SingAstro

Ha - SII:Ha:OIII 120 - 30:120:30

PENTAX SDUF II 400 mm APO f/4
SBIG ST8 XME

Ha - SII:Ha:OIII 120 - 30:120:30

My R.C. 14" f/8 carbon truss is provvided with field corrector and the field is flat, I don't understand what you mean. Professional R.C. telescope + feld corrector give flat-fields as well as a good refractor.

L-RGB

L 160 min
R 30 min
G 30 min
B 30 min
all frames bin 1x1

R.C. 14" f/8 + SBIG STL11000

80 min clear+15 min Ha 4.5nm
R 20 min
G 20 min
B 20 min

all frames bin 1x1

R.C. 14" f/8 + SBIG STL11000

L-RGB M8 closeup

My work on winter galxies goes on and now here is M51

No, the spike on the bright star is simply made with Photoshop's Plug-in. The mask was concentrated on NGC 3628 do too enhance detail.

A&M Apocromatic 525 mm focal lenght f/5.
The only NGC 3628 was enhanced by a mask from an image of mine taken with my R.C. 14" f8+SBIG STL11000

Trio Galaxies in Leo with APO 520 mm+SBIG ST2000