This processing malarky is hard!!!

[tich]

I'm finding this processing difficult, the picture below shows an image I did of the Witches broom using an ED80, modified Canon 1000D & 0.8 reducer. It needs flats which at the moment is an ongoing project. I did have a few issues with guiding not sure if it were flexture or the PA was out a bit so the stars to the edge aren't great & with only 55 minutes worth of data it's quite noisy but at least you're able to make out the nebula. The bright star is also blown out too but as I've only been doing guided imaging a short time I'm hoping I'll improve over time.



Anyhow I thought I'd have another bash at processing the same data & thought how hard can it be?

Well I managed to reduce some noise not blow out the bright star & even to get the background darker without clipping the black levels, the problem is I've got an image that's overwhelmed with more stars.





Any help or hints to reduce the stars & bring out more detail in the nebula would be appreciated, I know more data would help but I've not managed to get out much lately due to the lack of clear skies. What I use to process the images is Photoshop CS5 & apart from a few add ons I just alter levels, curves & saturation levels.

 

[Christopher Davenport]

Unfortunately, I can't help with the stars, but I saw a good post on controlling your stars

http://stargazerslounge.com/topic/9706-7-how-to-make-stars-smaller-and-sharper/

Maybe if Martin, see's this he can add some extra thoughts.

I am in a similar situation to you except, my image was not on a modified camera.

Now I have modified, so I am interested to see how much detail is appearing in your image.

Your image definitely has more Neb under the broom than mine and your colour is different.

http://cassiopeiascat.blogspot.co.uk/2014/07/the-veil-nebula-ngc6960.html 

Keep up the good work, as it ain't easy!

[tich]

Thanks for the Link Chris it could certainly help plus Martin's website could prove to be a handy link too so that's been put in my favourites. I do find the processing quite difficult & sometimes the images just seem to work other times I feel like I'm banging my head on a brick wall & getting nowhere. I do need to learn layering techniques especially when Orion comes around again as I need to image it at different subs then layer them over the top of each other.

[Christopher Davenport]

Thanks for the Link Chris it could certainly help plus Martin's website could prove to be a handy link too so that's been put in my favourites. I do find the processing quite difficult & sometimes the images just seem to work other times I feel like I'm banging my head on a brick wall & getting nowhere. I do need to learn layering techniques especially when Orion comes around again as I need to image it at different subs then layer them over the top of each other.

Layers in PS are great for galaxies, but I am struggling with nebula, although fairly new at the game.

When I did Orion last year I used HDR stacking in DSS, this gives you much better dynamic range in PS. 

Although, because it is not cappa sigma stacking, darks become very important.

I find HDR the best stacking mechanism when I have more than 3hrs of data and differing sub lengths.

[martin_h]

Here is a handy Action for Photoshop for reducing stars.............. Peter Shah's star reduction......... http://stargazerslounge.com/topic/48558-star-reduction-action/

[tich]

Thanks for the link Martin I've download it & just tried it out & it doesn't seem to work with my PS CS5 64Bit

[Thalestris24]

Hi Tich

You really should include flats in your calibration - they make the processing easier. Is there any reason you haven't been doing them? They don't take long to do! I assume you've included a set of matched darks?

I struggle with processing too so you're not alone!

Louise

[Christopher Davenport]

Thanks for the link Martin I've download it & just tried it out & it doesn't seem to work with my PS CS5 64Bit

Downloaded the actions from Peter and found it had little effect on my 5000 x 3000 stacked DSLR image.

So I reduced the image size down by 50% and then reran the script about 5 times, each time it makes a bigger effect.

Managed to clean up my image significantly, I am well impressed. 

[tich]

Hi Tich

You really should include flats in your calibration - they make the processing easier. Is there any reason you haven't been doing them? They don't take long to do! I assume you've included a set of matched darks?

I struggle with processing too so you're not alone!

Louise

I don't do flats as I set everything up at a dark site to image so looking at making up some sort of light box in the future, if I had a permanent setup at home I'd probably run off some sky flats.

Downloaded the actions from Peter and found it had little effect on my 5000 x 3000 stacked DSLR image.

So I reduced the image size down by 50% and then reran the script about 5 times, each time it makes a bigger effect.

Managed to clean up my image significantly, I am well impressed. 

The add on I have still doesn't work & I have installed it properly so I guess I'll have to look around for another one, if anyone knows of an add on that will work with my version of PS then if you could let me know please as it would be appreciated thanks.

[Thalestris24]

I don't do flats as I set everything up at a dark site to image so looking at making up some sort of light box in the future, if I had a permanent setup at home I'd probably run off some sky flats.

Hi

You can still do flats at home providing you can leave the camera in place and don't change the focus. You can use a monitor screen as the light source (open Notepad full-screen and position the monitor about a meter away from the scope.

Wish I could get to a dark site!

Louise

[tich]

The problem is that I have to dismantle everything so getting the focus & camera in the right orientation proves difficult especially when imaging with the 10" Newtonian plus I haven't got a laptop screen big enough to cover the aperture. There is the white T Shirt method but as I've already stated the whole set up has to be dismantled.

[Thalestris24]

The problem is that I have to dismantle everything so getting the focus & camera in the right orientation proves difficult especially when imaging with the 10" Newtonian plus I haven't got a laptop screen big enough to cover the aperture. There is the white T Shirt method but as I've already stated the whole set up has to be dismantled.

Hmm.... All is not lost! You can still create synthetic / artificial flats. I think there is more than one way to do it but there is one method here (see bottom of the page) http://www.dl-digital.com/photoshop_basics.htm

Plus if you do a search on here I'm sure there are several posts on the subject

You might also consider an led panel. This one can be powered via usb but I'm not certain if it will run from a laptop:

http://www.amazon.co.uk/Huion-Inches-Adjustable-Brightness-Tracing/dp/B00J3NRAV2/ref=pd_cp_kh_0

Maybe even a tablet would do - I think you only have to fill your scope's unfocussed field of view - not necessarily the whole aperture. I'm sure someone else here can confirm.

Louise

[Thalestris24]

Thinking about it, you probably would need a fairly big light source for your 250p but I'm not sure what you could get away with - some experimentation required!

Cheers

Louise

[Alien 13]

Artificial flats can be quite effective i use one similar to that in the link by Louise but invert the layre mask and add a levels adjustment layre then use colour burn blending mode, the levels adjustment can be tweeked to set the black level point.

The procedure detailed above is used to correct vignetting, dust bunnies are corrected by a an exposure taken with the camera with lens off and added into the mix as a new layre mask.

Alan

[tich]

The artificial flats sounds like a good thing but it's a bit beyond my Photoshop skills for the time being, not that it will stop me from trying one day.

I've just realised that I'm a muppet, I've got Astronomy tools installed with my version of PS & that has a star control option, I've ran it through a couple of times (It takes a while) & managed to pull out some more detail. With only around 55 minutes worth of data I doubt that much more could be got from it. Flats would definitely improve it but for now I'm reasonably happy with it.



I did some fiddling with this one yeah I know the blacks are clipped but I quite like it.