Jump to content

sgl_imaging_challenge_banner_31.thumb.jpg.b7a41d6a0fa4e315f57ea3e240acf140.jpg

Recommended Posts

9 minutes ago, mAnKiNd said:

I went from a QHY miniguidescope on the findershoe to an evoguide 50 screwed onto the top dovetail of the mounting rings and saw a huge difference in guiding i.e. went from a total RMS (px) error >1.5" to ~ -0.5-0.7".

P.S. excuse the cable wrapping mess...also, you can see that I'm now using the qhy finder rings to run camera cables through..!

 

IMG-20190812-WA0012.jpg.6ed9c827cfa8a426cd093fb71ba8e34e.jpg

 

Looks good in this photo, the cables in the first pic would drive me nuts

Link to post
Share on other sites
  • Replies 3.4k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Just a few of the goodies ive had from the 130pds over the past few months:            

All images have been made with a Canon450D (unmodded), on a HEQ5 PRO goto, 9x50 finder guider (QHY5). Me and my garden gnome: several M51 crops: M97 & 108: M81 & M82 (& NGC3077): M81

Not great pics from me, but this is what i got so far since beginning with AP in august this year. No guiding and maximum time of expousures 30 sek.

Posted Images

44 minutes ago, Frank the Troll said:

Looks good in this photo, the cables in the first pic would drive me nuts

There's no cable mess when I'm setup for a session, just in that photo i wrapped them around the equipment... Cable mess drives me nuts too!

  • Haha 1
Link to post
Share on other sites
2 hours ago, Galen Gilmore said:

Where could you buy a new set of OTA rings for the PDS? Mine have worn out threads, so I effectively only have one working ring.

Do you mean the threads have stripped through over-tightening? They shouldn't wear out

You can ask a local garage to fit a helicoil insert for you which will restore the thread and make it stronger than before.

Or even buy a suitable set and do it yourself, cheaper than new rings.

<edit>I assume you mean the threads that fit the rings to the wedge?

Edited by Stub Mandrel
Link to post
Share on other sites
1 hour ago, Stub Mandrel said:

Do you mean the threads have stripped through over-tightening? They shouldn't wear out

You can ask a local garage to fit a helicoil insert for you which will restore the thread and make it stronger than before.

Or even buy a suitable set and do it yourself, cheaper than new rings.

<edit>I assume you mean the threads that fit the rings to the wedge?

I am talking about the threads which clamp the two halfs of the ring together, not sure if what you said still applies.

You're probably right about them being stripped, and not worn out.

Link to post
Share on other sites
9 minutes ago, Galen Gilmore said:

I am talking about the threads which clamp the two halfs of the ring together, not sure if what you said still applies.

You're probably right about them being stripped, and not worn out.

Those should be pretty durable! They don't need to be very tight.

It should be possible to replace/repair them, can you post a pic of the worn one some time?

Link to post
Share on other sites
3 hours ago, spillage said:

Slightly off topic but It would be used in the 130pds if I brought one :) . Has anyone used one of these?

https://www.teleskop-express.de/shop/product_info.php/info/p5417_Lacerta-Thread-Adapter-for-using--Baader-MPCC-with-Skywatcher-Newtonians.html

Yes! I've been using one since i got my 130pds.

I also have this one:

https://www.teleskop-express.de/shop/product_info.php/info/p203_TS-Optics-T2-Fokaladapter-fuer-Skywatcher-Auszuege-mit-M54x1-Innengewinde.html

Edited by mAnKiNd
Link to post
Share on other sites

Im using the same kind of thing, but I built mine myself ;)

The only issue with this arrangement is that the camera rotation is arbitrarily set by the travel of the threads - so you dont have much wiggle room to get it right (to the nearest 90 degrees).

Link to post
Share on other sites
5 minutes ago, Uranium235 said:

Im using the same kind of thing, but I built mine myself ;)

The only issue with this arrangement is that the camera rotation is arbitrarily set by the travel of the threads - so you dont have much wiggle room to get it right (to the nearest 90 degrees).

Impressive that you built one. Yeah, no rotation is a bummer, but I suppose I've learnt to live with it.

I took off (and lost) the rotation ring on the FUFmpcc because it compromised stability, which was my whole purpose for using these adapters.

Edited by mAnKiNd
Link to post
Share on other sites
8 minutes ago, mAnKiNd said:

Impressive that you built one. Yeah, no rotation is a bummer, but I suppose I've learnt to live with it.

I took off (and lost) the rotation ring on the FUFmpcc because it compromised stability, which was my whole purpose for using these adapters.

I was pretty lucky in that mine rotated to portrait (with respect to the focuser) right at the point where the threads started to really tighten up. If it was to far before that I'd either have to come up with a different configuration - or take a chance and tighten it up as much as poss until the right camera rotation is achieved.... but the big danger with that is a cold-welded thread (never much fun to try and undo). Thats why I apply boot polish to my threads to reduce or prevent binding when doing things up fairly tight.

  • Like 1
Link to post
Share on other sites
4 minutes ago, Uranium235 said:

If i didnt know better, but whoever made that adaptor probably got the idea from here...lol.. :D

I built my mod a good 4 or 5 years ago:

 

I like it, especially for it's"built-in" tilter! Great job.

Link to post
Share on other sites

Hi Everyone. Posting some images taken by me through the 130 PDS. Taken from Brtle 3 skies of a small hamlet in the Himalayas called Kausani. All photos were shot without any guiding help hence with limited exposure time. The capture details are mentioned on the photos itself. I am not very hands on with post processing so I simple stack the subs in DSS and later do some post processing in Lightroom only before stamping the details in Picasa.

CR2-TIF- DSS PROCESS+LR PROCESSED+PICASA.jpg

CR2-TIF- DSS+LR PROCESSED+PICASA.jpg

JPEG+AUTOSAVE+LR+PICASSA.jpg

TIF DSS LR PROCESSED.jpg

TIF DSS LR PROCESSED.tif.jpg

TIF+AUTOSAVE+LR+PICASSA.jpg

  • Like 5
Link to post
Share on other sites
10 minutes ago, Pankaj said:

I fail to understand why do I get kind of ''drag'' lines in every image above. Any suggestion on the same ? 

it's called walking noise. You need to dither to get rid of it. It happens when you have a slight drift in one direction and becomes apparent in the stacked image.

Link to post
Share on other sites
3 minutes ago, cuivenion said:

it's called walking noise. You need to dither to get rid of it. It happens when you have a slight drift in one direction and becomes apparent in the stacked image.

Can I do dithering manually, since I do not guide. That means, can I simply slew the mount using the synscan ''just little bit'' between each sub ?

Link to post
Share on other sites
3 minutes ago, cuivenion said:

I think you can do that but it won't be random. Backyard EOS software gives you the option to dither while not guiding with a DSLR, not sure about APT.

Thanks a ton for the suggestion. I did use Backyard EOS couple of time earlier but never know dithering is an option there. But tell me, how would the mount move if imaging canon camera is connected to laptop and using backyard eos? I mean, its just the camera which is connected to backyard eos, not the mount. So how would dithering happen ? Excuse me if my question seems ridiculous...I am new to imaging...

Link to post
Share on other sites
1 hour ago, cuivenion said:

I think you can do that but it won't be random. Backyard EOS software gives you the option to dither while not guiding with a DSLR, not sure about APT.

It doesn't have to be random. Before I started using guiding, I dithered manually. Worked absolutely fine. 

@Pankaj: here's my recipe.

set the slewrate to 1x sidereal. After image 1, press the dec+ button for about as many seconds as your pixelscale (minimum of 1 second). This will give you a dither distance of 15 pixels. Let's call this one dither step. 

Take image 2. Then press ra+ for one dither step. 

Take image 3. After that press dec- for one dither step

Repeat the same after image 4 (dec-) 

Take image 5. Press ra- for one dither step.

Repeat efter image 6 (ra-) 

After images 7, 8, 9 each, dither in dec+

After images 10, 11, 12 each, dither ra+

After images 13, 14, 15, 16 each, dither one step in dec-

After 17, 28, 19, 20 each, one step in ra-

Etc. 

This will give you an outward spiraling dither pattern. Been there, done that, used a cheat sheet, and was never bothered by walking noise again. This will even work if you have a (moderate) backlash in dec. 

If you get tired of doing this manually, and you're not afraid of some diy, here's the automated version

 

Edited by wimvb
  • Like 1
Link to post
Share on other sites
8 hours ago, Pankaj said:

I fail to understand why do I get kind of ''drag'' lines in every image above. Any suggestion on the same ? 

Received wisdom is that it is caused by lack of dither.

Personally I can't see how fixed noise can become streaks when I'm guiding and the image drift over a session is far less than the length of a streak...

My pet theory is that it is associated with very thin cloud and it follows the wind direction.

Link to post
Share on other sites
8 hours ago, wimvb said:

It doesn't have to be random. Before I started using guiding, I dithered manually. Worked absolutely fine. 

@Pankaj: here's my recipe.

set the slewrate to 1x sidereal. After image 1, press the dec+ button for about as many seconds as your pixelscale (minimum of 1 second). This will give you a dither distance of 15 pixels. Let's call this one dither step. 

Take image 2. Then press ra+ for one dither step. 

Take image 3. After that press dec- for one dither step

Repeat the same after image 4 (dec-) 

Take image 5. Press ra- for one dither step.

Repeat efter image 6 (ra-) 

After images 7, 8, 9 each, dither in dec+

After images 10, 11, 12 each, dither ra+

After images 13, 14, 15, 16 each, dither one step in dec-

After 17, 28, 19, 20 each, one step in ra-

Etc. 

This will give you an outward spiraling dither pattern. Been there, done that, used a cheat sheet, and was never bothered by walking noise again. This will even work if you have a (moderate) backlash in dec. 

If you get tired of doing this manually, and you're not afraid of some diy, here's the automated version

 

That's an awesome solution indeed. I will try the manual version in the next imaging session surely. Are you doing any selling for this ditherbox you created ?

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 guydive
      Hey all,
      I'm considering the 250PDS. The main use is visual, and the second is EAA (I currently use a zwo183mm). 
      What I'm hesitant about is the primary focus. since It's mostly for visual, I'm wondering on how much back focus it has compared to the standard Skywatcher 10" dobsonians? with the standard dobsonias with the same optics and focuser you already need an extension tube for most eyepieces...
      Also, there's probably a "bigger" obstruction (bigger shadow on primary)? 
    • By AngHor
      I have a SkyWatcher AZ-EQ5 mount. It’s all working fine, except I have an issue with alignment. This applies whether I’m in EQ or Alt-Az mode.
      I set it up using  one or two star align without problems.
      However if I use the handset to GoTo another object, I usually need to do fine tuning adjustments to centre on the new object. But the mount disregards these adjustments, so if I use the GoTo system to centre on a nearby object, or revisit the original object a second time, it’s still off by the same amount.
      How do I tell the mount that I have centred on the new object and that it should now be aligned with that object ? 
      My iOptron MiniTower has a feature that does exactly this – once set up correctly and aligned, for each new object I go to there is an “ALIGN” option, and if I use this it now knows the correct position. Can I do this with SkyWatcher and Synscan ?
      Thanks. Angelo
    • By Planetarian
      Hi, I've got a Skywatcher Heritage 130p reflector, and if i insert anything less than 10mm eyepiece, the image won't get crisp. I guess it's normal, but as I'm very new to astronomy, I'd like to know what the sharpness depends on exactly. 
      Is that the focal length (how fast the telescope is? ) or the size of the mirror and how much light it gathers? Or both affect it the same way?  
      Are things the same with refractors in this regard? Thanks. 
    • By ThadeusB
      I have for sale my Skywatcher Startravel 120. Objective lens 120mm; Focal length . It is in excellent condition, clean and only very minor marks. Clean optics, no fungus. The focusser is the original one and works smoothly; 1.25" and 2" adaptors. With both caps.
      A very good starter scope, or good as a portable scope.
      Included accessories: red dot finder; 90 degree star diagonal; 10mm & 25mm EPs; mobile phone adaptor. All in as new condition.
      Please don't ask me to split this package.
      Price £140.00 no offers.
      It will be very well packed.
      Payment: paypal or bank transfer
      I can deliver by Hermes; I can get a quotation for this if you wish. Or you can make your own courier arrangement, or collect in person.
      Please PM me if you would like more information.









    • By Quentent
      Hi,
       
      So just today i got my new EQ3 mount and tripod delivered.
      Brought it out, balanced it leveled it etc etc.
      So i polar aligned it,  and selected 2 Star Alignment.
      1st star to align to: Betelgeuse.
      As soon as i hit confirm align the motors kick in but as soon as the mount starts to rotate the motors stop and the hand controller resets itself immediatly and starts initializing all over again.
      I discovered that moving Ra on its own works just fine as does moving Dec on its own but whenever i press for example the left and Up arrows at the same time the mount stops and the hand controller resets.
      Could this just be a problem with power draw? The Synpro box takes 12V DC and is supplied by a 12V DC car outlet type power source. However i changed this to a 3 Pin UK 12V 1A DC & AC plug.
       
      Im hoping the power supply is the issue and not something else.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.