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5 hours ago, RolandKol said:

I guess, it also depends how primary is colimated... Full in or Full out and etc... Not yet figured out...

I find the collimation on my 130's secondary never seems to hold, as well. The number of times ive had to adjust it is really frustrating, especially as it always seems to end up a bit hit or miss as to whether I ever actually acheive anything like collimation! :D 

It's definitely worth pulling the primary down towards the back end of the tube though, the light spill is quite impressive if the mirrors all the way up. I use a couple of hats to keep the light out now.

John

Edited by JohnSadlerAstro
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Just a few of the goodies ive had from the 130pds over the past few months:            

All images have been made with a Canon450D (unmodded), on a HEQ5 PRO goto, 9x50 finder guider (QHY5). Me and my garden gnome: several M51 crops: M97 & 108: M81 & M82 (& NGC3077): M81

Not great pics from me, but this is what i got so far since beginning with AP in august this year. No guiding and maximum time of expousures 30 sek.

Posted Images

ngc 1893

40 x120s Ha,S,O.

This is my first attempt at narrowband  and only my second image with PI. Lots of issue and my monitor is bad so cannot really see any bad colours. It looks a bit red to me and the stars seem to have a ring around them.

 

 

ngc1893.jpg

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On 30/03/2020 at 16:18, RolandKol said:

I am in the list of people who were not able to get a correct spacing with SW CC+ASI1600MM on 130PDS...
Standard ZWO rings were very close, but coma was present... With delrin spacers managed to reduce it, but not completely...

I guess, it also depends how primary is colimated... Full in or Full out and etc... Not yet figured out...

Hmm. Shouldn't depend on where the primary is.

Took me a  while to find this but I posted this back in December:

I've just taken some 'real world' measurements.

It looks to me that ZWO have supplied a pretty much optimal set of adaptors, assuming a standard 55mm back focus for the typical field flattener or coma corrector.

Without the EFW:

ASI1600 --->  21mm T2 adaptor** ---> female/female adaptor** ---> T2-48mm adaptor**

6.5mm + 21mm + 11mm + 16.5mm =   55mm

**supplied with ASI

 

With EFW:

ASI1600 --->  EFW --->  T2-T2 male/male adaptor* ---> female/female adaptor** ---> T2-48mm adaptor**

6.5mm + 19.97mm + 1.96 mm + 11mm + 16.5mm =   55.93mm

*supplied with EFW

**supplied with ASI

Allowing for ~0.7mm shortening of the light path by the filter, this is pretty close again at 55.2mm.

 

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Haven't been imaging for some time due to lack of clear skies, but got two good days in a row.

This is my latest image of the good old carina nebula  with about 5 hours of data processed with startools. I have a few more hours of previous data, but i'm getting some overlapping problems.

Forgive me for the huge coma around the corners, I gave up trying to use the gso coma corrector because the stars were looking better without it.

104608931_carinanebula31-03-2020.thumb.jpg.fbe5512a11fffe928e98d916bc3d533b.jpg

 

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1 minute ago, Atreta said:

Haven't been imaging for some time due to lack of clear skies, but got two good days in a row.

This is my latest image of the good old carina nebula  with about 5 hours of data processed with startools. I have a few more hours of previous data, but i'm getting some overlapping problems.

Forgive me for the huge coma around the corners, I gave up trying to use the gso coma corrector because the stars were looking better without it.

104608931_carinanebula31-03-2020.thumb.jpg.fbe5512a11fffe928e98d916bc3d533b.jpg

 

very nice

I can recommend the Baader MPCC if you are looking for a replacement. I have had very little issue getting it to work with both my 130PDS and my 200p

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1 hour ago, dyfiastro said:

very nice

I can recommend the Baader MPCC if you are looking for a replacement. I have had very little issue getting it to work with both my 130PDS and my 200p

Thank you.

I'm considering saving up for the MPCC as it is well recommended in here.  One thing that i liked about the gso cc is that it increases the focal length and  so we have to rack the focuser outwards and this removes the Pacman effect on  bright stars. 

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4 hours ago, dyfiastro said:

I can recommend the Baader MPCC if you are looking for a replacement. I have had very little issue getting it to work with both my 130PDS and my 200p

+1....  I agree, the MPCC works well for me too. Mine needed a little bit of initial setting up (just a few test shots) to get the correct spacing but that was easy enough to do.

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1 hour ago, alacant said:

Really? Are you sure you had between 75 and 80mm cc to sensor? 

I'll give a try with a larger spacer that i have, i remember to have tried with 75 and abou 77mm.

 

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On 29/02/2020 at 13:59, Stub Mandrel said:

Well done for coping with those lights! I use a 30mm long  'dewshield' made from camping mat lined with black flock; I bet if you used something like that you might see improved contrast.

Thanks for the suggestion, should work well ☺️

00100dPORTRAIT_00100_BURST20200401191925522_COVER.jpg

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9 hours ago, mAnKiNd said:

Thanks for the suggestion, should work well ☺️

00100dPORTRAIT_00100_BURST20200401191925522_COVER.jpg

Is that a home made or shop bought dew shield ? Looks tidy ! I'm using a DIY flocked camping mat at the moment.

I just bought an astrozap shield for my 200 PDS, it fits well and seems solid and well made, I'd like something similar for the 130 PDS if I could find it.

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12 hours ago, Atreta said:

I'll give a try with a larger spacer that i have

OK. In fact anywhere between 70 and 80mm. You should find it superior to the two element ccs. Unfortunately we didn't try it on the 130 as we already had the gpu by then.

IIRC, on a 150 f5, it was just over 70mm.

 

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5 hours ago, Spaced Out said:

Is that a home made or shop bought dew shield ? Looks tidy ! I'm using a DIY flocked camping mat at the moment.

I just bought an astrozap shield for my 200 PDS, it fits well and seems solid and well made, I'd like something similar for the 130 PDS if I could find it.

Hey buddy, it's this one:

https://www.ebay.com/itm/Astromania-Flexible-Dew-Shield-for-Telescope-Front-Outer-Diameter-from-148-167mm/324104286055?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

Cheers,

Minos

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For anyone interested in fixing their star shapes (subject is Vega) from this to this:

1493653969_aperturemaskfix.thumb.jpeg.41f4a46a8416934e74ab60444098c1eb.jpeg

I designed a 3D print on tinkercad (.sti file attached)Skywatcher 130PDS Newtonian Primary Mirror Aperture Mask.stl, found a local 3D print shop to make it for me and applied to the mirror clips as such:

IMG_20200328_132955.thumb.jpg.6a3de9f418d62106b8eed7103f3c6c5c.jpg36876823_IMG_20200328_133018-Copy.thumb.jpg.bf176068ff4548b63102771071c8a6f7.jpgIMG_20200328_133048.thumb.jpg.624dc12be354baca03f724e0b2d3ae45.jpg

Inner diameter is 125mm, which is sufficient to cover the mirror edge and mirror clips. The idea is that the mask blocks the stray light from the edges, which causes the flares you see on bright stars and the ghost flares from the mirror clips blocking the edge flare.

Hope this helps :)

Minos 

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12 minutes ago, Starfisher said:

nice, i might try that on a day as well

 

Go for it, it makes a big return for a very small cost. Just send the .sti file of the 3d design I made to your local shop to get it printed, then attach it to the primary in a centered fashion to hide the edges and clips and then done, star shapes fixed! :)

It also helps to sink your coma corrector further down the drawtube with spacers to avoid pacman stars. This way, when you maintain the correct distance of sensor to coma corrector, everything sinks further down and you have to focus outwards to reach the focal point.

Clear skies,

Minos

Edited by mAnKiNd
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On 02/04/2020 at 16:41, mAnKiNd said:

For anyone interested in fixing their star shapes (subject is Vega) from this to this:

1493653969_aperturemaskfix.thumb.jpeg.41f4a46a8416934e74ab60444098c1eb.jpeg

I designed a 3D print on tinkercad (.sti file attached)Skywatcher 130PDS Newtonian Primary Mirror Aperture Mask.stl, found a local 3D print shop to make it for me and applied to the mirror clips as such:

IMG_20200328_132955.thumb.jpg.6a3de9f418d62106b8eed7103f3c6c5c.jpg36876823_IMG_20200328_133018-Copy.thumb.jpg.bf176068ff4548b63102771071c8a6f7.jpgInner diameter is 125mm, which is sufficient to cover the mirror edge and mirror clips. The idea is that the mask blocks the stray light from the edges, which causes the flares you see on bright stars and the ghost flares from the mirror clips blocking the edge flare.

Hope this helps :)

Minos 

This looks great but how did you align the secondary mirror with the primary when you put it back together, as you won't be able to see the mirror clips in the secondary anymore? It does look like a worthwhile mod though, just curious how you got around the collimation problem.

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1 hour ago, cuivenion said:

This looks great but how did you align the secondary mirror with the primary when you put it back together, as you won't be able to see the mirror clips in the secondary anymore? It does look like a worthwhile mod though, just curious how you got around the collimation problem.

That indeed occured to me when I was collimating, but I could still see the inner rim of the 3d print well enough to be able to center the secondary so that the inner rim uniformly appeared concentric. Hope this makes sense! :) 

I also collimate the secondary with a glatter laser after using my cheshire, and then use the howie tublug for the primary. I use the parallizer also to keep all tools...well...parallel!

Edited by mAnKiNd
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Since we're on the subject of collimation, I'll share another neat little trick I use to ensure consistency when I attach my camera after performing a collimation routine. It involves female and male Canon EOS T-rings (Nikons would work too).

First, I use the female ZWO short EOS ring on the drawtube:

IMG_20200407_000009.thumb.jpg.cf80f96e44ab87553e198da7e1f4df8a.jpg

Second, I use a standard male EOS T-ring on the howie glatter parallizer, which allows me to snap it into the drawtube and use my collimation tools:

IMG_20200406_235954.thumb.jpg.f7ca5941f39c1087caf1afb9bfcf79be.jpg 

Like so:

IMG_20200407_000200.thumb.jpg.037243469e174c91d0db5c45ec64095d.jpg

Once I've performed my tripirtite collimation routine with the cheshire, laser and tublug, I unspap the parallizer from the drawtube, and snap in my camera, which also has a male T-ring (and the zwo t2 -> 1.25" filter adapter inside it):

IMG_20200407_000248.thumb.jpg.0960f7dfef9c481884673eebc0a00e16.jpg

Like so:

IMG_20200407_000309.thumb.jpg.018c0adcc6961113eeb1f8cac46514d1.jpg

After this, I crack open a can of guinness and proceed with my imaging session wearing a big fat collimated smile on my face 😀

Hope this helps,

Minos

Edited by mAnKiNd
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and yes!!! i had a try with my mount this morning at 4AM ( utc +2) 

i did choose the M13 with the moon who was still up. DSS took 42mins of my 51Mins exposures i gave it. 

so 42*60s light, 21 darks, 20flats,38 bias. stacked in DSS en processed inCpatureone Pro since i must re-install PI.

mount Skywatcher EQM35PRO with ofcourse my lovely 130PDS ☺️

 

Autosave.jpg

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On 02/04/2020 at 16:41, mAnKiNd said:

For anyone interested in fixing their star shapes (subject is Vega) from this to this:

1493653969_aperturemaskfix.thumb.jpeg.41f4a46a8416934e74ab60444098c1eb.jpeg

I designed a 3D print on tinkercad (.sti file attached)Skywatcher 130PDS Newtonian Primary Mirror Aperture Mask.stl, found a local 3D print shop to make it for me and applied to the mirror clips as such:

 

Looks great. I'd like to do this but I know nothing about 3D printing. If I just give that file to someone who has a 3D printer can they produce it for me and will it be scaled correctly ?

Thanks

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1 hour ago, Spaced Out said:

Looks great. I'd like to do this but I know nothing about 3D printing. If I just give that file to someone who has a 3D printer can they produce it for me and will it be scaled correctly ?

Thanks

Yep, that's the idea! Depending on the quality of their 3D printer, it will make it to either exacting or loose tolerances. The height and outer rim are not important in terms of tolerance, but the inner rim should be as smooth as possible.

Hope this helps ☺️

Minos

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