Imaging with the 130pds

[Adam J]

3 hours ago, Igwiz said:

Hi guys,

Having spent a long time getting my PA and guiding to a very decent level, I am now back to doing the fun stuff! But two questions if I may please.  Target last night was M3 in RGB but looking at my subs I have noticed two issues:

1/ The stars in the R image are "bigger" than B and G.  (And G is bigger than B).  Naturally that leaves red halos when I combine the images. Is this simply a focus issue with the filters not being exactly parfocal?

2/ I appear to be "cutting off" some of the star! (See photo zoomed in). Is this a drawtube issue or a pinched mirror?

Many thanks for any thoughts!

Ig

(150PDS with Atik 460EX)

What coma corrector are you using some of the cheaper ones will give chromatic aberration. Also are you using a UV/IR block ?

[Igwiz]

Hi Adam - Is that in reference to the "larger red stars"? I am using the suggested SW CC and no UV/IR block.

On the "cutting off",  I checked last year's images and I don't get this also I have changed cameras from a 314L+ to a 460EX but wouldn't have thought that would make a difference.  Before I go hacksawing, could it be the secondary mirror alignment?

 

[alacant]

3 hours ago, Igwiz said:

I have changed cameras from a 314L+ to a 460EX

I'd guess the latter needs extra inward focus. Also, the swcc needs an extra 11mm of inward focus -compared with the focus position without cc-  pulling the focus tube even further into the light path. HTH.

[Adam J]

3 hours ago, alacant said:

I'd guess the latter needs extra inward focus. Also, the swcc needs an extra 11mm of inward focus -compared with the focus position without cc-  pulling the focus tube even further into the light path. HTH.

Yes as its a 0.9 reducer it does just that.

7 hours ago, Igwiz said:

Hi Adam - Is that in reference to the "larger red stars"? I am using the suggested SW CC and no UV/IR block.

On the "cutting off",  I checked last year's images and I don't get this also I have changed cameras from a 314L+ to a 460EX but wouldn't have thought that would make a difference.  Before I go hacksawing, could it be the secondary mirror alignment?

 

The SW CC also suffers from internal reflections which have been known to cause halos around stars. Finally it does produce a little chromatic aberration if you dont use a proper IR/UV blocked filter. The MPCCMKIII is a better corrector.

[alacant]

With turbulence over the southern horizon rife, the 700d sensor at 38º and the smoke from the San Juan fires, it was StarTools' superb deconvolution to the rescue. There's noise but it's bearable, as isn't the chromatic aberration from the cheepo cc making it look like it's been taken with an expensive refractor;) Thanks for looking and cool clear nights.

Edited June 25, 2017 by alacant

[Stub Mandrel]

Cosmic!

Literally and figuratively!

[al-alami]

The moon two nights ago.

[alacant]

I've run out of excuses. Maybe we should have a tick list for each post: cloud, rain, cold, hot, hazy, owl, time, tracking, filter...

So how about it was hot, dark, late, sticky and noisy. Not had those for a long time. But seriously, any comments here most gratefully received. TIA and for looking. 24x150s.

 

Edited June 25, 2017 by alacant
colour balance

[Uranium235]

On 19/06/2017 at 12:00, Igwiz said:

1/ The stars in the R image are "bigger" than B and G.  (And G is bigger than B).  Naturally that leaves red halos when I combine the images. Is this simply a focus issue with the filters not being exactly parfocal?

Its usually standard practice to refocus between filters, even on an apochromatic system like a newtonian. Thats mainly due to the focus shift that occurs as the telescope cools over the course of a session, but also takes into accout any other bits of additional glass you may have between the telescope and camera (ie: coma corrector).

[alacant]

On 2017-6-24 at 22:12, al-alami said:

The moon two nights ago

Hi. Nice shots. JTOL; I wonder for the earthshine it would be possible to scale both shots and then layer them? It may make an interesting shot.

[al-alami]

On 6/27/2017 at 10:48, alacant said:

Hi. Nice shots. JTOL; I wonder for the earthshine it would be possible to scale both shots and then layer them? It may make an interesting shot.

Hi.  I don't think it would work .. the overexposed picture has the white light spread out covering the detail of the moon.  I think it might be possible if it was done in HDR, but honestly I would have to experiment to try it.

[al-alami]

Hi all,

So this is the first time I take the scope to a dark site with my QHY 163M and RGB filters.  Of course there were problems, which I guess is normal when you're doing something for the first time.  So here is my final image (cropped). This is:

20 X 1 min for R

32 X 1 min for G

20 X 1 min for B

Its not great, but I do think its a good start.  Now I wish I could get the spacing correct for the cc.

This is also the first time I ever process RGB images from a mono camera. (I guess that's what you might call as a disclaimer)

Edited June 28, 2017 by al-alami

[Susaron]

On ‎6‎/‎28‎/‎2017 at 16:43, al-alami said:

Hi all,

So this is the first time I take the scope to a dark site with my QHY 163M and RGB filters.  Of course there were problems, which I guess is normal when you're doing something for the first time.  So here is my final image (cropped). This is:

20 X 1 min for R

32 X 1 min for G

20 X 1 min for B

Its not great, but I do think its a good start.  Now I wish I could get the spacing correct for the cc.

This is also the first time I ever process RGB images from a mono camera. (I guess that's what you might call as a disclaimer)

Awesome, remember that when doing RGB imaging it is necessary refocus when you change the filter.

[al-alami]

3 minutes ago, Susaron said:

Awesome, remember that when doing RGB imaging it is necessary refocus when you change the filter.

Thanks  Not to mention learn to process properly.

[UKJay1971]

Picked up my 130dps last weekend and gave it a test run in light polluted Wakefield. I wasn't expecting much and the data could be a lot sharper but I am seriously impressed by how this scope can perform.

QHY163m & 0.9 FR
Baader 7nm Ha filter
8x360sec subs

Targetted NGC 6888 - Crescent Nebula - and I literally chucked the data into DSS with no calibration files at all. A very quick curve transformation in photoshop and I got this. Loving it

[UKJay1971]

On 6/28/2017 at 15:43, al-alami said:

Hi all,

So this is the first time I take the scope to a dark site with my QHY 163M and RGB filters.  Of course there were problems, which I guess is normal when you're doing something for the first time.  So here is my final image (cropped). This is:

20 X 1 min for R

32 X 1 min for G

20 X 1 min for B

Its not great, but I do think its a good start.  Now I wish I could get the spacing correct for the cc.

This is also the first time I ever process RGB images from a mono camera. (I guess that's what you might call as a disclaimer)

This from Wadi Rum? I love it!

[al-alami]

10 minutes ago, UKJay1971 said:

This from Wadi Rum? I love it!

Yes from Wadi Rum.   The scope handled being off-road quite well (or at least as far as I can tell).

 

[UKJay1971]

Just now, al-alami said:

Yes from Wadi Rum.   The scope handled being off-road quite well (or at least as far as I can tell).

 

A beautiful image from a beautiful country

[al-alami]

1 minute ago, UKJay1971 said:

A beautiful image from a beautiful country

Thank you.  But I wish we didn't have to buy everything from abroad.   Makes this hobby a lot more difficult.  

On the plus side, the 130 PDS is an amazing scope that you can carry around, so having it shipped from Europe was worth it.

[alacant]

Moon again. Last night of this sort of deep sky stuff for a week or so. Oh, and that awful halo-ridden aliexpress cc...  3 minute snaps with 700d.

Edited July 6, 2017 by alacant
wrong foto

[al-alami]

9 hours ago, alacant said:

Moon again. Last night of this sort of deep sky stuff for a week or so. Oh, and that awful halo-ridden aliexpress cc...  3 minute snaps with 700d.

 

Lovely

 

[Susaron]

On ‎7‎/‎3‎/‎2017 at 10:59, alacant said:

Moon again. Last night of this sort of deep sky stuff for a week or so. Oh, and that awful halo-ridden aliexpress cc...  3 minute snaps with 700d.

 

Which object is this?

[alacant]

17 minutes ago, Susaron said:

Which object is this?

Hi. ic5067 nebulosa del pelicano. HTH.

[Uranium235]

3 hours ago, Susaron said:

Which object is this?

Its also designated as IC5070 (Pelican Nebula). Another panel above that would be NGC7000 (North America Nebula)

4 panel mosaic - 130pds.

[Uranium235]

I've just been browsing a few images from the 130pds (as you do), just to see how many of my images turn up via Google when I noticed a couple of what seemed like my images with a watermark on.... errr... whats going on here?! (I thought) as quite a few of my colour images have a very distinctive colour scheme.

So, I've taken a closer look and yes - indeed they are mine. Any AP'er will usually know their images as well as their own kids, so its a bit of a silly idea to try and nick something then slap a watermark on it, because sooner or later it will get found out. Fortunately for them, I'm not overly precious about vast majority of my images - I'd only get seriously miffed (and take action) if one of my competitive images turned up in a similar way.

They could have at least asked me if it was ok! But, on the other hand I'll take it as a compliment that they've used it to try and sell something  

It looks like a Malaysian version of gumtree or fleabay, and probably the ad is a little misleading since the images were taken with a modified 130pds, and not with the actual scope on sale (if selling a scope, I awlays use images taken with that exact telescope).

http://www.mudah.my/Sky+Watcher+Explorer+130PDS+EQ3+Steel+Telescope-55553369.htm