Jump to content


Fitting a Polar Alignment scope

Recommended Posts

Greetings folks:


When I bought my refractor the other day, (Skywatcher 90) I bought a polar alignment scope to use with it.

Problem is, I've never used a polar alignment scope before and I can't see where the scope fits onto the mounting.

There are no instructions with the Polar-scope to enlighten me.  I've looked online, but whilst I can find plenty of info, on adjusting it, none of the texts tell me where on the mounting to put the Alignment scope.  (Basic info missing as it seems they assume I should know this. ) I had an idea it could go in the finder mounting, as long as it's  parallel with the Polar Axis, but I am unsure. And having to fit and remove the finder every time I set-up seems a bit of a faff!

I don't want to appear stupid, but I am really struggling here, through lack of info. So could someone help me please?

If I can't solve this, I will have to go back to the old method of taking sightings and then going back 12 hours later to adjust..

Takes ages! Qwwwwcher!

Thanks in anticipation


John     280.gif

Link to comment
Share on other sites

Which mount is your Skywatcher 90 on John ?

The smaller EQ2 mounts don't have the facility for a pole finder scope as I recall. In the EQ3-2 and EQ5 mounts the polar scope is fitted inside the right ascension axis. I'm assuming that we are talking about a polar finder and not the regular finder that is mounted on the scope tube.

  • Like 1
Link to comment
Share on other sites

Thanks Mark. I just can't see anywhere on the mounting that a Polar scope would fit. So maybe I should have read the literature properly.

I thought I had the right mounting for the polar-scope, but it seems I don't.  I'm just going to have the job of doing it by eye. Close enough for a hand operated mounting!  Either that or lock my mounting as an altazimuth, and do it all by aim and eye! Lol!


It will do me until I graduate to a GOTO set-up!  (Saw a nice 6" GOTO refractor for less than £2,000 as it happens. )


I am on the EQ1 mounting I think, but much smaller than  I thought it would be.


Anyhow, thank you gents. I am obliged.


John  280.gif

  • Like 1
Link to comment
Share on other sites

I've posted pictures below of the EQ1 (top) and EQ2 (bottom) mounts to help you identify yours. The EQ1 and 2 don't have the provision to fit a polar alignment scope.




Edited by John
Link to comment
Share on other sites



I wonder if by tool clips, you mean the  'Terry-Clips', those sprung clips that grip around tool handles and the like. Strange, because I have quite a few in my workshop, and I did wonder if they might do the trick.  I'll have a think about it, and see what I come up with.


Thank you.


The mounting is n EQ 2 btw.

Link to comment
Share on other sites

As long as the latitude scale on the mount is set to your latitude, pointing the right ascension axis towards Polaris should enable the tracking to be accurate enough for most visual observing. It's the imagers who need much more accurate polar alignment.


  • Like 1
Link to comment
Share on other sites

12 hours ago, John said:

As long as the latitude scale on the mount is set to your latitude, pointing the right ascension axis towards Polaris should enable the tracking to be accurate enough for most visual observing. It's the imagers who need much more accurate polar alignment.


Thank you John.


I rather thought that might be the case. Which makes my Polar-Alignment scope redundant; because when I decide I can look at imaging, I shall probably be using a GOTO set-up, and for that I would align my scope in the time-honoured way as described in ATM!  Wasted a few quid on the Polar-scope then! :hmh:

Link to comment
Share on other sites

On 01/12/2016 at 15:07, John said:

Which mount is your Skywatcher 90 on John ?

The smaller EQ2 mounts don't have the facility for a pole finder scope as I recall. In the EQ3-2 and EQ5 mounts the polar scope is fitted inside the right ascension axis. I'm assuming that we are talking about a polar finder and not the regular finder that is mounted on the scope tube.

Hi John.


My mount appears to be the EQ2, and doesn't have the facility to mount a Polar Scope... (Neither does the EQ1 it seems!)

I'll be doing it all by eye, once the weather clears a little!


Thank you.


John   280.gif

Link to comment
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 JimAnderson
      Hi All - I'm fortunate to have a EQ6R Pro that has been in residence for about a year (unfortunately predominately hidden in garage due to weather and forest fire conditions for most of the year).  The few times I've had it out, I've failed to get a proper Polar Alignment.  I've used all the tools Sharp Cap, PoleMaster, Plate Solving and so on.
      My main issue has been once I'm within a couple of degree's I can get it to position no better.  Fine adjustments on both RA and DEC give cause to jump around.  I've watch every video/help show and finally have to admit defeat (hopefully short lived).  
      The EQ6R Pro has the same issues the EQ6 has (with northern latitudes).  RA adjustments are just as horrendous no matter how sensitive I try to be.  
      The EQ6 had some tools created for it that one could purchase (RAIL Kit) that seemed to solve one of my issues (unfortunately not available for the Pro).  
      My question is:  Has anyone else experienced this and if so how have you addressed it.  I'm at that place where I'm thinking on replacing this mount if I can't resolve it and the next step is quite more expensive.   
      Vernon, BC
    • By Stefan87
      Hi guys I have a few questions 
      I've recently upgraded to an ASI533mc pro from a DSLR. As I am living in the southern hemisphere and in bortle 6 light pollution, I don't have site of Sigma octanis to get a rough initial polar alignment and previously found that using the reticle feature on my DSLR live view with the synscan polar alignment routine, I could get quite accurate polar alignment in 5-10 minutes (180second unguided subs with around 80% keepers, I don't trust the estimates but under 2 arcminutes generally) My initial setup is usually 3 or 4 degrees out in azimuth.
      I had a go with phd2 PA last night without much luck, I'm assuming because my initial setup was more than a couple of degrees out. I'm happy to just use the synscan routine as I can complete it quickly enough and achieve a good enough alignment, especially now that I'm guiding, and it would seem I would have to run a few iterations of it anyway to get my initial setup close to simulate you lucky northerners with your bright polaris in the polar scope. So my question is, what is a decent piece of software with reticle live view to use with my Asi533mc pro? I currently have NINA, ASI studio and PHD2 installed and I couldn't figure out how to superimpose a reticle last night.
      Also, Sharpcap pro seems to be the most commonly recommended software for polar alignment. However I am using an SCT telescope and a smaller sensor camera so my field of view doesn't meet the requirements stated by sharpcap. Has anybody tried using Sharpcap pro PA at 1500mm and 945mm (f6.3 reducer) with any success? 
      Besides drift alignment, which would take longer than the synscan routine for me, are there any other pieces of software that I should try that won't cost an arm and a leg?
      I'm running an HEQ 5 with a Celestron 6se using an Asi533mc pro imaging cam with an ASI290mm mini on a ZWO OAG for guiding.
      I'm open to suggestions for other software to use for imaging, I only installed NINA because the functionality and price point is amazing, and it gets rave reviews.
      Thanks in advance wonderful people!
    • By Albastars
      No questions but thought my experience with PA using Sharpcap and a Canon 800D might be of help to some.
      Although I thought I was nailing Polar Alignment with a polar scope on my Fornax Lightrack, I could not get longer subs than 150secs.  I considered buying a Polemaster but I thought was a bit pricey, so looked at a small guide scope and a webcam solution with Sharpcap which was a good bit cheaper.  
      Researching Sharpcap and DSLRs, I read that PA might be possible with my WO ZS73 (430mm) main scope.  I needed to install the ASCOM platform and then the DSLR Camera Setup for Ascom and, of course, Sharpcap.  Sharpcap recognised my 800D camera and I completed an "Excellent" PA within minutes.  On the first night I managed 180sec subs and experimented with 240sec - all nice round stars.  How far can I go?  I had done a manual PA first which was a fair bit off from the Sharpcap PA, so not as nailed on as I thought!
      I'd rather not be using a laptop but I can't argue against the results.
      I hope that might be useful for some.
    • By benzomobile
      It is long time I wondered whether the mount polar scope could be used in a less tiring, but more effective way to achieve a convenient, very quick and fairly precise polar alignment (till better as 1 arcminute), than could be achieved usually, and without having to buy rather expensive devices made for this purpose.
      The solution I found – easily achievable and doable for the most of Astro DIYers - is to mount a small video camera attached to the polar scope eyepiece. This will allow us to achieve an excellent alignment to the celestial pole.     
      I invented the acronym VAPA (Video Assisted Polar Alignment) to define my mount stationing method.                                                                                                                        
                                     NCP on January,  2018                                                                                                                                                                               NCP on May,  2021  (Stellarium)
      Theoretical premises

      In addition to the Polaris, there are two stars of mag 6.5 just around the North Pole celestial field, in Ursa Minor constellation.
      They are λ (lambda) and HIP 7283 (double star)
      As you can see the position of two stars is very interesting, in fact their RA position differs by a value very close to 135°.  In addition, it is possible to see in the same field two other fainter stars whose positions are very peculiar too.
      If you draw a line from each tiny star to meet the NCP, you will see that these two lines define a right angle having its vertex at the NCP. (see pics below)


      I made this modification on my standard HEQ5 (old black 'Heavy Duty' one), but the same arrangement can be applied to any other mount that has a polar scope with removable eyepiece and sliding ring with glass reticle.
      Considering that the HEQ5 has a very small polar scope (its objective lens has a diameter of about 14 mm), the system will work even better on other mount models, equipped with polar scopes of much larger aperture.
      Polar camera construction

      - 1 IMX 225 (or IMX322) module with 6mm lens, equipped with Video out, OSD and power supply cables (from Aliexpress)
      - 1 OSD menu pcb (optional)
      - 1 small plastic box
      - 1 film plastic can (135)
      - 1 rca panel connector
      - 1 coaxial power connector (3.5 mm)
      - coaxial cable (conductor plus shield)
      - some 2mm screws, spacers and bolts
      - 1 epoxy resin

      The small polar camera looks as you can see from the pictures below

      Making the Reticle
      Materials (see photos below):
      an A4 paper sheet on which we have printed a circle graduated in degrees
      0.030 mm (30 micron) fishing wire
      3 small truncated-cone springs
      scotch tape
      cyanoacrilate adhesive
      Construction technique
      - Unscrew the eyepiece and remove the three adjusting grubs of the reticle ring.
      - Remove the reticle ring and unscrew the threaded flange which holds the glass reticle in place
      - Remove the glass and reposition the flange.
      - Attach the ring to the centre of the graduated circle with a very small amount of vinyl glue (flange down)
      - Stretch (gently!) a piece of wire and fix its ends tightly (with small pieces of scotch tape) at 0° and 180°, in order to precisely bisect the circle and the ring.
      - Do the same thing with another piece of wire, stretching it between 45° and 225°.
      - Make sure that the two wires cross in the centre of the ring accurately (although extreme precision is not required). See photo below
      - Using a very small amount of cyanocrilate, solder the four wire ends on the ring, just where they get each other into contact.
      - Allow to dry.
      At the end of this procedure we will have created a wire reticle delimiting two couples of angles, 45° and 135° wide respectively.
      - From the inside of the eyepiece barrel, do insert the tiny truncated cone springs into the three grub threads, the smaller base pointing outwards from the barrel.
      - Replace the ring in its place with the reticle towards the polar scope objective.
      - Screw in the grubs until the ring is secured, but do not tighten them (see photos below)
      Calibrating the reticle
      - Adjust the eyepiece so that the reticle can get focused (use glasses if you wear them to see well at a distance!) then fix it with a drop of silicone just on the visible part of eyepiece thread.
      - Unscrew the locking ring of the polar scope tube and adjust the distance between the reticle and the objective so that you can see a distant object (a bright star, or a detail on the roof of a building) well focused together with the reticle.
      - Fix the tube ring.
      If there are one or more grubs around the locking ring, they must be screwed in tightly.
      Displaying the area of the celestial pole
      - 1 7" 1024x600 HDMI screen
      - 1 RCA -> HDMI video converter
      - Connection cables
      Insert the camera nose (135 film barrel) on the polar scope eyepiece and aim the polar axis at the sky area just around the Polaris
      If all the connections are correct, we will see the Polaris on the screen (if we don't see it right away, we can easily find it by searching near around) together with a good number of other stars.
      In a Bortle 6-7 sky (as it happens in many suburban areas) we can easily find out stars up to 10th magnitude (provided the atmosphere is transparent enough).  The field of view will be about 3°x 5° (see photo).
      Camera configuration by OSD menu
      The camera menu will get elicitaded pressing central button and you can do your choices pushing up, down, left and right buttons
      Fill in the follow parameter:
      Push central button to enter Main menu. Push down button to enter submenus and right or Left one to select voice:
      - Lens → Manual
      - Exposure → Shutter → 15-20
      → AGC → 6
      → Brightness 1
      → Return → Main menu
      - Day/night → B / W → Return → Main menu
      - NR → High → Return → Main menu
      - Special → Defect
      - live DPC → On → AGC level 50-60
      → Level 0
      → Return
      - White DPC → On → -level 0
      → AGC 5-7
      → Sense-Up 30
      → Start → Follow indications
      → Return → Return → Return → Save & end.
      Leave all other voices at default position
      Notice: DPC is the dead (hot) pixel control
      Video assisted reticle alignment
      This is done by grubs provided just for this task.
      Truncated cone springs make the operation very easy and confortable.   As you find Polaris in your screen, put it at the center of crosshair.
      Rotating the polar axis, you can see the star will move from its initial position, so, you should screw the three grubs in and out until Polaris will stay ever at the crosshair center in any direction you can rotate the polar axis.
      Grubs should be secured, but they should no be tighted.
      Video assisted Polar alignment procedure
      By adjustement of Alt-Az knobs, you should:
      1) put the reticle center on the right angle vertex (NCP position on current date) made by tracing two virtual lines, starting from the two faintest stars, as indicated in previous image.
      If you are very accurate, you can reach the NCP within a maximum error of 1 arcminute.
      2) rotate the polar axis till the two brighter stars get both hidden by two crossed hairs of reticle (the pair one crossing until each other at 135°). If it doesn’t happen, it mean your mount is too
      much far from NCP, so you must repeat the step 1).
      Note: performing step 2) doesn’t be mandatory, but it will enhance alignment precision.
      Photos above are recorded by SharpCap (stacking), thus they don’t display the correct image aspect ratio (12:7) as you can see visually, watching your ‘on the mount’ lcd screen.
      In fact, SharpCap do not change aspect ratio (720x576 lines for PAL system) of native analog image captured by a video grabber (Easy Cap or similia).
      That is why the above image appears a bit higher as it should be. Obviously, you can align your mount with your notebook screen rather as with lcd display on the mount.
      To do that, you must use a video grabber device and OBS Studio to record movies or snap shot.
      OBS Studio is a big free software allowing make all necessary image adjustement to reach the correct aspect ratio.
      Below I posted an OBS Studio clip (sorry for the big amount of dinamic noise due the sudden ‘défaillance’ of my chinese video grabber … )

      2021-05-07 22-41-02.mp4 Beppe
    • By benzomobile
      Hello Everyone
      I will explain  my experience about that as  soon as possible ... 
  • 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.