Go Back   IceInSpace > Beginners Start Here > Beginners Talk

Reply
 
Thread Tools Rate Thread
  #1  
Old 14-07-2020, 09:50 PM
Krypt0 (Adri)
Registered User

Krypt0 is offline
 
Join Date: Jun 2020
Location: Australia
Posts: 14
First night with skywatcher EQ6-Pro

I finally got my skywatcher mount today and spend the rest of the afternoon and evening going over the equipment and trying to find a way to attach my DSLR.
I realised that the mount does not come with a way to mount my camera to it, I don’t have an OTA yet. I have ordered an Orion camera mount that fits into the vixen dovetail, I looked for ADM or Losmandy however they look to attach to mount plates which I also don’t have.
I was able to use my current tripod mount plate to fit the vixen dovetail but it’s quite short and not as solid as it probably should be but the camera felt steady enough, not to mention I have no chance to balance it.

After taking the mount outside and set up, I faced the polar scope as south as possible, being that there are city lights exactly south from where I am, I can’t even see Octanis, I spent the next 2 hours trying to guess my way through drift aligning however I haven’t gotten my head around ra and dec vs alt and azimuth and knowing what to adjust to correct what error.

Performing the star alignment was also pretty tedious with the synscan, the star options I was being given were below the horizon so I was spending time going through different stars to align too and then once I did, my 100mm lense was showing me that I was nowhere near the actual star (most likely due to my inability to polar align).

I was then eventually able to get somewhat close to the Carina Nebula and able to take a number of images, I noticed that the nebula was moving up in each image despite tracking it, and even as low as 25 second images showed star trailing going up.

The mount works beautifully, however I realise I have a lot I need to learn about how to correctly polar align in areas with too much light pollution to use the polar scope and also what corrections I make when I adjust the azimuth vs altitude.

-Adri-
Attached Thumbnails
Click for full-size image (AB03287F-E6FE-4B06-B884-5D5B1CE46069.jpeg)
161.4 KB91 views
Reply With Quote
  #2  
Old 14-07-2020, 10:21 PM
raymo
Registered User

raymo is offline
 
Join Date: Sep 2011
Location: margaret river, western australia
Posts: 5,439
Congratulations on your new purchase.
First thing to remember is that it should be aligned on true south, not magnetic south, which can be a difference of many degrees. I mention this
because a 100mm lens should display very little trailing with even a
rudimentary alignment, so I'm guessing that your alignment was quite a way off.
raymo
Reply With Quote
  #3  
Old 14-07-2020, 10:50 PM
Manav's Avatar
Manav (Yugant)
Resident Rigel fanboy

Manav is offline
 
Join Date: May 2009
Location: North Sydney, Australia
Posts: 531
I used "andysshotglass" video a long time ago to understand the concepts of drift alignment. Alas that video no longer exists.

You want to read this tutorial from Dylan https://photographingspace.com/polar-align-phd2/
Good starting points with lots of reading to do.
Reply With Quote
  #4  
Old 14-07-2020, 11:34 PM
RAJAH235's Avatar
RAJAH235
A very 'Senior' member.

RAJAH235 is offline
 
Join Date: Jan 2005
Location: South Coast N.S.W.
Posts: 2,510
Ummm...Apparently...Andy's Shot Glass video is still on his web site...
> http://www.andysshotglass.com/DriftAlignment.html

May help Adri.

ps. If anyone has trouble getting to the site/page...I have the .swf video uploaded
& available for D/L on my mediafire site.

Only ~ 2.7 Meg.

Last edited by RAJAH235; 15-07-2020 at 12:19 AM.
Reply With Quote
  #5  
Old 15-07-2020, 07:59 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 2,490
Here’s how to set your Tripod up to point True South ( it will get you closer than a compass with magnetic declination offset )
Also Synscan Polar Alignment Routine using handcontroller

Finding Celestial True South using Solar noon ( Shadow ) method
Items needed
1 length of 12mm diameter timber dowel or rod with a 2mm deep hacksaw cut 90 degree criss cross on one end
2 x 3m pieces of 1mm diameter cotton builders string or similar
4 house bricks or pavers or weights
1 x straight edge , ruler or aluminium angle about 500 or 600mm long
1 x fine point permanent marker
1 x Stanley or similar 350mm builders bubble level
1 x PC or laptop with Stellarium down loaded or Smart phone

Location
Your observing location ( approx 2m2 ) or where you will set up your telescope mount should be a reasonably flat or level area with a good view of the sun around midday ( a paved, tiled or concrete ground is preferable) At a remote site you will have to clear the ground of rocks and debris to leave a fairly clear flat area

Procedure
Setting up for your solar noon shadow
Erect timber dowel or rod vertically at your telescope mount location and use the 2 strings to anchor the dowel to the ground like tent guy ropes at north , south , east and west. Use bricks , pavers or weights to hold down the strings tight so dowel sits firm upright. Now use a bubble level vertically against the dowel to ensure it is 90 degrees on all 4 sides N,S,E, W, The hacksaw cuts in the top of the dowel make it easy to make fine adjustments
either way

Finding Solar Noon Time

(Using a Planetarium like Stellarium )
Start your PC or laptop in the morning and open Stellarium
Move your planetarium view to the left or right until you reach the north (N) cardinal point and move up until you see the Sun
Click on the Sun and you will see it’s read out data on the top left of the screen
Now open the Time window and move the time forward until you view the Sun bisecting the north meridian line or until read out data on Az/ Alt degrees goes from 359 degrees to 0 degrees
At that very point and time , record the time from the clock ( eg 12.35pm )This time is your Solar noon time which you will use later

(Finding Solar noon on a website )
Most meteorological websites show solar noon times at or near your location

Marking your Celestial True South Line
Go to your location about 15 minutes before the designated solar noon time with your smart phone , ruler or straight edge and permanent fine tip marker
The timber dowel or rod should be casting a 500mm long thin shadow across the ground towards the south
At exactly solar noon time , mark a line on the ground from the centre base or the timber dowel or rod outward along the exact centre of the shadow to at least 500mm out. Use your ruler or straight edge and be as precise as you can.The more precise you are , the closer you will be to true south and eventually polar alignment.
This line represents the True South line and can now be used again and again when you set up your tripod , mount and telescope
I found the above method of finding True South far more accurate than any compass with magnetic declination or phone app etc....


Setting up a HEQ5 ,NEQ6 and EQ6-R Tripod
NB: This procedure is based on having your True South line already marked on the ground from a previous procedure ( length of true south line marked on ground approximately 500mm long or alternatively 2 fixed points marked on the ground 500mm apart)
1/ Open your tripod fully out and extend all 3 legs out by about 100mm then lock them
2/ Place foot of front tripod leg marked “N” directly on True South line and roughly line up the 2 rear tripod legs equally spaced in respect to the True South line
3/ Level the base platform of your tripod by adjusting the legs in or out as required .Check level of the tripod base in both north/south and east/west directions using a good quality builders aluminium bubble float level.Level the base as accurate as you can then lock the tripod leg adjusters nice and tight.
4/ Extend out your True South Line along the ground just past the intersection of the 2 rear tripod legs using a string line, aluminium angle or a straight edge. The feet of both rear tripod legs must be equidistant from the intersection of the extended True South Line. When adjusting make sure you only move the 2 rear tripod legs left or right whilst keeping the front tripod leg “N” stationary or pivoting but not moving off the True South Line
5/ Once the 2 rear tripod legs are equidistant from the true south line , the tripod is now set up level and pointing to Celestial True South
6/ Ensure you take care in setting up the tripod and measuring accurately to the nearest millimetre.This will assist the accuracy of your polar alignment procedure.

Synscan Polar Alignment Routine V3 and V4 Skywatcher EQ Mounts ( used when no view of SCP )

1/ You will be using a 2 Star Alignment to start the process so nominate your 2 Alignment Stars on the same side of the meridian, one of which will be your Polar Alignment Star ( Alignment Stars should be fairly bright stars where possible to ensure they appear in the Synscan hand controllers data base, usually greater than magnitude 2.5 )
(Alignment stars for polar alignment ideally should be located between 35 degrees and 70 degrees in Altitude and no more than 50 degrees in Azimuth from the meridian) Important - Your Polar Alignment Star or 1st Star Alignment Star will be the one closest to the south meridian. To assist with locating and nominating your Alignment Stars use a Star Chart, a Planetarium like Stellarium or Cartes Du Ciel.
2/ Complete a 2 Star Alignment generally in accordance with Syncan 2 Star Alignment procedure. Start with your 1st Alignment Star close to the south meridian ( this will be your Polar Alignment Star as well ) and then 2nd Alignment Star away from south meridian no further than 50 degrees in Azimuth
3/ After completing a 2 Star Alignment press “Menu” then “Alignment” then “Polar Alignment” and then “Enter”
4/ The screen will display “ Select Star”. Scroll through list of stars until you find your previous nominated Polar Alignment Star and press “Enter”
5/ Mount will slew to the selected Polar Alignment Star
6/ Use direction keys on the hand controller to centre the Polar Alignment Star in the telescope eye piece reticle or Computer screen reticle. Once centred press “Enter”
7/ The hand controller screen will now display the polar alignment error ( degrees: minutes: seconds) then press “Enter” to proceed
8/ The mount will now slew to the new Altitude position. Now use the Altitude adjustment bolts only to move the Star to the closest point to the centre of FOV on the reticle eye piece or computer screen reticle. Remember this position and then press “Enter” to show the new polar alignment error ( degrees: minutes: seconds )
9/ Press “Enter” again and mount will slew to the new Azimuth position. Now use the Azimuth bolts only to move the Star to the closest point where the Star was centred in step 8. Press “Enter” to show the new polar alignment error
10/ Press “Enter” again to end the Polar Alignment procedure
11/ Go back to the “Alignment” menu in the hand controller and execute another “2 Star Alignment”. 1st Alignment Star will be your Polar Alignment Star which you should be already centred on from the previous Polar Alignment routine and 2nd Alignment Star is further away from the south meridian.Once the 2 Star Alignment is completed , the polar alignment error will be displayed on the hand controller ( degrees: minutes : seconds )
12/ Repeat the above procedures ( iterations) 2 or more times as required to reduce your polar alignment error below 1 arc second in both Altitude and Azimuth.
Polar Alignment Error displayed on hand controller should show as many zeros as possible
Eg: 1 arc minute error 000 01’ 00” Eg: 20 arc sec error 000 00’ 20”
Try and get below 1 arc minute error in both Altitude and Azimuth if conditions and time permit.
13/ Note: you must perform a 2 Star Alignment before you start with a Polar Alignment routine each time
14/ To improve accuracy of your Star centering and alignments , de focus the star slightly into a small donut shape, this way you can perform more accurate centering operations looking into your reticle eye piece or at your computer screen reticle
15/ The 2 Star Alignment stars you use for Polar Alignment maybe different from 2 Star Alignment stars you use for locating objects ( Goto) as the accuracy of Goto may improve with a wider distance between alignment stars in Azimuth.The 2 Star Alignment stars for Polar Alignment are fairly close to each other near the meridian and only span a small part of the night sky. The Polar Alignment routine obtains better results ( lower error ) when Alignment stars are within 50 degrees apart in Azimuth and closer to the south meridian at between 35 degrees and 70 degrees in Altitude.
16/ With some experience the Synscan Polar Alignment routine can usually be completed with sub arc minute PA error in around 15 to 20 minutes depending on seeing conditions
17/ Note: Star Alignment and Polar Alignment are two different processes
Star Alignment is used to tell the mount exactly its location in the night sky on an object using singular or multiple pointing model algorithms.
Polar Alignment is aligning the central axis of the mount and telescope to the South Celestial Pole using the Altitude and Azimuth adjustments. Depending on the accuracy of Polar Alignment,the celestial object will remain stationary in the FOV for at least a minute or so before any noticeable drift.
However Polar Alignment and Star Alignment do affect each other when adjustments are made. An adjustment of Altitude or Azimuth affects your star alignment accuracy, that’s why you perform a 2 Star Alignment after PA is adjusted.

Hope the above helps

Cheers
Attached Thumbnails
Click for full-size image (424CB2FB-BA17-4148-961A-9A0E14615B45.jpg)
193.2 KB35 views
Click for full-size image (D528C66D-AFF2-473F-A2BD-2D4925EF2AF3.jpg)
205.1 KB30 views
Reply With Quote
  #6  
Old 15-07-2020, 08:33 AM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 2,648
If you can afford one a Polemaster camera is a great tool and time saver. Once you get used to it and learn how the sky around the pole looks (In case your initial setup is far enough off that you can't see Octans on screen) they turn accurate polar alignment in to a 5 minute job. The included software is pretty good but I understand that the likes of Sharpcap (The paid not free version I believe) uses plate solving to take even more guesswork out of it along with the need for the pole even to be visible from your location.
Reply With Quote
  #7  
Old 15-07-2020, 09:15 AM
Manav's Avatar
Manav (Yugant)
Resident Rigel fanboy

Manav is offline
 
Join Date: May 2009
Location: North Sydney, Australia
Posts: 531
Quote:
Originally Posted by RAJAH235 View Post
If anyone has trouble getting to the site/page...I have the .swf video uploaded
& available for D/L on my mediafire site. Only ~ 2.7 Meg.
Thanks Rajah - Can you share the link the video doesn't load in my browser for some reason.


Quote:
Originally Posted by The_bluester View Post
If you can afford one a Polemaster camera is a great tool and time saver.
I would second that!

But if you are tight on cash maybe get an autoguider and guidescope combination cause you will need that at some point and use PHD drift alignment routine.
Reply With Quote
  #8  
Old 15-07-2020, 12:33 PM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 2,648
That as well. it can be less than intuitive trying to drift align with the likes of PHD2 but it is doable. Most people who start out drift aligning and then get a polemaster or similar setup never look back though.

If you get an OTA with more than a couple of hundred mm focal length and you want to get multi minute exposure times, guiding becomes more and more essential and that does give you equipment to drift align with more easily than other methods.
Reply With Quote
  #9  
Old 15-07-2020, 08:59 PM
RAJAH235's Avatar
RAJAH235
A very 'Senior' member.

RAJAH235 is offline
 
Join Date: Jan 2005
Location: South Coast N.S.W.
Posts: 2,510
Manav (Yugant)...wrote...
Quote:
Can you share the link the video doesn't load in my browser for some reason.
Sure can. No probs.

Check your PM's.

Have fun & I hope you get things sorted out.

Regs, L..
Reply With Quote
  #10  
Old 30-07-2020, 01:07 PM
Krypt0 (Adri)
Registered User

Krypt0 is offline
 
Join Date: Jun 2020
Location: Australia
Posts: 14
Firstly,
Apologies for not responding to this earlier, I've had a few commitments take up a lot of my time.
Secondly,
Thank you very much for the detailed comments, it was a lot more detailed advise and information than I was expecting and I appreciate everyone's time taken to write it up.

I will definitely review and practice on polar alignment, my current struggle is clear nights to be able to do it (as I'm sure is a ongoing theme in this field).

My later challenge when I eventually get an OTA, I am interested in an EdgeHD 8" - I have found that there is a challenge of back focal plane due to an image train with a reducer, Celestron OAG and a DSLR (This would be my initial set up as I don't know how I'm going to go with 2032mm FL and the camera body is too big for a hyperstar with an 8" mirror).

I hope some others around Aussie are having better luck with clear nights.

-Adri-
Reply With Quote
  #11  
Old 04-08-2020, 12:51 PM
Krypt0 (Adri)
Registered User

Krypt0 is offline
 
Join Date: Jun 2020
Location: Australia
Posts: 14
I had another opportunity last weekend to practice this, had a clear night all night and was outside with my mount from 5pm till after midnight.
I started out looking at magnetic south and attempting to eyeball it as best I can, I then moved it 11deg East to attempt to get a closer alignment to SCP (I was obviously still off, but fairly close). I used the latitude of my current location to guess what Alt I needed to set my mount too, again eyeballing it on the mount measurements (close but not quite) - Thank you from everyone on the tips and detailed explanations to help my understanding.

I attempted to use sharpcap however when trying to polar align it would keep crashing, I gave up with that application.
I also recently purchased Astrophotography tool which I love, it has a tool for focus assisting as well as ability to control DSLR camera Lenses which I found fantastic for fine focusing (it has 3 levels of speeds for focusing).

Using APT I can use my camera live view to see what I'm looking at, my current south viewing is so light polluted with orange industrial lights that I cant see any stars unless I take an exposure. I was able to take 5 minute exposures at 500mm f6.7 to get an idea on star arch to identify where SCP was. This took a bit of time, but I was able to physically see where I needed to be aiming at, APT had crosshairs that helped me align the centre of the sensor to the SCP (also with magnification tools). I adjusted the Alt and Az until I was aiming at my best guess on what it was.

I was pretty happy with the outcome as I was able to track the Carina at 500mm f6.7 unguided for about 90seconds, still had some star trailing but otherwise wasn't bad.

My obvious issue further from this was the fact that using the camera lens connected via a tripod vixen dovetail screw (from a normal camera tripod and is about 5cm long) is that this means the camera isn't at the mount centre axis meaning I'm polar aligned above the centre axis (and also possibly not straight in RA at the camera), as I started taking photos of objects further away from SCP I found trailing got worse.

Thanks to Manav (Yugant) on the night for giving me advice.

Today I received a QHY Polemaster which I'm really excited to use (pictured below), it was a bit costly, but in my current situation its the best option to ensure I have accurate polar alignment which I really need until I can auto-guide.

Thanks for the help, hopefully I'll be able to progress and improve and show that I'm progressing with some images.

-Adri-
Attached Thumbnails
Click for full-size image (IMG_3270.jpeg)
140.4 KB14 views
Click for full-size image (IMG_3271.jpg)
129.8 KB14 views
Reply With Quote
  #12  
Old 05-08-2020, 11:36 AM
xelasnave's Avatar
xelasnave
Gravity does not Suck

xelasnave is offline
 
Join Date: Mar 2005
Location: Tabulam
Posts: 13,631
When you get your image on screen via Pole master you may still have trouble finding Sig.O ..I often do...it can be outta screen and I have even had it on screen but could not recognise it..for whatever reason..so try this...with the mount switched off of course just take a long exposure via Sharpcap using Pole master camera and you will be able to hone in using the arcs of the star trails...those arcs have a center and that center is...can you guess...CSP...When I did not have Pole master I would find CSP this way having earlier in day time making sure that the polar scope and the main scope were pointing at the same spot...Anyways I hope it helps as certainly in my case it did when Sig.O was off screen...make sure gain is as low as possible and go for about five minutes.
Also ones mount should track rather well without auto guide before you use auto guide...you may care to take a test 3xposure of say 10 minutes, minimum gain so you can see what is going on..you can probably notice hiccups due to periodic error but must likely that even though your mount was perfectly balanced that it needs weight to one side..usually to the East but doing such a long exposure will tell you something I am sure..you never know you may find after 10 minutes you have round stars..my old eq6 ( tuned beyond belief) managed 11 minutes that was acceptable..spec trained perfect alignment balance and luck.
Good luck and remember we all have problems and so often help is almost instantaneous when you post your problem.
Alex
Reply With Quote
  #13  
Old 06-08-2020, 04:28 PM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 2,648
Now that is an idea I had not thought of Alex, that would sometimes come in handy at star parties where it can be easy to waste a lot of time the on first night chasing the pole around to get Octans on screen as you have set up somewhere unfamiliar. You do get used to the asterisms around the pole after a while but if you set up somewhere really unfamiliar you can still chase your tail.
Reply With Quote
  #14  
Old 16-09-2020, 02:05 PM
AdamJL
Registered User

AdamJL is offline
 
Join Date: Sep 2010
Posts: 60
Quote:
Originally Posted by The_bluester View Post
If you can afford one a Polemaster camera is a great tool and time saver.
I'm an absolute novice at this. I'm greener than green, but can confirm, I managed to polar align my astrotrac last night using a Polemaster, and it was quick! I was so impressed.

My initial run (20mins) didn't go well because I don't know what the stars should look like in that part of the sky.

So I ran Stellarium, added the Polemaster to the camera/telescope setup and then aimed the program at Sigma Octantis. This gave me a pattern I could search for in the Polemaster, which only took 30 seconds to find once I had a working pattern to compare against. The polar aligning was done a few minutes after I found the star. Really easy.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 06:07 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Lunatico Astronomical
Advertisement
Bintel
Advertisement
Astromechanics
Advertisement
Astronomy and Electronics Centre
Advertisement