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RyanJones
30-04-2019, 10:42 PM
Hi all

I took the opportunity to go out last night and grab some more data on M83. This image is a combination of 2 1/2 hrs at home ( Bertole 8 ) and 1 1/2 at my dark site ( Bertole 3 ). I was planning more time but it just didn't work out that way.

C5 SCT
Canon 350d unmoddified
Nextguide guiding

Combination of 90sec ( home ) and 300sec ( dark site ) both at ISO800

There's a lot I still need to work on with using this OTA......

Mickoid
30-04-2019, 11:09 PM
Ryan, you've gathered a lot of data on this object so I can only imagine you were having difficulties processing this one. Was your focus good on both nights? The stars look a bit bloated or maybe you did something in the post processing that you went too far on. It's a fine line when using some of these sliders in the tool bar. With so many effects to choose from, it's easy to get a little bit excited and try them all! I know in Startools there's a before and after button. If the image doesn't look better than the before image, I'll cancel whatever I've done and start again. The good thing is your original data (hopefully) is always there to come back to.

You've done well for more than half your data being captured under a Bortle 8 sky! :thumbsup:

RyanJones
30-04-2019, 11:23 PM
You're right with the stars and the processing Micheal. This is where I've got all my learning to do. The actual data I'm quite happy with, especially guiding 1250mm focal length with my particular stand alone guide setup on this OTA. I've really got to learn a good quantity of subs to create enough data to stretch without introducing as much noise. The softness in this image is down to me dealing with the noise and gradients. With the light pollution I have to get so much more data because I have to clip the sky glow leaving me not a lot to stretch. I find galaxies so much harder for this too than DSOs.

assbutt94
01-05-2019, 06:34 AM
Every 4x captures gives you half the noise, so there are diminishing returns after 40-50 captures and the amount of noise reduction is very minimal.

If you've captured much more, you could go through each individual shot and zoom in 100-200% and pick the very best of your data and narrow it down to 40 and stack with them.
I like to use two stars very close to each other if possible, almost touching, and use the tiny gap to judge the quality of a shot.

Best of luck, you've brought out quite a bit of colour, I like it!

Startrek
01-05-2019, 07:35 AM
Ryan
Great result and yes galaxies are difficult to image due to the hidden detail within
I’m an advocate for dithering both at my Bortle 8 Sydney home and my Bortle 3/4 holiday home near Ulladulla. For me there’s a huge difference between dithered and un dithered images when it comes to noise reduction
I don’t start getting really good detail in galaxies until I have at least 3 hours of guided dithered data
Startools is working well for me but still a learning curve, it has so much to offer
Well done !!
Martin

RyanJones
01-05-2019, 07:12 PM
Thank you Martin and Nathan,

There is no doubt that data is the answer is to the issue. I'm guilty of playing with too much equipment at one time. I've pretty much dialled in my capture requirements and what Im capable of with my newt but only at my dark site. I'm getting there now with the C5.

As far as dithering is concerned. My guider is stand alone so I don't have the option to " instruct " it to do it, however it's not the most accurate guider so pixel for pixel I get a form of dithering anyway. Talk about a silver lining.

We all know that there are no hard and fast rules for every setup but I do appreciate others input on what works for them and i guess what that's how we all end up getting better so thanks guys :thumbsup:

Jono090
07-05-2019, 07:07 PM
Great shot Ryan!