My first (awful) narrowband image

[samir_ansari]

I thought I would have a shot a narrowband with my new SII filter having just arrived.

ED80 at F6.3 (with a focal reducer)

R - SII / 5 x 600s / bin 2x2 / no flats or darks

G - Ha / 4 x 600s / no binning / with flats and darks

B - OII / 1 x 600s / bin 2x2 / no flats or darks

And here are my excuses for this Greek tragedy of an image:

- Had software issues which limited my imaging time

- Accidentally binned the SII and OIII when I didn't mean to

- Only managed one picture of the OIII before the moonrise

- Am very sceptical about my OIII filter in the first place as seen here: http://stargazerslounge.com/imaging-discussion/170513-oiii-imaging.html

- Had to apply so much noise reduction to the SII and OIII that in the end I just shrank the whole image so it's harder to see.

Ok I think that's all of them

Be gentle

[JohnC64]

I wouldn't be so hard on yourself. Its recognisable as Rosette so It can't be all that bad!!. I always have problems when introducing a new piece of Kit or a new technique that requires something else to think about when imaging.

Cheers John

[Quatermass]

Well if that's awful my pictures must be the worst ever! That is a great image if you had my cheapo set up this would be like heaven on a stick. Perfection is something that comes later for now thats a good image.

[GordonH]

Hi Samir

Don't be too hard on yourself, we have all been there and that is part of the learning process. Narrow band imaging requires one very important skill that nobody can teach you, you either have it or you don't and that is patience. Think in the region of only doing one filter per night and you will be heading in the right direction, also i would recommend longer sub frames if you can (I use 30 minute subs with an f5 system and aim for at least 6-8 hours of data per filter), as you quite rightly noticed there was little if any nebulosity with the OIII filter, this will be the same with SII in a lot of cases except for the odd exception like M1. You will likely need more sub frames for OIII and SII as those two channels will need more pushing in the processing to get the data to show. Keep at it and you will find that perseverence will pay off

Best wishes

Gordon

[samir_ansari]

Thanks for the words of wisdom everyone. Gordon, I think 30 min subs may be the way forward but I noticed that even at 10 mins my picture looks very over exposed. My data starts about half way up the histogram and gets clipped when the values are still at about 0.2. Perhaps even though the moon was still very low in the sky it was still effecting my picture?

I was just informed in another thread that binning can also cause problems in narrowband images so I will be trying some bin 1 pictures tonight.

[GordonH]

Thanks for the words of wisdom everyone. Gordon, I think 30 min subs may be the way forward but I noticed that even at 10 mins my picture looks very over exposed. My data starts about half way up the histogram and gets clipped when the values are still at about 0.2. Perhaps even though the moon was still very low in the sky it was still effecting my picture?

I was just informed in another thread that binning can also cause problems in narrowband images so I will be trying some bin 1 pictures tonight.

It may be the method of processing you are using that causes your image to look over exposed. You certainly won't get an over exposed image using more than 10 minutes with narrow band, check all the recent narrowband images on my website Imaging The Heavens - Home Page and also elsewhere on the internet and you will find that a lot of images use sub frames in excess of 10 minutes as routine, make sure you don't bin the sub frames to get the best quality and ensure you calibrate all the sub frames before stacking

Best wishes

Gordon

[samir_ansari]

Thanks Gordon, I found last night that it was indeed the binning that was over exposing the mid tones so I had another go at bin 1 and I'm finally getting normal looking subs.

Tonight I may try and stretch to 20 min subs for the SII and OIII but I seem to be getting an extremely heavy gradient which is a real pain to get rid of when you have a target as big as the rosette!