Personally, I think that for the improvement of your eShel, and according that C.Buil says in his report the ASI1600MMpro is the camera that you should use, because its slow read noise is useful for detect and keep the low signal that have our "modest" telescopes.
You only need to be safe of the spectral response of your octogonal fiber, and of courseyou would need two scramblers to reduce the modal noise.
We only know that the Richarson echelle gratings are better than the Thorlabs, but I thinkthat you don't have the origin of your echelle grating, is it Ricahson ?Is it Optometrics ?Is it Thorlabs ? You could ask for it from Shelyak.
I put my hands on my head, when I was reading Tobias' report, because I have always bought Thorlabs the Echelle gratings, ( I didn't want to hear my possible sixth sense that told me my echelles didn't have much sensitives ).
Three months ago I bought an echelle grating by Optometrics and put it into a NOU_T that I sent to one observer. Of course I tested the echelle and noted that its exposure times have halved.
I have bought another Optometrics one, its delivery time is 10th August, we're going to wait for that and know if the light difference that I noticed is true.Recently I have found that on the internet, https://www.edmundoptics.com/f/richards ... ngs/39690/
, so the game is open.
Best regards, Joan.