2 replies to this topic

[chrishalpha2017]

hello,

 

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..

 

 

 

 

 

 

[chrishalpha2017]

 

 

 

[chrishalpha2017]

 

 

 

 

 

Of course , when i use a 600 gr/mm diffraction grating there is more light and i have to close the slit a bit more but it really seems that they are more details and the height and size of the proms are closer than what i can see on photos taken by  you guys that have a real h alpha filter

 

 

Chris