Jump to content

Walking on the Moon

Rosette Nebula wearing 7nm - R channel only


Recommended Posts

I just recently bought a Williams Optics 0.8 RD/FF and a baader 7nm HA filter, my intention being to get more filters for NB imaging given my desperately light polluted location. I put these on my 100mm F6 Achro and gave it a whirl last night as a test. I wasn't sure if the spacing was 100 dialled, I think I need to adjust it a little but I'm not sure how as it's about as low as I can get it. Focusing was a pig as the Bat mask wouldn't split the light for some reason so I did my best with live view. Imaging in narrow band is a first for me and I've never processed purely HA data before. Well I say purely, that's not strictly true as I took this with a DSLR.

Given that I wasn't sure about the processing I did some research. My tools of choice are DSS and PS. I do have Star tools but I've only just bought it and am more familiar with PS, so I stuck with what I know for this one. I set DSS up with the usual lights, darks, flats and bias with the stacking set to "create super pixel". I then opened the image in PS duplicated and deleted the G+B channels leaving only the R channel. I then worked on this. I tried not to bash it with to much noise and applied a high pass filter to maintain the detail. I would greatly appreciate any advice or suggestions for processing as it's all rather new for me. 

100mm f6 Achro + 0.8 RD/FF imaging at f4.8 + 7nm Baader filter + 550D full spec

5 x 900 sec lights + 5 darks, 20 bias, 20 flats


180mm guide scope QHY5L II M

No polar alignment (yep you heard that right - can't see Polaris)

Anyway I hope you like it.  

Rosette 7nm HA - R only to greyscale small.jpg

  • Like 8
Link to comment
Share on other sites

22 minutes ago, Physopto said:

Not bad at all. Managing 900 second subs when not being able to polar align is not to be sniffed at. Nice image.


Thank you Derek :) . I am severely limited when imaging off the balcony. Polaris is a no go, and the alignment process on the handset is practically impossible due to the limited view, It's down to permanent markers and gaffa tape lol. I need to get it drift aligned but I use this mount when I go out. Once I get another mount, I'll make a bracket for the wall and then I can drift align it and leave it there. Cheers buddy. 

  • Like 2
Link to comment
Share on other sites

7 hours ago, toxic said:

great image even with polar alignment :hello2:

Thanks :) uuurm - well a kinda rough guess at where Polaris is. My apartment faces west and runs from north to south so seeing or even using other stars as a reference to give me a rough idea is impossible. 

1 hour ago, gorann said:

Very nice!

clearly you have proven that you do not need an apo for narrow band imaging.

Thanks :) . Seems like it, swapping filters will be a pain and will require re-focusing each time... I have a lot of noise in the image which I suspect would be reduced with a lot more subs. Stacking with DSS using the super pixel mode and 2x drizzle certainly helps with detail when using DSLR data for NB. I'm thinking of getting another camera as they are two a penny over here. Then removing the CFA on this one to make it a mono.

  • Like 1
Link to comment
Share on other sites

5 hours ago, MARS1960 said:

Very nice and no PA, there is hope for me yet :icon_biggrin:.

Thanks Mark :)..It's certainly not going to win any awards and isn't clean, but for a first go with NB on a DSLR with only 5 noisy subs. I'm quite pleased! 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.