Imaging with the 130pds

[RolandKol]

On 13/07/2018 at 11:31, pipnina said:

Finding this thread just makes me more excited for the coming darkness! I got to do a few tests with my 130-PDS (hopefully I've got the hang of it all now!) during and just before summer twilight. Not sure what I'm going to photograph first though. My camera has pitiful Ha response (One day I'll complete the build with OAG and a cooled CMOS...) and the central milky way nebulae (M8, M16 etc) are too low down for me to image (without exposing the precious to the road and pavement... and street lamp glare!)

On a side note, has anyone else found the 130-PDS prone to stray light? In an image I took recently I noticed a gradient in the image that seemed too "sharp" to be vignetting or sky gradients. (The glowing pale lobe to the left hand side)

Are there measures that can be taken to prevent this?

Yep,  @carastro mentionned she has the same problem with stray light, she noticed it while taking darks during a daytime.
 

[dyfiastro]

Hi everyone, fantastic shots everyone is getting

My 130PDS is currently in storage until next month but cannot wait to get it back on the mount and start imaging with it again.

Has anyone replaced the secondary mirror on the 130PDS with a larger one to help with vignetting?
I have just won an ebay auction for a 200p spider to replace the one I currently have that has kink in it.
The auction also comes with a secondary mirror, I was thinking about replacing the secondary on the 130 with the spare I will have from a 200p

Any thoughts on this?

regards

Mark

[lnlarxg]

Just tried out pixinsight on my photos (transformed my M31 pics), I am loving my 130pds more and more

[Susaron]

9 hours ago, dyfiastro said:

Hi everyone, fantastic shots everyone is getting

My 130PDS is currently in storage until next month but cannot wait to get it back on the mount and start imaging with it again.

Has anyone replaced the secondary mirror on the 130PDS with a larger one to help with vignetting?
I have just won an ebay auction for a 200p spider to replace the one I currently have that has kink in it.
The auction also comes with a secondary mirror, I was thinking about replacing the secondary on the 130 with the spare I will have from a 200p

Any thoughts on this?

regards

Mark

 

Be carefull with that change, as far as I remember the 130PDS secondary mirror axis is 46mm long. So you shouldn´t use any secondary larger than 50 or 52mm. Think that on one side you reduce vignetting but on the other you reduce the amount of incoming light.

The vignetting can be erased with flats, anyway if you take a look to my last pictures they have been calibrated without flats, as the PixInsight DBE tool makes miracles.

Cheers.

[dyfiastro]

4 hours ago, Susaron said:

 

Be carefull with that change, as far as I remember the 130PDS secondary mirror axis is 46mm long. So you shouldn´t use any secondary larger than 50 or 52mm. Think that on one side you reduce vignetting but on the other you reduce the amount of incoming light.

The vignetting can be erased with flats, anyway if you take a look to my last pictures they have been calibrated without flats, as the PixInsight DBE tool makes miracles.

Cheers.

Thanks for the reply. From what I can see the 200p secondary mirror is 52mm, so should fall within tolerance.
I have been removing the Vignetting with flats and using DBE however having the secondary in effect for free, I thought it may just help a little to get better images out of camera.
 

[spillage]

On 13/07/2018 at 11:31, pipnina said:

On a side note, has anyone else found the 130-PDS prone to stray light? In an image I took recently I noticed a gradient in the image that seemed too "sharp" to be vignetting or sky gradients. (The glowing pale lobe to the left hand side)

Are there measures that can be taken to prevent this?

Hi

Wilko do a cheap self-adhesive felt that you can use to flock the scope and also placing thick card on the rear mirror helps with light leak.

 

Mark.

[Uranium235]

I flocked mine (including the drawtube), made a cover for the bottom and use a flocked dewshield. Also I take flats with the dewshield in place and use a light source not too bright, and slightly backed off (a large monitor helps). Also helps to diffuse the light a bit more with copier paper -  epecially important if your monitor or other light source has a slightly reflective screen/cover.

[Susaron]

Dear 130PDS friends.

Last Friday with quarter Moon we went to the La Mancha fields as this year we are not suffering in our spanish skies from clouds of Sahara´s dust.

I did shoot 3 objects from 23h to 4AM, first was this M17 and M18 couple. I changed the position of the camera and my mistake was not to recalibrate PHD2, so I found some small trails on all my subs.

The M17 & M18 is a stack of 27x180 subs with the QHY168C at Gain 10, Offset 30, Temp = -10C. Processed with Pix.

Clear skies.

Mario.

[Stub Mandrel]

Great image, Mario.

[Susaron]

Second picture from the same night, the Moon was then out.

A Crescent Nebula 27x180s subs, definitely it needs longer subs in order to catch fine details inside the nebula.

[Susaron]

And the last image from the same night a duo M52 + C11 (NGC7635) Bubble Nebula. 24x180s subs processed with Pix.

QHY168C (Gain 10 Offset 30 Temp -10ºC) + AZEQ5 + SW130PDS Moonlite tuned + IDAS D1 + Baader MPCC + ASI385MC + 30mm guidescope.

Cheers.

[pipnina]

When it comes to dew shields, what are you guys using? Off-the-shelf solutions or something more DIY?

[Stub Mandrel]

130P-DS Camp mat - rolled into a tube, stuck with superglue, ringed with gaffer tape, and lined with flock.

150PL never seems to need one.

C90 Mak - 3D printed tube, lined with flock.

[JohnSadlerAstro]

Card and Black Paper.  

[Adam J]

On 22/07/2018 at 23:12, pipnina said:

When it comes to dew shields, what are you guys using? Off-the-shelf solutions or something more DIY?

Honestly have not needed one since I started using my obsy but before that I made a DIY one. 

[sagramore]

I've not needed one for the 130-PDS yet! I am sure it'll happen one day though and I will be unprepared....

[rotatux]

my DIY: Opened a cereal box flat, black felt stuck on inside, adhesive velcro bands on outside, et Hop ?

Goes around my 130PDS as well as MAK127.

[dyfiastro]

My Dew shield is a section of camping mat cut to size and lined with flocking material.
Industrial sticky back velcro to connect the two ends. I have since made another for the guide scope as well.

Here is a quick shot from a while back showing it.

[Pid]

Here is a image of Ngc6960 from Friday night taken in my back garden consists of 

Heq5 mount 

Skywatcher 130pds 

9x50 guide scope 

Zwo asi120 

Canon 450d modded 

17x240s lights

10x240s darks 

[Adam J]

On 27/07/2018 at 12:32, dyfiastro said:

My Dew shield is a section of camping mat cut to size and lined with flocking material.
Industrial sticky back velcro to connect the two ends. I have since made another for the guide scope as well.

Here is a quick shot from a while back showing it.

where did you get the little bag covering the primary end of the tube?

[Stub Mandrel]

We need a show us your 130_DS thread, or at least more pics here! I will take one next time I set up - hopefully tomorrow!

 

[dyfiastro]

On 15/08/2018 at 17:25, Adam J said:

where did you get the little bag covering the primary end of the tube?

Ha that is a simple bit of grey / black doubled over cotton with some Knicker elestic around the outside.
I have a small section of of the left over camping mat inside it and it cuts out any stray light from behind (at this point I was still setting up each night and the laptop was always setup behind it).

The normal process was to take it off at the beginning of the night before imaging to allow the scope to cool and then put it on before starting a run.
Now I am in the obsy, its sits on the end of the scope all the time and only comes off for collimation.

[Stub Mandrel]

9 hours ago, dyfiastro said:

Ha that is a simple bit of grey / black doubled over cotton with some Knicker elestic around the outside.
I have a small section of of the left over camping mat inside it and it cuts out any stray light from behind (at this point I was still setting up each night and the laptop was always setup behind it).

ScopeKnickers are the unique and innovative way to protect your precious optics and keep them in perfect condition:

• Unique 'patent pending' elasticated waistband ensures a perfect fit around your OT to within 1/8 wave PV.
• Impervious to rain, honeydew, bat droppings and errant drones.
• Innovative 'left over camp-mat technology' means you never get a cold fundament.
• Stray Light Absorption(TM) improves your viewing by 178% while combatting coma, astigmastism and bad breath*
• Genuine Egyptian Cotton harvested under a dark sky lets your mirror breathe.
• Super stretchy elastic to ISO9000 will never leave you with droopy draws.
• SAS Black/Grey design to preserve your night vision under the most arduous conditions.
• Also functions as a hairnet when preparing food for star parties.
• Only $375! Take yours to the checkout now!

*in independent tests 9 out of 10 cats found they didn't notice any of these issues while playing with ScopeKinckers.

 

[Ross1204]

Hi,

I have recently started to get the secondary mirror on my 130pds dew up pretty fast and am wondering if one of these heaters would be suitable? I am just a little unsure on how to measure the stalk as there are two sizes available. I also already use a dew shield  which has helped but not stopped the problem on the bad nights. 

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8593_AST-Heizmanschette-fuer-geklebte-Fangspiegel-mit-Halter-D-50-mm.html

https://www.teleskop-express.de/shop/product_info.php/info/p8571_AST-Heater-for-glued-Newtonian-secondary-mirrors-with-holder-D-31-mm.html

The product also states for a 'glued secondary mirror' is that what the 130pds has?

Any help would be much appreciated.

Ross

[JohnSadlerAstro]

Hi,

Im not aware I ever posted this one up--M81 and 82, just over 1 hour 300 sec subs at ISO 800 I believe, unmodded 1000d on EQ5 non GoTo, autoguiding. This is the best result I've got so far, as I've been having  big issues with every aspect of the setup since then. However, they are gradually being resolved one by one so any day now it will be back into service!  

John