Maxim and Pinpoint astrometry

[swag72]

I am looking at moving to Maxim for guiding and capture, but before I can do this I need to sort out pinpoint astrometry. Can someone give me some pointers of what I put in what box please? It's all a little bit daunting.

Here's what I have at the moment.

[steppenwolf]

Try these, Sara:-

Brightness = 0.00

Standard Deviation = 3.00

Maximum Number of Stars to solve = 500

Pixel Scale = pixel scale for your CCD and Telescope

Approx. Centre = the RA and DEC of your chosen object (could be extracted from the the FITS header if available)

Reference Catalog = GSC-1.1 (corrected) (download from here)

Use stars from magnitude = -2.00 to 20.00

Search area (as % of image) = 256

[swag72]

Brilliant Steve, I'll try these tonight - Thank you.

[FraserClarke]

If you set-up your telescope parameters in Maxim (File->Settings->Site & Optics), then it will make an estimate of your pixel scale for you depending on the camera parameters (useful if you use different pixel binnings for different projects, i.e. LRGB type imaging).

I think you can get away with substantially less than 500 stars (I use 40), but see how quickly it runs (fewer stars will help it run quicker, but might make it slightly less reliable). It probably depends on the field of view of your set up.

You could also use stars 4.0 to 16.0 (brighter than 4.0 are almost certainly saturated and useless, and you probably don't detect fainter than 16.0 (and GSC-1.1 doesn't include things fainter than ~16.0 anyway)). Won't make much difference though.

Good luck Probably just needs a bit of tweaking for your specific set-up to make it run quickly & reliably

[Helen]

Just to reassure you its easy to use Sara - even I can do it! I always let Maxim fill in the approx centre.

Helen

[swag72]

Right, this is probably the dumbest question yet - How do I use this?!!

Say I want to go to a certain point in the sky, I slew to it using my EQMOD controls - Then what? What does this actually do and how do I do it?!!!!

[Helen]

OK...

you need the mount connected to Maxim

you slew to where you want to go then take a picture

then click on Analyse>pinpoint>process

if your pointing model is pretty good then it will quite quickly solve the picture and gives you details of where it assesses the mount is pointing

open the Observatory box and click the telescope tab> choose sync then when prompted choose the option which says something like 'use solved' (not in the obs now)

that will add an accurate point on to the EQMod pointing model. If you want to go to a certain point then again on the obs tab>telescope put in your target coordinates and goto

There's also an option to 'image centre from pinpoint' so on a future night when you want to take more subs of the same spot, solve the previous sessions' sub and then don't sync but click on 'image centre from pinpoint' and it'll put you back where you were

Its easier than it sounds just experiment a bit!

Helen

[steppenwolf]

Excellent description, Helen!

[swag72]

Great description Helen - Thank you. I am doing a couple of other bits tonight, but hope to try this soon.

[Komet]

Sara .... before you part with an extraordinary amount of cash for Maxim (not a downer on Maxim at all - it is very good but rather pricey) have a look at Sequence Generator Pro for capture, plate solving, auto focus (if needed). For guiding you could use PHD (free but personally I think its not good) or and this adds stacking and processing alongside superb easy guiding, AstroArt 5.

SGPro has features that Maxim does not have. Brilliant plate solving (Elbrus - free) that adds some of that functionality and is a fraction of the price. Plate solving plus the ability to take an image from a previous session or from Astrobin and use that as your target and GoTo putting that targets coordinates right in the centre of your chip to within a pixel. Like Maxim it also has the very useful "Centre Here" function - except SGPros way it is easier to use imo. It is constantly being developed by two passionate imagers. For a full list of capabilities and a Demo go to http://www.mainsequencesoftware.com/

Astroart 5 offers superb guiding (If it was sold as a standalone program it would be very popular). It also will align, stack, process and do everything Maxim will do on the processing front.

Add CdC as your planetarium (free) which integrates beautifully with SGPro.

I am an ex Maxim user and use the above. I would not go back if you paid me. Maxim is very good but it is extremely expensive. I run my observatory with all of the above. I can be up and running with the previous sessions target on the screen in about 10 minutes (including CCD cool down). Its all very stable.

Really, at least have a look before you part with your cash.

[swag72]

Cheers for that info Mick - I already have Maxim, so not parting with any cash!!

I tried the plate solve, but just couldn't get it working well, despite Helen holding my hand a little!! So I reverted to Artemis for capture, Maxim for guiding and Chaos Crystal on the Maxim screen to align Artemis captures with a capture from the session before. Works out really well and while not the approach many would take, it works well for me. So ........ I tried!! ............. but just felt happier and more confident with my more roundabout method!!

[Komet]

I used to use the Chaos Crystal method .... (I think it was me that posted the CC link ages ago - perhaps not, can't remember now). SGP using Elbrus just blows it away for ease of use and accuracy.

As long as your happy - that's the main thing. Maxim plate solve was, I found, very good once it was working and although very useful it was limited.

One day, when you want to have a play with something, then try SGP and Elbrus.

Good luck

One question .... why don't you use Maxim for capture?

[swag72]

Because I like Artemis!!

I WAS going to use Maxim for capture, so that I could dither as well, hence the pinpoint questions, but I found that when I return to Artemis and Chaos Crystal, it's just easier to use Artemis rather than mess about again and go back into Maxim.

Just laziness and personal preference I guess!

[Komet]

That's cool. Whatever you do It is only a means to an end after all ......