M81/M82 in Ha LRGB

[Dave Smith]

This was taken over 3 nights, night 1 Luminance 28 x 300s, night 2 Ha, 15 x 900s and night 3 RGB each 12 x 300s. Processed in StarTools, photoshop and with RegiStar. Captured using SGPro. Telescope used, Megrez 90 with 0.8x FR/FF and Atik 460EX mono camera with Astrodon filters. Not remotely comparable with Peter's image but I enjoyed doing this and have been surprised at the detail esp in M81 from my 90mm refractor.

I am intending to get some more data as the dwarf irregular galaxy Holmberg IX is just visible below M81.

Dave

[toxic]

thats a nice image.

and i see a lot more than a couple of galaxies in your shot  ​ 

i had a go at this but need more data  i didnt use i used  S2 it seemed to be better than HA for the starbust of m82 but hey just my opinion lol

[ultranova]

wow the HA is making the picture pop, and as you

say lots of detail in there, nicley done Dave

Paul

[Dave Smith]

thats a nice image.

and i see a lot more than a couple of galaxies in your shot  ​ 

i had a go at this but need more data  i didnt use i used  S2 it seemed to be better than HA for the starbust of m82 but hey just my opinion lol

That is interesting Chris. It looks as if it is going to be clear tonight and with the Moon very evident I will have a go at SII.

wow the HA is making the picture pop, and as you

say lots of detail in there, nicley done Dave

Paul

Many thanks Paul

Dave

[tingting44]

excellent shot and very well processed! love the Ha in this shot also

[Dave Smith]

Thanks Martin

Dave

[Coco]

Delightfully processed, superb!

[daz]

That's very nice Dave!

Interesting comment about the SII - I have just set it running for more Ha, but next time out I'll give the SII a go

[Dave Smith]

Many thanks Guy and Daz.

@Chris (Toxic) and @Daz    I've just tried a 15 min sub in SII and can see no sign of the jets in M82 ? Have I misunderstood something?

Dave

[michaelmorris]

Hi Dave

That's really great shot.  Thanks for sharing.

[daz]

Many thanks Guy and Daz.

@Chris (Toxic) and @Daz    I've just tried a 15 min sub in SII and can see no sign of the jets in M82 ? Have I misunderstood something?

Dave

Well, searching on the internet, I can't see any images with SII either Dave!

[Dave Smith]

Hi Dave

That's really great shot.  Thanks for sharing.

Thanks Michael, much appreciated.

Well, searching on the internet, I can't see any images with SII either Dave!

Very strange. There must be some sort of misunderstanding. I'm currently collecting a load more of luminance - just hope the Moon isn't causing the detail to be lost.

Dave

[Xplode]

The Ha layer looks really good, but the rest of your image lacks color, especially M81.

If you want these galaxies to look the best you need to process them separate and combine with layer masks in PS

[Dave Smith]

The Ha layer looks really good, but the rest of your image lacks color, especially M81.

If you want these galaxies to look the best you need to process them separate and combine with layer masks in PS

Many thanks for that. It is precisely what I plan to do when I get more data. I'm hoping the Moon hasn't had too much of an effect on the data I am collecting tonight.

Tonight I have been getting more luminance, but plan on getting more RGB at a later stage.

Dave

[jeremile]

Hello Dave,

Really pretty image with great processing.

[Dave Smith]

Thanks Jeremile

Dave

[swag72]

Hate to say it Dave - But I reckon the moon will have a massive effect. On another forum last evening, someone was saying that their luminance with the full moon was giving them an ADU of 26000 on the background, compared to 600 when there's no moon. I'm sure there's a lot of data between that 20k ADU that will be lost.

Just my opinion of course ...... I love it of folks prove me wrong

[Dave Smith]

I haven't processed last nights stuff yet but I strongly suspect you are right. I had hoped to try the SII idea but with that not producing anything I thought I'd just give it a go. Nothing to lose but I am expecting to discard last nights efforts.

I will try measuring the adu and add the figures to this post in a few minutes.

Dave

[swag72]

Will be interested to compare the ADU figure from last night to what you normally get Dave.

[Dave Smith]

Well that has surprised me. Last nights adu is around 9500, the adu for the luminance of the image posted above taken on 24 Feb 2015 is around 4000 - 4500 there was a 0.37 illuminated Moon and fro a lum image taken from a dark site (Kelling Heath) was around 800.

I don't take many broad band images and cannot find one taken from home with no Moon.

It looks as if I should keep LRGB images for the dark site (4 weekends each year)

Dave

[swag72]

So if I understand right based on these observations - In your case any fine detail that falls between zero and 9500 from last night will not register on the sensor. Compared to your dark site where you have an ADU of 800, EVERY bit of detail above the 800 floor will regsiter.

Am I right or just being too simplistic?

[Dave Smith]

Sounds right to me. I had better get on and process last nights data and see how bad it is.

Dave

[Dave Smith]

OK you were right Sara. I haven't given it long but it was so much more difficult to process and came out very noisy and not as detailed as above. This was with 65 x 300s.

So I must resist imaging in LRGB when there is a Moon. Perhaps I will have to go back to imaging the actual Moon when there are no nb targets around. (That will at least make use of my C9.25)

Dave

[paulobao]

Hi Dave,

Very nice image, congratulations!

Cheers,

paulo

[Dave Smith]

Thanks Paulo

Dave