Masked images

[tornado33]

Hi all

Ive used the masking technique in Photoshop again to get better results from some of my past images that otherwise were burnt out white in the brightest parts.
[IMG]http://www.iceinspace.com.au/forum/attachment.php?attachmentid=5682&st c=1
Lagoon Nebula, 2 x 20 mins ISO 1600, and 1 x 20 mins ISO 200, Baader UHCS filter
[/IMG]http://www.iceinspace.com.au/forum/attachment.php?attachmentid=5683&st c=1
Lagoon Nebula, 2 x 15 mins ISO 1600, masked with darker versions of the same images, Baader 7 NM Hydrogen Alpha filter
[IMG]http://www.iceinspace.com.au/forum/attachment.php?attachmentid=5684&st c=1
Triffid Nebula 2 x 30 mins ISO 800 masked with darker versions of same Baader UHCS filter
[/IMG]http://www.iceinspace.com.au/forum/attachment.php?attachmentid=5685&st c=1
Omega Nebula, 2 x 15 mins ISO 1600 masked with darker version of same. UHCS filter.
All shots with my 10 inch F5.6 scope and 300D camera.
Scott

[ving (David)]

gee that second lagoon looks interesting!

gret pics all!

[Itchy]

Hi Scott,


Interesting technique. This type of masking is usually used to combine exposures of different lengths (or ISO) to account for the high dynamic range of the object. You say that you have used a darker version of the same image to achieve the same result. To my mind, this would indicate that the detail you have achieved in the brighter areas of the objects was infact already there in the original images, but was most likely processed out in the attempt to bringout fainter detail. Is this what is happening here or am I way off the mark?

Cheers

[tornado33]

Thanks David.
Yep, Tony thats right I do lose some inner detail when processing the images to get the fainter stuff. Also, when I extract the raws using Photoshop, I can extract them as "camera default" which is what I do normally. For the mask, I drop the exposure one or 2 stops with the Photoshop raw plugin, then extract it, it comes out much darker. However for really bright objects like M42 or the inner parts of the Lagoon, a separate, shorter exposure/s is the only way to go as if the pixels of the camera sensor are flooded, then no amount of extraction will recover the detail. The trapezium area of M42 floods in just a few mins, so I must use a separate exposure of no more than a minute or so to still see the inner detail.
Scott

[h0ughy (David)]

your going to have to show me this process one day Scott. I love the triffid, very dark lanes

[PhotonCollector (Paul)]

Hi Scott,

Awesome images - what can I say?

Paul

[RB (Andrew)]

Yes I agree.
Scott Awesome images.

Well done.

[venus (Lydia)]

Great work!

[tornado33]

Thanks all
Heres the method I used http://www.astropix.com/PFA/SAMPLE4A/SAMPLE4A.HTM
Its fiddly at first but with practise its not too bad.
Scott

[[1ponders] (Paul)]

Thanks for posting those images Scott. I bought the CD a week ago (still waiting for it to arrive) so its good to see what I mightbe able to achieve with a bit of practice.

[avandonk]

You have raised the bar again Scott!Very nice pictures.The good thing about this hobby is we can always improve with more effort.


Bert

[rumples riot]

Truely beautiful images. The structure of the lagoon is well defined and the nodules have 3d effect. The Omega has lovely sworls near the right hand side. Also the dust lanes of the Trifid really make the image standout. You should be proud of these images. 15 years ago even the large observatories struggled to get these sort of shots with hours of exposures. Congratulations.

[beren]

Just stunning...congratulations

[zipdrive (Dave)]

wow they are amazing!!! especially the 30min sub with the DSLR, excellent work!!!

[TidaLpHasE]

Awsome stuff, they are awsome.

Did i mention that they are Awsome