have you looked into adding a
ha filter as well?,some galaxy show really well in
ha , you'll need to lrgb and then subtract the red data from the
ha data.
i believe The same could be done with setups using 3nm filters as a 3nm
ha filter cuts out nii and instead of buying a nii filter you could image a target in 3nm
ha and 5nm
ha then subtract to pull out the nii data.
http://www.aicccd.com/archive/aic2007/SchurAIC2007.pdf
i have some new filters on the way and i opted for a
lp filter instead of a typical lum, apparently the
lp filter gives a very slight blur and isn't as sharp as a clear lum filter, i don't know,but that's what i've been told and it's probably from the missing wavelengths the filter is removing , galaxies are made of many broadband wavelength stars with dust/nebula ectt.
i'll settle with a
lp filter as it gives me a tiny bit more contrast despite the resolution , colour balance.
I don't realy image galaxies much, i'll post some images,you can see a cls works ok. some of my older work,the processing needs a little more work on the colour balance,but you can see there's still plenty of resolution.
bortle 5-6
if you need a
lp filter,you might be better of with something not as strong. really you could do it just as well with no filter,just sink in more time. a
lp filter will just increase a tiny bit of contrast.
scopes :gso/bintel f4 12"truss tube, bresser messier ar127s /skywatcher 10'' dob,meade 12'' f10 lx200 sct
cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
mounts : eq6 pro/eq8/mesu 200 v2
filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .
