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ST80 Mods for Imaging

Gina

By Gina
in DIY Astronomer

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Gina

Gina

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Final DSO of the night was M42 (the Pacman area of the sky clouded over) fairly low in the east.  Hard edged halos in the OIII could be due to internal reflections in the ST80 - I haven't tackled this yet and I know the lens edges need blacking and there are several reflective bits elsewhere inside too.  I was leaving this until I was satisfied that this would be a useful scope.  I will now be bringing the scope indoors for further attention.

post-13131-0-77849900-1416939240_thumb.p

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Gina

Gina

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Yes indeed :)  Now that I've satisfied myself that the ST80 is suitable for NB DSO imaging I plan to buy a second one together with a third Atik 460EX mono CCD camera.  OTOH I may see if I can get a 300mm telephoto lens and Atik 314L+ camera set up on the rig as an interim.  These will cover a similar FOV.  The problem is that the 314L+ camera has quite a large diameter - much bigger than the lens - so this will need thinking about the mounting :D

I'm also working on a triple imaging rig using SLR camera lenses and that needs the third 460EX as the 314L+ won't fit so I'll be wanting the 460EX - might as well spend the extra less than £100 and get the ST80 :D  Mind you I haven't got enough funds available ATM for the camera let alone camera and scope :(

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Gina

Gina

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The 300mm lens turned out to be unusable due to looseness in the body where the tripod mounting ring fitted.  Both focussing and alignment would have been affected.  I can see no way of fixing this - the lens is worn out.  So I've given up on that and ordered another ST80 from FLO :D  Next week I shall have sufficient funds available to buy another 460EX :)

I have taken my present ST80 apart and blackened the edges of the lenses which was a prime suspect for the hard edged blue halos on my M42 image.

I have also 3D printed geared alignment adjusting levers to provide finer adjustment of the ST80s than just sliding the ring mountings on the ali plate.  One hole in the ali plate is elongated to allow the bolt that holds the scope ring to move sideways when loosened slightly.  The larger lever plate has nornal round holes to engage with the mounting bolts to adjust the alignment.   The second part is a manual adjusting lever/handle with a pinion which engages with a rack on the first part.  An M4 bolt and washer screwed into a tapped hole in the 10mm thick ali plate provides the pivot for the adjusting lever.

This screenshot shows the design in SketchUP
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And these photos show the printed parts as they will be used in practice.

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With ST80 scope mounted.  The focussing gears can be seen too.

post-13131-0-69695400-1417106580_thumb.j

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Gina

Gina

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Ah yes :)  I'm afraid I don't find the moon all that interesting any more :D  But I have taken plenty of images of it in the past with various scopes - best were with the MN190 and 460EX.  It can sometimes be useful for setting focus when it's around though :D

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Gina

Gina

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Have you also flocked your one?

I am soon to order that wilko black velor for mine, have already painted inside and the glass edges.

No, I haven't - the insides are painted a good matt black and there is also a baffle.  Same as my Esprit.  I haven't flocked any of my refractors so far.

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Gina

Gina

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A nice new mate for my first ST80 has arrived and been unpacked and I shall be mounting it on the ali plate today and probably setting everything up :)  I shall be using an Atik 314L+ on it initially - 40% less FOV than the 460EXs, but will cover the DSOs I have in mind for imaging ATM.  That's if we get any clear night skies before I get my third EX460 :D

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Gina

Gina

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The weather is totally miserable and I'm not having a good day even though it started well with an early delivery of the ST80.  I think my best bet is to leave the mounting of the second ST80 for today.  I drilled the hole for the alignment adjusting lever and had nearly finished tapping it when the tap broke in the hole :(  Now I have a real problem!  Not only do I not have an M4 tap any more but there is a broken piece of tap in the hole where I want the pivot to be :(

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Gina

Gina

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Thanks folks :)  Tonight looks like rubbish now anyway and nothing in the forecast until Tuesday and that may disappear by the time Tuesday comes.  I'll just steadily plod on until I'm ready :D  Think I may have a solution to my problem having had time to think.  Also been out to get my tablets and some groceries including a bar of dark chocolate :)

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Gina

Gina

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Sorry it's not all going to plan Gina, have a glass of something, there's always tomorrow, though not a lot of them in my case  :grin:

Dave

Probably not that many for me either but who knows :D  I try to take one day at a time and make the best of it :)

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Gina

Gina

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More prozac Gina, and slow down its not a race more Stars will come alone next year.

Yes, well... it could be next year before we see more stars in the night sky! :D

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Starlight 1

Starlight 1

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Thanks folks :)  Tonight looks like rubbish now anyway and nothing in the forecast until Tuesday and that may disappear by the time Tuesday comes.  I'll just steadily plod on until I'm ready :D  Think I may have a solution to my problem having had time to think.  Also been out to get my tablets and some groceries including a bar of dark chocolate :)

I hope the dark chocolate is to eat and not to put round the inside of the tube . :grin:

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Gina

Gina

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Solved my problems :)  Swapped the alignment adjuster to the other side,  then tapped the plastic to 5mm and drilled a 5mm hole in the ali plate to take a 5mm bolt.  The lever now pivots in a hole in the ali plate and the bolt/axle is now fixed in the plastic lever.  Works just as well.  I may post photos later - didn't stop to take any today - wanted to get done ASAP.

I now have all the scopes on the mount and mount aligned using the Esprit and the tree on the far hill, just before it disappeared in the mist!  The half moon is still shining brightly though so unless the mist gets a lot worse I should be able to align the ST80s and focus on the moon.

I've stopped for a cuppa and get warmed up - it's turned cold out.

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Gina

Gina

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Seems clear above here so I'm setting up on the Pacman - see what I can get.  Having a laptop problem ATM amd just waiting for it to reboot before trying again.  The EQMOD ASCOM drops out sometimes and then it needs rebooting to clear it.  One day I might find out why :D

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