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IC then I don't C


Brian28

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Supposedly it was going to be clear here the weekend 👍. Friday night was pretty good and my rig all worked fine , guiding no problem ..😎however last night ( Saturday) although it was supposed to be clear there seemed to be some high  cloud around and in-laws told me today that when coming back on the island In the early hours - 1-2 am , there was a lot of mist across the area. Consequently it was a hellish night and had to keep pampering the guiding .. i even rechecked , mount level and Polar alignment at 1 am ☹️.. I was imaging IC1396 and had gathered some good data on Friday and was hoping for another full night , but alas , after the meridian flip ! The target had gone , yes I could not locate it for love nor money , I spent another hour trying to centre on it with no luck 😤.. so after checking the alignment, I pointed my scope at something else and gathered a few hours on NGC1499 ..  the California Nebula ..  
anyone else have issues with meridian flip in SGP ..  I can't set the bloody thing up 🤔😂

Anyway here is my IC1396 .. 

30 x 600 sec Ha 
8 x 600 sec OIII

6.3 hours total Integration Time , processed in APP, PS and LR

reprocessed .. this morning   

 

 

IC1396 SHO Rev 3 .jpg

Edited by Brian28
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Thank s Dave .. I was hoping to use a TS65Q to get a wider FOV and see more of the nebula , however ! ... having put the small scope on the mount , it didn't take long to realise that I couldn't balance it with the large ioptron weight , and I didn't have anything smaller too hand .. so I put the 130 back on for this shot .. 

Edited by Brian28
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That looks great.  I HATE it when I lose the target after the meridian flip.  It happens quite often with longer focal lengths.  It has to do with 3 factors 1) polar alignment 2) the GOTO model being accurate, and 3) the orientation of the scope mounting tubes.  It is quite common to have one tube (or both) slightly out of alignment.  The folks at Astro Physics recommended using very thin shims under the mounting tubes to align them--through a trial and error process.  I didn't do this (I hate losing clear sky time). 

Rodd

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39 minutes ago, Rodd said:

That looks great.  I HATE it when I lose the target after the meridian flip.  It happens quite often with longer focal lengths.  It has to do with 3 factors 1) polar alignment 2) the GOTO model being accurate, and 3) the orientation of the scope mounting tubes.  It is quite common to have one tube (or both) slightly out of alignment.  The folks at Astro Physics recommended using very thin shims under the mounting tubes to align them--through a trial and error process.  I didn't do this (I hate losing clear sky time). 

Rodd

Hi Rod , thanks for your "Flipping " comments 😂.  

1. Polar alignment is normally pretty good , the mount is fitted with a polemaster , and I still take my time making sure it's right 2 . The Goto model being accurate , can you expand on this one please ..  😊

3 . I only have one scope on the mount , and the guiding is though the camera .. QSI583 WSG ..  so I don't think that's the problem 

 

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13 minutes ago, Brian28 said:

Hi Rod , thanks for your "Flipping " comments 😂.  

1. Polar alignment is normally pretty good , the mount is fitted with a polemaster , and I still take my time making sure it's right 2 . The Goto model being accurate , can you expand on this one please ..  😊

3 . I only have one scope on the mount , and the guiding is though the camera .. QSI583 WSG ..  so I don't think that's the problem 

 

Gogtos have to be "trained"  The really accurate models used by the SKY X need 100 goto movements to really be spot on.  I am far from an expert in GOTO technology, but I do know that when you slew to a star then center it and tell the computer its centered, then slew to another star, it will need to be centyered as well--then another....etc.  After a certain number the computer/mount can very accurately move "in that section of the sky"    When you do a meridian flip--its not that section of sky, so there is more error unless you have built a very accurate, all sky model.

As far as the rings not being exactly oriented--it doesn't matter how many scopes.  It can be that way with any ring mounted scope.  It doesn't affect anything except meridian flip accuracy.  It doesn't take much--.25mm and a narrow FOV will be off.  I have not looked into this cause because I hate losing clear sky time--and putting shims (pieces of foil) under the rings seems like it would take a long time to do right.  As long as the target--or star is in the FOV thats OK with me....but when its not it is really annoying.  It helps to have a widefield guidescope you can use as a finder.  Or--figure out if the flip is usually off in a particular direction--then its a simple matter of manually slewing after the flip in that direction ( I never know if pushing the bN button will nove the scope toward N or the stars in the FOV toward N!).   The problem is when you just can't find the target---and I have no visual finder and looking down the barrel to see where the scope is pointing is complicated by the fact that my guider cam has a green light that interferes with this.  After hunting for my target star after the flip for an hour at 3:00am I really wanted to try the shim technique.   Either that or sometimes I avoid flips entirely.

Rodd

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5 minutes ago, Rodd said:

Gogtos have to be "trained"  The really accurate models used by the SKY X need 100 goto movements to really be spot on.  I am far from an expert in GOTO technology, but I do know that when you slew to a star then center it and tell the computer its centered, then slew to another star, it will need to be centyered as well--then another....etc.  After a certain number the computer/mount can very accurately move "in that section of the sky"    When you do a meridian flip--its not that section of sky, so there is more error unless you have built a very accurate, all sky model.

As far as the rings not being exactly oriented--it doesn't matter how many scopes.  It can be that way with any ring mounted scope.  It doesn't affect anything except meridian flip accuracy.  It doesn't take much--.25mm and a narrow FOV will be off.  I have not looked into this cause because I hate losing clear sky time--and putting shims (pieces of foil) under the rings seems like it would take a long time to do right.  As long as the target--or star is in the FOV thats OK with me....but when its not it is really annoying.  It helps to have a widefield guidescope you can use as a finder.  Or--figure out if the flip is usually off in a particular direction--then its a simple matter of manually slewing after the flip in that direction ( I never know if pushing the bN button will nove the scope toward N or the stars in the FOV toward N!).   The problem is when you just can't find the target---and I have no visual finder and looking down the barrel to see where the scope is pointing is complicated by the fact that my guider cam has a green light that interferes with this.  After hunting for my target star after the flip for an hour at 3:00am I really wanted to try the shim technique.   Either that or sometimes I avoid flips entirely.

Rodd

Thanks Rod , very interesting .. I have loosing clear sky time as  well , that's why I gave up and pointed at something else , but I don't like to be beaten ..  😉

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7 minutes ago, Brian28 said:

but I don't like to be beaten

Me neither.  We have all this expensive, high end gear and it can't even point where I want it to sometimes!   It is frustrating.  If I lived in an area that had more clear sky than not, I would no doubt get to the bottom of many little problems I have.  Good luck with it.   We may lose a battle (or two) but as long as we can take pictures of a distant object in the universe, can it be aid that we really lose?  I remind myself that the text books and calendars of the 1970s and even 1980s can't hold a candle to what we can do from our backyards today.  Its quite remarkable.

Rodd

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2 minutes ago, Rodd said:

Me neither.  We have all this expensive, high end gear and it can't even point where I want it to sometimes!   It is frustrating.  If I lived in an area that had more clear sky than not, I would no doubt get to the bottom of many little problems I have.  Good luck with it.   We may lose a battle (or two) but as long as we can take pictures of a distant object in the universe, can it be aid that we really lose?  I remind myself that the text books and calendars of the 1970s and even 1980s can't hold a candle to what we can do from our backyards today.  Its quite remarkable.

Rodd

I couldn't agree more ..  😉

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1 hour ago, Rodd said:

I remind myself that the text books and calendars of the 1970s and even 1980s can't hold a candle to what we can do from our backyards today.  Its quite remarkable.

Rodd

Yes indeed, I have a print of the Horsehead Nebula region taken with the 40” (I think) Schmidt camera at Siding Springs in the late 80’s, and I have taken a better image from my own backyard, even with my limited skills.

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6 minutes ago, tomato said:

Yes indeed, I have a print of the Horsehead Nebula region taken with the 40” (I think) Schmidt camera at Siding Springs in the late 80’s, and I have taken a better image from my own backyard, even with my limited skills.

That's pretty cool, huh?

Rodd

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