Further to my other thread, I have reprocessed the RGB data removing as much gradient as I could and I think I have made a better job of it this time. Still unable to use the Luminance.
Same info as before:
Ha 21 x 900secs + 10 x 600secs - Almost 7 hours
RGB 32 x 150 binned total 1hour 20mins
Grand total 8 1/4 hours
SW130PDS & Atik460EX, HEQ5
(https://cdn.astrobin.com/thumbs/czVJ8wRug1HQ_1824x0_vEFfvLwC.jpg)
This is looking good Carole. It's never going to look as smooth as a monochrome frame with the RGB added, you've got some nice Ha detail and it's interesting to compare the dust below the Horsehead to my slightly over MMT transformed version.
Thanks Duncan, I guess I am never going to get the detail you have managed from my location. Trouble is getting to a dark site in the winter is not really easy.
Carole
I forgot to mention.
The target went behind next door's tree and I was waiting for the guiding or imaging to go weird before I stopped it (as I was indoors doing it remotely). Was very surprised to find that with one exception, the guiding managed to keep going as did the images. The branches are quite thin, so I guess the 900sec exposures evened themselves out, but I was surprised that the guiding didn't throw a hissy fit.
So that was interesting.
Carole
Blimey that is amazing from Bromley Carole - well done & shows just what can still be done despite the light pollution - John
Just a thought Carole, you've got lots of detail in the emission nebulae but a lot less in the reflection nebulae. This must be because you have a lot of Ha data compared to RGB, maybe you could up the percentage of RGB and spend a little less time on the Ha? As I only shoot RGB I have found lots and lots of shorter subs have improved my images no end - 300s vs. 120s, half the subs in my latest stack were done with light pollution and only a UV-IR filter and these are mixed with subs taken after 'lights out' at 23:00 CET (I'm very lucky on that front!) but because of the number of subs it doesn't seem to matter too much.
Thanks very much John.
QuoteJust a thought Carole, you've got lots of detail in the emission nebulae but a lot less in the reflection nebulae. This must be because you have a lot of Ha data compared to RGB, maybe you could up the percentage of RGB and spend a little less time on the Ha? As I only shoot RGB I have found lots and lots of shorter subs have improved my images no end - 300s vs. 120s, half the subs in my latest stack were done with light pollution and only a UV-IR filter and these are mixed with subs taken after 'lights out' at 23:00 CET (I'm very lucky on that front!) but because of the number of subs it doesn't seem to matter too much.
The reason I didn't take so much RGB Duncan is because I tried it while the Moon was up, and the data was quite awful, so had to wait until the Moon had disappeared and then I only had a short window before the HH disappeared behind the trees. On the 2nd night, I didn't have that window as with the Moon coming up that much later that cut it down to even less, but then clouds came in anyway.
I must confess, that I have a LP filter, but because I do so little RGB from Bromley, I keep forgetting to put it on. So this was done entirely without a LP filter, which of course doesn't matter for the Ha.
Lastly, I would have got more detail on the emission nebula if I could have used Luminance as well, but I started to take it but it was quite awful.
If I get a chance I will try to get Luminance and some more RGB using a LP filter, though how effective it will be with LED lighting I am not sure, but there is probably still a lot of sodium lighting around as some nights I look at the sky with averted vision, and the whole sky looks red.
Thanks for the thoughts though, gives me something to think about.
Carole
Ah yes Carole, but plenty of awful data can add up to a decent image in the end. Hence why I now try to take 100+ short subs rather than 30 long ones.
I'll post up the rubbish Luminance to give you some idea of what I am talking about.
I am taking shorter RGB these days, I find 150secs binned works quite well.
BRB
Carole
This is 3 x 600secs Luminance. After examining the subs I decided to give up capturing any more.
(https://cdn.astrobin.com/thumbs/YnYHZFh7bUSb_620x0_vEFfvLwC.jpg)
Which night did you take them?
If the moon was out then there's no surprise you have gradients.
Mark
I waited until after the Moon had set Mark to take the RGB and Luminance.
Carole