Getting the Mount back to a previous imaging coordinates

[lensman57]

Hi,

I know this might be a silly question to most of the imagers but I have to move the HEQ5 in and out every time, how can I make sure that I can return the mount and the camera to the same location in the sky so that I could add more data to a previous  capture? I use NEB3 for capture and most of the time due to the less than ideal stretching I can't even see what I have on the chip. I could go back to Artemis Capture but then I'd loose the dithering and the histogram.

Any help is well appreciated.

Regards,

A.G

[jambouk]

I can't answer the question, but it is possible to just leave the mount outside between sessions?

James

[lensman57]

I can't answer the question, but it is possible to just leave the mount outside between sessions?

James

Hi James,

Even if there was a 1 in a 1000 chance that this would be possible the question of returning the camera to the exact previous orientation remains unanswered. I am just a little fed up of doing two sessions on the same target and loosing half the capture during the aligment and registeration.

Regards,

A.G

A.G

[PhotoGav]

I feel your pain AG, the set-up / break-down time is increasingly frustrating.

I have obsy envy!

[Freddie]

You could use the marker function in Artemis to get you in the right place and then swap over to Neb for the capture.

[fredcs]

Astrotortilla. take a little time to get it set up and all you have to do is load a previous image and it'll do a plate-solve and center the same area. Pretty awesome.

[lensman57]

Astrotortilla. take a little time to get it set up and all you have to do is load a previous image and it'll do a plate-solve and center the same area. Pretty awesome.

Hi,

I had it on my laptop and then got of it, perhaps I sshould pend a little time on software, many thans for pointing the way. Would it work with an HEQ5 SynScan as I only use the hand controller?

Regards,

A.G

[fredcs]

I just took a look at HEQ5'S specs and it seems that it has a rs232 port. I have an LX200 classic with a rs232 port. I start up AT and link to the scope thru ASCOM using  POTH.  Than I start TheSky5 and link the same way. I have to set my scope up each night. The tripod and wedge stay out in the same position, so my PA isn't that far off. I drift-align for however long siubs I want. Than using the sky I slew pretty much whereever in the sky. It doesn't HAVE to be an actual object, but I usually pick a star (does not matter really) so I can monitor visually in BYEOS. After the slew is complete I use AT to take an image with BYEOS. It'll do so, and do a blind plate-solve. Itknows where the scope SHOULD be pointing via TheSky5, after the plate-solve AT knows where the scope is ACTUALLY pointing. It syns the scope to the correct coordinates, figures the error and slews the scope. It'll do this to whatever accuracy you want (mount permitting). For initial syn I just do the one sync. 

[fredcs]

I  than have AT open a previous nights image and  solve it. It'll do so and slew to the object, resync and reimage to 1 arc-minute of center of field. My mounts not a great mount, but it always puts the image in field on the first slew. After the second its pretty centered. Sounds like a lot, but only takes a few mibutes (minus the drift algning). It took a little while to tweak ATfor my setup. 10" f6.3 with canon7d and an old ST7E. I get a plate-solve in under 10 sec with my laptop now. For the first time now I have the problem of what to do while the subs are being taken!

[PhotoGav]

Fredcs, brilliant info there. I will definitely add Astrotortilla to my list of things to investigate.

I have to set my scope up each night. The tripod and wedge stay out in the same position, so my PA isn't that far off.

Do you leave the mount head out too? I'm guessing not as it's attached to the scope, right? I'd like to leave my tripod with HEQ5 attached out, but wonder if that is a silly thing to do. If not, what would be the best way to protect it all from the elements?

Thanks,

Gav.

[jambouk]

I have started leaving my tripod and mount head outside. I have onenof those green canvas bags from green witch, that covers the mount head nicely, but the tripod legs stay exposed, so i hand made some sleeves out of a £1 ground sheet off ebay, and these stay on the legs permanently (they pull up or down if i need to alter the leg height, or slide off if i want to dismantle the whole set up, the legs are trapped by the spreader plate at the top so they don't fall down):

James

[Mike Hawtin]

If you leave the camera attached to the scope between sessions and assuming you detach the scope and tube clamp/dovetail as a unit you just need to pick a bright easily identifiable star in the frame and use that as a reference.  Then when you set up next time take a series of short exposures to fine adjust your reference star to its first session position.  Nebulosity gives you a readout of the cursor position which makes it easy to match frames.

Mike

[Bizibilder]

Lensman - Have you considered using EQMOD to control your HEQ5?  It is freeware but you would need to have a laptop (a pretty basic one would do) and a connecting cable.  This gives you full goto (and much more functionality than the official handset) as well as a simple and accurate polar align routine.  It is also compatible with guiding software like PHD.  For target aquisition all you need do is align the mount, do a three star align and then goto your target.  It will be bang on every time.  If you want perfection then either Astrotortilla or Star Locator Elbrus will both do the plate solving you need.

As for the camera rotation - I use a pen mark on the focusser to align with the camera body - its good to a degree or two between sessions which is usually good enough as you normally have to crop the edges of a stacked image anyway.

[Steve 1962]

..another vote from me for Astrotortilla - it has quite simply revolutionised my imaging sessions. I found it more reliable than Elbrus, although I do know people who find Elbrus better.

..and another vote for EQMOD - just brilliant.

...and both are free.

My only outstanding, which I have struggled with, is camera rotation - I have paper self adhesive stickers on my camera and focusser - a sharp pencil mark is good enough.

[cfpendock]

I have to agree with the comments on Astrotortilla.  I have to set up from scratch every time, but I do leave the camera and filter wheel attached to the scope.  I use AT for initial alignment, and then the "go to photo" function.  AT also has a very quick polar alignment routine.  It works a treat, although I did have some initial difficulties setting the programme up - there is an extensive tutorial on this site.  Just occasionally I do have problems with interupts on the ASCOM connections, but the benefits far outweigh this occasional inconvenience. 

Chris

[Gina]

Another vote for AT here - and EQMOD

[jambouk]

My vote is for "imaging just seems too much hassle for me"

[Gina]

I love a challenge - if it's too easy I can't be bothered

[ollypenrice]

I must look at AT but my own method is simple.

1) Whenever possible I image in landscape or portrait aligned along RA and Dec. To check this orientation (if you have had to remove the camera, which I don't) just expose for a few seconds while slewing. The stars will trail at the current angle of the camera, so you can soon get it orientated. This is also repeatable years later.

2) Once aligned, re-synch your alignment on a bright star near your target.

3) Slew to target, centre it and write down the co-ordinates of the actual picture as framed. The mount will give you this information.

Next time you're on the same target, orientate the camera, align, slew to the bright star and re-synch, then GoTo the co-ordinates you've written down.

Above all, make it a habit always to work aligned to RA and Dec if the target allows it.

Olly

[lensman57]

and the

Lensman - Have you considered using EQMOD to control your HEQ5?  It is freeware but you would need to have a laptop (a pretty basic one would do) and a connecting cable.  This gives you full goto (and much more functionality than the official handset) as well as a simple and accurate polar align routine.  It is also compatible with guiding software like PHD.  For target aquisition all you need do is align the mount, do a three star align and then goto your target.  It will be bang on every time.  If you want perfection then either Astrotortilla or Star Locator Elbrus will both do the plate solving you need.

As for the camera rotation - I use a pen mark on the focusser to align with the camera body - its good to a degree or two between sessions which is usually good enough as you normally have to crop the edges of a stacked image anyway.

Hi Roger,

Thank you for your reply,

Yes I have the EQMOD on the imaging laptop, Cartes du Ciel and the EQ DIR usb cable, just have not got around to setting it up and having a go with it.

Regards,

A.G

[PhotoGav]

I have started leaving my tripod and mount head outside. I have onenof those green canvas bags from green witch, that covers the mount head nicely, but the tripod legs stay exposed, so i hand made some sleeves out of a £1 ground sheet off ebay, and these stay on the legs permanently (they pull up or down if i need to alter the leg height, or slide off if i want to dismantle the whole set up, the legs are trapped by the spreader plate at the top so they don't fall down):

James

Excellent! Thanks for this.

Great thread with loads of good info. Look forward to filling up the laptop, spending yet more hard earned and waiting for the clear skies!

Sent from my iPhone using Tapatalk

[russellhq]

I have to take my setup inside after each imaging session as well.

I use Astrotortilla to get me back on target, it's not that difficult to get set up and I get back on target without problem.

My method usually goes like this:

1) Eqmod polar align with polar scope

2) Check drift in phd2

3) 3 point align with AT setting sync points

4) Go to bright star near target and set focus

5) Goto target and calibrate PHD

6) Using AT, Goto saved bookmark from previous session

[lensman57]

I have to take my setup inside after each imaging session as well.

I use Astrotortilla to get me back on target, it's not that difficult to get set up and I get back on target without problem.

My method usually goes like this:

1) Eqmod polar align with polar scope

2) Check drift in phd2

3) 3 point align with AT setting sync points

4) Go to bright star near target and set focus

5) Goto target and calibrate PHD

6) Using AT, Goto saved bookmark from previous session

That is a pretty comprehensive procedure, how long does this take you to achieve?

Regards,

A.G

[russellhq]

When starting from scratch if the mount head has been adjusted between sessions, it can take over an hour. The tricky part is getting the polar alignment set. Once that's done then it's pretty quick from there on in.

If everything's as it was from the previous session, then 1 & 2 take the longest (up to 30mins) and 3, 4, 5 & 6 usually go quite quickly and take about 15mins.

[Gina]

I use AT for PA.