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Old 28-02-2021, 03:55 PM
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mswhin63 (Malcolm)
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Tarantula

Hi All,

Trying to learn a bit of processing using DSS, Startools, GIMP and Darktable. Darktable being similar to one of Photoshop extremely expensive software.

Anyway, I am not sure but my flats may not have been the best for this one as there appears to be some gradient on the lower section. I have 2 processes one with and one without gradient removal.

For DSS, I have managed to find this so far the best of all free stacking tools I have used, only as long the right configurations are applied.

Startools, also I am improving learning small steps at a time moving past the defaults on occasions. There is so much flexibility with this software, but there is so much to learn.

GIMP is as GIMP will be, improving in its capability slowly over time. I now can look at Photoshop tutorials and can apply them to GIMP.

Darktable, Is a great touchup tool and has an Astro Noise filter. Not bad, but it contrast' features work well. The issues left are:

Calibrated monitors, and a new camera. My 450D bloats badly, it is 11 years old and noisy as hell. This noise level requires too much postprocessing that it appears out of focus.

Image:
80 Lights
40 Darks
40 Flats
40 Dark FLat
40 Bias

Flow DSS -> Startools -> Darktable -> GIMP

Can anyone let me know if the red streak at the bottom is a gradient or is it real?

There is an obvious amount of compression done to the attached images on IceinSpace, but My images are not worthy of a dedicate website until they can improve.
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  #2  
Old 28-02-2021, 04:58 PM
JA
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Quote:
Originally Posted by mswhin63 View Post
Can anyone let me know if the red streak at the bottom is a gradient or is it real?
Hi M,

Whilst there is red and blue in the nebula, your red looks a little too straight and parallel to the edges of the frame to really be there, especially in the absence of the other red colour that should be nearby elsewhere in your images referencing it to other images on line, an example is below.
https://ptes.hu/gallery/ngc2070/ngc2070_large.html


There is, as you suggested, the possibility that it is a gradient . There is also the possibility it is some sort of stacking artifact in combination with flats/vignetting issues. Even though you are using DSS, I have noticed similar long shaded patches parallel & perpendicular to image edges in Sequator.

Then again, who knows ....?




Best
JA

Last edited by JA; 28-02-2021 at 05:56 PM.
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Old 28-02-2021, 06:12 PM
Alchemy (Clive)
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Looking at what Iíve done a long time back 2008 and 2010, itís definitely darker in the area youíre concerned about, my scale is closer in but that looks to be possible. Given Iíve improved a bit since then that may or may not be completely accurate
Itís a very complex area that one, requires quite a bit to get detail across the whole field.
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Old 28-02-2021, 06:15 PM
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Nikolas (Nik)
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Spider area came out nicely but there is a lot more nebulosity
that can come out, try not to clip the blacks so much you'll get a more aesthetic result.
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Old 28-02-2021, 09:42 PM
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mswhin63 (Malcolm)
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I think I know what the problem might be, thanks for the suggestions. I believe the way I am taking flats might be from interference from the power supply used in my EL Panel I made years ago. It provides great light, but the electronics are very noisy. I will have to re-think my flats again.
The main reason I know is that I took some filtered images where I saw the same flat band on the lower section of the image only with a second band running through the middle. It has different colouring. The filter is a CLS filter. Thanks all.
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Old 28-02-2021, 09:46 PM
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mswhin63 (Malcolm)
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Quote:
Originally Posted by Nikolas View Post
Spider area came out nicely but there is a lot more nebulosity
that can come out, try not to clip the blacks so much you'll get a more aesthetic result.
The camera is not the best, I do though go very close to the clipping point but I do monitor that point. I believe it looks more clipped due to JPG, while the TIF's lower limits are around 12, 12, 12 thereabouts at worst.

Still not keen to place it on a website until I sort out all processing and setup issues. Guiding is the latest challenge resolved.
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