Veil Nebula DSLR - not pretty!

[Tommohawk]

Hi All

Well I was initially quite pleased with the subs I got with my Tamron 300mm lens at F2.8. However stacking them was a complete nightmare - resolved thanks to fellow SGL folk - and processing was not a lot better!

I've been generally fairly chuffed with my previous DSO images but this one is really pretty grim -there are just too many stars! Looking at other recent submissions here - all of them brilliant -  it looks like this really calls for narrowband filters and probably CCD rather than DSLR. Anyhow, if anyone can see a way to do improve this image I'd be grateful - I tried using a star mask layer but it hasnt helped much. Thanks for looking.

SW200PDS, modded Canon 550D, 20x 240sec subs ISO800, flats bias, darks.

[Jannis]

That's a nice capture i think. It's a faint target drowning in stars and for me at least wasn't a very easy target to capture.

I think you mainly need a lot more and/or longer exposures to get the fainter details. How does a single untouched exposure look?

Your capture is extra interesting for me as i also have the 550D and i've been wondering for a long time now if it's really any point trying to capture any narrowband deep sky with my "guide-cam" compared to modding and using my 550D.
I hope you don't mind, i had a little play with your picture and tried to drag out a bit more fainter details and reduced the stars.

[Tommohawk]

Hi Jannis thanks for the reply, and you definitely have found some more detail there - how did you do that??

BTW, on another thread someones posted a narrowband image done with a DIY cooled Canon 1000D - see here

20 minute subs though!

[Maximidius]

Well done, tough to process and control all those stars when trying to bring out all that nebulosity, i can't offer much in the way of advice, but i'll encourage you to keep at it and keep producing fine images like this.  

[StargeezerTim]

Hi Tommo,

I'vd recently got much better at reducing stars with the star layer and minimum filter. I find that practice, and lots of it, is needed! I have even written an action that works most of the time in creating a star layer.

Having said that, i've never produced an image of the veil i'm happy with. Its very faint stuff...

[Tommohawk]

On 10/9/2016 at 09:10, Maximidius said:

Well done, tough to process and control all those stars when trying to bring out all that nebulosity, i can't offer much in the way of advice, but i'll encourage you to keep at it and keep producing fine images like this.  

That's kind of you, thanks for the encouragement!

 

On 10/9/2016 at 10:47, StargeezerTim said:

Hi Tommo,

I'vd recently got much better at reducing stars with the star layer and minimum filter. I find that practice, and lots of it, is needed! I have even written an action that works most of the time in creating a star layer.

Having said that, i've never produced an image of the veil i'm happy with. Its very faint stuff...

I tried several things to reduce the stars, and in the end I couldn't remember quite what I'd done!! Half the problem is that whilst I did save the image in layers whilst working on it, I didnt save the history, so couldn't replicate my exact technique - AKA random fiddling.

I did a star mask layer, as per Doug Gerber's excellent tutorial which helped, but what I really wanted was to replicate a star layer which I'd created with an adjusted (much darker) version of the DSS image. This also eliminates much of the CA on the really bright starts. I tried using a mask for this, but the areas of nebulosity are so.... errrr.... nebulous, that's its difficult to open (blacken) the mask in the right places.

It took me forever just to get this far, and I decided to quit before it became an obsession (too late for that, according to my wife)

I think the best way forward has to be narrowband - but with limited clear skies the idea of super long exposures seems fanciful.

[Jannis]

I did many many rounds of curves and star reduction to increase the nebula. Also used many low-pass masks in the process to drag out only the fain nebulosity. 

It's a long process that needs many small steps, but i strongly recommend you to buy this set of tools if you use photoshop: http://www.prodigitalsoftware.com/Astronomy_Tools_For_Full_Version.html
It really speeds up the process a lot and make time-consuming processes into a click of a button. 

As for narrowband, i both love it and hate it. Love it because of the increased contrast, but hate the low sensitivity of my unmodded DSLR for the Ha. My 550D also gives me loads of horizontal banding that i don't have without narrowband filters. 
Without filters i can usually on a moonless night get maybe 600s at ISO 400 without overexposing, but with Ha filter in place i just get enough exposure with 600s and ISO6400. OIII works much better though, and i can imagine Ha will work fine for you as you have a modded camera. 
 

[Droogie 2001]

I love the field of view you have captured.
Don't despair I have recently taken an image of the Western Veil with my CCD and it has been the most difficult image to post process due to the vast volume of stars. I have attempted many processing runs at it and have finally got to the stage where I have tamed the stars a bit but not completely happy with them. 
I think this because I am imaging in Broadband LRGB which does not help as this is subject to causing star bloat at least from the luminance channel.

Like someone else said its a feint object in a field of bright stars, certainly more exposures will help as well.

[gorann]

I never tried the whole Veil with a telephoto lens (I have just gone for the East or West using telescopes) and I wonder if this may just be a poor target for wide field AP since the stars drown the nebulosity? Maybe using a telescope (with around 1000 mm focal length) and making a mosaic is the way forward even if it is much more work? I think in theory (and practice) that the star sizes (measured as the amount of pixels taken up by a particular star on your chip) will be about the same for a telephoto lens and a telescope, so the stars will be relatively smaller in a mosaic made with a telescope.

[ollypenrice]

It's the prodigious star count which makes the Veil difficult. Outside the Milky Way it would be easy.

First thing is focus. It has to be incredibly tight and this isn't easy with lenses. Star masks help a little, and do you have Noels Actions (now called Pro Digital Star Tools or some such name?) the  'Make stars smaller ' action is excellent.

Olly

[Maximidius]

3 minutes ago, ollypenrice said:

It's the prodigious star count which makes the Veil difficult. Outside the Milky Way it would be easy.

First thing is focus. It has to be incredibly tight and this isn't easy with lenses. Star masks help a little, and do you have Noels Actions (now called Pro Digital Star Tools or some such name?) the  'Make stars smaller ' action is excellent.

Olly

Is this the action set you are refering too? 

http://www.prodigitalsoftware.com/Astronomy_Tools_For_Full_Version.html

[ollypenrice]

Just now, Maximidius said:

Is this the action set you are refering too? 

http://www.prodigitalsoftware.com/Astronomy_Tools_For_Full_Version.html

That's right. Some of the actions are outstanding and I use them all the time. We have a multiple dead column on one CCD and vertical banding noise removal handles it well, used as a layer. I also use the star selection tool, the star reduction and Local Contrast Enhancement.

Olly

[Maximidius]

1 minute ago, ollypenrice said:

That's right. Some of the actions are outstanding and I use them all the time. We have a multiple dead column on one CCD and vertical banding noise removal handles it well, used as a layer. I also use the star selection tool, the star reduction and Local Contrast Enhancement.

Olly

Awesome, that'll be in my PS setup pretty soon then! Cheap too, which makes a pleasant change. 

[Tommohawk]

2 hours ago, Jannis said:

I did many many rounds of curves and star reduction to increase the nebula. Also used many low-pass masks in the process to drag out only the fain nebulosity. 

It's a long process that needs many small steps, but i strongly recommend you to buy this set of tools if you use photoshop: http://www.prodigitalsoftware.com/Astronomy_Tools_For_Full_Version.html
It really speeds up the process a lot and make time-consuming processes into a click of a button. 

As for narrowband, i both love it and hate it. Love it because of the increased contrast, but hate the low sensitivity of my unmodded DSLR for the Ha. My 550D also gives me loads of horizontal banding that i don't have without narrowband filters. 
Without filters i can usually on a moonless night get maybe 600s at ISO 400 without overexposing, but with Ha filter in place i just get enough exposure with 600s and ISO6400. OIII works much better though, and i can imagine Ha will work fine for you as you have a modded camera. 
 

Thanks Jannis. I'm still using an early CS2 version of Photoshop and I think the first step would be go get a later version - and then as you say get some actions. At $22 the ones you mention are a bargain. 

I don't think I'd go the NB route with my DSLR anyhow - too long winded. I'm trying to justify the cost of a newer camera - but with so little clear sky its hard to justify. Unless of course I get a travel mount - the M Zero appeals. (£££££)

1 hour ago, Droogie 2001 said:

I love the field of view you have captured.
Don't despair I have recently taken an image of the Western Veil with my CCD and it has been the most difficult image to post process due to the vast volume of stars. I have attempted many processing runs at it and have finally got to the stage where I have tamed the stars a bit but not completely happy with them. 
I think this because I am imaging in Broadband LRGB which does not help as this is subject to causing star bloat at least from the luminance channel.

Like someone else said its a feint object in a field of bright stars, certainly more exposures will help as well.

Thanks yes I thought it would look good in wider field. I will keep working on it over time - more exposures would help, although one nice thing about f2.8 is at least you get the data pretty quickly. I guess F2.8 4 min subs are same as F4 16 mins, no? I wonder if many more but slightly shorter subs might help? Moon causing probs now though!

 

[Tommohawk]

42 minutes ago, gorann said:

I never tried the whole Veil with a telephoto lens (I have just gone for the East or West using telescopes) and I wonder if this may just be a poor target for wide field AP since the stars drown the nebulosity? Maybe using a telescope (with around 1000 mm focal length) and making a mosaic is the way forward even if it is much more work? I think in theory (and practice) that the star sizes (measured as the amount of pixels taken up by a particular star on your chip) will be about the same for a telephoto lens and a telescope, so the stars will be relatively smaller in a mosaic made with a telescope.

I agree that most of the interest is in the veil, and the vast number of stars just adds visual clutter so maybe its not a great widefield target - when I zoom in on my image in the veil areas, it looks much better.... apart from the bloaty stars! 

Maybe a mosaic with the 200P is the way to go - might experiment with this later. 

33 minutes ago, ollypenrice said:

It's the prodigious star count which makes the Veil difficult. Outside the Milky Way it would be easy.

First thing is focus. It has to be incredibly tight and this isn't easy with lenses. Star masks help a little, and do you have Noels Actions (now called Pro Digital Star Tools or some such name?) the  'Make stars smaller ' action is excellent.

Olly

Thanks Olly. Re focus I use my 200P Bahtinov with Vega it works really well on the Tamron lens, not least because Vega is overhead-ish so the mask stays put!! And I have a high-tech digital modular friction system (rubber band) around the focus dial which means I can get the Bahtinov image bang on... needs a steady hand though.

[Tommohawk]

Have just noticed that the star tools mentioned above work on CS2 v9  which I have - Paypal at the ready!!

[gorann]

18 minutes ago, Tommohawk said:

Thanks Jannis. I'm still using an early CS2 version of Photoshop and I think the first step would be go get a later version - and then as you say get some actions. At $22 the ones you mention are a bargain. 

I don't think I'd go the NB route with my DSLR anyhow - too long winded. I'm trying to justify the cost of a newer camera - but with so little clear sky its hard to justify. Unless of course I get a travel mount - the M Zero appeals. (£££££)

Thanks yes I thought it would look good in wider field. I will keep working on it over time - more exposures would help, although one nice thing about f2.8 is at least you get the data pretty quickly. I guess F2.8 4 min subs are same as F4 16 mins, no? I wonder if many more but slightly shorter subs might help? Moon causing probs now though!

 

Well, it is not that bad with f/4. You would need 8 min subs. Each "full" f-step increase on your telephoto lens (f/2.8, f/4, f/5.6, f/8, f/11, f/16 etc) corresponds to a doubling of the exposure time

[Xiga]

Lots of good advice here. I also use the PS actions above, they're excellent. 

Here's another method for star reduction, that doesn't cost anything:

Under channels click the wee dotted circle icon to "load channel as selection" and,  using the magic wand tool, proceed to erase the brighter parts if they get selected automatically, now go to "select" > "modify">"expand" here give a size of 4 pixels then go to "select" again, "modify" and "smooth" here give a vallue of 2 pixels.

Next go to "filter" then "other" then "minimum" and choose 1 pixel as vallue, click "ok". This is usually too much so you must smooth it out, go to "edit" then "fade minimum" and put some 50 or 60% in there, then go to "select" and choose "deselect" and that's it, smaller stars that don't overtake the image

?

I've found it to be slightly better than the PS action 

[Knight of Clear Skies]

I struggled with the Veil as well when I shot it with my 200mm lens, as others have said the mass of background stars is the biggest problem. I could stretch out some of the fainter structure in the centre but the background ended up as a real mess. I re-shot it with an Ha filter the other night, I'm hoping that will help.

[Tommohawk]

4 hours ago, Xiga said:

Lots of good advice here. I also use the PS actions above, they're excellent. 

Here's another method for star reduction, that doesn't cost anything:

Under channels click the wee dotted circle icon to "load channel as selection" and,  using the magic wand tool, proceed to erase the brighter parts if they get selected automatically, now go to "select" > "modify">"expand" here give a size of 4 pixels then go to "select" again, "modify" and "smooth" here give a vallue of 2 pixels.

Next go to "filter" then "other" then "minimum" and choose 1 pixel as vallue, click "ok". This is usually too much so you must smooth it out, go to "edit" then "fade minimum" and put some 50 or 60% in there, then go to "select" and choose "deselect" and that's it, smaller stars that don't overtake the image

?

I've found it to be slightly better than the PS action 

I tried this and a few other variants, but found the stars looked weird. I think thats a lot to do with CA, and if I sort that first I think the PS treatment would be better. My old CS2 doesnt have good CA correction, so thats manual for now. 

I ant help but wonder if it would be helpful to do some batch processing with the CR2 files first - anyone have any thoughts on that?

1 hour ago, Knight of Clear Skies said:

I struggled with the Veil as well when I shot it with my 200mm lens, as others have said the mass of background stars is the biggest problem. I could stretch out some of the fainter structure in the centre but the background ended up as a real mess. I re-shot it with an Ha filter the other night, I'm hoping that will help.

Sounds like Im not the only one to struggle with this then!

Are you shooting Ha with the DSLR? My 300mm Tamron has a slot for filters and I might explore this option - maybe narrowband at F2.8 + DSLR wouldnt be so bad. 

[Xiga]

4 minutes ago, Tommohawk said:

I cant help but wonder if it would be helpful to do some batch processing with the CR2 files first - anyone have any thoughts on that?

When you open a raw file in Photoshop for the first time, there is an option on one of the tabs to correct for CA, and with some options for tweaking it how you like. But did you know, you can access these filters at any time, even with TIFF files, under the Filters tab. maybe try that?

Personally, I like to use the colour noise reduction one with my DSLR pics, but of course there are more than 1 way to skin a cat! ;-)

[Knight of Clear Skies]

14 minutes ago, Tommohawk said:

Are you shooting Ha with the DSLR? My 300mm Tamron has a slot for filters and I might explore this option - maybe narrowband at F2.8 + DSLR wouldnt be so bad. 

Yes, I have a 12nm clip-in filter. Narrowband + DSLR isn't an ideal combination but fitting the filter shouldn't block much Ha signal, a transmission of 97% is quoted on the data sheet. I'm also shooting at f2.8 with my 200mm lens which should help compensate for the bayer filter, I'll post my Veil when I've had a go at processing it (unfortunately I left my laptop with the subs on it down in Cornwall, and will have to wait until it is posted to me).

 

[orion58]

On 10/10/2016 at 05:50, Jannis said:

It's a long process that needs many small steps, but i strongly recommend you to buy this set of tools if you use photoshop: http://www.prodigitalsoftware.com/Astronomy_Tools_For_Full_Version.html
It really speeds up the process a lot and make time-consuming processes into a click of a button. 

 I will second that recommendation - a wonderful set of tools for not much $$.

[Stub Mandrel]

On 10/10/2016 at 11:50, Jannis said:

I did many many rounds of curves and star reduction to increase the nebula. Also used many low-pass masks in the process to drag out only the fain nebulosity.

I have Noel's star recuction action, but can you explain how to make/use a low pass mask - I suspect it's just what I need for some of my images.

[Tommohawk]

8 hours ago, Xiga said:

When you open a raw file in Photoshop for the first time, there is an option on one of the tabs to correct for CA, and with some options for tweaking it how you like. But did you know, you can access these filters at any time, even with TIFF files, under the Filters tab. maybe try that?

Personally, I like to use the colour noise reduction one with my DSLR pics, but of course there are more than 1 way to skin a cat! ;-)

The CA correction in the early CS2 which I have is pants - it doenst have the correct colour options. Later version were changed - Im told  and are much better. 

The Canon softare also has a CA fixer, but only works for Canon lenses. NOt sure how the software knows which lens is used - maybe the EXIF data. The Tamron 300 is probably similar to the Canon 300, so if I could cook the EXIF data maybe that would work. Another job for a cloudy night!

8 hours ago, Knight of Clear Skies said:

Yes, I have a 12nm clip-in filter. Narrowband + DSLR isn't an ideal combination but fitting the filter shouldn't block much Ha signal, a transmission of 97% is quoted on the data sheet. I'm also shooting at f2.8 with my 200mm lens which should help compensate for the bayer filter, I'll post my Veil when I've had a go at processing it (unfortunately I left my laptop with the subs on it down in Cornwall, and will have to wait until it is posted to me).

 

Look forward to seeing that when you post.

I dont fancy a clip in filter really - the Tamron has a filter slot in the rear cell - but it takes 43mm filters. So a 1,25 inch with step up adapter might work but is smaller - so only works at about F4. A 2" filter with step down is too wide for the slot.