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View Full Version : Urban Orion Area 35mm 12-1-11 Orlando,FL



Hellobozos
2011-Dec-01, 08:12 PM
Me, being in the middle of the "Theme Park Triangle", (Universal,SeaWorld,Disney) This shot below is from 6min subs at f8, ISO200 for 1 hour 12 minutes,No darks,flats,etc,only light frames, CanonT1i (Mod) an 18-35mm lens. I can't wait to Move!..8^)
15887

Enjoy!

RickJ
2011-Dec-02, 03:17 AM
LP makes color accuracy difficult. Still removing the gradient will bring out some color hidden behind the LP.
Rick

Hellobozos
2011-Dec-02, 06:29 PM
I shot in raw, put in DeepSkyStacker,then Registax5,Last a Canon EOS program (which really is a no,no),I didn't put it in Neb2 or Gimp2 which level's it out nice,The whole Top Right corner is a Universal search lite beam thats fixed,in any long term astro photograpghy i do, i have to trail through 5 of them...8^(..Hey,you lost the Horsehead area..;^)..Oh the Whoas of City observing

Enjoy!

RickJ
2011-Dec-04, 12:51 AM
Humm, my answer was here Try again.

Yes, I missed seeing the horsehead so treated it as gradient. Not sure I see it in your shot. See a nasty panda eye around a bright object about where it would be and a faint glow. With heavy LP the best solution is to either go narrow band or take your gear to a dark site. I did the latter for more than 45 years. LP filters might help but not with broad band sources like those searchlights. For emission nebula and using camera lenses you might try Lumicon's so called H alpha filter. Really a deep red absorption filter. I used one with good results from in town with 2415 film. Cheap (compared to the real thing) and quite effective for its low cost. Of course only the red pixels would see any light wasting much of your chip. OSC greatly limits what you can do to fight LP.

Rick

Hellobozos
2011-Dec-06, 08:15 PM
This Orion is from same camera,12-6-11,but on a 8" 2000mm F10 scope instead of a 35mm lens, I like LPN-P2 filter for my heavly polluted sky's,In prossing you just subtract some blue..
they make a P1 for less polluted sky's, the color they give it great, i just heard there shy on faint blue an green objects like Heliex nebula an Trifid (time to do pallets i guess)..8^)..this Shot below is raw 1hour 30 min. 3min40sec subs,Iso 800, did flats,off-set an couple dark flats,the Dew was comming up fast,Orlando bad on it till get cold enough, then it's clear sky's all night

15920

RickJ
2011-Dec-06, 10:08 PM
Not bad but the image is clipped both at the dark and light ends. So detail at both extremes was lost. You will want to watch the histogram while processing to be sure that doesn't happen. M42 has such a wide dynamic range you need to use two different exposures. One for the core (very short) and one for the rest, much longer. Then blend the two when processing.

Increasing f ratio does help cut LP as it dims the LP more than the object in most cases. That's what you've done here going to f/10. Doesn't help with a camera lens as that also decreases aperture so you lose light but with a scope of fixed aperture increasing f ratio by not using a reducer (as you did here) or adding a barlow will cut through LP surprisingly well.

Forgot you are using a OSC chip so narrow band isn't really an option for you unfortunately.

Rick

Hellobozos
2011-Dec-07, 10:24 PM
Its the curveture of the mirror in my scope,above shot is full frame un cropped prime focus,F10. If i use the 6.3 reducer it gets even worse. I'll be going to full field astrograph soon. Nice crisp stars to the edges an editing is whole lot less complicated..8^)..Coma Free is the only way to go,wish i'd known that when i started astrophotography..

Enjoy!