Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: The Thing on Nov 08, 2013, 16:15:42

Title: NGC281 Pacman Nebula
Post by: The Thing on Nov 08, 2013, 16:15:42
This is 37 x 600s subs taken over two nights for my first attempt at the Pacman. The subs were processed in IRIS and the result cropped but no other processing applied. Then the image was saved as a FIT and loaded into the trial version of Star Tools to see what it could do. This image is screen scrapped so this is full size as you can't save in the trial version. I am fairly pleased with the result though I am sure the expert processors out there could make vastly more from the data.


Image date, time and location:           20131029 - 20131104
Telescope aperture and focal ratio:           Meade LX90 @f10 (2000mm)
Camera and filters used:                   Canon EOS 1000D, Astronomik CLS-CCD
Processing applied:                           IRIS for stacking and StarTools for processing

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/Pacman2000_StarToolsSD.jpg)
Title: Re: NGC281 Pacman Nebula
Post by: MarkS on Nov 08, 2013, 17:38:52
Looks like you've got some good data there!  I'm sure you can pull more out of that image.

If you post the FIT file it could be a cloudy night challenge for us.

Mark
Title: Re: NGC281 Pacman Nebula
Post by: RobertM on Nov 08, 2013, 19:08:13
I agree with Mark, there's more within to be teased out.  Like he said, it would make a good rainy day challenge.

What do you think of Startools - takes some getting used to doesn't it ?

Robert
Title: Re: NGC281 Pacman Nebula
Post by: JohnP on Nov 08, 2013, 22:57:10
Look good Duncan - nice and close up.. good detail as well for Beckenham...I think this is one of your best images todate - John
Title: Re: NGC281 Pacman Nebula
Post by: Carole on Nov 08, 2013, 23:06:25
Yup agree with Mark, good capture with lots of data still to pull out.  Would be great to have a crack at the tiff file.

Carole
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 09, 2013, 05:47:42
The FIT is tooo biig for the gallery, I'm looking for another home for it. It goes along with not having a host for my astro website anymore which I must sort out. Off to Gatwick now or I would be out there imaging :( Beautiful morning!
Title: Re: NGC281 Pacman Nebula
Post by: MarkS on Nov 09, 2013, 06:59:49
Quote from: RobertM
What do you think of Startools - takes some getting used to doesn't it ?

Looks like it has some very interesting features - I must give it a go.  Wonder how it compares with PixInsight.
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 09, 2013, 07:55:58
Quote from: MarkS on Nov 09, 2013, 06:59:49
Quote from: RobertM
What do you think of Startools - takes some getting used to doesn't it ?

Looks like it has some very interesting features - I must give it a go.  Wonder how it compares with PixInsight.
It seems very powerful without overwhelming you with settings and terminology. It's worth watching the YouTube videos first for a quick start. My initial impression is that it's PixInsight for mere mortals with a much shallower learning curve. I particularly like the fact you seem to be able to apply processing in almost any order without implications. Mind you you can still mess up an image quite adequately!
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 09, 2013, 08:37:38
Quote from: MarkS on Nov 08, 2013, 17:38:52
Looks like you've got some good data there!  I'm sure you can pull more out of that image.

If you post the FIT file it could be a cloudy night challenge for us.

Mark

Hi Mark, you should be able to get a zipped FIT here. (http://www.dewityourself.co.uk/astro/RAW/pacman_2000_1.5.zip) That's as it came out of IRIS using your script, sigma 1.5 (2000 is the focal length used). My One.Com webspace also has gallery facilities included so my astro photo collection should reappear soon!
Title: Re: NGC281 Pacman Nebula
Post by: MarkS on Nov 09, 2013, 09:26:17
Hmmm - I'll try downloading later.  I was only getting 220 bytes/sec :-(
Title: Re: NGC281 Pacman Nebula
Post by: Fay on Nov 09, 2013, 13:15:44
Duncan have you got a FITS that has not been thru IRIS?
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 09, 2013, 14:30:24
Quote from: Fay on Nov 09, 2013, 13:15:44
Duncan have you got a FITS that has not been thru IRIS?
No, the output from DSS wasn't as good and I've messed with it.
Title: Re: NGC281 Pacman Nebula
Post by: MarkS on Nov 09, 2013, 14:49:07
Fay, why do you want a non-IRIS version?
Title: Re: NGC281 Pacman Nebula
Post by: Fay on Nov 09, 2013, 15:45:37
Well it does not come up too well on my computer as it is. I don't know iris and would be better to have a go from scratch
Title: Re: NGC281 Pacman Nebula
Post by: MarkS on Nov 09, 2013, 16:37:56

I was right - there's plenty of good data in there. Here's my re-processing of Duncan's file:

(http://www.markshelley.co.uk/webdisk/duncan_pacmanfinal_small.jpg)

Larger version here:
http://www.markshelley.co.uk/webdisk/duncan_pacmanfinal.jpg
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 09, 2013, 19:06:23
That's a lovely rendering Mark, I think I am trying too hard to get a wowee looking image rather than aiming for a good balance of detail and colour.
Title: Re: NGC281 Pacman Nebula
Post by: Carole on Nov 09, 2013, 20:01:15
I wasn't able to do much with the Fits file as for some reason the data in the corners came out all glittery.

So this is what I managed just from the image that Duncan posted.  If this can be got out of an 8bit image then it just goes to show how much data is actually there.  

Would have liked to have tried processing a tif file, any chance of uploading to Dropbox Duncan?

(http://farm4.staticflickr.com/3785/10764403724_f8bb2ca25c_b.jpg)



Title: Re: NGC281 Pacman Nebula
Post by: Mac on Nov 09, 2013, 21:06:23
Thats fantastic Carole,
How did you manage to pull all of that writing out of the image, :cheesy:

Silly me, You've mucked up the link from flicker. ;)

Any chance of updating to the correct link.

Mac.
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 09, 2013, 22:38:27
Here you are Carol. Shame I can't see your first go. TIF here. (http://www.dewityourself.co.uk/astro/RAW/pacman_2000_1.5.tif)
Title: Re: NGC281 Pacman Nebula
Post by: Carole on Nov 10, 2013, 15:25:09
QuoteYou've mucked up the link from flicker.
Getting a bit fed up with some of these links -  it shows up perfectly well on my computer, so how am I supposed to know it doesn't work for others. 

Thanks for the Tif Duncan I'll give it another go.

Carole
Title: Re: NGC281 Pacman Nebula
Post by: Carole on Nov 10, 2013, 15:41:25
I downloaded the Tif but once again the corners on one side were really weird and when I stretched it the data is unuseable, no idea why.  

This is what the Tif looks like when it arrives on my computer:
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10047/normal_pacman_2000_1.jpg)

So I have uploaded the Jpeg I stretched to the gallery and this is what I got by just copying Duncan's original image and processing it some more.
Obviously I am working with 8bit data

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10047/normal_Pacman_Duncan_Nov_13.jpg)

Title: Re: NGC281 Pacman Nebula
Post by: MarkS on Nov 10, 2013, 16:12:44
Those extreme red values are where the FITS file had negative numbers (arising from the black level being already set).  FITS files handle negative numbers, as does IRIS.  The TIF file needed to be saved differently, without the black level set.

Mark
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 10, 2013, 16:31:06
The FIT was created from the output of COMPOSIT with a sigma of 1.5 and the cropped using WIN (IRIS commands...).

I have recreated the TIF from the FIT by using OFFSET 300  and STAT to check the minimum values are above zero, try downloading it again Carole.
Title: Re: NGC281 Pacman Nebula
Post by: Fay on Nov 10, 2013, 17:28:19
that is same as on mine Carole
Title: Re: NGC281 Pacman Nebula
Post by: Mac on Nov 10, 2013, 19:46:46
QuoteGetting a bit fed up with some of these links -  it shows up perfectly well on my computer, so how am I supposed to know it doesn't work for others. 

Normally for flicker, if you goto show all sizes, select the size you want, small medium ect.
then when the image is on the screen, right mouse click the image and select copy image url.
If you copy and paste that link, it should normally work for everyone.
The link address should be something like this.

http://farm7.staticflickr.com/6003/6019161908_679b7fc28f_q.jpg

as opposed to

http://www.flickr.com/photos/43711844@N04/6019161908/sizes/q/

If it says flickr in the url, then its probably not going to work
Mac.
Title: Re: NGC281 Pacman Nebula
Post by: Carole on Nov 10, 2013, 23:18:25
I'm still confused Mac.

Firstly, why does the image appear for me and not others?

2ndly, this is the URL for that image which is similar to the top one you posted that you say is what it should look like.
http://farm4.staticflickr.com/3785/10764403724_f8bb2ca25c_b.jpg

Quoteright mouse click the image and select copy image url.
That's what I always do except I am using Firefox these days and it doesn't show you the URL, it just says copy image location. 

Carole

Title: Re: NGC281 Pacman Nebula
Post by: MarkS on Nov 11, 2013, 05:13:37
Quote from: Carole
Firstly, why does the image appear for me and not others?

A I understand it (and I might be wrong) when you are logged into Flickr to update images you are seeing things in a stucture that is not externally visible.  So you need to ensure that the URL you post is not a URL that is only available to you as the logged-in owner but a URL that everyone can see.

I don't know Flickr so I can't help further.

Mark
Title: Re: NGC281 Pacman Nebula
Post by: JohnP on Nov 11, 2013, 08:13:56
Why don't you try:

http://www.astrobin.com/

A lot of guys & gals on the other forums seem to use this... or why don't you upload to your own webspace & use that.. that's what I do....

John
Title: Re: NGC281 Pacman Nebula
Post by: Carole on Nov 11, 2013, 09:57:32
Hi John,

Yes I use Astrobin for my own images, but when posting things like Duncan's Pacman, I don;t want to post it on Astrobin amongst my own images.  

I didn't used to have a problem when I had my own webspace and had a page specifically for this purpose, but something happened to the software and it stopped working, I got no help at all from Serif and it seems others have had the same problem, so I went over to Google Free websites, but when I try to upload images from there I get a similar problem of images not showing.  

I don't want to have to go out and buy yet more web making software when I have a perfectly useable free site except I can't upload images from it (not to mention all the work it will entail moving the web data yet again), so this is why I started trying to use flicker.  I also can use Google+ and that seems to work, so I'll use that one next time.

I'm going to see whether if I upload Duncan's image as a "work in progress" to Astrobin if it will NOT appear publicly.

Carole
Title: Re: NGC281 Pacman Nebula
Post by: Carole on Nov 11, 2013, 10:45:46
OK, uploading to the staging area in Astrobin seems to be the answer:

My process of Duncan's Tif file:

(http://cdn.astrobin.com/images/thumbs/48fb432853b06c99132f42c7c8471613.620x0_q100_watermark.jpg)
Title: Re: NGC281 Pacman Nebula
Post by: Fay on Nov 11, 2013, 11:43:21
I use Flickr ok, Carole, and then delete it when i dont want it any more
Title: Re: NGC281 Pacman Nebula
Post by: The Thing on Nov 11, 2013, 17:00:44
Now I see what I was getting wrong, I assumed all the nebulosity as seen at the top of Carole's version was part of the sky background gradient and so tried very hard to remove it while leaving the Pacman bit!  :roll: