt exactly at the focus of the collimating lens ; even if you focused the imaging lens on the lines or on the order zero.

That means in other words that you can get a sharpt spectrum when the slit is very thin but once you open it the prominence image wont be sharp whatever you do ; unless you defocus the image of the sun on the slit.

(hope I wasnt too confusing).

[Montana]

That's a super arch prominence

Alexandra