These Fits files are giving me the Fits. Help Please

[BlackWidow (Mardy)]

Having a bit of trouble understanding how to process my Fits files. Last night I took 10 light shots, 10 Bias shots and 10 flats. Nebulosity saved them in its folder as Fits files names series 1. I re-named the flats and Bias files as such.

I have read and been told by other members that I need to conver these files before stacking to see the colour. I have been having fits all day trying to work this out. I have been able to convert one image by selecting image-DeMosiac RAW and then able to see colour within Nebulosity..

Surly I don't have to convert each file seperatly? Can I Batch change all the lights, flats and bias shots together and then open them in Deep Space Stacker to stack and align them? I like DSS as it is easy for me to use and understand as I am still learning.

This is the first attemp at using my QHY8 and the start of a learning curve. The images I have are out of focus, but are good enough for me to learn this next stage before improving on my focus routine...

once I can get my images in colour and stacked I can then process in Photoshop CS..


Assistance Please

Regards
Mardy

[multiweb (Marc)]

Calibrate your subs before debayering.

First you need to make a master dark, a master flat and a master bias with all your flats, darks and bias frames. Do not try to align them and don't debayer them.

Calibrate your subs with the master calibration frames still with the bayer matrix. Save your calibrated files, then you can debayer your calibrated subs and see the color.

[leon]

By Gee Marc you are a master at this stuff, I got confused just reading this, but then again I'm getting on a bit. LOL

Leon

[cventer]

Mardy

Did you read this PDf in the link i posted in your other thread ?

This one:
http://qhyccd.com/ccdbbs/index.php?P...2159.0;id=2338

This explains each step you need to take in detail within nebulosity. There are batch commands that allow you to do this processing for groups of images. You dont need to do one by one.

Here they are very quickly

Ref:
http://www.stark-labs.com/help/nebul...sing_HowTo.pdf
1. Batch – Pre-process B/W Raw Images
a. Click Dark – select the master dark frame
b. Click Bias – select the master bias frame
c. Click Flat – select the master flat frame
d. Check autoscale dark
e. Click OK
f. The files will be saved as pproc_original_name.fit
2. Normalize your light frames (batch normalize) – the files will be saved as
norm_original_name.fit
3. Convert your light frames to colour (Batch – Demosaic and select the
norm_orginal_name.fit files) – the files will be saved as
recon_original_name.fit
4. Grade and remove bad light frames (optional) (Batch – Grade Image
Quality, select your recon_orginal_name.fit files)
5. Align and combine the light frames (Batch – Align/Combine)
a. Save Stack, Use Translation, Average/Default (for GEM)
b. Select all good quality light frames
c. Click on a suitable star (not fat, big, bloated, or core at 65536)
d. Nebulosity advances to next light frame, star should be circled
e. If circle is on correct star – Ctrl-Click (else click on the star)
f. Enter a filename to save the aligned/combined image
6. Crop the image
a. Draw a rectangle around the part you want to keep
b. Image – Crop
c. Save file
7. Remove the skyglow
a. Image – Adjust Color Offset
b. Accept default values, click OK
c. Save file
8. Stretch the image to bring out the finer detail

[BlackWidow (Mardy)]

Thanks guys and yes cventer I did use your link and printed the documentation. I have also been to the Stark Labs site and read some of the tutorials. I think I will now try you step by step approach that you have gone to great trouble of typing (thank You). I guess it's better to do all the work in Nebulosity. I was trying to convert the images to colour and then using Deep Space Stacker to process them. I have used Deep Space Stacker when using a DLSR camera with good results. This CCD stuff is all new to me. Marc keeps talking about De-Bayer and I if I understand this is to do with the Bayer filter on a one shot Colour CCD. However I can never find any Ref to this term in any of my programs. I assume this is the same function as the Demosaic function in Nubulosity..

Could I also do the Demosaic of all files, that being Lights, Bias and Lights as batches for each group, and then they are now all colour and then stack is Deep Space Stacker?


Thanks all for giving me this assistance

Mardy

[multiweb (Marc)]

Debayer is what they call demosaic in Nebulosity.
Your monochrome FIT file contains a bayer matrix. Let's say:

RG
GB

Your whole sensor would be:

RGRGRGRGRG..
GBGBGB..
RGRG..
GB..
..

You get the idea. So your whole frame contains the color information embedded in it. 2Gs for 1 R and one B. Debayering or demosaicking means get all the reds, all the blues and all the greens (combined) in three separate files. Then those three files are recombined to make your RGB channels.

What is important to understand is that your flats, darks and bias contain a bayer matrix as well. So if you debayer your subs you have to debayer your master flat, dark and bias as well to calibrate them.

If you don't debayer your subs, then you must not debayer your flat, dark and bias masters. There is no point debayering before calibration. It's just more work. Hope this all makes sense now.

Another very important point is that you must not crop, scale or register/align any file containing a bayer matrix. The reason is obvious. You modify the bayer matrix.

[cventer]

In Neb

The idea is to pre process your one shot color files BEFORE you debayer

So you combine darks, flats and bias without debayering.

You pre process your lights by subtracting dark, flats and bias in neb before debayering.

Once this is done you can then batch demosiac (debayer) the pre processed fits files in NEB.

Once this is done you can then use the debayered light frames in DSS to align and stack as per normal how you are used to.

No doubt you can do some or all of these pre process steps in DSS. I just dont know how to do it.