Holmes from Cakovec - remake

My first image of Holmes was made in hurry, after whole night of imaging.
Later I found some more time to make it better.
The same seven subs as described in my last post were processed more
carefully with 2x drizzle in DSS.
One of attached images is prepared to show interesting interior of the
comet. The second represents coma and green halo. I suggest to watch this
image from longer distance (at least 1 meter) to see the halo better.
Greetings to all!
Gordan

Gordan wrote:
My first image of Holmes was made in hurry, after whole night of imaging.
Later I found some more time to make it better.
The same seven subs as described in my last post were processed more
carefully with 2x drizzle in DSS.
One of attached images is prepared to show interesting interior of the
comet. The second represents coma and green halo. I suggest to watch this
image from longer distance (at least 1 meter) to see the halo better.
Greetings to all!
Gordan


Good image. Your stars look good to me and aren't any fuzzier than
those of George. The difference is the amount of stretch you applied to
get the outer halo. That also picked up a lot of stars he didn't.
Stars always get fuzzier the deeper you go into your data. Cut back the
stretch - lose the outer halo but gain sharp stars. You have to decide
which to do as it's your picture.

Yes, his shot is mirror flipped. When I use FITS Liberator to move a
FITS image into photoshop it does that for some reason. Flips it
vertically like that. I have to remember to flip it back. Sometimes I
don't.

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

"Gordan" wrote
...

........ to see the halo better.

Shows well Gordan! Great image!

George N

Rick Johnson wrote:

Gordan wrote:
My first image of Holmes was made in hurry, after whole night of imaging.
Later I found some more time to make it better.
The same seven subs as described in my last post were processed more
carefully with 2x drizzle in DSS.
One of attached images is prepared to show interesting interior of the
comet. The second represents coma and green halo. I suggest to watch this
image from longer distance (at least 1 meter) to see the halo better.
Greetings to all!
Gordan


Good image. Your stars look good to me and aren't any fuzzier than
those of George. The difference is the amount of stretch you applied to
get the outer halo. That also picked up a lot of stars he didn't.
Stars always get fuzzier the deeper you go into your data. Cut back the
stretch - lose the outer halo but gain sharp stars. You have to decide
which to do as it's your picture.

Yes, his shot is mirror flipped. When I use FITS Liberator to move a
FITS image into photoshop it does that for some reason. Flips it
vertically like that.

Personally that drives me crazy! What is the reason for the flip.
Other software I use does the same thing (including spectro processing
software) and sometimes it does become crucial. WHY! do they allow this? I once
asked one of the authors "why" this
flip and he sloughed this off saying "does it really matter"? I
was speechless. Darn right it matters ... to me.

Oh well.



I have to remember to flip it back. Sometimes I
don't.

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Nice deep image.

Stefan

"Gordan" schrieb im Newsbeitrag
...
My first image of Holmes was made in hurry, after whole night of imaging.
Later I found some more time to make it better.
The same seven subs as described in my last post were processed more
carefully with 2x drizzle in DSS.
One of attached images is prepared to show interesting interior of the
comet. The second represents coma and green halo. I suggest to watch this
image from longer distance (at least 1 meter) to see the halo better.
Greetings to all!
Gordan

"KLM" wrote
......
Yes, his shot is mirror flipped. When I use FITS Liberator to move a
FITS image into photoshop it does that for some reason. Flips it
vertically like that.

Personally that drives me crazy! What is the reason for the flip.
Other software I use does the same thing (including spectro processing
software) and sometimes it does become crucial. WHY! do they allow this? I
once
asked one of the authors "why" this
flip and he sloughed this off saying "does it really matter"? I
was speechless. Darn right it matters ... to me.

I think it's just what convention the programmer uses to write the data to
the screen. I've always thought that the early PC convention of making the
upper left corner the zero-zero point for screen writes was quite weird -
but nearly everyone still uses it for Windows software. I think that the
author of IRAS (and some others from the Unix world) haven't considered that
someone might actually transfer data to another program for final
processing, and they use the lower left as the zero-zero point. That results
in the flip. IRIS doesn't like unsigned 16-bit fits file data either. I
guess it's not 'professional' enough for a guy who works for the French
Space Agency. I can live with it considering that the software is top-notch,
and free.

George N

George Normandin wrote:

"KLM" wrote
......

Yes, his shot is mirror flipped. When I use FITS Liberator to move a
FITS image into photoshop it does that for some reason. Flips it
vertically like that.

Personally that drives me crazy! What is the reason for the flip.
Other software I use does the same thing (including spectro processing
software) and sometimes it does become crucial. WHY! do they allow this? I
once
asked one of the authors "why" this
flip and he sloughed this off saying "does it really matter"? I
was speechless. Darn right it matters ... to me.


I think it's just what convention the programmer uses to write the data to
the screen. I've always thought that the early PC convention of making the
upper left corner the zero-zero point for screen writes was quite weird -
but nearly everyone still uses it for Windows software. I think that the
author of IRAS (and some others from the Unix world) haven't considered that
someone might actually transfer data to another program for final
processing, and they use the lower left as the zero-zero point. That results
in the flip. IRIS doesn't like unsigned 16-bit fits file data either. I
guess it's not 'professional' enough for a guy who works for the French
Space Agency. I can live with it considering that the software is top-notch,
and free.

George N

FITS Liberator was written to as a Photoshop plug in. The problem
really isn't with it but with Window's based CCD control software.
Apparently the true FITS format is as you say, starting at the lower
left. But my FITS programs, AIM4Windows, CCDSoft and CCDOpps all record
FITs from the upper left it appears. At least if you use the FITS files
from the DSS database they load correctly using FITS Liberator. I think
it was originally developed to load those DSS plates into Photoshop to
make color images using a derived green and so follows DSS FITS format.

You'd think there'd be some way to set a flag in the header as to where
the origin is located and then the reader would adjust accordingly. The
FITS format certainly is capable of including this. Apparently it isn't
done however. So I try and remember to do that flip in addition to any
rotation needed to orient my images with North up and West to the right.

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

In article ,
Rick Johnson wrote:

snip

You'd think there'd be some way to set a flag in the header as to where
the origin is located and then the reader would adjust accordingly. The
FITS format certainly is capable of including this. Apparently it isn't
done however. So I try and remember to do that flip in addition to any
rotation needed to orient my images with North up and West to the right.

You could make a Photoshop Action with a file-open dialog immediately
followed by the flip command -- you'd still have to remember to use the
action instead of hitting control-o or whatever, but it could become
routine in a little while.

--
Odysseus

George Normandin wrote:

"KLM" wrote
......
Yes, his shot is mirror flipped. When I use FITS Liberator to move a
FITS image into photoshop it does that for some reason. Flips it
vertically like that.

Personally that drives me crazy! What is the reason for the flip.
Other software I use does the same thing (including spectro processing
software) and sometimes it does become crucial. WHY! do they allow this? I
once
asked one of the authors "why" this
flip and he sloughed this off saying "does it really matter"? I
was speechless. Darn right it matters ... to me.

I think it's just what convention the programmer uses to write the data to
the screen. I've always thought that the early PC convention of making the
upper left corner the zero-zero point for screen writes was quite weird -
but nearly everyone still uses it for Windows software. I think that the
author of IRAS (and some others from the Unix world) haven't considered that
someone might actually transfer data to another program for final
processing, and they use the lower left as the zero-zero point. That results
in the flip. IRIS doesn't like unsigned 16-bit fits file data either. I
guess it's not 'professional' enough for a guy who works for the French
Space Agency.

Funny! but true...

I can live with it considering that the software is top-notch,
and free.

George N