Sharpstar 150 F2.8 HNT astrograph

[CCD-Freak]

11 hours ago, gorann said:

Yes, looks promising John! The stars look a bit squarish to me - is that a collimation issue?

The square look is caused by the diffraction effects of the spider.  The original size image doesn't show the square that much but when I resampled the image 3x3 to make it a smaller size for posting it got a bit blocky.  I think I need to try different software for resizing the image.    I am still working on getting the 15028HNT dialed in.  The collimation is shifting around a bit and it looks like the primary mirror is shifting slightly in it's cell so I will be working to fix that and I also will be working to find the optimum spacing.  Once I get it dialed in I think it will be a very capable imaging scope.

John Love
CCD-Freak
WD5IKX

[gorann]

I remember that there was a thread here on SGL a few months ago about a primary mirror shifting in Sharpstar, I think it was this one. It may give some suggestions:

 

[CCD-Freak]

18 hours ago, gorann said:

I remember that there was a thread here on SGL a few months ago about a primary mirror shifting in Sharpstar, I think it was this one. It may give some suggestions:

 

Thanks.....I remember that thread and was going to go back and read it again as it might save some time.  The shift is not huge but any shift on an F2.8 system is significant. 

John Love
CCD-Freak
WD5IKX

[Davey-T]

9 minutes ago, CCD-Freak said:

Thanks.....I remember that thread and was going to go back and read it again as it might save some time.  The shift is not huge but any shift on an F2.8 system is significant. 

John Love
CCD-Freak
WD5IKX

Managed to get the mirror cell apart by tapping a craft knife blade in the joint, seemed to have some sort of adhesive holding it, I've ordered some flocking material to replace the thin stuff that's on there.

Good idea to remove the mirror and check all the screws in the brackets holding the cell to the tube as all mine were nearly falling out.

Dave

Edited September 27, 2020 by Davey-T

[CCD-Freak]

Good to know...So far, all the screws I have checked have not been loose.

I will report what I find.

 

John Love
CCD-Freak
WD5IKX

[Davey-T]

Flocking arrived today, needed three layers to contact the mirror  as opposed to the one layer fitted in factory.

Now that the front ring contacts the mirror those small silver grub screws make sense as they could be used to adjust the contact to the mirror whereas they served no purpose at all before.

Dave

Original felt too thin and didn't even extend far enough to the edge of the ring to cover the mirror which only just goes under the ring by a fraction.

New felt three layers and covers mirror edge

 

These little silver grub screws might serve a purpose now

[CCD-Freak]

Good info Dave. 

I plan to take the cell out of mine today to see if I can secure the primary mirror.  Your pictures give me a better idea of what I will be doing and I think I have some flocking material on hand if I need to replace it.  I will take pictures to document what I do.

 

John Love
CCD-Freak
WD5IKX

[Davey-T]

These were the screws that were loose on mine some on the point of falling out.

Dave

 

[CCD-Freak]

Hi Dave

All the screws were tight and and many had that silicon or whatever it is under the heads.  I installed some felt pads on top of the factory strips that don't reach the edge of the  mirror and adjusted the position of the rings to get just the right amount of presure to secure the mirror without pinching it.   This is temporary to get me through my trip out west and I will make more permanent mods when I get back.  I will lay out and cut some arcs out of cardboard or something similar to replace the undersized pads like you did.  BTW...How did you cut the pads you installed?  I may also install some cork pads to replace the little copper studs the mirror sits on now.

The primary mirror does not tilt in it's cell now and the scope holds collimation as I change positions.

I would also like to clean the stuff off the screws but acetone did not seem to phase it at all....any ideas?

 

John Love
CCD-Freak
WD5IKX

 

[Davey-T]

Edited October 1, 2020 by Davey-T

[Davey-T]

You can buy silicone dissolver.

Dave

[CCD-Freak]

Hi Dave

 

Those screws you indicated were tight on mine as all the others have been.  Several were very tight and a bit hard to break loose.

I will see if I can find some of that silicon dissolver to clean the screws but I will have to test a spot to make sure it doesn't take off the black paint on the other parts.

How did you cut the pads for the retaining ring?  Did you just stick the stuff on and then trim it with an Xacto knife?

 

John Love
CCD-Freak
WD5IKX

 

 

[Davey-T]

19 hours ago, CCD-Freak said:

Hi Dave

 

Those screws you indicated were tight on mine as all the others have been.  Several were very tight and a bit hard to break loose.

I will see if I can find some of that silicon dissolver to clean the screws but I will have to test a spot to make sure it doesn't take off the black paint on the other parts.

How did you cut the pads for the retaining ring?  Did you just stick the stuff on and then trim it with an Xacto knife?

 

John Love
CCD-Freak
WD5IKX

 

 

Guess the guy that put mine together was in a hurry to knock off  😂

It shouldn't dissolve the black if its anodized.

Yes  cut to length and trimmed after, face down on cutting board.

Got mine all ready for another test but won't stop raining now.

Dave

[CCD-Freak]

30 minutes ago, Davey-T said:

Guess the guy that put mine together was in a hurry to knock off  😂

It shouldn't dissolve the black if its anodized.

Yes  cut to length and trimmed after, face down on cutting board.

Got mine all ready for another test but won't stop raining now.

Dave

Hi Dave

Good info about installing the felt on the ring.  I may take mine apart again before my trip to do it the way you did. 

I am not sure if the cell is anodized or not.  It looks more like paint or possibly powder coated. 

Thanks for your input and ideas.  Looking forward to seeing some of your images once the weather lets you get out.

John Love
CCD-Freak
WD5IKX

[ollypenrice]

Does anybody else on here think that telescope manufacturers who sell kit-form telescopes should actually state that this is what they are selling?

Olly

[CCD-Freak]

We will be arriving in New Mexico tomorrow....."Gentlemen....Start your imagers"

 

John Love
CCD-Freak
WD5IKX

[CCD-Freak]

Here is a quick stack of some M42 data from last night under Bortle 1 sky.  I will be tweaking the collimation a bit today as I search for the sweet spot.

This OTA is a "photon sponge" ... 180 x 15 seconds for a total of 45 minutes with an ASI-533MCP and Astro Art 7.   Still need to take Flats and Darks for calibration.

Six more nights to go!  😀

 

John Love
CCD-Freak
WD5IKX

Edited October 13, 2020 by CCD-Freak

[CCD-Freak]

Here is another quick stack of some image data I took last night.  IC5070 Pelican Nebula  80 x 60 seconds (80 minutes total) I plan to shoot more subs tonight and I will reprocess later with all the calibration files.  The combo of the ASI-533MCP and the SS 150 F2.8 Hyper Newt is proving to be much fun.

 

John Love
CCD-Freak
WD5IKX

 

[CCD-Freak]

Here is another SS15028HNT / ASI-533MCP image from New Mexico.   I just did a quick process of the B33 Group (B33, IC434, NGC2024, NGC2023, IC431, IC432 and IC435)  60 x 60seconds (1 hour total)
I am looking forward to adding more subs and doing a more careful process.

 

John Love
CCD-Freak
WD5IKX

[Paul M]

 

Wow!  If I only ever produce one worthwhile image I hope it's as good as this.

Very striking colours and I actually like the optical artifacts. They add another dimension.

[gorann]

Enjoy the scenery and keep the coming John! Lovely image.

[CCD-Freak]

I just got back from New Mexico today.  I captured over 20 Gigs of image data over six nights so now I start the careful image processing. 

Here is another quick stack of NGC2264  I don't have my notes handy but I think this was 75 x 120 seconds.

Much more to follow.

 

John Love
CCD-Freak
WD5IKX

Edited October 23, 2020 by CCD-Freak

[Davey-T]

Very nice John look forward to more.

Dave

[CCD-Freak]

I am starting to process the 20+ GB pile of image data so here is another image from the Rodeo,NM trip.
IC1396  Elephant Trunk Nebula.  150 x 120 seconds (5 hours total) captured over several nights
This is a tough object and I am still working on this on this one to see what I can pull out.  I want to try to capture some Ha data to add to it.

Edit:  A buddy of mine pointed out what looks like a horse to the right of the Elephant Trunk. (^8

John Love
CCD-Freak
WD5IKX

 

Edited October 25, 2020 by CCD-Freak

[CCD-Freak]

This is my latest image with the SS15028HNT / ASI-533MCP combo.  150 x 30" (75 minutes total) taken at the Okie-Tex Star Party 2021.  Captured and processed with AstroArt 8.