Imaging with the 130pds

[kaelig]

@Jamgood Thank you for your answer. There is a problem with all these elements. I think that the corrector coul be sold in a full package in order to have all the elements. Myself, I lost a lot of time to choose Baader adaptators. It is a waste of time and waste of money !

[Jamgood]

2 hours ago, kaelig said:

@Jamgood Thank you for your answer. There is a problem with all these elements. I think that the corrector coul be sold in a full package in order to have all the elements. Myself, I lost a lot of time to choose Baader adaptators. It is a waste of time and waste of money !

I totally agree @kaelig, it could be made easier. Sadly though, there are too many combinations of telescopes, camera and eyepieces to make something like this that simple. 

As with everything to do with Astronomy and Astrophotography, a lot of it is trial and error to find what's right for your set up.

I read once that it is 99% frustration and 1% fun. That's not far off accurate for me but when everything works, it's amazing!

In the few short months I've been doing it I've tackled polar alignment and polar scope calibration, telescope collimation, eqmod and Stellarium connectivity, APT software, plate solving, PHD2 guiding. It's a never ending lesson in new toys.

👍

Edited October 13, 2020 by Jamgood

[Pankaj]

On 22/05/2020 at 02:25, Uranium235 said:

A bit of messing around for an hour last night (LRGB) :

WOW ! the image also has a galaxy that is 470 million LY away. Forgot the name of the galaxy though. It can be seen as a faint smudge in the picture at the 8 O' Clock position from the center of the cluster.

 

[StamosP]

18 hours ago, Uranium235 said:

@StamosP wow.... newtons rings.... ive never seen that before in a reflector!

https://en.wikipedia.org/wiki/Newton's_rings

http://www.365telescopes.com/how-to-deal-with-newtons-rings-in-cmos-imaging/

It only usually affects solar H-alpha images, so Im a bit clueless as to why its appearing in a DSO image. Remove the corrector and try imaging again, if it disappears - youve found the culprit.

I actually think it is the classic Airy diffraction pattern Rob. 

But it shouldn't happen. I wonder if there is someone else who has also used the GPU coma corrector with 130pds and what the results were...

 

18 hours ago, Adam J said:

Maybe a reflection within the corrector. Have seen it before with a TS branded corrector, its possible you have a missing coating.

In the smaller stars  its like a reflection of the out of focue airy disk overlayed on the star.

Adam

I will perform some tests with a different corrector this weekend and see if this is a corrector problem.

 

11 hours ago, kaelig said:

Problem of collimation or the eyepiece holder moves in extra-focalisation state (like Airy) or reflection effect (filter, corrector). 

Could you give us the results of your investigations, thank you.

Of course i will post the results, it is a very interesting phenomenon (but very, very annoying...)

[Spaced Out]

1 hour ago, StamosP said:

But it shouldn't happen. I wonder if there is someone else who has also used the GPU coma corrector with 130pds and what the results were...

I recently started using a TS optics GPU CC with the 130PDS. I have no problems with it so far, no odd rings like that. I use it with a ZWO ASI 1600.

[StamosP]

1 hour ago, Spaced Out said:

I recently started using a TS optics GPU CC with the 130PDS. I have no problems with it so far, no odd rings like that. I use it with a ZWO ASI 1600.

Very interesting...

Have you used it with narrowband filters? 

[Spaced Out]

23 hours ago, StamosP said:

Very interesting...

Have you used it with narrowband filters? 

No I haven't yet but will do soon, I'll report back !

[Whistlin Bob]

It has taken me ages to get this one into a state where I'm happy with it. I think part of the problem is that the IKI observatory published their data on the same target on the same night I was imaging this. I've been having a lot of fun playing with their data, and when I started on my own data, my little reflector felt a bit outgunned.

Think about it:

Not only that- they've got 80 hours of integration time under a dark sky. I've got 3 hours in suburbia. With LED streetlights. You can pop over to the IKI thread to see how their data turned out, but all things considered I think the 130pds acquitted itself pretty well. 

My data was:

20*30 secs each of RGB for the stars, 60*60 secs Ha and 90x60ses Oiii all at gain 250.

The channels were mixed HOO, with the Blue at 150% to give the oxygen envelope around the nebula a blue tone. I had a lot of trouble trying to balance the brightness of the crescent with the background nebulosity- in the end I did two versions in Pixinsight, one for the Crescent and one for the rest and then merged them as layers in GIMP.

 

 

[Galen Gilmore]

I finally got around to doing some more stuff with the good 'ole 130PDS!

I used a new processing technique called the arc hyperbolic sine stretch to edit this image, and it has done absolute wonders to make the image feel more natural!
Here's the link to the video in case anybody is interested.

[sagramore]

On 18/10/2020 at 04:34, Galen Gilmore said:

I finally got around to doing some more stuff with the good 'ole 130PDS!

I used a new processing technique called the arc hyperbolic sine stretch to edit this image, and it has done absolute wonders to make the image feel more natural!
Here's the link to the video in case anybody is interested.

 

Thanks for sharing that. I'm always interested to see processing techniques in PS as I am certain that my processing leaves a lot to be desired still! I'll have to give this one a try sometime.

[Anthony1979]

Does anyone know which bahtinov mask to get for my 130pds

Edited October 26, 2020 by Anthony1979

[Spaced Out]

On 13/10/2020 at 21:23, StamosP said:

Very interesting...

Have you used it with narrowband filters? 

Last night I used the TS GPU CC for the first time with narrowband filters. Unfortunately I had a terminal issue with my autoguiding, I managed just 3 subs before spending 3 hours failing to diagnose a PHD2 problem ! 

Anyway here's one of the subs with a quick and dirty process. Pacman neb Ha.

 

[kaelig]

For the Bathinov mask, I use the 3D model found in this topic:

https://www.thingiverse.com/thing:3514044

[Anthony1979]

55 minutes ago, kaelig said:

For the Bathinov mask, I use the 3D model found in this topic:

https://www.thingiverse.com/thing:3514044

Will the 125-180mm be ok then

[Erling G-P]

3 hours ago, Anthony1979 said:

Does anyone know which bahtinov mask to get for my 130pds

I had a Bathinov mask large enough for my 200PDS, but ordered a smaller one more fitting for my 130PDS.  However, once it turned up, I found it gave a very small and squashed image of a star, and thus was much more difficult to use than the larger one for the 200PDS.  As a result, I use the big one for both scopes - the small pins keeping it in place can be adjusted and moved inwards enough for use with the 130PDS too.   Can't say if it's the size or the form causing the problems the small one  - it does seem to be more 'closed' than the large one, and I have seen others reporting no problems using smaller Bathinov masks with smaller scopes.

[Jamgood]

12 hours ago, Anthony1979 said:

Does anyone know which bahtinov mask to get for my 130pds

I wasn't sure what to go for out of all those when I bought one, so I got one of these. Much easier decision. 

https://www.ebay.co.uk/itm/293046850694

[kaelig]

9 hours ago, Anthony1979 said:

Will the 125-180mm be ok then

I have made a print & I have test it. I have selected ABS black due to the use in outside conditions.

I freelabster service, price is 40 euros (~ 37 pounds).

Edited October 27, 2020 by kaelig

[Spaced Out]

13 hours ago, Anthony1979 said:

Does anyone know which bahtinov mask to get for my 130pds

 

I just got one of these (130P) , a couple of £ more than the ones your looking at but it fits and works perfectly.

https://www.firstlightoptics.com/bahtinov-focus-masks/starsharp-bahtinov-focus-masks.html

[Jamgood]

Pleiades and the Wizard Nebula from last night. Still testing the new mount out and guiding. Everything seems to be set and running sweet.

Pleiades
12 x 300 Lights ISO1600
12 x Darks
30 x Bias
30 x Flats

Wizard Nebula
24 x 300 Lights ISO1600
12 x Darks
30 x Bias
30 x Flats

Skywatcher 130PDS - HEQ5 Pro - Canon EOS60Da - Astronomik CLS Filter - Baader MPCCIII - Orion 50mm Guide Scope + Orion Star Shoot Auto Guider

[kaelig]

It's very beautiful, the blue of the pleiades is amazing. Congratulations 

[kaelig]

I have a question about filters use for nebula & galaxy observations with a camera.

I have mount an optic train: coma corrector baader Mpcc + extensions T2 + Atik Infinity color camera with UV/IR cut filter.

The backfocus (distance between the corrector and the camera sensor is 57,5mm in theory).

I will want to add 2" filter front of the coma corrector in order to improve the contrast and the photo result.

I have two filters: IDAS LPS P2 filter & Baader Neodynium

With your experiences, are they sufficient with the 130PDS tube?

In your opinion, what is the best for:

- galaxy

- nebula

Thank your for your feedbacks about your experience with 130PDS

[kaelig]

No one to answer me? I am alone? eh oh ... someone here?

[alacant]

On 29/10/2020 at 15:45, kaelig said:

two filters:

Hi

I don't think we can answer very well apart from, 'It depends'. Filters can only prevent light from reaching the camera, never add to it, so unless you live in a light polluted area or are looking for a specific colouring to your photos, my preference would be no filter. 

Perhaps best to try without first. Try the same target three times. Compare.

Cheers and HTH.

[kaelig]

Here, clouds & clouds since one month, so I could not image. Yes, of course, I will test without & with.
When the tests will be done, I will post the results here,

nice black sky for everyone

[rotatux]

On 29/10/2020 at 15:45, kaelig said:

have two filters: IDAS LPS P2 filter & Baader Neodynium

With your experiences, are they sufficient with the 130PDS tube?

In your opinion, what is the best for:

- galaxy

- nebula

Ok I don't have much experience but I can relate on what I've read so far.

About matching with 130PDS : I don't think there such a thing as matching filters per instrument, photographically speaking, since they will darken the sky background more or less, and hence allow more or less long exposures. Visually that's another story : their filtering intensity should match your instrument diameter, roughly small or big, e.g. you're probably not going to add a dark-colored filter to a low (<=80) diameter tube.

On matching targets : galaxies are more wide-band so you should not use nebula filters (usually more narrow-band) on them. So on nebulas go for the IDAS (though it's still wide-band, just somewhat less than Neodymium), and for galaxies check visually the Neodymium first then swap with the IDAS to see the difference.