EQMOD or Synscan

[void]

This is more of a curiosity thing.

If you were comparing EQMOD and Synscan are one of these methods more accurate / better for viewing / astrophotography.

[red dwalf]

nothing wrong with using the handset, alot of people prefer it, but if you like to image and sit behind a laptop then eqmod is better at controlling the scope from the laptop and i find easier too, don`t need to keep putting in the data everytime you start up, or do 2 or 3 star alignments, i use stellarium and eqmod, eqmod uses the system time and date, all other details have been put into the settings before hand regarding latitude and longitude, so i polar align as normal, slew to a star, sync it on the star and i`m away for the night.

you can also use tracking software like PHD and so on to track objects when imaging

[oldpink]

EQMOD is well worth the time and effort
I spent 2 days installing it and cabling it up to control most all features so I can remote my setup linked to my laptop
with the ability to remoter view and control the scope from the comfort of my computer room

you need to add some of the add-ons but well worth the effort and time setting it up

[Merlin66]

For casual non-observatory observing I'd go with the Synscan controller.

As soon as you have a permanent mounted scope (in/ out observatory) and doing any sort of imaging then EQMod is almost mandatory.

[wxsatuser]

Eqmod and CdC all the way for me, just recently added a wireless Xbox controller as well, brilliant!

BTW have never used the handset on my HEQ5.

[void]

Is one method more accurate?

[Merlin66]

More accurate for what?

[red dwalf]

wireless Xbox controller for me too, so easy to use and slew with, i can`t remember the last time i used the handset either

[Bizibilder]

The hand controller has a database of around 13,500 objects and can goto any one of them.  I use CdC and have downloaded the larger databases (all stars down to mag 16) and can therefore goto several million objects.  As to accuracy - you need to specify what you mean please.

[void]

Sorry i my head the question made sense.

Basically from what I understand there is an amount of inaccuracy with goto. Is using EQMOD any more or less accurate at tracking than Synscan?

[Bizibilder]

They both track at the same rate (actually rates as they can track at siderial, lunar and solar rates which are all slightly different).  If you need the precision required for astrophotography then you will also need to guide using a seperate guidescope and camera or off axis guider (oag) and camera.  The greatest errors will be in the mechanics of the mount rather than the software, guiding will eliminate these and allow you to take images of up to 10 or even 20 mins with no apparent error (ie perfectly round stars). 

[red dwalf]

i think from what i`ve seen others do with there handsets using two and three star alignments is there little difference as long as your properly polar aligned and location details, time and date are all correct, especially for visual use, it`s just that when your sitting at the laptop wanting to image eqmod is alot quicker and easier to get going, for me anyway.

long exposure image tracking is another ball game 

[chrisshillito]

Sorry i my head the question made sense.

Basically from what I understand there is an amount of inaccuracy with goto. Is using EQMOD any more or less accurate at tracking than Synscan?

Both EQMOD and the synscan are commanding the same mount controller which in turn is driving the same mechanicss. So the absolute resoltution of pointing is the same. However, the synscan and EQMOD use a different system to model errors caused by polar alignment, home position, cone error, optical distortion and atmospheric distortion. Whilst the handcontroller provides 1,2 & 3 star alignments using a fixed catelogue of bright stars EQMOD provides an n-point alignment (as many as you need) and these can be made using any star or any plate solved position.

If you can remove the sources of error in your setup then the sophistication of the pointing model is irrelavent. If you can't, or don't want to spend the time obtaining a perfect setup, then EQMOD's alignment method may offer an advantage to you particularly if you want goto accuracy accross the entire sky.

Chris.

[Dave_D]

Is one method more accurate?

for me, a combination of eqmod and astrotortilla for plate solving has proved to be vastly more accurate than synscan. i started with synscan but quickly realised the potential of a full eqmod-phd-cdc-apt-alignmaster-astrotortilla setup even with not having a permanent obsy. yeah, synscan is a lot quicker to set up,  but the extra time with eqmod is well worth it.

[chrisshillito]

.... and then there is tracking. Both EQMOD send the same commands to the mount to track at sidereal, lunar, solar etc. EQMOD however has a more sophisticated PEC capability which can reduce periodic tracking errors on the RA axis. EQMOD is also able to implement variable tracking rates based upon an objects ephemeris data allowing for more accurate tracking of comets, asteroids or the moon. When it comes to guided tracking EQMOD provides a greater range of guide rates in its pulse guide solution than are available via ST-4.

Chris.

[ultramol]

Can I just ask, what is the difference in price between these two methods( bearing in mind you have the laptop for EQMOD. ) I know there is no limit and you can just keep going adding things, but to get the basic EQMOD going doing the same job as a Synscan hand set I would be interested to know ?

Regards.....Geoff

[Tinker1947]

EQMod is free, just the cables and a adapter to come by the adapter from FLO is £27.95 but you can make your own, as for accuracy if you need to image a DSO that you can't see then zero in on a bright star or something you can see close bye, hit the sync button, focus you camera, then slew to the hidden object it will be right in the centre of you FOV, not sure you can sync a handset...A wireless X-box gamepad is a good add-on.....

The Adapter 

http://www.firstlightoptics.com/astronomy-cables-leads-accessories/hitecastro-eqdir-adapter.html

[chrisshillito]

For a mount with a synscan handcontroller the cost of adding EQMOD is just that of a usb-RS232 connector (asuming your mount came with a syscan firmware update cable). Alternatively you can loose the handcontroller and make or buy an EQDIRECT interface (around £10 to build yourself, £25-£40 to buy).

Additionally most EQMOD users will add a gamepad - prices vary but cheap wired ones work fine.

Of course EQMOD can save some folks money as they can buy the syntrek versions of the mount rather than the synscan.

Chris.

[malc-c]

One thing that hasn't been mentioned is that EQMOD has multipoint maps, so once you have centred your target you can tell EQMOD that it's centres and it builds up a far more accurate alignment map rather than the handsets three stars.  However this only really comes into its own in a permanent set up, otherwise the points will be of no use once the scope has been moved.

For  those of us who have an observatory EQMOD is an essential element in the software  we use.  It's more flexible with it's settings, is constantly being developed to add new functionality, and above all, support is terrific and available through different sources.

[RikM]

The difference between the syntrek and synscan mounts is about £110. To get going with EQMod and a syntrek mount (assuming you buy rather than build) is an EQDir module, USB cable and Wireless gamepad, so about £60. You are saving about £50 but it isn't about a cost saving. The key is the extra functionality with EQMod for imaging. Soon I will have a permanent set up, so I am switching to EQMod / Maxim DL mainly to avoid putting the time and date info in each time, the pulse guiding feature, the ability to sync to any star, the interface with plate solving to allow accurately coming back to the same field for multi-night imaging, and a custom park position with the scope horizontal.

[chrisshillito]

Please note an eqdirect and gamepad are not essential for a minimal EQMOD setup on a synscan equipped mount. You can interface via the synscan in pc-direct mode. Slew control can be achieved using a mouse (left right butons control direction, centre button selects axis and wheel changes rate), a keypad or the direction butons on the EQMOD user interface.

So depending on the standard pc equipment you already have around, using EQMOD doesn't have to require any specialist equipment or cost anything - at least to try and see how you get on.

For a synscan mount you will at least need an eqdirect. Making a usb version of this is little more than splicing 3 wires of a RS232 cable to an ftdi or prolific type usb-ttl adapter (but many folks just buy ready made units).

Chris.

[void]

Seems like the EQMod on Synscan is the preferred option giving you more flexibility.

[oldpink]

yes I use mine in PC direct mode

[ultramol]

I am getting giddy now, I am going to go down the EQMOD road and get myself started...

[void]

EQMOD seems to be the thing to do so long as you dont mind taking out one extra bit of kit (laptop).

It seems like a nice bit of kit.

Does it only work on the skywatcher mounts? Or does it work on the VX celestron mounts also. I understand they basically come from the same factory.