Search found 959 matches

by oopfan
Fri May 14, 2021 6:25 pm
Forum: Gallery
Topic: Narrowband Imaging - Results for M27
Replies: 11
Views: 199

Re: Narrowband Imaging - Results for M27

All right, last night I captured one more hour of Ha. Now the Ha and OIII stacks are perfectly in balance at SNR 59 for a total SNR 84. Total integration time 6.4 hours. Now, I'm going to concentrate on wideband stacks: LRGB. Theoretically, LRGB will add "punch" to the stars. Last night, I...
by oopfan
Thu May 13, 2021 8:35 pm
Forum: Gallery
Topic: Coma cluster. Spotting active star-forming galaxies far far away
Replies: 2
Views: 38

Re: Coma cluster. Spotting active star-forming galaxies far far away

Tim,

Excellent work! You should look at submitting it to a magazine.

I think there is a typo. SII is deep red at 672nm. You say it is 272nm which is ultraviolet.

Brian
by oopfan
Thu May 13, 2021 8:13 pm
Forum: Gallery
Topic: Narrowband Imaging - Results for M27
Replies: 11
Views: 199

Re: Narrowband Imaging - Results for M27

Everyone, I had another clear night. I devoted it to Ha. As of now: Ha-7nm: 39x300s SNR 51 OIII-7nm: 26x300s SNR 59 Total SNR 78 5.4 hours Ha is still a little weak, but it is good enough to combine with OIII without boosting. The goal: Ha-7nm: 74x300s SNR 71 OIII-7nm: 37x300s SNR 71 Total SNR 100 9...
by oopfan
Thu May 13, 2021 8:04 pm
Forum: Gallery
Topic: Narrowband Imaging - Results for M27
Replies: 11
Views: 199

Re: Narrowband Imaging - Results for M27

Hi VPR, Re: Scouting images, and the funny thing is that I came up with that idea only after I tried applying mathematics to the problem of balancing the filters. I think that "scouting" is a good idea regardless, even if you aren't interested in balancing the SNR. At a minimum it gives yo...
by oopfan
Thu May 13, 2021 7:58 pm
Forum: Gallery
Topic: Narrowband Imaging - Results for M27
Replies: 11
Views: 199

Re: Narrowband Imaging - Results for M27

Hi Tim, Agreed, SII is a challenge. I am by no means an expert in narrowband but I haven't seen any objects strong in SII. Planetary's are stronger in OIII than Ha. Regular emission's are strong in Ha, but sometimes it is a toss-up on second and third place. For example, the Pac Man Nebula: stronges...
by oopfan
Wed May 12, 2021 4:35 pm
Forum: Gallery
Topic: Narrowband Imaging - Results for M27
Replies: 11
Views: 199

Re: Narrowband Imaging - Results for M27

Last night I captured more OIII frames with the goal of doubling the total SNR. I've got a couple more sessions to go before reaching total integration time of 9 hours. Hopefully by then the outer shell will reveal itself clearly. According to my analysis, I need to capture twice as many Ha frames a...
by oopfan
Tue May 11, 2021 10:00 pm
Forum: Gallery
Topic: NGC7023 Iris nebula
Replies: 4
Views: 55

Re: NGC7023 Iris nebula

Up late? I love those dark nebulae!
by oopfan
Mon May 10, 2021 10:22 pm
Forum: Gallery
Topic: M82 Cigar Galaxy (multiband)
Replies: 6
Views: 124

Re: M82 Cigar Galaxy (multiband)

Thirteen hours! That is true dedication, Menno.

Brian
by oopfan
Mon May 10, 2021 1:56 pm
Forum: Gallery
Topic: Narrowband Imaging - Results for M27
Replies: 11
Views: 199

Re: Narrowband Imaging - Results for M27

Thanks, Dave. That was a wise investment you made. It benefits us all. I like "HOO2". That's what I am using, but I also like "LRGBHOO". I've decided to capture another 7 hours of Ha and OIII in an effort to further reveal the outer shell. After that, I'll work on capturing the &...
by oopfan
Mon May 10, 2021 1:49 pm
Forum: Gallery
Topic: Narrowband Imaging - Results for M27
Replies: 11
Views: 199

Re: Narrowband Imaging - Results for M27

Thanks everyone for your up-votes. I'd like to use this opportunity to repeat something I've said in other posts, but it bears repeating: The purpose of calculating the signal-to-noise ratio (SNR) is to optimize my time at the telescope. If I did the "normal" thing and captured the same nu...