Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep14_banner.thumb.jpg.27eb9b06c9c8a1fe5ac3bae21c92743b.jpg

Russe

Imaging with the 130pds

Recommended Posts

Here's my m45, m42 and m31 with 130 PDS..

All 3 min unguided subs with canon 1100d

M45

http://www.astrobin.com/140413/

M42

http://www.astrobin.com/124109/

M31

http://www.astrobin.com/122877/

Thanks,

Ishan.

Excellent! How precise are your exposure lengths? Do you time manually or tether to a laptop?

I have tended to limit myself to uding the M mode on my Pentax, not been brave enough to try B yet [emoji15]

Share this post


Link to post
Share on other sites

Excellent! How precise are your exposure lengths? Do you time manually or tether to a laptop?

[emoji15]

I use a laptop..helps a lot with polar alignment and field selection..not to mention autoguiding when I get the Orion MMAG.

  • Like 1

Share this post


Link to post
Share on other sites

Just a little WIP to keep it simmering nicely.... caught this a couple of nights ago under probably the best sky of the year. However - the gear got rained on (slightly!), so there was a nervous check on the primary mirror - glad to say it was just one small spot.

Hoping to finish it off Friday night.

16038699245_5c94ecf578_c.jpg
 

  • Like 3

Share this post


Link to post
Share on other sites

A quick run out for the 130 at f4.5 last night, it hoovered this lot up in just 2.5 hours - easy to see where this one is going ;)

15525406134_c16d8202fb_b.jpg

  • Like 7

Share this post


Link to post
Share on other sites

I really enjoy the images shared from this telescope. The detail and stars just seem so deep and velvety.

Share this post


Link to post
Share on other sites
Clockwork_Orange, on 30 Dec 2014 - 8:16 PM, said:Clockwork_Orange, on 30 Dec 2014 - 8:16 PM, said:

Stunning is the only word that come to mind Uranium, cant wait to see the end result.

Regards

JP

Cheers :)

Heh, neither can I!!! Ive been hankering after an mosaic of this area ever since I started AP - and now that tree is going down next door, I can get a full night on it rather than having to wait until it crosses the meridian.

  • Like 1

Share this post


Link to post
Share on other sites

I'm seeing enough from this little jewel to give me a hankering, especially at the price, something I could buy on spec, so to speak.

So what are the gotchas?

OK, it needs collimating, but how bad is it? I remember collimating my old 8" newt,which was a pain and it was f/8 to boot, not f/5. Am I really going to have to collimate before every session? If yes, and it's going to take an hour or so then forget it, there isn't that much imaging time to waste, especially during the week when I turn in at 10.30.

Star spikes I'm aware of, just have to decide how much I dislike them, and If I can live with them.

How bad is the focuser? I know it's a crayford and thus suspect as it doesn't have the robustness of a R&P. The crayford on my Meg 90 is a disaster as it cannot pull the camera in on its own. I have to give it a push. If the Skywatcher is anything like that then I'd have to replace it, and a Feathertouch is 21/2 time the price of the bare OTA  :eek: .

I'll need a coma corrector obviously, and I think I'd go for the Baader given the comments I've seen re: the Skywatcher one.

So it could go from cheap 'n' cheerful to quite serious very quickly, and I just want to know what I'd be letting myself in for.

Share this post


Link to post
Share on other sites

The focuser is pretty sturdy - it is quite happy with my fairly ancient Pentax ist DS - even when mounted via a 2x T-thread barlow in the 1.25" to 2" adaptor.

Collimation should be a 5 minute job. Not done it a lot on this TBH, but it is fairly tight and doesnt alter much...that being said I'm not that picky, and the seeing is pretty pants here anyway!

Hope this helps!

Share this post


Link to post
Share on other sites
DaveS, on 30 Dec 2014 - 11:04 PM, said:DaveS, on 30 Dec 2014 - 11:04 PM, said:DaveS, on 30 Dec 2014 - 11:04 PM, said:DaveS, on 30 Dec 2014 - 11:04 PM, said:

I'm seeing enough from this little jewel to give me a hankering, especially at the price, something I could buy on spec, so to speak.

So what are the gotchas?

OK, it needs collimating, but how bad is it? I remember collimating my old 8" newt,which was a pain and it was f/8 to boot, not f/5. Am I really going to have to collimate before every session? If yes, and it's going to take an hour or so then forget it, there isn't that much imaging time to waste, especially during the week when I turn in at 10.30.

Star spikes I'm aware of, just have to decide how much I dislike them, and If I can live with them.

How bad is the focuser? I know it's a crayford and thus suspect as it doesn't have the robustness of a R&P. The crayford on my Meg 90 is a disaster as it cannot pull the camera in on its own. I have to give it a push. If the Skywatcher is anything like that then I'd have to replace it, and a Feathertouch is 21/2 time the price of the bare OTA  :eek: .

I'll need a coma corrector obviously, and I think I'd go for the Baader given the comments I've seen re: the Skywatcher one.

So it could go from cheap 'n' cheerful to quite serious very quickly, and I just want to know what I'd be letting myself in for.

Ok, the 130.... its not as difficult as you might think.

Firstly, collimation. No, you will not need to collimate it every time - in fact, months can elapse between collimation - and even then its only out by a small amount. Mine normally gets done when I take the imaging train apart for cleaning. But getting it right first time does matter, you need as little tilt in the secondary as poss (preferably none), that will ensure your field is corrected properly by the coma corrector.

Secondly, focuser. It helps to know the combined weight of your imaging train (camera, FW, corrector), anything up to 1kg is fine - but you may need to tweak the tension grub screws a little to get it "just so" (this is normal on any scope ive owned). You will also need to drill and tap a third thumbscrew hole in the 2" EP holder, that improves the rigidity considerably. Unfortunately, there is no replacement focuser for this telescope so you have to work with what you are given (makes it more fun!!).

My imaging train is ~1.6kg, the 383, 2" FW, tilt adaptor and corrector make for a fair old lump - but it copes alright. However, to cope with the weight (and cos I hate push-fit) I did have to convert my focuser to a threaded connection (custom built adaptor).

Third, corrected field. Your CCD chip is smaller than the 8300 right? Then either the Baader or SW corrector will suffice (both have pros and cons), your corners should be pretty good with that sized chip.

Fourth, performance. Again your CCD has small pixels? Going 2x2 bin at that FL with those sized pixels you could pretty much tear strips out of the sky with it and still get a good image. F5 (or F4.5 with the SWCC) @ 2x2 totally wipes the floor with f6 1x1 (in terms of signal to noise). Going from a frac to a newt may be a bit of a shock and you may think it looks a little "softer" or less contrast than a frac - but what you have is speed and depth of signal..... and if you have lots of signal then sharpness and constrast can be won back at the processing stage.

Other stuff:

1) Bottom end, make a cover for it or you will get light leaks

2) Flats, can be a pain in the rear end at times. So once you have a good set, dont touch the camera!!!

3) Sweet spot: If you have a slightly dodgy corner, slew to a bright star then place it toward the affected corner (about 2/3 way out) - refocus (using the B-mask), then that should balance the field out. But its unlikely you may need to do that given your chip size.

Hope that helps :)

Oh, forgot to add... the 5" primary isnt what you would call heavy, so there is a good chance you will be camera heavy. I strapped x2 0.5kg leg weights to the bottom of mine so it balances out without me having to slide it all the way back in the mount saddle.

  • Like 2

Share this post


Link to post
Share on other sites

Many thanks for your replies guys. Lots to think about, but pushing me towards the "buy" button as I've seen nothing that could be a deal breaker for me.

I'll weigh my imaging train, but it shouldn't be too heavy.

As a note, I've been running my rig with the WO 0.8 F/R IV and binning 1x1.

Share this post


Link to post
Share on other sites

It will be slightly faster than the WO, but with more focal length. And with your cameras pixel size, the resolution will be 1.44" p/p (2.88 binned) - anything below 3.5" p/p is useable, its down to personal preference really. It would help if you knew your camera's gain between 1x1 and 2x2, mine was measured at x2.23 (however I suspect the Sony chip will be a little lower). Easy way to do that is take some flats at 2x2 and achieve a target ADU (something like 24000), then switch to 1x1 and then see how long it takes to achieve the same ADU level - divide one by the other, and there you go! Another way is to do it under starlight using a non saturated star.

If im working on just 1-2 panes I usually go 1x1, but for more than that I opt to take a hit on the resolution but halve the time it takes for each pane - so its pretty easy to rack up a large scale image quickly. I'd like to figure out a way to combine both types of data in a sort of "halfway house" of signal and resolution.

Share this post


Link to post
Share on other sites

Well, I've been to FLO and ordered a 130 PDS, a MPCC and two Bahtinov masks (For the 130 and Meg 90). I already have a Premium Cheshire collimator, so fingers crossed!

  • Like 2

Share this post


Link to post
Share on other sites

Well its been a long time since I had a chance to get out and the weather has obliged but I did get one night over the Christmas break  :grin:

get.jpg

and 

get.jpg

Cheers

Ross

  • Like 4

Share this post


Link to post
Share on other sites
DaveS, on 31 Dec 2014 - 2:01 PM, said:

Well, I've been to FLO and ordered a 130 PDS, a MPCC and two Bahtinov masks (For the 130 and Meg 90). I already have a Premium Cheshire collimator, so fingers crossed!

Welcome to the club! :)

Good news is that you have the MPCC, which maintains the parfocal nature of the 130. So no need to refocus between Ha and OIII (done it for myself).

It will require more cooldown time than your frac, about 30min until its settled down enough to get good feedback from the b-mask. If you do it hot, the pattern jumps about all over the place making it difficult to judge.

Two things you need, the spacing for the MPCC:

From bottom of T2 thread: 55 (quoted), 57 (actual)

From bottom of M48 thread: 57.5 (quoted), 59.5 (actual)

The numbers marked as actual are what I needed to do in order for it to cover the 8300 chip.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks Rob, those figures are just what I need. I went for the MPCC after reading most of this long thread with people saying the MPCC was parfocal but the Skywatcher wasn't

Share this post


Link to post
Share on other sites

If you get a Baader MPCC make sure it has been machined correctly. I had to send one back after I (eventually) realised it wasn't sitting orthoganally in the 2" holder when clamped up due to poor machining.......

Share this post


Link to post
Share on other sites

OK, I'll be sure to check that out. Would have expected better from Baader though TBH

Share this post


Link to post
Share on other sites

Mr Fed-Ex has just been and delivered my new baby :)

  • Like 3

Share this post


Link to post
Share on other sites

Just had my baby out after almost a year with the new camera - and suddenly it started raining. So I hurriedly ran everything inside. Now, 30min later it's clear skies... :(

I'm going to sleep...

Share this post


Link to post
Share on other sites

Oh, dear!

It's still clear here but I'm imaging with my Meg 90 ATM, first light will have to wait until later in the week after I've had a chance to collimate it. I've been reading up on the procedure but can't find any good tutorials. Did find some videos but the guy waffled so much I gave up.

Share this post


Link to post
Share on other sites

Just had my baby out after almost a year with the new camera - and suddenly it started raining. So I hurriedly ran everything inside. Now, 30min later it's clear skies... :(

I'm going to sleep...

It has been on-again, off-again all evening east of the river as well.

Share this post


Link to post
Share on other sites

Hi all

Anyone know if you can attach a Skywatcher autofocuser motor (or other autofocuser) to the 130pds?

Thanks

Louise

Edited by Thalestris24

Share this post


Link to post
Share on other sites

Hi all

Anyone know if you can attach a Skywatcher autofocuser motor (or other autofocuser) to the 130pds?

Thanks

Louise

Yes you can attach SW auto focuser, no modification needed

Edited by tingting44

Share this post


Link to post
Share on other sites

Oh, dear!

It's still clear here but I'm imaging with my Meg 90 ATM, first light will have to wait until later in the week after I've had a chance to collimate it. I've been reading up on the procedure but can't find any good tutorials. Did find some videos but the guy waffled so much I gave up.

I found Astro-Baby's tutorial, very clear so I've bookmarked it. It's been decades since I had to collimate a newt (My home-built 8" f/8), the turorials refreshed my memory, so I'll be giving it a proper go.

But imaging will have to wait until I get the USB socket of my SX filter wheel repaired.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By Cedric Schweizer
      Hello community,
      Does anyone know if I can use a Skywatcher Explorer 130pds with a Sony alpha a7iii? I'm quite new to AP... I know that I need a T-Adapter but I'm a little concerned about the potential vignetting I could get...
      Thanks a lot for the help!
      Cédric
       
       
    • By Naveen
      Hi all - looking for some
      advice on eyepieces. I have seen beautiful views of Jupiter with its moons and Saturn and of course the moon. I have two extra 32mm and 10mm plossls but am looking for better lenses for planets which will show more detail? Which ones would you suggest? Many thanks in advance!
    • By deanchapman2705
      Hi,
      I'm relatively new to the whole telescope thing but have done my research and was fixed on getting the Orion skyquest XT8i or XT10i. By spending that much money, I didn't like the idea of purchasing it online from their website without seeing it in person (and not having the reassurance of being able to take it back) and looked for stores in the UK that would supply them. After plenty of research, it seems like they don't exist anymore and they are only in the US? Is this right or could anyone help me?
      (I've looked at the Sky-watcher 250PX/200PX flextube skyscan goto but it is significantly heavier and the noise of the goto mechanism sounds like a table saw so that's put me off of it...)
      Any help would be much appreciated,
      Thanks
    • By AstroMuni
      In my own journey while learning this process and seeing similar areas of confusion among others, I decided to compile this FAQ.
      This FAQ has been put together using a combination of information from SkyWatcher manuals, my own experience and suggestions by various contributors on the forums. As most of the confusion is around the newer reticle, this FAQ deals with this in detail.
      Q: What is Polar alignment and why is it needed?
      A: Polar alignment refers to the act of aligning the Polar axis of an Equatorial mount telescope, so that it is parallel with the axis that the Earth revolves around. It makes the job of following objects across the sky much easier.
      Its of minor benefit to the visual astronomer but a necessity to the astrophotographer who is trying to take images of the night sky. Once a telescope is polar aligned and an object centred in the eyepiece, then assuming an RA motor is attached to the telescope, the object will stay centred. The better the polar alignment, the longer it will stay there.
      If no motor is attached then simply nudging the telescope around one axis will bring the object back to the centre of the eyepiece again.
       
      Q: Do I need to accurately do a Polar alignment?
      A: If you are a visual astronomer then its not that critical and you should be able to manage just doing a simple polar alignment by positioning the mount so that Polaris is in the centre of the reticle.
      But if you are doing astrophotography with long exposures then accurate polar alignment becomes critical to improve the quality of the images.
       
      Q: My reticle looks different to what is shown in the manual.
      A: There are 2 versions of this – the older one which has a bubble showing the location of Polaris Fig.1 and the newer one which has a clock face Fig.2.

      Figure 1
       

      Figure 2
       
      Q: How do I Polar align with the new Reticle?
      A: As Polaris is not located exactly at the North Celestial Pole (NCP), we can see it orbit the North Celestial Pole in a polar scope. The large circle seen in the centre of the pattern in Fig.2 is a representation of the Polaris’ orbit around the North Celestial Pole. When performing the polar alignment process, it is necessary to determine the orientation of the Polaris on the circle. The reticle is marked like a clock face with 0 at the top. Imagine this is the 12 position in a traditional clock.
      At the end of the initialization of the SynScan hand control, after entering the proper local longitude, latitude, date, time, and daylight-saving time, the SynScan hand controller will display the message: “Polaris Position in P.Scope=HH:MM”. Imagine the larger circle in Fig.2 as a clock’s face with 12:00 at the top, with the current time pointing to the “HH:MM”. The orientation of the hour hand of the clock represents the orientation of Polaris in the polar scope. Put the Polaris to the same orientation on the large circle to finish the polar alignment.
      In case you don’t use the Synscan hand controller, there are several apps available on Android and IOS which give you the position of Polaris on the clock face (such as SynscanInit for Android and Polar Scope Align for IOS). Skwatcher has their own app as well called Synscan Pro which shows the position of Polaris in the new reticle.
      The Polaris position also changes as time passes. The reticle displays 3 circles to represent Polaris’s orbit in the year 2012, 2020 and 2028. It also gives sub-dials at 0, 3, 6, and 9 o’clock position for year 2016, 2024 and 2032. An engraving labeled with the above years is also displayed on the right of the FOV for memo purpose. When doing polar alignment in the Northern hemisphere, the user should put Polaris on the correct circle corresponding to the present year for better alignment precision.
      This reticle is also covered in the SW EQ6-R manual.
       
      Q: When I position my mount in the Home position with the counterweight at its lowest point, the 0 mark on the reticle is not at the top. Is this a fault and how can I fix it?
      A: There is nothing wrong with your mount You just need to rotate the mount in the RA axis till the 0 is at its highest position. Now lock the RA axis and continue with the alignment process.
       
      Q: How can I ensure that the 0 is accurately positioned at the very top?
      A: 1) Firstly, level the mount and set it up pointing north as if making it ready for polar alignment.
      2) Next use the Alt and Az bolts to centre Polaris in the reticle - i.e. put Polaris right in the centre of the cross-hairs, not on any circle. Be as accurate as you can. 
      3) Now using ONLY the Alt bolts, move Polaris vertically upward in the reticle from its central position until it reaches any of the circles.
      4) Because you started with Polaris dead centre and moved it only vertically, Polaris is now exactly in the zero (12 o’clock) position on the circle. Now rotate the RA axis to put the reticle zero mark in exactly the same position as Polaris. Again, be as accurate as you can.
      5) Lock the RA axis in this position and using a marker pen put alignment marks on the mount housing so that you can find this position again without the need to use Polaris.
      [Courtesy Jif001 on SGL]
       
      Q: How do I Polar align with the older reticle?
      A: Here is a good article http://www.astro-baby.com/astrobaby/help/polar-aligning-the-skywatcher-heq5orion-sirius-mount/
       
      Q: How can I check if my polarscope reticle is aligned with the RA axis of the mount?
      A: Before using the polar scope for polar alignment, the polar scope itself must be calibrated to ensure the pattern in the polar scope is aligned to the mount’s R.A. axis. The following steps will outline how to calibrate the polar scope:
      This process is best done during daytime. Choose a fixed object (eg. a faraway object such as the tip of a TV antenna). Centre the reticle on the object by adjusting the two azimuth adjustment knobs and the two elevation adjustment bolts. Rotate the mount in R.A. axis for half a turn (180 degrees). Tighten the R.A. clutch after the rotation. If the object remains at the centre of the reticle in the polar scope after the rotation, then it means the polar scope has been aligned to the R.A. axis and no calibration is needed. If its not aligned, read this article which explains how to recalibrate https://www.myastroscience.com/polarscopecalibration There are also videos on YouTube that explain this process.
      Hope this helps. 🙂
      Do let me know if you have other questions (and answers) and I can add to this.
       
    • By NallyFace
      Hello,
      Is anyone on here signed up for the SkySafari and SynScan beta testing to natively support IOS? If so how has it been going?
      https://support.simulationcurriculum.com/hc/en-us/community/posts/360043282514-Beta-Testing-SkySafari-6-iOS-Only-SynScan-WiFi-Read-This-To-Participate-?page=2#community_comment_360012192693
      Its 2020.
       
       
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.