North America Nebula and the Pelican

[Stub Mandrel]

Ladies and Gentlemen,

With the assistance of my good friend 130P-DS, I offer you this as proof that the NEQ3-2 Mount can be used for astrophotography. What DSS says are the best 80% of 87 60-second subs (proving you can get plenty of usable decent-length subs with the EQ3) at ISO 1600, astro-modded Canon 450D. Also my first use of a £10 light pollution filter off eBay and the first image I haven't had to do ANY gradient correction on at all.

(Can you tell I'm chuffed - even so I know it's not perfect, I expect to keep coming back to this and reprocessing it for a month or more and constructive advice more than welcome).

[Knighty2112]

Well done!  

[davefrance]

You have a right to be chuffed, well done.

[Stub Mandrel]

Playing around with the separate channels I tried to make a 'synthetioc OII' in cyan. It sort of worked and blended as an extra luminance layer with the original image it brings out the 'wall' in more detail.

[PatrickGilliland]

Super result for the equipment in use well done - Paddy

[Adam J]

Great result,

Ill give you a huge tip though. Never use ISO1600 with the 450D. I have done lots of testing and under almost all conditions you get almost twice the signal to noise ratio at ISO800, this is especially so under summer conditions which increase noise further. Took me 6 months to work that out lol.

[Stub Mandrel]

5 minutes ago, Adam J said:

Great result,

Ill give you a huge tip though. Never use ISO1600 with the 450D. I have done lots of testing and under almost all conditions you get almost twice the signal to noise ratio at ISO800, this is especially so under summer conditions which increase noise further. Took me 6 months to work that out lol.

Thanks Adam, I found a site (I can never find it again) that suggested otherwise but I will do some experimentation because noise seems to be a limiting factor for me on fainter objects.

[Adam J]

10 minutes ago, Stub Mandrel said:

Thanks Adam, I found a site (I can never find it again) that suggested otherwise but I will do some experimentation because noise seems to be a limiting factor for me on fainter objects.

You will have a much easier time of it  (noise wise) in autumn and winter mate, its frost that will give you issue at that point lol.  DSLR noise halves for every 7c drop in temperature. You can sometimes get away with ISO1600 when its close to freezing. I just posted a pic of the pelican nebula myself in the same section, its much longer exposures at ISO800, but you will note that I dont have much noise if any visible at all. All thats left is a little photon noise. That is because I cooled the camera to -4c. But even at -4c I would not use ISO 1600 on a 450D or 1000D myself, maybe the 550D after them moved to newer processor...but even then.

 

[StargeezerTim]

That is a very nice image... 

[laudropb]

Very nice image.

[Rodd]

Great shot--I think the color balance is off a bit (if you want opinions).  Maybe I am not familiar with DSLRs and this is normal.  Seems yellow to me.  This isn't per chance an SII image is it?

[Stub Mandrel]

7 hours ago, Rodd said:

Great shot--I think the color balance is off a bit (if you want opinions).  Maybe I am not familiar with DSLRs and this is normal.  Seems yellow to me.  This isn't per chance an SII image is it?

No, it's straight RGB. I've reprocessed it with a more aggressive stretch of the 32-bit file in DSS first and this seems to greatly reduce the noise. It also looks redder.

[Rodd]

2 hours ago, Stub Mandrel said:

No, it's straight RGB. I've reprocessed it with a more aggressive stretch of the 32-bit file in DSS first and this seems to greatly reduce the noise. It also looks redder.

I think you need a color calibration--On the histogram are the 3 colors equal in left-right distribution?  If they are not--they should be.  If they are, then it should be easy to lower the saturation of red and inctrese the saturation of Blue and/or green--though I see allot of green too--do you have a tool like SCNR in PI to get rid of the green?

[Stub Mandrel]

12 hours ago, Rodd said:

I think you need a color calibration--On the histogram are the 3 colors equal in left-right distribution?  If they are not--they should be.  If they are, then it should be easy to lower the saturation of red and inctrese the saturation of Blue and/or green--though I see allot of green too--do you have a tool like SCNR in PI to get rid of the green?

The histograms appear balanced although naturally red has a big 'shoulder' on the right which is all the extra red signal. A problem with this image is that it doesn't like gradient exterminator - its balancing is great to get images with plenty of black background of to a good start. I have HLVG which is the same thing as SNCR (it says it's based on it) so I'll look at removing any green - although I can't see much (edit - yes zoomed in there is a faint mottle of green in the background)! I suspect some of the difference is down to monitors - I do a lot of work with publications and the look of photos retouched by different people on my monitor is remarkable and anything prepared as CMYK for printing looks horribly garish.

Here we go, colour balance shifted slightly towards red and HLVG applied (plus a sneaky sniff of local contrast to pull the brighter stars forward a touch). I think this is starting to get 'punch'.