I finally bought a new camera : ZWO ASI 178MM : pixels are much smaller that the ASI 120MM that I had (2.4 vs 3.75 um) and the chip is bigger too with means 2 things for me : beeing able to image a bigger part of the sun's limb and sampling at k=3 with the Bresser 127/1200 ; wich means no need to use a barlow lens . No more need to do flats either as there arent fringes due to barlow lens.
so, here are what I got with it yesterday.
I also noticed somethinf i'm gonna work on : I already noticed that the more grooves the grating I used had , the more shrunk the image was getting. So I tried a 600gr/mm grating (like Secchi had) and the result is interesting . The images have more fine details. It seems that the anamorphosis "destroys" détails in this technique. I have to make more tests..
Click on the image to see them full size..