ASTRO: Hope Santa was good to you all

My Christmas came a few months early when I finally got the telescope
setup the way I wanted it. I've not posted shots of the final setup so
here's my early present from Santa.

I've shown the LX200R and Paramount before so features my new "back
end". As you can see there's a lot going on back there. Connected
first is a 3" Omicron, Robo-Focus powered focuser. I lock the mirror in
the LX200R, the knob closest to the camera so the focuser (farther knob)
no longer works. The Omicron has one inch of travel which is plenty to
focus everything once you set the mirror at the right point and lock it.
The Robo-focus unit moves the focuser in 1/20,000" of an inch steps.
I get a readout in the observatory of its position. At 0C that is about
12000 or 0.6" out from closest in focus. With each 1/2 degree C drop in
temp it moves out by about 33 units or .00165". This may not sound like
much considering the focal depth at the CCD is about .00866". It would
appear the temp could drop 2.5C or nearly 5F before I'd have a problem.
That would be true if the scope's field of view was flat. It isn't.
By experiment (I haven't seen any published figures) I find the
difference in focal point for the center and corners of a 35mm frame to
be .006" That means if the temp changes enough to move the focus only
..00266" the corners start to go out of focus. That's less than 1C.
During the exposure for the Flaming Star Nebula I posted earlier the
temp dropped 4.5C. The Robo-Focus unit jogs the focus every half degree
C by the 33/20000" needed to keep the nebula in focus. At the start of
the photo the reading was 11831, by the end it was 12130. That's .015"
difference or nearly twice my depth of field at the focus plane if it
was flat. Before I got the Omicron/Robo-Focus unit I had to watch the
temp and manually tell the Meade focuser to move. I had a chart I made
up that told me how much to move it but it meant I had to watch things
very closely and I didn't get any feedback that it moved as intended.
Now I can set it and go off and do other things, like process images or
to bed as I did with the B33 photo a while back.

The other attachment is a multi port adapter, Van Slyke Sidewinder, that
allows the use of a parfocal eyepiece, best seen in second photo and a
web cam port (now occupied with a red cap on the bottom as well as the
main port for the STl-11000 on the back. A mirror can be flicked in to
select which gets the light. It's handle is seen pointing at the camera
in the second photo. The ST-7 (best seen in the 1st photo) is at the
off axis port and always gets light no matter which other port is
selected. With the 3" focuser it can get nearly a fully illuminated
view without butting into the fov of the STl-11000's 35mm frame if the
short axis runs north south. Thus I can also use it in this position
for photometry work.

I've now got all my cables running through the polar axis of the
Paramount then down the declination axis to the mounting plate. One
cable goes forward to the dew heater, under the dew shield -- need both
when you are on a lake! The others all come out the back of the mounting
plate and go to the cameras and focuser. These are best seen going into
the polar axis in the first photo and coming out the baseplate in the
second. I have no worry about cables hanging up with I do a meridian
flip with this arrangement. Why more mount manufacturers don't do this
I don't know. It's really handy for remote operation.

So what did Santa get you?

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".

That's a nice setup Rick. With all those stuff hanging on the focuser I'm
not surprised that you needed to replace the Meade device.

Stefan


"Rick Johnson" schrieb im Newsbeitrag
...
My Christmas came a few months early when I finally got the telescope
setup the way I wanted it. I've not posted shots of the final setup so
here's my early present from Santa.

I've shown the LX200R and Paramount before so features my new "back
end". As you can see there's a lot going on back there. Connected
first is a 3" Omicron, Robo-Focus powered focuser. I lock the mirror in
the LX200R, the knob closest to the camera so the focuser (farther knob)
no longer works. The Omicron has one inch of travel which is plenty to
focus everything once you set the mirror at the right point and lock it.
The Robo-focus unit moves the focuser in 1/20,000" of an inch steps.
I get a readout in the observatory of its position. At 0C that is about
12000 or 0.6" out from closest in focus. With each 1/2 degree C drop in
temp it moves out by about 33 units or .00165". This may not sound like
much considering the focal depth at the CCD is about .00866". It would
appear the temp could drop 2.5C or nearly 5F before I'd have a problem.
That would be true if the scope's field of view was flat. It isn't.
By experiment (I haven't seen any published figures) I find the
difference in focal point for the center and corners of a 35mm frame to
be .006" That means if the temp changes enough to move the focus only
.00266" the corners start to go out of focus. That's less than 1C.
During the exposure for the Flaming Star Nebula I posted earlier the
temp dropped 4.5C. The Robo-Focus unit jogs the focus every half degree
C by the 33/20000" needed to keep the nebula in focus. At the start of
the photo the reading was 11831, by the end it was 12130. That's .015"
difference or nearly twice my depth of field at the focus plane if it
was flat. Before I got the Omicron/Robo-Focus unit I had to watch the
temp and manually tell the Meade focuser to move. I had a chart I made
up that told me how much to move it but it meant I had to watch things
very closely and I didn't get any feedback that it moved as intended.
Now I can set it and go off and do other things, like process images or
to bed as I did with the B33 photo a while back.

The other attachment is a multi port adapter, Van Slyke Sidewinder, that
allows the use of a parfocal eyepiece, best seen in second photo and a
web cam port (now occupied with a red cap on the bottom as well as the
main port for the STl-11000 on the back. A mirror can be flicked in to
select which gets the light. It's handle is seen pointing at the camera
in the second photo. The ST-7 (best seen in the 1st photo) is at the
off axis port and always gets light no matter which other port is
selected. With the 3" focuser it can get nearly a fully illuminated
view without butting into the fov of the STl-11000's 35mm frame if the
short axis runs north south. Thus I can also use it in this position
for photometry work.

I've now got all my cables running through the polar axis of the
Paramount then down the declination axis to the mounting plate. One
cable goes forward to the dew heater, under the dew shield -- need both
when you are on a lake! The others all come out the back of the mounting
plate and go to the cameras and focuser. These are best seen going into
the polar axis in the first photo and coming out the baseplate in the
second. I have no worry about cables hanging up with I do a meridian
flip with this arrangement. Why more mount manufacturers don't do this
I don't know. It's really handy for remote operation.

So what did Santa get you?

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".

Just the STL-11000 alone caused the Meade focuser to flex some. The
lowest corner of the camera frame was always out of focus with that
focuser and camera weight. Also at only 2" outside diameter it
vignetted the image quite a bit. The 3", 2.9" inside diameter focuser
has plenty of room for the off axis camera and the 35mm frame of the
STL-11000. A great combination and while he doesn't advertise it buy
buying both he knocked a major amount price! The Meade focuser worked
well with the Paramount's focus control system needing nothing else to
control remotely but just doesn't have the size and mechanical strength
for the load I put on it. With your camera it would work just fine I'd
think.

Rick


Stefan Lilge wrote:

That's a nice setup Rick. With all those stuff hanging on the focuser
I'm not surprised that you needed to replace the Meade device.

Stefan


"Rick Johnson" schrieb im Newsbeitrag
...

My Christmas came a few months early when I finally got the telescope
setup the way I wanted it. I've not posted shots of the final setup so
here's my early present from Santa.

I've shown the LX200R and Paramount before so features my new "back
end". As you can see there's a lot going on back there. Connected
first is a 3" Omicron, Robo-Focus powered focuser. I lock the mirror in
the LX200R, the knob closest to the camera so the focuser (farther knob)
no longer works. The Omicron has one inch of travel which is plenty to
focus everything once you set the mirror at the right point and lock it.
The Robo-focus unit moves the focuser in 1/20,000" of an inch steps.
I get a readout in the observatory of its position. At 0C that is about
12000 or 0.6" out from closest in focus. With each 1/2 degree C drop in
temp it moves out by about 33 units or .00165". This may not sound like
much considering the focal depth at the CCD is about .00866". It would
appear the temp could drop 2.5C or nearly 5F before I'd have a problem.
That would be true if the scope's field of view was flat. It isn't.
By experiment (I haven't seen any published figures) I find the
difference in focal point for the center and corners of a 35mm frame to
be .006" That means if the temp changes enough to move the focus only
.00266" the corners start to go out of focus. That's less than 1C.
During the exposure for the Flaming Star Nebula I posted earlier the
temp dropped 4.5C. The Robo-Focus unit jogs the focus every half degree
C by the 33/20000" needed to keep the nebula in focus. At the start of
the photo the reading was 11831, by the end it was 12130. That's .015"
difference or nearly twice my depth of field at the focus plane if it
was flat. Before I got the Omicron/Robo-Focus unit I had to watch the
temp and manually tell the Meade focuser to move. I had a chart I made
up that told me how much to move it but it meant I had to watch things
very closely and I didn't get any feedback that it moved as intended.
Now I can set it and go off and do other things, like process images or
to bed as I did with the B33 photo a while back.

The other attachment is a multi port adapter, Van Slyke Sidewinder, that
allows the use of a parfocal eyepiece, best seen in second photo and a
web cam port (now occupied with a red cap on the bottom as well as the
main port for the STl-11000 on the back. A mirror can be flicked in to
select which gets the light. It's handle is seen pointing at the camera
in the second photo. The ST-7 (best seen in the 1st photo) is at the
off axis port and always gets light no matter which other port is
selected. With the 3" focuser it can get nearly a fully illuminated
view without butting into the fov of the STl-11000's 35mm frame if the
short axis runs north south. Thus I can also use it in this position
for photometry work.

I've now got all my cables running through the polar axis of the
Paramount then down the declination axis to the mounting plate. One
cable goes forward to the dew heater, under the dew shield -- need both
when you are on a lake! The others all come out the back of the mounting
plate and go to the cameras and focuser. These are best seen going into
the polar axis in the first photo and coming out the baseplate in the
second. I have no worry about cables hanging up with I do a meridian
flip with this arrangement. Why more mount manufacturers don't do this
I don't know. It's really handy for remote operation.

So what did Santa get you?

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".

Rick you must have been especially good this year to get all that stuff. I
got a new monitor (LCD) and a new very strange barlow. It has a rotating
clip like a filter wheel but instead of filters it has barlow heads on it.
It's the best thing since sliced bread. Now I don't have to switch out
barlows all the time to get a higher mag. Clear Skyz, LA


"Rick Johnson" wrote in message
...
My Christmas came a few months early when I finally got the telescope
setup the way I wanted it. I've not posted shots of the final setup so
here's my early present from Santa.

I've shown the LX200R and Paramount before so features my new "back
end". As you can see there's a lot going on back there. Connected
first is a 3" Omicron, Robo-Focus powered focuser. I lock the mirror in
the LX200R, the knob closest to the camera so the focuser (farther knob)
no longer works. The Omicron has one inch of travel which is plenty to
focus everything once you set the mirror at the right point and lock it.
The Robo-focus unit moves the focuser in 1/20,000" of an inch steps.
I get a readout in the observatory of its position. At 0C that is about
12000 or 0.6" out from closest in focus. With each 1/2 degree C drop in
temp it moves out by about 33 units or .00165". This may not sound like
much considering the focal depth at the CCD is about .00866". It would
appear the temp could drop 2.5C or nearly 5F before I'd have a problem.
That would be true if the scope's field of view was flat. It isn't.
By experiment (I haven't seen any published figures) I find the
difference in focal point for the center and corners of a 35mm frame to
be .006" That means if the temp changes enough to move the focus only
.00266" the corners start to go out of focus. That's less than 1C.
During the exposure for the Flaming Star Nebula I posted earlier the
temp dropped 4.5C. The Robo-Focus unit jogs the focus every half degree
C by the 33/20000" needed to keep the nebula in focus. At the start of
the photo the reading was 11831, by the end it was 12130. That's .015"
difference or nearly twice my depth of field at the focus plane if it
was flat. Before I got the Omicron/Robo-Focus unit I had to watch the
temp and manually tell the Meade focuser to move. I had a chart I made
up that told me how much to move it but it meant I had to watch things
very closely and I didn't get any feedback that it moved as intended.
Now I can set it and go off and do other things, like process images or
to bed as I did with the B33 photo a while back.

The other attachment is a multi port adapter, Van Slyke Sidewinder, that
allows the use of a parfocal eyepiece, best seen in second photo and a
web cam port (now occupied with a red cap on the bottom as well as the
main port for the STl-11000 on the back. A mirror can be flicked in to
select which gets the light. It's handle is seen pointing at the camera
in the second photo. The ST-7 (best seen in the 1st photo) is at the
off axis port and always gets light no matter which other port is
selected. With the 3" focuser it can get nearly a fully illuminated
view without butting into the fov of the STl-11000's 35mm frame if the
short axis runs north south. Thus I can also use it in this position
for photometry work.

I've now got all my cables running through the polar axis of the
Paramount then down the declination axis to the mounting plate. One
cable goes forward to the dew heater, under the dew shield -- need both
when you are on a lake! The others all come out the back of the mounting
plate and go to the cameras and focuser. These are best seen going into
the polar axis in the first photo and coming out the baseplate in the
second. I have no worry about cables hanging up with I do a meridian
flip with this arrangement. Why more mount manufacturers don't do this
I don't know. It's really handy for remote operation.

So what did Santa get you?

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".

Don't recall seeing that barlow system before. Could come in handy
viewing as well.

Rick

LA wrote:

Rick you must have been especially good this year to get all that stuff. I
got a new monitor (LCD) and a new very strange barlow. It has a rotating
clip like a filter wheel but instead of filters it has barlow heads on it.
It's the best thing since sliced bread. Now I don't have to switch out
barlows all the time to get a higher mag. Clear Skyz, LA


"Rick Johnson" wrote in message
...

My Christmas came a few months early when I finally got the telescope
setup the way I wanted it. I've not posted shots of the final setup so
here's my early present from Santa.

I've shown the LX200R and Paramount before so features my new "back
end". As you can see there's a lot going on back there. Connected
first is a 3" Omicron, Robo-Focus powered focuser. I lock the mirror in
the LX200R, the knob closest to the camera so the focuser (farther knob)
no longer works. The Omicron has one inch of travel which is plenty to
focus everything once you set the mirror at the right point and lock it.
The Robo-focus unit moves the focuser in 1/20,000" of an inch steps.
I get a readout in the observatory of its position. At 0C that is about
12000 or 0.6" out from closest in focus. With each 1/2 degree C drop in
temp it moves out by about 33 units or .00165". This may not sound like
much considering the focal depth at the CCD is about .00866". It would
appear the temp could drop 2.5C or nearly 5F before I'd have a problem.
That would be true if the scope's field of view was flat. It isn't.
By experiment (I haven't seen any published figures) I find the
difference in focal point for the center and corners of a 35mm frame to
be .006" That means if the temp changes enough to move the focus only
.00266" the corners start to go out of focus. That's less than 1C.
During the exposure for the Flaming Star Nebula I posted earlier the
temp dropped 4.5C. The Robo-Focus unit jogs the focus every half degree
C by the 33/20000" needed to keep the nebula in focus. At the start of
the photo the reading was 11831, by the end it was 12130. That's .015"
difference or nearly twice my depth of field at the focus plane if it
was flat. Before I got the Omicron/Robo-Focus unit I had to watch the
temp and manually tell the Meade focuser to move. I had a chart I made
up that told me how much to move it but it meant I had to watch things
very closely and I didn't get any feedback that it moved as intended.
Now I can set it and go off and do other things, like process images or
to bed as I did with the B33 photo a while back.

The other attachment is a multi port adapter, Van Slyke Sidewinder, that
allows the use of a parfocal eyepiece, best seen in second photo and a
web cam port (now occupied with a red cap on the bottom as well as the
main port for the STl-11000 on the back. A mirror can be flicked in to
select which gets the light. It's handle is seen pointing at the camera
in the second photo. The ST-7 (best seen in the 1st photo) is at the
off axis port and always gets light no matter which other port is
selected. With the 3" focuser it can get nearly a fully illuminated
view without butting into the fov of the STl-11000's 35mm frame if the
short axis runs north south. Thus I can also use it in this position
for photometry work.

I've now got all my cables running through the polar axis of the
Paramount then down the declination axis to the mounting plate. One
cable goes forward to the dew heater, under the dew shield -- need both
when you are on a lake! The others all come out the back of the mounting
plate and go to the cameras and focuser. These are best seen going into
the polar axis in the first photo and coming out the baseplate in the
second. I have no worry about cables hanging up with I do a meridian
flip with this arrangement. Why more mount manufacturers don't do this
I don't know. It's really handy for remote operation.

So what did Santa get you?

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".