Narrowband M8 - Hubble palette

[JohnH]

Here is my fist go at a tri-colour narrowband image - I recently added Sii to my Oiii and Ha Astronimic filter collection.

I have also recently swapped the focuser on my 127 ED for a motorised moonlite CFL and automated the focus routines and filter selection with a script in AA$ so this was run totally hands off for the first time which is great.

There are some issues here - first I did not get enough data due to breaking the power cord to the mount during the meridian flip - just me being clumbsy but I lost 2 hrs of good light time fixing and re-starting everything so there is only about 40 mins (10x 4 min subs) each of Sii, Ha and Oiii, second I should not have collected equal amounts of light with each filter and my processing was a a bit sloppy also. My focus offset for the Oiii filter was not correct so there was a little distortions in star shapes due to that and I need to insert periodic re-focus into my script to compensate for temp shifts - one step at a time -but I am on the road I think...

[multiweb]

Great stuff John. The data looks real good. It's just processing from there on. Definitely on the right path. Have fun. :thumbsup:

[strongmanmike]

Sounds like there was a bit of unscripted fully automated caos too :lol:

Nice start in NB John

I use AA4 too but have never bothered scripting :question:

Mike

[Paul Haese]

This is quite a smooth Narrow band image. Something I am yet to get into myself. Which scope are you using? This looks quite narrow field to me. Perhaps another target that is suited for narrow field would be interesting to work on next. Perhaps an eagle. :)

[TrevorW]

Nicely done John

[JohnH]

Spot on Mike....and thanks for the comments guys....here's is my AA script fyi - still a wip and not industrial strength but you will get the idea....I left out the code for the cable break...;)

REM - Narrowband Capture - JH 10/6/10
REM - 145m Bin modes
REM - 1x1 = 6 - 16 bit res
REM - 2x2 = 5
REM - 4x4 = 4
REM - 1x1 = 3 - 8 bit res
REM - 2x2 = 2
REM - 4x4 = 1
REM - Filters loaded 1=L,2=R,3=Sii,4=Oiii,5=Ha
REM - Images stored to path$
input "Si (s) - 0 for none ?",Sexp
input "Ox (s) - 0 for none ?",Oexp
input "Ha (s) - 0 for none ?",Hexp
input "Number of exposures ?",expcount
input "Object Name ?",object$
input "Path ? eg C:\temp\ - folder MUST exist",path$
seq$ = "SOH"
FocusInt=3600
Wheel.Goto("H")
Camera.Binning(2)
Camera.Start(2)
Camera.Wait
message("Click OK then Select a Focus Star")
pause(15)
message ("Start Auto Focus")
x = Image.GetPointX()
y = Image.GetPointY()
Camera.Autofocus(x,y)
Print "Autofocusing..."
pause(60)
LastFocusTime=0
image.close
for j= 1 to expcount
for i = 1 to 3
filter$ = seq$[i]
bin = 6
if filter$ = "S" then
exposure = Sexp
offset = 5
endif
if filter$ = "O" then
exposure = Oexp
offset = 45
endif
if filter$ = "H" then
exposure = Hexp
offset = -50
endif
if exposure <> 0 then
name$=filter$+"_"+object$+"_"+str$(j)+".fit"
print i;filter$;bin;exposure;name$
Wheel.Goto(filter$)
Focuser.GotoRelative(offset)
pause(5)
Camera.Binning(bin)
Camera.Start(exposure)
Camera.Wait
Image.Save(path$ + name$)
Image.Close
LastFocusTime=LastFocusTime+exposur e
endif
next i
if LastFocusTime>FocusInt then
Print "Autofocusing..."
Camera.Binning(2)
Wheel.Goto("H")
Camera.Start(2)
Camera.Wait
Camera.Autofocus(x,y)
pause(60)
LastFocusTime=0
endif
next j
Print "Finished!"
End

[JohnH]

Paul the scope is a North Group 127mm ED which is F7.5 but my ccd is an Opticstar 145m Ice - this has the Sony ICX285AL chip in it which is 2/3 format - hence my FOV is small at 31.4'x23.6'.

I would love to use an FR to go a bit larger scale-wise but have found none that work with my imaging train (OAG/FW/CCD) I think I will have to get a bigger chip eventually...