Imaging with the 130pds

[richyrich_one]

22 hours ago, Owmuchonomy said:

Primeluce Labs do M48 X 0.75mm spacers for a few Euros. I bought 3 for my now defunct frac but they are like gold dust.

Thanks Chris, I'll check them out.

[sagramore]

Hello everybody. I hope this is the right place to post because this is my first post on this forum and I absolutely love this thread in particular for reasons that should become apparent....

I just received my 130-PDS and I cannot wait to get out there with it. I recently treated myself to a NEQ6 (I figured better safe than sorry when it comes to the mount!) and have just finished acquiring all the bits and pieces to get it working in the field. I am pretty new and you'd probably describe me as "all the gear but no idea" at the moment! I've upgraded to this kit from a 200P 8" dobsonian so it's a bit of a step up in complexity to say the least.

What I have managed to do so far is get the mount fully controlled by my laptop with EQMOD and Stellarium/StellariumScope and I was able to take some photos using APT and my (unmodified) EOS 550D on it via my ST80. I think my polar alignment isn't too shoddy as I have managed up to 90 second exposures without guiding on the ST80. I was originally trying to mount the 8" dob OTA on the NEQ6, which I think can handle the weight, but the 1200mm reflector is just not built for it and I was getting some mirror slop & tube flexure so I gave up and decided the 130-PDS was the way forwards.

Anyway, my real reason for posting is to show these three photos of my setup (which I have not yet used!) to ask if anybody can see I am doing something very obviously wrong or not? I plan to try and use the ST80 as a guide scope with an old webcam I have modified to fit into the 1.25" connection on the ST80 but as yet I'm not actually sure if it's a good enough camera. I'd like to avoid another £200-£300 on a guide cam for now if I can, especially seeing as my local light pollution is pretty high and I might well be limited with my exposure times anyway.

There is a skywatcher coma corrector between the DSLR and the focuser and I know it's unconventional to angle the camera down like that but it was the only way I could get it to all balance! So - criticisms and advice gratefully accepted for this very new hobbyist! The forecast says I might get some clear skies on Tuesday so I'm hoping to give it all a try then.

Thanks for looking! 

 

Hamish / sagramore

[Pompey Monkey]

3 minutes ago, sagramore said:

Hello everybody. I hope this is the right place to post because this is my first post on this forum and I absolutely love this thread in particular for reasons that should become apparent....

I just received my 130-PDS and I cannot wait to get out there with it. I recently treated myself to a NEQ6 (I figured better safe than sorry when it comes to the mount!) and have just finished acquiring all the bits and pieces to get it working in the field. I am pretty new and you'd probably describe me as "all the gear but no idea" at the moment! I've upgraded to this kit from a 200P 8" dobsonian so it's a bit of a step up in complexity to say the least.

What I have managed to do so far is get the mount fully controlled by my laptop with EQMOD and Stellarium/StellariumScope and I was able to take some photos using APT and my (unmodified) EOS 550D on it via my ST80. I think my polar alignment isn't too shoddy as I have managed up to 90 second exposures without guiding on the ST80. I was originally trying to mount the 8" dob OTA on the NEQ6, which I think can handle the weight, but the 1200mm reflector is just not built for it and I was getting some mirror slop & tube flexure so I gave up and decided the 130-PDS was the way forwards.

Anyway, my real reason for posting is to show these three photos of my setup (which I have not yet used!) to ask if anybody can see I am doing something very obviously wrong or not? I plan to try and use the ST80 as a guide scope with an old webcam I have modified to fit into the 1.25" connection on the ST80 but as yet I'm not actually sure if it's a good enough camera. I'd like to avoid another £200-£300 on a guide cam for now if I can, especially seeing as my local light pollution is pretty high and I might well be limited with my exposure times anyway.

There is a skywatcher coma corrector between the DSLR and the focuser and I know it's unconventional to angle the camera down like that but it was the only way I could get it to all balance! So - criticisms and advice gratefully accepted for this very new hobbyist! The forecast says I might get some clear skies on Tuesday so I'm hoping to give it all a try then.

Thanks for looking! 

 

Hamish / sagramore

Hi, and welcome to SGL!

Your set-up looks fine. The position that your DSLR finished in is actually a very logical one for balancing and works very well, even if it looks counter-intuitive to the inexperienced. 

Also, APT is my capturing software of choice and will see you a long way into your imaging career. As you are using a DSLR, I'll add one more thing: dither, dither, dither. Dithering is the best DSLR noise reduction strategy (in conjunction with taking more subs) there is.  Dithering works great with APT and PHD

[Uranium235]

Nothing wrong with the setup, the only thing that might need to be improved is the guide camera - something that has an ST4 port on it (QHY or ZWO). Nowt wrong with the way the DSLR is set up either, as sometimes you need to put it that way in order to make tagets land on the chip the right way up. You might find yourself switching between that and a 90^o rotation to suit your target (especially if its big).

The guide scope doesnt really have to be pointing at the same patch of sky as your main OTA, just roughly in the same area is good enough.

[sagramore]

Thanks for the comments! I was able to catch just a few minutes with the scope tonight between all the clouds here and I'm really pleased so far. My major problem with the Skywatcher 200P reflector tube (1200 mm version) was that even after careful balancing and alignment I was unable to get objects in the FOV after slewing to them. I figured it was likely due to some mirror slop and a lot of tube flexure. Nothing of the sort with this new scope! Things were bang on.

One problem I encountered was that neither of my rubbish little webcams are sensitive enough to pick up guide stars so I will have to leave out the guiding (and the ST80) for now until I get a dedicated planetary/guide scope, which is out of budget for now. However, I did manage to (finally) get the auto dithering working in APT without the need for a guide scope, and it works very nicely.

I've included a very quick shot of M81 / M82 / NGC 3077 that I took with the 130 PDS tonight. Image details below the image. I know there's a nasty orange gradient still but sadly my back garden is in the middle of Swindon so it's pretty light polluted. That's something to work on in the future. There's also the same problems that some others have seen in this thread - namely still some coma in the corners even with the CC and also the focus tube is so far in it's taking bites out of some of the brighter stars. All things I still need to address in the future....

 

Skywatcher 130 PDS on NEQ6 mount. Unguided.

Canon EOS 550D (unmodified) and Skywatcher coma corrector.

16 x 30s = 8 minutes @ ISO 800, 20 darks, 27 flats, 1 library master bias/offset. Acquired with APT using unguided dithering.

Stacked in DeepSkyStacker, post-processing in Photoshop CS3 and resized in IrfanView.

 

 

All in all I'm pleased so far and tomorrow night I'm taking the scope out to a much better location to give it a proper run. Hoping to catch Catalina while it's still close to cluster NGC 1502 and still bright enough to see at all. 

Thanks for looking!

Edited February 23, 2016 by sagramore

[sagramore]

 

EDIT: I had a go at reprocessing the same data after watching some tutorials on YouTube. It's still pretty poor because of the noise (only 8 minutes of data and no dithering!) however I think ti's a lot more even and the detail in the galaxies is a little better.

 

EDIT 2: I don't know what I've done but I've somehow managed to remove the originally processed image.... sorry! I think I will have to be more careful with double-posting and editing posts in future!

Edited February 26, 2016 by sagramore
Accidentally reposted the same info as the previous post!

[StamosP]

Hello again,

i've noticed that around bright stars the diffraction spikes appear to split in two (for example my m45 pic, page 31).

How can i fix that?

I've tried to align the spider vanes perfectly and i think i've done it but the problem remains...

[Uranium235]

Its still the spider vanes, its not a case of them being aligned - but one (or two) of them may be slightly twisted.

[StamosP]

How can i be sure that they are not twisted, even slightly? Is there a method?

As i can see by eye they are not...

[richyrich_one]

I would use a piece of wood or the like, as long as it has a nice flat face, about the same length as the vane. Pinch it against the vane at the secondary end and make sure that the rest of the vane sits flat against it.

There might be a more technical method but that should work.

As is always the rule, do this with the scope horizontal.

[Uranium235]

8 hours ago, StamosP said:

How can i be sure that they are not twisted, even slightly? Is there a method?

As i can see by eye they are not...

I did mine by eye, its not an exact science. I had the same problem a while back and twisting them straight was the only thing that fixed it. I had it on one diffraction spike, like this:

[sagramore]

2016-02-23 - Local Nature Reserve (Wiltshire, England)
Comet C/2013 US10 ("Catalina") in the top centre, open star cluster NGC 1502 on the lower-right, and planetary nebula NGC 1501 in the centre left (see next image for a zoom in of this!).

The first "decent" image taken with my new 130 PDS 5" reflector and NEQ6 mount. Really pleased with it considering my inexperience. Probably the best processed image to date as well thanks to some YouTube guides from Doug German (www.budgetastro.net).

See this Flickr link for full resolution version: Flickr

Technical details:
Skywatcher 130-PDS, Skywatcher NEQ6, Canon 550D (unmodified) with Skywatcher 0.9x coma corrector - f/4.5 (585 mm)
29 x 120s exposures @ ISO 800 (dithered with APT and no guide camera) = 58 mins
15 darks, 28 flats, 52 bias
Captured in APT, stacked in DeepSkyStacker, processed in Photoshop and Irfanview

 

Thanks for looking!

[simmo39]

Wow! really like this..

[StamosP]

15 hours ago, richyrich_one said:

I would use a piece of wood or the like, as long as it has a nice flat face, about the same length as the vane. Pinch it against the vane at the secondary end and make sure that the rest of the vane sits flat against it.

There might be a more technical method but that should work.

As is always the rule, do this with the scope horizontal.

 

11 hours ago, Uranium235 said:

I did mine by eye, its not an exact science. I had the same problem a while back and twisting them straight was the only thing that fixed it. I had it on one diffraction spike, like this:

 

Thanks guys, i checked it again and i think one was indeed slightly twisted.

Tomorrow is the test, i hope i will have 3-3.5 hours of data on Flame-Horsehead! 

[Pompey Monkey]

Lovely - understanding what you are taking pictures of is sadly missing in too many examples nowadays - you have an excellent appreciation of the "bigger picture" as they say.

[sagramore]

I finally have some more photos to post and I am really very pleased with myself as they are really the 2nd and 3rd images I have taken since getting my new mount & scope  I *love* this 130-PDS! Okay, on to the photos:

 

Globular Cluster M3
2016-03-07, near Swindon, England

Gear:
Skywatcher 130-PDS with 0.9x coma corrector (585 mm, f/4.5)
Skywatcher NEQ6-Pro Synscan (unguided)
Canon EOS 550D (unmodified)

Acquisition:
- AstrophotographyTools (APT) using APT dithering (unguided)
- 14 x 60s = total 14 minutes @ ISO 800
- 33 flats + library bias & darks
- Stacked in DeepSkyStacker and post-processed in Photoshop CC 2015

High res Flickr link: Here

 

 

Great Orion Nebula (M42, M43) and Running Man Nebula (NGC 1973/5/7)
2016-03-07, near Swindon, England

Gear:
Skywatcher 130-PDS with 0.9x coma corrector (585 mm, f/4.5)
Skywatcher NEQ6-Pro Synscan (unguided)
Canon EOS 550D (unmodified)

Acquisition:
- AstrophotographyTools (APT) using APT dithering (unguided)
- 15 x 120s, 17 x 60s, 20 x 30s = total 57 minutes @ ISO 800
- 33 flats + library bias & darks
- Each exposure stacked separately in DeepSkyStacker and post-processed in Photoshop CC 2015
- Final merge of the three different exposures in Photoshop to create manual HDR image

High res Flickr link: Here

 

 

I am most pleased with the Orion nebula image - I had never hoped to get such a good photograph with my local city light pollution and with under 1hr of data + my processing inexperience. I was glad to be able to take three different exposures and combine them into a sort of hoome-made manual HDR composition so that there was a little more detail in the core without it being too blown out and without me losing too much of the softer detail in the dust.

Thanks for looking and I welcome any comments or advice on what I could improve!

[Robp]

Been a while since my 130pds has been out on the mount.  With the majority of my WO star 71 narrowband targets in the area of a street light I'm going to have to move onto something else.

I decided to have a go with the 130pds on M81, try my hand at LRGB imaging see how I get on.

With the amount of light pollution I face I don't hold out much hope.

This is 3 Hours worth of 300 second luminance exposures, roughly processed to see how its going.

Planning to add a lot more data to this if I get some clear nights, I must say I'm tempted to dust of the 200P and see if I can get it to focus with my CCD.

[richyrich_one]

6 hours ago, sagramore said:

I finally have some more photos to post and I am really very pleased with myself as they are really the 2nd and 3rd images I have taken since getting my new mount & scope  I *love* this 130-PDS! Okay, on to the photos:

 

Globular Cluster M3
2016-03-07, near Swindon, England

Gear:
Skywatcher 130-PDS with 0.9x coma corrector (585 mm, f/4.5)
Skywatcher NEQ6-Pro Synscan (unguided)
Canon EOS 550D (unmodified)

Acquisition:
- AstrophotographyTools (APT) using APT dithering (unguided)
- 14 x 60s = total 14 minutes @ ISO 800
- 33 flats + library bias & darks
- Stacked in DeepSkyStacker and post-processed in Photoshop CC 2015

High res Flickr link: Here

 

 

Great Orion Nebula (M42, M43) and Running Man Nebula (NGC 1973/5/7)
2016-03-07, near Swindon, England

Gear:
Skywatcher 130-PDS with 0.9x coma corrector (585 mm, f/4.5)
Skywatcher NEQ6-Pro Synscan (unguided)
Canon EOS 550D (unmodified)

Acquisition:
- AstrophotographyTools (APT) using APT dithering (unguided)
- 15 x 120s, 17 x 60s, 20 x 30s = total 57 minutes @ ISO 800
- 33 flats + library bias & darks
- Each exposure stacked separately in DeepSkyStacker and post-processed in Photoshop CC 2015
- Final merge of the three different exposures in Photoshop to create manual HDR image

High res Flickr link: Here

 

 

I am most pleased with the Orion nebula image - I had never hoped to get such a good photograph with my local city light pollution and with under 1hr of data + my processing inexperience. I was glad to be able to take three different exposures and combine them into a sort of hoome-made manual HDR composition so that there was a little more detail in the core without it being too blown out and without me losing too much of the softer detail in the dust.

Thanks for looking and I welcome any comments or advice on what I could improve!

That M42 is really nice!

I am working on a HDR of that exact same region...too scared to post it now :-)

[sagramore]

4 hours ago, richyrich_one said:

That M42 is really nice!

I am working on a HDR of that exact same region...too scared to post it now :-)

Thanks for your comment! Never be too scared to post an image is what I have learned. They're always worth a look and in my case people have had a lot of helpful comments to make. Look forward to seeing it

[spiraleye]

Hi All, Another 130PDS owner over here! The images on this thread are mindblowing! Managed to get my first light processed with about 10 minutes total exposures of the core area of the Orion Nebula to test things out hopefully the weather will clear up again soon for a proper session. Love this scope so much. Still need a coma corrector and filters but this has really encouraged me for such a short exposure period with very little setup. Light pollution here is pretty awful I'm hoping the filters will greatly improve things. I am keen to move to narrow band as soon as I can afford the kit  Hope this isn't too bad for a first go at using all the processing gear.  

Taken with canon 550D with 2x barlow on the 130PDS attached to EQ3 PRO GOTO. 30 x 20s ISO1600

 

[sagramore]

Hi spiraleye - welcome to the club! Haha.

Really nice image for such a short amount of time. There's a lot of nice detail in the core, which is pretty overexposed in my photo so you've got me on that

One bit of advice for any deep sky images would be to forget the barlow if you can. I know you end up "zoomed out" but (if I have my maths correct) a doubling in focal ratio requires FOUR times the exposure duration to get the same detail, so by taking the 2x barlow out of your setup you would get as much light collection as if you had done 80 second exposures. The difficulty is finding this balance for smaller targets.

Look forward to seeing more of your work. I would love to move to narrowband as well but sadly I don't have the spare £2000-£3000 necessary for even the basic level stuff! Haha.

[spiraleye]

Yes I am keen to get rid of the 2x Barlow but I currently only have a 1.25" adapter for the dslr and was unable to achieve focus without the lens on the end of the Barlow tube. Perhaps I can do it and just didn't try the right combination I will look at that later, it was a first light situation so I was just trying to enjoy the moment and snap what I could with minimal fiddling. I plan to pick up the 2" adapter before long as I think the spacing should work out fine with that. I'm looking forward to stretching the exposure times a bit once I have a light pollution filter fitted as I am battling it a bit hard in processing right now. We are in the suburbs so whilst not as bad as it could be it's going to need some work to overcome it to a reasonable degree. For narrow band I was hoping to pick up a monochrome ccd and a Ha filter to get me started in adding some detail to the full color images and start the collection from there. It is encouraging to see the detail you are picking up at those exposures as we are using the same unmodified 550D. Hopefully I can get somewhere closer to that with a bit more practice. Are you using a light pollution filter with your current setup? Thanks for the kind words I look forward to improving on these results!  

[sagramore]

Hi spiraleye.

No filters at all in my setup at the moment. I do have to be careful with light pollution as well, it was starting to become more and more apparent in the 120s exposures. I can highly recommend a series of tutorials by Doug German (see his Youtube tutorial session here) which I can strongly recommend if you are new like I am! It does focus on Photoshop more than anything else, but the general processes are applicable to a lot of software. It really helped me with removing gradients caused by light pollution without having to buy extra expensive gradient removal software.

As for getting the camera set up: sorry if I say anything incorrect here as I am doing it from memory and I am currently using a coma corrector, which changes things a bit. However, it is my understanding that you should be able to connect the camera using *just* a T-ring and no need for a 1.25" or 2" adapter. There is a part of the 1.25" connection on the focuser that screws off to leave a T-thread that screws directly onto the T-ring on your camera. This should allow you to get the focus you need without the barlow in place. It's also much closer to the body of the scope then so a lot less chance of flexure or slop too. It's a pretty good focuser for such a cheap scope! This post has two images of the part I am talking about, before & after unscrewing to reveal the T-thread. Hope that helps!!

 

 

 

[spiraleye]

Ahhhh I see. I had completely missed that you could unscrew the adaptor section! What a boon. I thought I was going to need some extra bits. I will have a play later and see how it all goes together without the coma corrector, this is on the list anyway so if it works for now that's just an extra bonus. It is the nice wide field you have there I was super keen to achieve. I'm off on holiday on Friday and wasn't expecting to get another shot at it until I return but it looks like the weather is going to be perfect down here in Bristol tomorrow night so hopefully I should be able to get some good shots without the Barlow  Really appreciate the tips thank you so much!

[richyrich_one]

I didn't get as much data as I wanted but my first HDR.

ISO 800

20x5, 25x10, 20x30, 9x300

30 flats, no darks, library superbias

Stacked and processed in PI

Really not sure of the processing...

As always observations and suggestions gratefully received.