Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - John_Gill

Pages: [1] 2 3 ... 19
1
General / Re: Can't create proper stretched image
« on: Today at 12:16 »
Hey Jim,

I usually create a duplicate image and on one I do the STF and HT. On the second image I do two small stretches with ArcsinhStretch and then a little HistogramTransformation.  I normally select the AS and HT as the best. I have played with MaskedStretch but not had the best results.

space is not black
John

2
General / Re: Can't create proper stretched image
« on: Today at 00:11 »
Hi,

I have read that you should stretch the images/channels before combining them.
A non-stretched (linear) image will always look "black" in any application. When using HT did you push the apply button (small blue triangle) onto the image.  If yes, then the image should be non-linear and the stars, nebula, etc should be visible.


So, try this : stretch the RGB (If the RGB is individual channels, then stretch each channel spearately) and the Ha and then do a ChannelCombination or as I prefer LRGBCombination. 


space is not black
John



3
General / Re: Pi wont start
« on: 2019 October 09 23:49:46 »
Hi,

What operating system are you using? Windows 10, MacOs. Linux.....

John

4
General / Re: Stacking frames of different exposures
« on: 2019 October 09 23:35:52 »
Correct.  Basically calibrate and clean up all the images per stack (filter/exposure) and then StarAlignment for everything.  This also will work when using images from different scopes/camera FOV.


John

5
General / Re: Stacking frames of different exposures
« on: 2019 October 09 04:40:12 »
Hi,,

I would do the following for each stack of images: ImageCalibration ---> CosmeticCorrection. You will now end up with separate stacks of "clean" images.  Now load all the images into SubFrameSelector to determine the reference/weighting of the images.  (You can output only the "approved" images to a folder). Finally continue with StarAlignment using the reference image from the SFS and add all images (or add just the approved images from SFS) and you are done.


space is not black
John

6
General / Re: HA Luminance...
« on: 2019 October 07 05:42:31 »
Hi,

I have heard that you should do more Lum and Ha than the other filters but I have had great results, sometime with only 5 or 6 subs (30 minutes).

If using LRGBCombination to combine images, you can "Weight" the channels to have more impact than the others or set L=NGC1234_Ha, R=NGC1234_Ha, G=NGC1234_Sii and B=NGC1234_Oiii.

In PixelMath you could multiply your Ha by a value to increase its effect i.e. (NGC1234_Ha * 1.3) + NGC1234_Oiii + NGC1234_Sii or something similar. 


space is not black
John

7
General / Re: Collection of Darks and Bias useful?
« on: 2019 October 07 02:16:38 »
Hi,

Some calibration files are temperature dependant.  Bias and flats files are quick to take, so I run those after an imaging session.  Darks are the issue, especially with a DSLR.  Some people put their DSLR in the freezer until the required temperature is met and then they do darks.  I do not have huge temp differences so I just bring the scope inside and run my darks at whatever temp.  Now I am using a cooled camera (ZWO 1600mm), I bring the scope indoors, set the temp on the camera and run my darks.

I think the temperature and gain combinations can make the library large and then you need to redo the library every 6 months which becomes a pain.
So, a library will work for either DSLR or a cooled camera ... I just prefer to get calibration frames per imaging session.

space is not black
John

8
General / Re: high spec pix server - improving performance??
« on: 2019 September 30 23:08:23 »
erm, that is a terrible PC, get rid of it, but send it my way!!! ;)

9
General / Re: Image calibration help
« on: 2019 September 23 00:37:24 »
Hi,

mmmh, that is some serious amp glow.  Firstly try reducing the cooling to -5 or -10 and see if the amp glow is still so severe.  Darks will not fix the amp glow but Flats should.  Can you reshoot the Flats?  Most likely the focus and optical train will have changed and your flats might not be the same.  I have "cheated" and used flats from different sessions and had a little success in removing unwanted artifacts.

When doing the ImageCalibration, the Bias does not need to be calibrated and the Darks and Flats are already calibrated and only the Master Dark needs to be Optimized to ensure that the Master Darks match the Lights.

space is not black
John

10
General / Re: Processing RAW format
« on: 2019 September 23 00:25:22 »
Hi,

Perhaps this will configure the RAW file format.  From the top menu select View ---> Explorer Windows ---> Format Explorer ---> RAW ---> Edit preferences ---> Pure Raw ---> Ok. Now try your BPP again.


space is not black
John

11
Hi,

Try this....find a PixInsight data file (.XISF) and right-click ---> Open with ---> Choose another app, scroll down to find the PixInsight program and also check the box that says "Always use this app to open .XISF files ---> Ok.   I do the same for .FITS files.

space is not black
John



12
General / Re: Increasing Oxygen (Blue) in NGC6995
« on: 2019 September 20 07:32:00 »
Hi,

Try this, go to http://www.werbeagentur.org/oldwexi/PixInsight/PixInsight.html and there are a number of excellent tutorials.  The one that deals with the Veil Nebula is called "Oiii Ha LRGB Linear Combination"  …. maybe that will help.


space is not black
John

13
General / Re: Masked stretch and big star appearance
« on: 2019 September 20 03:52:32 »
Hi,

Have you tried "ArcsinhStretch"  I do a small stretch and then a larger stretch and then finish with a tweak of the HistogramTransform.

space is not black
John

14
General / Re: PixInsight Processing and Linux
« on: 2019 September 18 23:59:48 »
Hi,

I would go for OpenSuSE but only cos I use SuSE at work.


John

15
General / Re: HOO palette - when to combine masters in workflow
« on: 2019 September 04 23:14:27 »
Hi,

After I have created my masters (Ha, Sii, Oiii), I then use LRGBCombination.  I normally set L=Ha, R=Ha, G=Sii and B=Oiii and then play with the "Weighting per channel" and Saturation.  For bi-color, I set L=Ha, R=Ha, G=Oiii and B=Oiii.  After the combination, I continue with noise reduction, curves etc etc.  I do the same for L,R,G,B images.

space is not black
John

Pages: [1] 2 3 ... 19