M27 - Dumbbell nebula with 8'' newton and an Antlia ALP-T

[ONIKKINEN]

First image with a new narrowband filter, the Antlia ALP-T. 4h14min in total, with a mixture of 2 minute and 4 minute exposures with the majority being 4 minutes. Early on it was very windy, so i took the compromise regarding underexposing with 2 minutes rather than lose too many exposures to wind. It was technically a full Moon night, but it was barely above the horizon and went away completely towards the end, so closer to no Moon at all really. Seeing was very good, which i was able to make decent use of once the wind died down a bit. In the end the stack has 2'' fwhm, which is very good with my kit, certainly in the top 10% seeing of all nights so far.

Kit used is an 8'' newtonian, TeleVue Paracorr, RisingCam IMX571 OSC camera and the ALP-T. Downsampled to around 1''/px.

First time processing a planetary nebula of my own data, and first time with a filter this narrow. Tricky target to process, the outer shell is extremely faint while the core is very bright. Feels like walking on a tight rope with balancing out the 2 extremes to a point where it looks like they both belong in the same image and were not forced to coexist. You can be the judge on whether i managed this or not but i am very satisfied with the result thus far.

Stacking/calibration in Siril, Processing in PixInsight and Photoshop with the latter seeing the majority of the action. RC-astro tools leveraged at every possible point of course.

Feedback very much welcome!

-Oskari

[geeklee]

Excellent result Oskari - great detail in the core, lovely subtle contrast in the outer edges of the main area of M27 looking like folds and holding a super depth... then bringing those faint outer shells out so well (without any sort of forced look to my eye).

[WolfieGlos]

Superb result Oskari, and I echo Lees words.

Just over 4 hours makes my recent efforts look poor for the vast difference in total time (thanks for the Like by the way 👍), so much so that I think I’m going to revisit not only my processing but stacking. Thanks for the inspiration, and like Lee says, the outer shells don’t look forced at all. 

[ONIKKINEN]

Thank you @geeklee and @WolfieGlos , much appreciated.

43 minutes ago, WolfieGlos said:

Superb result Oskari, and I echo Lees words.

Just over 4 hours makes my recent efforts look poor for the vast difference in total time (thanks for the Like by the way 👍), so much so that I think I’m going to revisit not only my processing but stacking. Thanks for the inspiration, and like Lee says, the outer shells don’t look forced at all. 

I think you are being too harsh to yourself with the comparison, after all i am imaging with a scope that has almost 4x the aperture area to yours so in a sense the comparison is always going to be unfair. With that in mind the difference in integration time does not seem so drastic anymore.

If you want to compare to your stack, here is what the preprocessed but still linear stack looked like with an autostretch (Gradients, crude colour calibration, BXT, bit of NXT, nothing else):

This autostretched view also nicely shows the issue at hand when processing this target, the core is completely blown and the shell is still faint.

[Sterrenland]

Stunning! I want a bigger scope!!

[WolfieGlos]

13 hours ago, ONIKKINEN said:

I think you are being too harsh to yourself with the comparison, after all i am imaging with a scope that has almost 4x the aperture area to yours so in a sense the comparison is always going to be unfair. With that in mind the difference in integration time does not seem so drastic anymore.

If you want to compare to your stack, here is what the preprocessed but still linear stack looked like with an autostretch (Gradients, crude colour calibration, BXT, bit of NXT, nothing else):

 

This autostretched view also nicely shows the issue at hand when processing this target, the core is completely blown and the shell is still faint.

Thanks Oskari, I've just compared my linear images and in Broadband (bulk of my time) I have more of the outer shells than I have in NB, although they are not as well defined and bright as yours are. I won't derail your topic with discussions over my images, but good point about the aperture. Even so, 4 hours is a superb result 👍

[Stuart1971]

Superb job there and the handling of the extreme brightness of the core, compared to the faint outer shell, is sublime..👏🏻👏🏻

[ONIKKINEN]

23 minutes ago, Stuart1971 said:

Superb job there and the handling of the extreme brightness of the core, compared to the faint outer shell, is sublime..👏🏻👏🏻

Thank you!

54 minutes ago, WolfieGlos said:

Thanks Oskari, I've just compared my linear images and in Broadband (bulk of my time) I have more of the outer shells than I have in NB, although they are not as well defined and bright as yours are. I won't derail your topic with discussions over my images, but good point about the aperture. Even so, 4 hours is a superb result 👍

Interesting about the broadband thing. I thought the shell was mostly 0lll and a bit of Ha, but maybe there is a dust and reflection nebulosity component too that is bright in broadband. My knowledge of nebula imaging is not too great, but i just assumed NB was the way to go here. I am also trying to get a broadband night in, if only just for the stars but am also getting a new scope soon so we will see if i get sidetracked (most likely will).

Oh and no worries about derailing threads, threads are meant to be derailed 🙂.