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Old 01-03-2021, 07:51 PM
DamienB (Damien)
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Skywatcher EQ35-Pro Help

Hey all,


Apologies if this is a long post, but I have been struggling for the last month with this and having been a forum user over the years, I recognise how vital it is to have a detailed post.



I am new to astrophotography and have spent the last 9 months researching what I wanted to buy within my budget of $5000. The goal being to take photos of nebulae like Orion, horsehead, flame, pinwheel etc. I finally took the plunge and purchased the following:

Nikon D750 DSLR (and some kit lenses to help me learn the camera, remote controls etc).
Skywatcher Evostar 80ed
Skywatcher EQM-35 Pro GoTo Mount


Here's where I need some assistance. I have scoured the internet to find someone who has actually setup from start to finish the EQM in the southern hemisphere. But I have had no luck and all the videos/tutorials all seem to be from the northern hemisphere.


Here is what I have encountered so far:

1. Aligned the leg marked N towards south so that way the polar alignment scope as part of the mount facing the correct way.


2. I am in Adelaide (Seaford Rise), I set my latitude as best I can on the scale for 35.


3. Looking through the polar view finder I can see that Octans is marked as the top right quadrant of the view. But according to the Stellarium app, it currently lies at the bottom in the real world. So if I am to rotate the mount so it lines up, it puts it square upside down with counter weight pointing right up. Not exactly usable with a telescope on it....


3a. Carrying on without a scope, I then try to do an alignment, lets pick 1 star and Canopus. I can see that nearly above me if the app is correct Hit go (once synscan is setup with correct time, date and long/latitude). It then zooms around and basically points sideways to the fence. Nowhere near up.


3b. Reset it so the weight is at what I'd call "home" aka pointing down. Octans in the upper right spot marking and attempt to do the star alignment again. This time it zooms about and is somewhat in the right area. Cool, getting somewhere and it's dark out. I did have Dylan O'Donnell from youtube respond to a tweet when I complained I couldn't use the arrows to adjust it and he said to change the rate. So did that, I align the scope with the Canopus star using a green laser pointer through the view finder and click ok. Alignment successful.


3c. I do notice that if I hold the Synscan, sometimes it will reboot itself and go through initialising. I am suspecting the cable link is dodgy. It seems to be a standard RJ45 so might just make a new one.



4. Right time to do some imaging. With alignment successful () I decided to select M42 - Orion. It's the beginners choice right? Slew to target..... Nope does some zooming about, ends up pointing to the ground. So i decided to loosen the tightening/locking bolts and manually move it to where it should be. Afterall it will still "think" it's locked into it right? So it should be tracking at the rate of the earth.....


5. With camera mounted, focus sorted I go to take some photos. Except I cannot take photos more than 10 seconds in duration, otherwise I get star trails. If I take 10-20 shots, I notice the star/nebulae I am tracking has drifted well out of center of view. It almost seems like it is tracking in the reverse direction, down, instead of up, and at the wrong speed. Adjusting the rate from 3 to 7 makes no difference. So I have to adjust the mount again. It becomes tedious and essentially ruins any photos I put into DeepSkyStacker.

With the DSLR camera, no-one explicitly explains that with the Nikon, if you attach it to a telescope you need to setup in the menu a Non-CPU Lens and give it the F of the "lens" otherwise it won't take any photos. According to Oz Scopes site where I purchased this gear from, The Evostar has an F of 7.5. Closest I could choose in the Nikon menu was 8.

I see a number of youtubers taking amazing photos and they all have long exposure times. 2 minutes, 5 minutes etc.


Ideally my goal is to be able set the mount up before the sun goes down. Then do an alignment, attach scope, fine tune. Once it's dark, literally key in the nebulae I wish to shoot and it actually lock on it. I am fine with spending 30 mins or so getting it right. What I am tiring of is spending hours stuffing about and then at midnight packing it in.



It'd be nice to set the remote control to take the multiple subs. Then I can enjoy being out in the night, delving into the universe. Currently I have managed to get one decent stack of Orion. The rest I have perhaps 10 nights of failures.

Any assistance would be greatly appreciated.

Damien
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Old 01-03-2021, 08:21 PM
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Rerouter (Ryan)
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I cannot help much with the synscan side of things, but I can atleast help with the trailing, this is because your not dialed in exactly on the south celestial pole, the better that alignment is, the longer you can image before you get trailing stars

With your scope when the controller is behaving itself it has some routines to make polar alignment much simpler, until then I can atleast explain the manual process to get yourself aligned so you can get some longer images

How I went about finding it for my home was set the tripod up in the day where I image, but pointing about 30 degrees away from south so the leg cleared when I drew a line later on (without the scope or mount, no need for that to get hot)

Leveled it out as best I could with a bubble level, used a weight and a string off the mount screw to draw a vertical shadow under the center of the scope

Used an online calculator to work out the time of solar noon, when solar noon came, used a ruler to mark the line, extending it out to where the south leg should sit,

Measured off a point on that line to get the other 2 legs set as close to the same as possible,

Rechecked I was level, then marked off around each leg with a permernant marker so next time I just know exactly where south is for when I set up

When your imaging, make sure your tripod is level, and if you found south like I did, you can center out the 2 fine rotation screws, in the worst case when your controller is working again it lets you start from a much better polar alignment than you would usually have (phones and compasses turn out to not be as accurate as one would hope when near a chunk of metal)

Another recommendation after doing this would be align you camera with the RA / DEC axis, this way you can do a fine trim of where any other small offset is, e.g. you see the stars trail exactly horizontal, you know its an issue with your azimuth fine tuning, as for what way to adjust, I recommend taking a 1 minute exposure, and about 10 seconds in, hold the lense cover over for a few seconds, this gap will let you know which direction its drifting to trim it back the other way.

For context, I am waiting for a guide cam as I can let PHD2 work all this mess out for me, but until then, I have had to get creative.
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Old 01-03-2021, 10:27 PM
Startrek (Martin)
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Damien
I’m sure the EQ35 mount is similar to the HEQ5 mount just a lesser payload
Here’s some set up procedures and how to polar align using the Synscan handcontroller ( you don’t need to have a view of the South celestial pole or use polar scope )
Hope the attached helps in some way
Good luck !!
Martin
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Old 01-03-2021, 10:30 PM
Startrek (Martin)
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Quote:
Originally Posted by Startrek View Post
Damien
I’m sure the EQ35 mount is similar to the HEQ5 mount just a lesser payload
Here’s some set up procedures and how to polar align using the Synscan handcontroller ( you don’t need to have a view of the South celestial pole or use polar scope )
Hope the attached helps in some way
Good luck !!
Martin
Forgot to attach one procedure
Tripod set up and alignment
I’ve maxed the download limit so I’ll send another post
Cheers
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Old 01-03-2021, 10:32 PM
Startrek (Martin)
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Can’t send any more attachments on this post
I’ve exceeded the limit
Sorry
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Old 01-03-2021, 10:39 PM
Startrek (Martin)
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Here you go
I’ve copied and pasted from notes

Setting up a Tripod to Align to True Celestial South

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.

Cheers
Martin
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Old 01-03-2021, 11:15 PM
kens (Ken)
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@Damien I'm afraid that at a focal length of 600mm imaging deep sky objects you are very soon going to have to autoguide.
The D750 has 6um pixels. At 600mm focal length that is 2 arcseconds per pixel. And your mount will typically have a periodic error of 60 arcseconds peak to peak. It has a worm period of around 10 minutes (638 seconds to be more precise). So every 5 minutes or so the mount drifts around 30 pixels in Right Ascension then back the other way for another 5 minutes.
Until you start autoguiding you would do better imaging at 200mm focal length or less and keep your exposures short.
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Old 02-03-2021, 01:27 PM
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Hi Damien. When you entered your latitude into the Synscan, did you remember the minus sign? I.e. -35 degrees, not 35 degrees. It sounds like the mount thinks it is in the Northern hemisphere with you saying ‘it’s almost like it’s tracking the wrong way’ and ‘it pointed down instead of up’.

Cheers,
Andrew
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Old 02-03-2021, 06:02 PM
DamienB (Damien)
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Quote:
Damien
I’m sure the EQ35 mount is similar to the HEQ5 mount just a lesser payload
Here’s some set up procedures and how to polar align using the Synscan handcontroller ( you don’t need to have a view of the South celestial pole or use polar scope )
Hope the attached helps in some way
Good luck !!
Martin



Thanks I will give this a go!
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Old 02-03-2021, 06:05 PM
DamienB (Damien)
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Quote:
Originally Posted by kens View Post
@Damien I'm afraid that at a focal length of 600mm imaging deep sky objects you are very soon going to have to autoguide.
The D750 has 6um pixels. At 600mm focal length that is 2 arcseconds per pixel. And your mount will typically have a periodic error of 60 arcseconds peak to peak. It has a worm period of around 10 minutes (638 seconds to be more precise). So every 5 minutes or so the mount drifts around 30 pixels in Right Ascension then back the other way for another 5 minutes.
Until you start autoguiding you would do better imaging at 200mm focal length or less and keep your exposures short.

I plan to get an autoguider, but shouldn't this mount be really doing that anyway? Tracking along with the earths rotation....

Quote:
Hi Damien. When you entered your latitude into the Synscan, did you remember the minus sign? I.e. -35 degrees, not 35 degrees. It sounds like the mount thinks it is in the Northern hemisphere with you saying ‘it’s almost like it’s tracking the wrong way’ and ‘it pointed down instead of up’.

Cheers,
Andrew
Now you have me doubting if i have the minus sign in there. Jeez i REALLY hope it's that simple.
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Old 03-03-2021, 08:14 PM
DamienB (Damien)
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So i looked at the longitude and latitude settings and yes, no minus, however you cant put a minus in. I read that it's not co-ordinates as such, but the degrees and minutes. So i looked this up and my numbers are correct. Will get to trying the other stuff out on the weekend!
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Old 03-03-2021, 09:38 PM
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middy
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It has been many years since I used the Synscan hand controller on my mount, but there will be some way of specifying that you are in the Southern Hemisphere. I still think that is the problem.
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Old 04-03-2021, 07:05 AM
Startrek (Martin)
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Quote:
Originally Posted by middy View Post
It has been many years since I used the Synscan hand controller on my mount, but there will be some way of specifying that you are in the Southern Hemisphere. I still think that is the problem.
To ensure your mount is operating in the correct hemisphere ( Southern ) you have to set “Time Zone” in Set up
For example in Sydney Eastern standard time is +10 and for Daylight Saving will be +11

Also ensure your location info is correct for Latitude and Longitude and your date and time are correct , remember the Synscan shows Month / Day / Year in that order ( US Method of Displaying date )

Refer Synscan manual pages 8 and 9

Cheers
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Old 04-03-2021, 10:15 AM
AdamJL
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Quote:
Originally Posted by Startrek View Post
To ensure your mount is operating in the correct hemisphere ( Southern ) you have to set “Time Zone” in Set up
You also need to put S in for South under Set Latitude
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Old 04-03-2021, 02:57 PM
DamienB (Damien)
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You also need to put S in for South under Set Latitude

Yes done all that.
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Old 04-03-2021, 03:17 PM
Startrek (Martin)
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Originally Posted by AdamJL View Post
You also need to put S in for South under Set Latitude
Time zone is the critical setting in conjunction with your local latitude to determine your hemisphere
And yes all latitudes in Australia are South or S
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Old 05-03-2021, 04:25 PM
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NorthernLight (Max)
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I appreciate that you might not be on a spending spree, but I had issues setting up in the backyard too and got there eventually. But if you really want to be in business in minutes, do this:

Get a polemaster
Get a keyspan USB to serial adapter
Get a EQDIR adapter
Get Ascom and Astro Tortilla (both free)
Get Stellarium and Stellarium scope plug in (free)
Get backyard Nikon
Set up gear and balance
Wait to darkness
Use polemaster to align mount
Use Astrotortilla via BackyardNikon to platesolve
Use Stellarium to dial in your object of interest
Put hand controller in safe place until you sell mount
Enjoy <5min pole alignment and spot on (deadcenter) pointing accuracy of GOTO

It will set you back some money but the most expensive kit is the polemaster. You will never look back.

Again, it all can be done without the things listed and it’s fun to learn and grow through it. But time is of the essence and frustration is not making this hobby more fun with so few nights to spend on all the expensive gear we acquire.

Just my 2cents

Edit: initially post was missing the EQDIR adapter, which is crucial for the serial port conversion

Last edited by NorthernLight; 06-03-2021 at 11:39 AM.
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Old 05-03-2021, 11:20 PM
DamienB (Damien)
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Quote:
Get a polemaster

Is this what you mean?


https://www.aliexpress.com/item/3288...archweb201603_


https://www.qhyccd.com/index.php?m=c...36&id=32&cut=3
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Old 06-03-2021, 11:23 AM
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Yes, that’s the one. It comes with adapters to mount in the opening where the pole scope inside the mount head has its aperture. The adapter I got works in both my CG4 and the NEQ6 as it’s the same bore diameter. The EQ35 PRO looks like a rebadged Celestron CG4 with added motors and encoders for GOTO. So I hazard a guess and say it would work with the same mount adapter. They are all Synta mounts after all. But it’s worth double checking. You have to chose the adapter for your mount at time of purchase. Mine also came with a free adapter that mounts for the majority of star trackers, like the iOptron Skyguider.
I used to kneel behind my NEQ6 mount in the cold damp grass peeping through the pole scope trying to locate Octans, which had to be done after nightfall but prior to mounting the scope and counterweights etc. Now I just need to wait until it’s dark enough for the polemaster to “see” the constellation and sensitivity/gain on the camera is easily pushed up whereas eyes need dark adaption and a reasonably dark sky with enough contrast to spot octans. Since it’s all on the laptop, the job can be done sitting on chair next to the mount. The first time I used it, it took me a little while to recognise Octans on screen. But once I had found it, I found it every time in a very short time. Granted, the better your initial altitude and true south orientation, the quicker it shows up on screen. But the field of view angle provided by the polemaster is reasonably wide, so scanning with the mount head from left to right (azimuth) will bring it up quickly. Plus, once you aligned your mount with polemaster in your backyard, the altitude will be spot on for next time (in your backyard), so you really only have to point the thing broadly in the direction of the SCP, which every phone app will show with enough accuracy to ensure the centre pin on the mount’s tripod faces the pole close enough that when you swivel the mount head left and right, the pole will show up on your laptop screen (i.e. not outside the azimuth rotation limit).
NOTE: if you have no clear view of the SCP, the polemaster will be no good to you as it relies on a visual confirmation procedure where you need to identify sigma octans and centre it with an overlay displayed on screen.
I like astrophotography and guiding is a big deal. I can honestly say that my guide graph shows subarcsecond guiding on many nights when aligned with the polemaster and i spend some time setting up the tripod properly. I mainly image at 600mm with an APS-C Sensor, unguided, I can go up to 2min. exposures and get images without unpleasant star shapes (sure, if you pixel peep, then you’ll see some but not when printed on a postcard).
In combination with the software mentioned, and leaving most of the equipment pre-assembled, I am setup in 30min. and that means mount aligned, target centred (even if it’s not visible in the viewfinder), guiding procedure complete and guiding stable, exposures dialed in for auto capture with dithering and remote controlling the whole shebang from my iPad via TeamViewer.

Last edited by NorthernLight; 06-03-2021 at 05:14 PM.
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Old 15-03-2021, 07:17 AM
DamienB (Damien)
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Quote:
Originally Posted by NorthernLight View Post
NOTE: if you have no clear view of the SCP, the polemaster will be no good to you as it relies on a visual confirmation procedure where you need to identify sigma octans and centre it with an overlay displayed on screen.
I like astrophotography and guiding is a big deal. I can honestly say that my guide graph shows subarcsecond guiding on many nights when aligned with the polemaster and i spend some time setting up the tripod properly. I mainly image at 600mm with an APS-C Sensor, unguided, I can go up to 2min. exposures and get images without unpleasant star shapes (sure, if you pixel peep, then you’ll see some but not when printed on a postcard).
In combination with the software mentioned, and leaving most of the equipment pre-assembled, I am setup in 30min. and that means mount aligned, target centred (even if it’s not visible in the viewfinder), guiding procedure complete and guiding stable, exposures dialed in for auto capture with dithering and remote controlling the whole shebang from my iPad via TeamViewer.

I suspect I have a slight dilemma in that my house obscures a clear view of south and my backyard is tiered so I can only go lower which makes it worse... I'm still learning the night sky and everything looks like Octans shape if you try hard enough.


Last night was moonless and I went out there. I hooked the mount up via laptop and used stellarium + EQMASCOM. I managed to get it to work the other day during the day (just forwarded stellarium to 9pm) and it moved relatively close to where Orion would typically be etc. But last night it didn't want to play properly and whilst I had it line up with Canopus, selecting Rigel meant the mount moved perhaps 5 degrees and just stayed there, rather than spin nearly 180 degrees to face North West-ish.

As time was of the essence I just manually moved it. It still tracked ok, not ideal but I managed to take 80, 30 second exposures @ 4000 ISO. The uploaded photo is an unstacked shot from the camera. It's not good. No matter how i fine tune focus, and at 30 seconds I get pretty average star trails. Crazy thing is, it looks excellent in the view finder, and even if I export them to the PC.. it's when you crop and zoom in, do you find out how bad it is.


Still, one must persist!
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