First images with AP1200 GTO


bcoote37
 

Hi All
As the proud owner of a new/second hand AP1200 GTO and a clear night I just had to try it out.
Nothing too challenging. Living in Australia there is really only one choice, the eternal magnet Eta Carinae.
Living in the bush this is actually the first AP mount of any type I have seen.
I was a little suprised in that is wasn't quite as petite as I had imagined from the illustrations and images I have seen

I am trying to implement lessons from Adam Block's DVD tutorials and have made a 3 image htm with images of Ha-HaRGB, straight RGB & straight Ha.
These show some halos around the stars in colour but at least I am not clipping the data (much) any more.
This is at:-
http://www.bcoote-astro.com/eta_tri_panel.htm

If you are on dial-up this is a rather large load and you would probably be better to skip it.

Any comments or suggestions welcome
Brian Coote


http://www.bcoote-astro.com/default.htm


dan kowall
 

The greyscale Ha is especially compelling, Brian.
Don't be afraid to load up the 1200, it probably didn't even notice the AP130 was riding up there.
My regards,

dan kowall

______

Brian Coote <dbcoote@bigpond.net.au> wrote: Hi All
As the proud owner of a new/second hand AP1200 GTO and a clear night I just had to try it out.
Nothing too challenging. Living in Australia there is really only one choice, the eternal magnet Eta Carinae.
Living in the bush this is actually the first AP mount of any type I have seen.
I was a little suprised in that is wasn't quite as petite as I had imagined from the illustrations and images I have seen

I am trying to implement lessons from Adam Block's DVD tutorials and have made a 3 image htm with images of Ha-HaRGB, straight RGB & straight Ha.
These show some halos around the stars in colour but at least I am not clipping the data (much) any more.
This is at:-
http://www.bcoote-astro.com/eta_tri_panel.htm

If you are on dial-up this is a rather large load and you would probably be better to skip it.

Any comments or suggestions welcome
Brian Coote

http://www.bcoote-astro.com/default.htm








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Ray Gralak <rgr@...>
 

Hi Brian,

Those are very nice images! It's nice to see a "conventionally colored" HaRGB
image! You did a nice job integrating the star colors into the image. I think
all narrowband images should be done this way. Unfortunately many don't,
probably because it requires a good amount and skill and effort above and beyond
just letting your scope collect many hours of data.

-Ray

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
On Behalf Of Brian Coote
Sent: Saturday, June 16, 2007 4:09 AM
To: ap-gto@yahoogroups.com
Subject: [ap-gto] First images with AP1200 GTO

Hi All
As the proud owner of a new/second hand AP1200 GTO and a
clear night I just had to try it out.
Nothing too challenging. Living in Australia there is really
only one choice, the eternal magnet Eta Carinae.
Living in the bush this is actually the first AP mount of any
type I have seen.
I was a little suprised in that is wasn't quite as petite as
I had imagined from the illustrations and images I have seen

I am trying to implement lessons from Adam Block's DVD
tutorials and have made a 3 image htm with images of
Ha-HaRGB, straight RGB & straight Ha.
These show some halos around the stars in colour but at least
I am not clipping the data (much) any more.
This is at:-
http://www.bcoote-astro.com/eta_tri_panel.htm
<http://www.bcoote-astro.com/eta_tri_panel.htm>

If you are on dial-up this is a rather large load and you
would probably be better to skip it.

Any comments or suggestions welcome
Brian Coote

http://www.bcoote-astro.com/default.htm
<http://www.bcoote-astro.com/default.htm>







Roland Christen
 

In a message dated 6/16/2007 8:54:07 AM Central Daylight Time,
dbcoote@bigpond.net.au writes:


These show some halos around the stars in colour but at least I am not
clipping the data (much) any more.
This is at:-
http://www.bcoote-astro.com/eta_tri_panel.htm
That is a pretty amazing image. By the way, it is well known that Astrodon
filters do cause halos around bright stars. It's because of the type of coatings
they use.

Rolando


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Kent Kirkley
 

In a message dated 6/16/07 5:46:49 PM, chris1011@aol.com writes:


By the way, it is well known that Astrodon
filters do cause halos around bright stars. It's because of the type of
coatings
they use.

Rolando
What? Well known???

Where did that come from?
Sure, depending on optical system, I sometimes get halos around stars due to
reflections between coverslip and filters, but I don't think that only happens
with Astrodon filters.

Kent Kirkley


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peturnielsen
 

do all H-alpha filters cause halo (i'm looking to buy one and was
thinking about getting the astrodon). what h-alpha filter would you
recommend ?

Peter


$--- In ap-gto@yahoogroups.com, chris1011@... wrote:

In a message dated 6/16/2007 8:54:07 AM Central Daylight Time,
dbcoote@... writes:


These show some halos around the stars in colour but at least I am
not
clipping the data (much) any more.
This is at:-
http://www.bcoote-astro.com/eta_tri_panel.htm
That is a pretty amazing image. By the way, it is well known that
Astrodon
filters do cause halos around bright stars. It's because of the type
of coatings
they use.

Rolando


**************************************
See what's free at
http://www.aol.com.


[Non-text portions of this message have been removed]


Roland Christen
 

In a message dated 6/20/2007 8:00:49 PM Central Daylight Time,
peturnielsen@yahoo.com writes:


do all H-alpha filters cause halo (i'm looking to buy one and was
thinking about getting the astrodon). what h-alpha filter would you
recommend ?
I use the Baader 2" filter now. It does not cause any halos.

Rolando


**************************************
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Kent Kirkley
 

In a message dated 6/21/07 12:13:55 PM, chris1011@aol.com writes:



I use the Baader 2" filter now. It does not cause any halos.

Rolando
Roland:
I responded to your post, with wonderment, some days ago where you mentioned
that Astrodon filters caused halos. And, now you say the Baader filter(s?) do
not cause any halos.

This is the first I have heard of this 'situation', while halos have been
evident since the beginning of their use in ccd imaging, I thought all filters
produced some level of halos, especially with faster optical systems. I also
thought all filter manufacturers anti-reflection coated their filters.

So what is unique about the Baader's?
Is Baader producing only the Ha or a complete line of LRGB, Ha, etc. filters?

Kent Kirkley






**************************************
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Roland Christen
 

In a message dated 6/21/2007 12:38:25 PM Central Daylight Time,
kgkirkley@aol.com writes:


you say the Baader filter(s?) do
not cause any halos.
I have been testing the Baader filters for the last week under all kinds of
sky conditions. I do not see any halos around any bright stars. My H-a images
are very sharp with no reflections or ghost images around any stars. Maybe I am
mistaken about Astrodon filters (I have not tested them myself, but go only
on what I have heard from others). I do know that several of my RGB filters in
my ST10 camera cause multiple reflection ghosts near bright stars. I don't
know who makes these filters for SBIG, but they are not of the quality level of
the Baader series. In my STL11K camera I have installed 3 of the narrow band 2"
Baader filters and the images they produce are super nice. All Baader filters
have high grade multi-layer coatings on them to insure freedom from
reflections.

It may also be that the original poster's reflections are coming from his
cover glass and filter rear surface, something that can't be avoided unless the
coverglass is coated with a multi-layer.

Rolando


**************************************
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Roland Christen
 

In a message dated 6/21/2007 2:32:22 PM Central Daylight Time,
stuart.j.heggie@sympatico.ca writes:


Roland, the SBIG filters are from Custom Scientific I believe. I get very
strong halos from my green Astrodon. I had thought it was due to the fast
f-ratio I was shooting with the scope I've had till now.
I have an older SBIG ST10E which has very strong multiple reflections form
the green filter and fainter ones from the blue. These filters have no coatings
on one side, so about 4% of the energy keeps bouncing between front and rear
surface. I do not know where SBIG got those filters. The STL11K camera that I
got from Ray Gralack have Custom Scientific RGB filters, he tells me. I have
not had any reflection problems with them.

Rolando


**************************************
See what's free at
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Kent Kirkley
 

In a message dated 6/21/07 1:42:04 PM, chris1011@aol.com writes:



I have been testing the Baader filters for the last week under all kinds of
sky conditions. I do not see any halos around any bright stars. My H-a
images
are very sharp with no reflections or ghost images around any stars. Maybe I
am
mistaken about Astrodon filters (I have not tested them myself, but go only
on what I have heard from others). I do know that several of my RGB filters
in
my ST10 camera cause multiple reflection ghosts near bright stars. I don't
know who makes these filters for SBIG, but they are not of the quality level
of
the Baader series. In my STL11K camera I have installed 3 of the narrow band
2"
Baader filters and the images they produce are super nice. All Baader
filters
have high grade multi-layer coatings on them to insure freedom from
reflections.

It may also be that the original poster's reflections are coming from his
cover glass and filter rear surface, something that can't be avoided unless
the
coverglass is coated with a multi-layer.

Rolando
Roland:

Thanks for the clarification.

Kent


**************************************
See what's free at
http://www.aol.com.


Stuart Heggie <stuart.j.heggie@...>
 

Roland, the SBIG filters are from Custom Scientific I believe. I get very strong halos from my green Astrodon. I had thought it was due to the fast f-ratio I was shooting with the scope I've had till now.

Stuart
============================================================
From: chris1011@aol.com
Date: 2007/06/21 Thu PM 02:37:23 EDT
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: First images with AP1200 GTO

In a message dated 6/21/2007 12:38:25 PM Central Daylight Time,
kgkirkley@aol.com writes:


you say the Baader filter(s?) do
not cause any halos.
I have been testing the Baader filters for the last week under all kinds of
sky conditions. I do not see any halos around any bright stars. My H-a images
are very sharp with no reflections or ghost images around any stars. Maybe I am
mistaken about Astrodon filters (I have not tested them myself, but go only
on what I have heard from others). I do know that several of my RGB filters in
my ST10 camera cause multiple reflection ghosts near bright stars. I don't
know who makes these filters for SBIG, but they are not of the quality level of
the Baader series. In my STL11K camera I have installed 3 of the narrow band 2"
Baader filters and the images they produce are super nice. All Baader filters
have high grade multi-layer coatings on them to insure freedom from
reflections.

It may also be that the original poster's reflections are coming from his
cover glass and filter rear surface, something that can't be avoided unless the
coverglass is coated with a multi-layer.

Rolando


**************************************
See what's free at
http://www.aol.com.





============================================================


Wiggins, Rick
 

Hi Guys,
It is well known (meaning I personally know more than ten imagers
that have had this problem and it is regularly discussed on several
imaging forums) that the blue and green filters cause halos in RGB
images. Many people believe that they are very bad in the AstronDon
filters. They definetly happen with the AstroDons. I don't have
enough data on non-AstroDon filters to do an objective comparison.
It is obviously more prevalent around bright stars and is worse the
more you stretch the image. I have not seen halos with narrow band
filters of any brand.
Thanks, Rick

--- In ap-gto@yahoogroups.com, chris1011@... wrote:

In a message dated 6/21/2007 12:38:25 PM Central Daylight Time,
kgkirkley@... writes:


you say the Baader filter(s?) do
not cause any halos.
I have been testing the Baader filters for the last week under all
kinds of
sky conditions. I do not see any halos around any bright stars. My
H-a images
are very sharp with no reflections or ghost images around any
stars. Maybe I am
mistaken about Astrodon filters (I have not tested them myself,
but go only
on what I have heard from others). I do know that several of my
RGB filters in
my ST10 camera cause multiple reflection ghosts near bright stars.
I don't
know who makes these filters for SBIG, but they are not of the
quality level of
the Baader series. In my STL11K camera I have installed 3 of the
narrow band 2"
Baader filters and the images they produce are super nice. All
Baader filters
have high grade multi-layer coatings on them to insure freedom
from
reflections.

It may also be that the original poster's reflections are coming
from his
cover glass and filter rear surface, something that can't be
avoided unless the
coverglass is coated with a multi-layer.

Rolando


**************************************
See what's free at
http://www.aol.com.




Tom Davis
 

I know this would be difficult to do, but it would be very
illustrative to see a same target, same scope, same camera but
different filters (especially RGB) side by side image comparison. I
currently have A-dons and unfortunately sold my SBIG/CS filters.

Tom


--- In ap-gto@yahoogroups.com, chris1011@... wrote:

In a message dated 6/21/2007 2:32:22 PM Central Daylight Time,
stuart.j.heggie@... writes:


Roland, the SBIG filters are from Custom Scientific I believe. I
get very
strong halos from my green Astrodon. I had thought it was due to
the fast
f-ratio I was shooting with the scope I've had till now.
I have an older SBIG ST10E which has very strong multiple
reflections form
the green filter and fainter ones from the blue. These filters have
no coatings
on one side, so about 4% of the energy keeps bouncing between front
and rear
surface. I do not know where SBIG got those filters. The STL11K
camera that I
got from Ray Gralack have Custom Scientific RGB filters, he tells
me. I have
not had any reflection problems with them.

Rolando


**************************************
See what's free at
http://www.aol.com.




peturnielsen
 

and price ?

astrodon (6nm) is $695 vs baader (7nm) is $335 !!(for STL 11000)

p


--- In ap-gto@yahoogroups.com, kgkirkley@... wrote:


In a message dated 6/21/07 1:42:04 PM, chris1011@... writes:



I have been testing the Baader filters for the last week under all
kinds of
sky conditions. I do not see any halos around any bright stars. My
H-a
images
are very sharp with no reflections or ghost images around any
stars. Maybe I
am
mistaken about Astrodon filters (I have not tested them myself,
but go only
on what I have heard from others). I do know that several of my
RGB filters
in
my ST10 camera cause multiple reflection ghosts near bright stars.
I don't
know who makes these filters for SBIG, but they are not of the
quality level
of
the Baader series. In my STL11K camera I have installed 3 of the
narrow band
2"
Baader filters and the images they produce are super nice. All Baader
filters
have high grade multi-layer coatings on them to insure freedom from
reflections.

It may also be that the original poster's reflections are coming
from his
cover glass and filter rear surface, something that can't be
avoided unless
the
coverglass is coated with a multi-layer.

Rolando
Roland:

Thanks for the clarification.

Kent


**************************************
See what's free at
http://www.aol.com.


[Non-text portions of this message have been removed]


elraeburn <eraeburn@...>
 

--- In ap-gto@yahoogroups.com, chris1011@... wrote:

I have been testing the Baader filters for the last week under all
kinds of sky conditions. I do not see any halos around any bright
stars...several of my RGB filters in my ST10 camera cause multiple
reflection ghosts near bright stars. I don't know who makes these
filters for SBIG, but they are not of the quality level of the Baader
series.
This raises an issue I've been wanting to ask about for some time: how
do the Baader RGB filters perform for CCD imaging? The transmission
curves look to me like they are not designed for this application
(unequal coverage across the visual spectrum). How do they handle the
"Astrodon Teal Criterion" (blue and green transmission curves
intersecting at the OIII line)? Also, is it true they are available
only in 1.25" models?

-Eric


ayiomamitis
 

--- In ap-gto@yahoogroups.com, chris1011@... wrote:

on what I have heard from others). I do know that several of my RGB
filters in
my ST10 camera cause multiple reflection ghosts near bright stars. I
don't
know who makes these filters for SBIG, but they are not of the
quality level of
the Baader series. In my STL11K camera I have installed 3 of the
narrow band 2"

Rolando,

It is my understanding that SBIG's filters are produced by Custom
Scientific (at least the LRGB ones).

Anthony.


ayiomamitis
 

Rick,

I have SBIG's standard CLRGB filters and I do not experience such a
problem. I image a lot of clusters (ie. lots of starry fields) and I
have never encountered such a problem not even once.

Is it possible that slight ambient temperature changes are affecting
your focus point, thus giving you the false impression that the
filters are doing something? I amvery careful of the ambient
temperature and do refocus if necessary.

Anthony.

--- In ap-gto@yahoogroups.com, "Rick Wiggins" <rickwiggins@...> wrote:

Hi Guys,
It is well known (meaning I personally know more than ten imagers
that have had this problem and it is regularly discussed on several
imaging forums) that the blue and green filters cause halos in RGB
images. Many people believe that they are very bad in the AstronDon
filters. They definetly happen with the AstroDons. I don't have
enough data on non-AstroDon filters to do an objective comparison.
It is obviously more prevalent around bright stars and is worse the
more you stretch the image. I have not seen halos with narrow band
filters of any brand.
Thanks, Rick

--- In ap-gto@yahoogroups.com, chris1011@ wrote:

In a message dated 6/21/2007 12:38:25 PM Central Daylight Time,
kgkirkley@ writes:


you say the Baader filter(s?) do
not cause any halos.
I have been testing the Baader filters for the last week under all
kinds of
sky conditions. I do not see any halos around any bright stars. My
H-a images
are very sharp with no reflections or ghost images around any
stars. Maybe I am
mistaken about Astrodon filters (I have not tested them myself,
but go only
on what I have heard from others). I do know that several of my
RGB filters in
my ST10 camera cause multiple reflection ghosts near bright stars.
I don't
know who makes these filters for SBIG, but they are not of the
quality level of
the Baader series. In my STL11K camera I have installed 3 of the
narrow band 2"
Baader filters and the images they produce are super nice. All
Baader filters
have high grade multi-layer coatings on them to insure freedom
from
reflections.

It may also be that the original poster's reflections are coming
from his
cover glass and filter rear surface, something that can't be
avoided unless the
coverglass is coated with a multi-layer.

Rolando


**************************************
See what's free at
http://www.aol.com.


[Non-text portions of this message have been removed]


Roland Christen
 

In a message dated 6/22/2007 5:40:49 AM Central Daylight Time,
ayiomami@otenet.gr writes:


It is my understanding that SBIG's filters are produced by Custom
Scientific (at least the LRGB ones).
My ST10XE is one of the first ones. It is quite old, and the filters are not
fully multi-coated on all surfaces. I don't care who made these filters. If
one surface is left without coatings, there will be 4% reflection from that
surface, which will indeed cause a 4% ghost image.

Rolando

Rolando


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Roland Christen
 

In a message dated 6/22/2007 11:23:05 AM Central Daylight Time,
ayiomami@otenet.gr writes:


The concern I have with my set is the nice big circles which
show up when taking flats.
That's caused by dust particles.

Rolando


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