M8

[Alchemy]

Equipment used

Scope 12 inch modded Newtonian
Mount Losmandy G11
Camera QHY8 (total 114 mins exposure) Offset 117 , Gain 50
Guidescope ED80
Guidecamera DMK
Guideprogram PHD

Extra gadgets used - 4 dewheater strips running at full. 12 inch at rear of scope, 4 inch at guidescope front, 2 inch on secondary, 2 inch on camera extension adapters to MPCC


That covers the technical stuff, i will just be shooting some of the common objects for a while to see how they shape up against earlier efforts ..... (put in a couple of Ha images shot earlier Binned 4x4 object designation on file name)

see you all later

Clive.

[monoxide]

nice Clive,
heaps of detail in M8, nice and smooth too.
the binned Ha shots look good too, plenty of detail.
how long were the binned shots by the way?

[Hagar]

Nice images Clive. You certainly nailled M8, the detail in the whispy areas is fantastic.
Funny enough I an imaging IC4628 as I type. Don't think I will get near the detail you have got with the big scope and Ha filter. I think I will have to get one.
I notice Ha filters come in a lot of differing nm figures but don't know what they mean. Any advice???

[Gama]

I think he used 4x4 binning on IC4628.
You guys should just try binning at 4x4 just for the sake of seeing what a difference it makes.
Remember, when binning a color camera, you lose the debayer info, so it turns out B/W.

Theo

[Alchemy]

Monoxide..... the Binned shots (both black and white) were 6 min exposures the prawn neb at my usual offset of 117 and gain of 50, i forgot to change the binning before i started imaging the other i dropped the offset to 114 ..... its a bit blurry as i think the focus was slightly off. its a much dimmer image to start with compared to normal without theHa filter as you are cutting out all the other light. However it records a much brighter image compared to 1:1 but you lose 3/4 of your image size plus any color. worth a try if only for fun.

Hagar....the Ha filters come in all sorts of bandwidths from 3nm up to about 20 ish. i chose the 13nm Astronomic check out these links
http://www.narrowbandimaging.com/filter_compare_astrodon_cust_sci_pa ge.htm
http://www.narrowbandimaging.com/comparsion_of_ha_filters_page.htm
http://www.iceinspace.com.au/forum/showthread.php?t=28505&highlight=narrowband
http://www.iceinspace.com.au/forum/showthread.php?t=31029&highlight=narrowband

i went for the 13nm because i wanted a brighter image, you can also buy a set (OIII and sulphur) and hopefully more or less matched for the job, a brighter image showing some stars also allowed me to check the focus. I did not choose the wider versions in case they sucked up some IR...... funnily enough i could look through the Ha filter in daytime and tell the sky was blue and traffic lights show some color as well so at least some extraneous light must pass through (less than 1% perhaps)..... not enough to change the image from what ive seen..... I will save it for moon nights mostly , although its hard to find stuff without goto under a bright moon. one day i would like to put together a narrowband tricolor image or two , but that will be a while away yet.

[jase]

M8 looks good Clive. Nice details, but the image is lacking even illumination. When you look at the hour glass neb and compare it to the outer regions of the lagoon, the brightness is not in proportion. The image brightness appears to drop off rather quickly. I'm rather surprised by this. Perhaps you can extract more from the data. Actually, you could almost blame it on a flats issue, but feel certain you'd be taking these.

[Alchemy]

hmmm...... jase , here is the original image with 4 stops added, NO other processing. The whole gammut of flats, darks, dark flats, etc done and enough to ensure a reasonable effect.

on the one i put up originally the saturation has been upped and i did mask certain areas to stop blowing out of highlights, along with selective sharpening ,perhaps the darker saturated areas could be given a higher luminosity rating, but it aint that much different from what was captured. the exposures were 6 minute subs.... i have had a tracking issue possibly a flexure which i havent been able to nail down yet (plate which scopes are on is solid, both cameras are tightly locked, as is loccking screw on focusers, rings are all metal and i cant see the problem there... i currently suspect the tube on the big scope itself) its only small but enough to out of round the stars on longer exposures i have the guidescope on stars within the image and its not a rotation problem.... so thats why only 6 min subs so maybee i need longer to get the faint extensions .

interested in your thoughts as you now have pretty much the original image.

clive.

have added stacked image from Win 4 aip ... as i thought maybee Depskystacker had not done job properly, similar sort of result with slightly different color balance. Flats and darks applied to this as well.


EDIT putting it all in the too hard basket for now.... its a color balance issue i think, i killed all the blues trying to make it red will do it again another day

[jase]

Pondering on this for a while. I think its a mid tone management issue Clive. Actually, your unprocessed version is beginning to show signs of white clipping which is alarming so early on in the a routine. Perhaps this compounded your efforts as this would limit how far you could apply a non linear stretch (unless you were using layer masks to manage the intensity). What do you mean by 4 stops? Binning 4x4? I've attached a "nasty" rehash - not much I can do with a jpeg data, but I think it convey the point I'm trying to make around the fainter nebulosity - dark nebs top right and lower extensions (be it a very crude example).

EDIT: Now seeing your second image you uploaded above, I think you're on the right track. Undoubtedly, the intensity around the hour glass limited your ability to stretch the fainter regions. Masks maybe your only answer as you suggest.

[Tamtarn]

Good to see you had a chance to catch some data Clive. The QHY8 is performing well for you :thumbsup:

[Alchemy]

Tamtarn (barb n David) Nice to hear from you thanks for your comment. Been a while since i saw you posting ... hope youve captured some images.

Jase. ... done an edit here...... im going to leave it for a while and redo it when i can figure out what color it should be , i think this will make a major difference...... thanks for your input


cheers clive