Plate Solving with Pinpoint LE, CCD Commander, EQMOD

[Euan]

Hi folks,

I've getting a lot of good results using Plate Solving in Pinpoint LE using CCD Commander & EQMOD so I thought I would do a wee write up for anyone thinking of trying it out

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What is Plate Solving?

Plate Solving is a method of measuring the exact position and field of view of an imaging CCD camera or DSLR, and in turn can be used to sync to a go-to mount to enhance the pointing accuracy. The PS software will take an exposure, identify the stars and use this against various star catalogues to perform the calculation.

What is Pinpoint LE?

Pinpoint LE is a Plate Solving program included in MaximDL. Various depths of star catalogues can be downloaded separately.

What is CCD Commander?

CCDC is an imaging automation program that can communicate and automate a range of other programs. In this case it is doing the hard work of automating MaximDL / Pinpoint and EQMOD. It is the main interface for Plate Solving where the tasks are set up and the results can be seen. It can also use a planetarium program for choosing targets, I use The Sky by Software Bisque.

What is EQMOD?

EQMOD is a alternative PC interface for various go-to mounts. It allows much more flexibility over standard PC/Mount interfaces. In this case I am using EQDIR to go directly into a Skywatcher EQ6.

How does it work?

All the user input is done within CCDC and The Sky. CCDC has an action list where you can drop in and configure different processes. I can go into The Sky and select an imaging target or alignment position. CCDC can then see this position and use it as a go-to action. After each go-to action I add and configure the "Plate Solve" action.

Then just hit play and away it goes. CCDC gives a comprehensive log of the action results, and from here you can see the calculation including position, arc seconds per pixel, and even the focal length of the imaging scope. After the Plate Solving is complete you can then add in a imaging action, and it will also automate all of your exposures. Now this is too easy.

Advantage number 1: forget about manual star alignment

If you are using your set-up just for imaging, do you have to use your eyes to look through a finder scope or have to replace your CCD camera to use an eyepiece then go through a star alignment procedure? The problem with this is that it is time consuming, frustrating and possibly inaccurate unless you have a very good understanding of your alignment stars.

With CCDC, pick 3 points in the sky where you want to do you alignment and it will take exposures at these 3 positions and perform the alignments with EQMOD automatically. Why are you cold, go and have a cup of tea.

Advantage number 2: forget about pointing and pointing accuracy

Although there is an advantage for pointing in terms of star alignment, if you have a permanent polar-aligned setup, what I have found is that you don't need star alignment at all. When the Plate Solving is down to 1 or 2 mins to calculate a position, you can Plate Solve at every step of the imaging process.

I can switch on my mount, and just point it north in it's standard starting position. From then I go to my first imaging target and then Plate Solve, and from there just Plate Solve on every target. The accuracy is incredible and it means I can be imaging in 10 minutes even with focusing included.

Advantage number 3: easy returning to targets

One of the things I have found hard when imaging is the framing of objects and especially returning to objects. Returning to objects with Plate Solving is really easy. When on a target you can Plate Solve in CCDC to record the position of the CCD, then just recall this position when you wish to return to it. It works really well and is very fast to use.

Combine this with an ASCOM instrument rotator and it would be a powerful weapon. This would add the CCD angle into the equation and allow the exact framing within CCDC and The Sky, making composing images and especially mosaics a breeze.

Sounds too good to be true, what's the catch?

With my QHY8 and Equinox 80, it works great and is starting to make a huge difference to how I do things. I've only tried it a few times with my 8" Newt, but it's much much harder to get a result. I've yet to really have a good go at it, but I suspect it's because of the smaller FOV and therefore bigger room for error. This might be something that is very hard to full off at longer focal lengths.

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Thanks

Euan

[ribuck]

Hi Euan,

I'm really interested in this post. Hope you dont mind if i come and ask you lost of questions in the new year.

Your setup is almost identical to mine, as I have an 8" newt and 80mm skywatcher for guiding, and use EQMOD, Maxim DL5 and the Sky6.

I'm almost finished building my DIY dome rotation system, so i'll be very keen to see play around with CCDC to make my life easier.

One area in particularly interested in is plate solving, I currently use EQMOD Sync's to get good pointing accuracy, but if i can slick this up with plate solving, then even better.

Rich.

[brendant]

An interesting thread Euan, is CCDC a must for automation or can the sequencing be achieved in Maxim.

Brendan

[ribuck]

Brendan,

As far as i'm aware, the power of CCDC is when using several different packages.

e.g. I use FocusMax which can talk to MaximDL, but i dont think Maxim DL can directly control Focus Max from within Maxim, hence needing to control it outside of Maxim.

This is one simple example where CCDC fill the void and steps in. When you have lots of apps like EQASCOM, The Sky, Focus MAX etc does not have the abilities to control all of these together, but CCDC does.

I love the idea of CCDC, so looking forward to finish my dome automation so i can use it.

Rich.

[Euan]

Hi Euan,

I'm really interested in this post. Hope you dont mind if i come and ask you lost of questions in the new year.

No probs just let me know

An interesting thread Euan, is CCDC a must for automation or can the sequencing be achieved in Maxim.

Brendan

I'm sure you can do custom scripting in Maxim, but it's probably just for it's own actions.

CCDC talks to 4 programs in my setup, but potentially it could do loads more. Throw in ASCOM obs control, instrument rotator, weather monitoring, the list goes on....

It's an amazing piece of software

[MartinB]

Hi Euan thanks for that post. Just a couple of questions. If your home position is "scope pointing north c/w down" I presume you aren't parking the scope. Do you find you can position the scope accurately enough for plate solving? My experience is that the scope has to be pointing pretty close to the co-ordinates put into pinpoint otherwise it takes a long long time for pinpoint to spread it's net.

An odd problem I have with Maxim is that whenever I platesolve for the first time I get the message that pinpoint can't find the catalogue at the path given. If I ask it to try again everything works fine. I've had this problem on multiple laptops and versions of Maxim. Is it something you've encountered?

[Euan]

Hi Euan thanks for that post. Just a couple of questions. If your home position is "scope pointing north c/w down" I presume you aren't parking the scope. Do you find you can position the scope accurately enough for plate solving? My experience is that the scope has to be pointing pretty close to the co-ordinates put into pinpoint otherwise it takes a long long time for pinpoint to spread it's net.

I was surprised this worked at all to be honest. I don't do the park command it EQMOD, at the end of the night I just turn it off. The next time out I align it pointing north by hand and it plate solves in a few seconds, and is always accurate. It may be because I'm using essentially a 400mm scope (or 389mm according to Pinpoint) after using the reducer. I've got a very big field of view

Making the exposures shorter helps, the less stars it has (50-100 is good), the faster the solving can work through the catalogue

An odd problem I have with Maxim is that whenever I platesolve for the first time I get the message that pinpoint can't find the catalogue at the path given. If I ask it to try again everything works fine. I've had this problem on multiple laptops and versions of Maxim. Is it something you've encountered?

Not had any issues so far, something like that would be a problem for CCDC as it won't know what to do it any user pop ups block the process in Maxim. Maybe it's down to the catalogues you are using or where they are kept?

[MartinB]

Not had any issues so far, something like that would be a problem for CCDC as it won't know what to do it any user pop ups block the process in Maxim. Maybe it's down to the catalogues you are using or where they are kept?

That's one of the reasons I haven't gone down the CCDC route yet. I would love to be able to do an automated flip during the night. The catalogue was downloaded on from the site linked to from the Maxim help file and is placed in the root directory as recommended. I can't understand why it wont find the path the first time but does afterwards. I feel a message to Diffraction coming on!

[daz]

Martin

Would be happy to go through it on the phone with you if you like. Mine works just peachy

Once I have the alignment done in EQMOD, I never have a problem with plate-solving, works everytime.

As for parking, I ALWAYS park the scope. Due to the height of the pier, I also a "LEVEL" park in EQMOD. This is RA horizontal (weights right, scopes left - accurately measured with a level and a Wixey) and DEC also horizontal (both scopes parallel to the ground). Because this is a KNOWN position, I can easily recover if anything goes slightly wonky with alignment. I check the HOME position every couple of sessions, as I do with polar alignment.

Martin - I've not yet had a problem with automated flips using CCDCommander - I will happily go to bed and leave it running! Making sure your cables are tidy and do not get in the way is key, of course!

[MartinB]

It's not CCDC itself but the hiccough with plate solving. I use plate solving to set up MaxPoint and it works great but I have to be around for the first plate solve to tell it to try again when looking for the catalogue.

When I get this glitch sorted I will definitely be on the phone!

[daz]

Sorry, I meant to go through the catalogue set up, but I don't have MaxPoint, so it may be a config??

[Grinde]

I can switch on my mount, and just point it north in it's standard starting position. From then I go to my first imaging target and then Plate Solve, and from there just Plate Solve on every target. The accuracy is incredible and it means I can be imaging in 10 minutes even with focusing included.

Wow this is exactly what I've been looking for, thanks for posting this! I got some new gear on the way, widefield refractor w robofocus & a ccd, & I'm moving from handcontroller to EQMOD.

Are you using MaximDL's focusroutine, or focusmax?

I'm interested in running maxims, since it can create focus-offsets for each filter & the robofocus got temperature-compensation too (if I remember it correctly).

I've ordered Maxim DL pro, so pinpoint LE should be included.

So I guess I'll be ordering CCDC soon, & a planetarium program too.. or can free programs like Cartes du Ciel do the same operations needed? Benefits of choosing TheSky?

Thanks!

Jonas

[Euan]

Are you using MaximDL's focusroutine, or focusmax?

I'm still on manual focus just now after moving to a Borg with a helical focuser, but if I was using a stepper I would use CCDC and Focusmax

Benefits of choosing TheSky?

Unfortunately its needed for CCDC. I wish it was Starry Night, the interface in TheSky really sucks

Your setup sounds spot on, do you have an obs as well then?

[Robfal]

An interesting thread, I've been going through the same process recently with pretty much the same setup. My trial version of CCDC has just run out so I'll be upgrading soon.

Plate solving and being able to slew to a nearby star to re focus between filter changes is ace.

I do have one problem though

I hold alignment points in EQmod and at the end of the night park the scope (horizontally). The next time I use the setup EQmod reloads the alignment points however the alignment it then out; so I then have to re-align. Perhaps I'll try not aligning but using plate solve only. I,ve not tried pier flipping yet; don't I have to do something called 'cone alignment?

An excellent piece of software, and cheap too

Rob

[ribuck]

I'm looking to go down this route as well.

I've got a new refractor, and i've ordered the lakeside focuser which i plan to use with focus max.

I also use maxim V5 for image aquisition but i've never used the plate solving side of things.

Euan, do you have a step-by-step idiots guide to configuring it all with Maxim, Focus Max and the sky etc. In particular, i'm interested in configuring the pinpoint & cdc side of things.

Does the plate solving have to slew to several different stars, or does it simply image take a single image and then plate solve from that ?

Rich

[Helen]

Thanks Euan - an interesting read!

I've just started out on the pinpoint route - reading the Maxim manual and tutorials helped me get going, and I'm looking forward to being able to use it in anger.

I've managed to get some subs solved quickly, but others have taken an age (and I lost patience before they finished!). So still some work to do to ensure a quick solve is the norm! (Oh, and I fully agree with you about the interface for the Sky - I really don't like it at all!!)

Helen

[Grinde]

I'm still on manual focus just now after moving to a Borg with a helical focuser, but if I was using a stepper I would use CCDC and Focusmax

Unfortunately its needed for CCDC. I wish it was Starry Night, the interface in TheSky really sucks

Your setup sounds spot on, do you have an obs as well then?

Fair enough, CCDC + TheSky it is... Which version of TheSky should I go for?

& about focusing, does FocusMax support saving offsets for different filters, & temperature compensation? Since the control-box for the robofocus has a thermometer, but since I haven't recived it yet, I'm not fully familiar with its features.

I haven't got an obs yet, but building one outside of town for the spring/summer, on my sisters property, but until then, I'm mobile.

Thanks again for the tips, & happy new year all!

[ribuck]

Helen,

I'm looking to go down the samw route as yourself and Euan.

I have the following setup :

102mm refactor, Heq5 Pro + Eqmod, Lakeside Focuser + FocusMax, Maxim DL 5.12, TheSky 6, GSC 1.1

I know it's a lot to ask, but would it be possible for you to write a step by step guide on how you have configured CCDC to talk to Eqmod, Maxim etc

Rich.

[Grinde]

Good one Ribuck, we're in the same boat then, I'm reciving my FSQ106EDX + reducer tomorrow, along with a QSI583wsg & a copy of MaximDL Pro, so it'll be quite a handful to learn.

By the way, how powerfull computer would I need out in the field? I'm currently using an Asus EEE 1005HA netbook, which works fine for imaging with my Canon 50D + PHD guiding. Will it be allright, or will it suffer from tossing TheSky, EQmod, FocusMax & MaximDL into the game? Will heavy work load increase readout noise to the ccd?

Thanks

Jonas

[ribuck]

Hi Jonas,

I have a ibm 1.8ghz laptop with 1.5gb Ram which is about 3 years old and that struggles a bit running everything so not sure how a net book would handle it.

I'm just hoping that helen or Euan can write us a guide on how to setup CCDC with maxim etc

Rich.

[Euan]

I do have one problem though...I hold alignment points in EQmod and at the end of the night park the scope (horizontally). The next time I use the setup EQmod reloads the alignment points however the alignment it then out; so I then have to re-align. Perhaps I'll try not aligning but using plate solve only. I,ve not tried pier flipping yet; don't I have to do something called 'cone alignment?

Some people will probably say something different, but personally I don't want to rely on a pointing model for accuracy of the mount. There are just too many things that can go wrong for me

I don't save any alignment data from each session but do park the scope. The pointing accuracy comes from doing a plate solve as soon as I first slew the scope and for each target thereafter. If you have good polar alignment this should work fine at a reasonable focal length.

If you can get them to work correctly, I reckon constant plate solves must be more accurate than any built up pointing model

[Euan]

Euan, do you have a step-by-step idiots guide to configuring it all with Maxim, Focus Max and the sky etc. In particular, i'm interested in configuring the pinpoint & cdc side of things.

I will see what I can do over the next few days

Does the plate solving have to slew to several different stars, or does it simply image take a single image and then plate solve from that ?

It can resolve any point in the sky as long as:

It knows the Arc Sec per pixel value to calculate the FOV

This can be calculated using the CCD pixel size and focal length, then put into the settings

It has enough stars to resolve with

I'm not sure what the exact number required is, but if you are short expose for longer. It's more of a problem if you have too many stars as this will push up the processing time per area searched, this can be limited, I limit it to 150 stars

The mount is as close to the position as it can possible be

PinPoint uses a spiral search to find it's location and depending on the speed of the PC and the number of stars, this can take quite a while per search area. The closer the mount is the quicker this will be. If the mount is too far out the spiral will fail to get there and the plate solve will fail.

[Euan]

Fair enough, CCDC + TheSky it is... Which version of TheSky should I go for

I use Pro v6 but I reckon you could get away with a lighter version, it would be worth asking Matt who writes CCDC (Matt at astromatt dot com). This may save a bit of cash

does FocusMax support saving offsets for different filters, & temperature compensation? Since the control-box for the robofocus has a thermometer, but since I haven't recived it yet, I'm not fully familiar with its features.

ASAIK yes, although I've yet to play with it to this level

[Beyond_Vision]

Good one Ribuck, we're in the same boat then, I'm reciving my FSQ106EDX + reducer tomorrow, along with a QSI583wsg & a copy of MaximDL Pro, so it'll be quite a handful to learn.

By the way, how powerfull computer would I need out in the field? I'm currently using an Asus EEE 1005HA netbook, which works fine for imaging with my Canon 50D + PHD guiding. Will it be allright, or will it suffer from tossing TheSky, EQmod, FocusMax & MaximDL into the game? Will heavy work load increase readout noise to the ccd?

Thanks

Jonas

I use a dual core atom 510 Zotac Zbox netop PC which runs Starrynight Pro +6, Maxim V5, EMOD, Focusmax, PHD, Pinpoint without any problems.

Regards

Kevin

[chrisshillito]

I don't save any alignment data from each session but do park the scope. The pointing accuracy comes from doing a plate solve as soon as I first slew the scope and for each target thereafter. If you have good polar alignment this should work fine at a reasonable focal length.

If you can get them to work correctly, I reckon constant plate solves must be more accurate than any built up pointing model

I don't quite follow this. Plate solving itself doesn't improve pointing accuracy it simply tells you where you're currently pointing. If you then sync on the plate solved location (either manually or as part of some script/automation) then a subsequent goto to your target should be more accurate - but in making the sync you are still creating/adding to a pointing model and it is that model that compensates for previously measured errors to ensure an accurate goto.

Chris.