Problems with first drift align (and can't control mount with PC)

[Scooter]

So I set up tonight with the intention of doing some drift alignment. Mount setup, align the finder and a 25mmEP, Do a 3 star alignment with the mount, pop in the DSLR, focus, orient the DSLR (live view has a grid so the intent is to drift align using that) using the left and right controls the star travels left and right along the horizontal line in LV and then bam!!! – LV turns off. Oh well I think must be some sort of auto switch off……..not enough battery for LV……..NOOOOOOO

Lesson learned is recharge the damn camera battery after I use it for a few hours taking photos the other night. Oh well battery on charge so I figure I am all hooked up so will try controlling the scope with Starry Night Pro via Ascom. Hmmm no option for the EQ6 Pro check the net, needs to be Celestron 5i, try that and no go just get an error about no Celestron telescope connected. Update Ascom package (needed me to update .net framework) and then update drivers as well for Celestron. Now can select Skywatcher mount but still just keep getting that damn – no scope connected error. Using supplied cord into serial port (no need to convert to USB etc.) so should be sweet – but no (tuning into a great night ;)). Anybody got any ideas? EQ6 mount, Latest ASCOM and Celestron drivers on a Dell Latitude lappy using supplied cord.

Now enough time has gone buy trying to get the damn lappy controlling the mount that I figure I will go back to what I was originally shooting for – drift alignment (yeah the battery is now charged - that is how much time I spent trying to get the lappy controlling the scope).

All looks good to go (mount is roughly aligned using compass and inclinometer) and LV looks like it will work well. Done all the reading on drift alignment (great site here http://www.petesastrophotography.com/ (http://www.petesastrophotography.com/) - even did the little sim he has) and had a copy of the quick and nasty guide doing the rounds here I think – basically says:-

Orient EP with axes of the mount – check
Check star moves along up down lines as indicated by up down arrows – hmm well no it was controller up star goes down and left send star left and right sends start right (that’s how it was for a newt in the sim linked above so I figured that was OK but maybe I was supposed to have up/down oriented correctly and have left/right inverted??).
Place star on horizontal line – check
Star drifts above line – move star left – never did
Star drifts below line – move star right – check

So I start doing this. Star keeps drifting down so I keep moving the mount head (small at first and then bigger figuring maybe the star will start going up) but after some 30-40 mins I have run out of play in the mount and the damn star still drifts down. Gotta be doing something wrong as the mount is now way off my initial alignment. Any ideas people?

I figure I must not have oriented the DSLR in-correctly (on screen left/right keys caused the same behavior on screen and up/down keys caused the opposite behavior on screen) or it is something to do with Southern Hemisphere (although I was following the guide I thought some of you folks used). Also just one more thing tracking should be on yeah (i.e. I use goto to go to the star I intend to drift align on and it then is tracking whilst I perform the drift align)?

Anyway time for me to go to bed so thanks in advance. Guess I will have to see what happens next time I setup (and do a bit more reading on drift alignment with a newt in the SH tomorrow).

Cheers

[madwayne]

Hi Scooter

You will look back on nights like the one you had last night and laugh about it in the future. The frustration makes the end result all worth it.

First thing I will ask is did you have your mount tracking in Sidereal?

Not sure what other people here think but personally I would be getting myself an illuminated reticle eyepiece. I don't think you will get the magnification needed for an accurate drift alignment using your DSLR.

If you did want to use your DSLR I know of people who use a method for polar aligning using theirs by taking an exposure of 40 seconds to start with, this works best with a remote like a Canon TC80N3. Brightish star focussed, hold position for 5 seconds then slew left on slowest slew speed for 15 seconds and then back right for 20 seconds with aim being to get the star trail to go back past your starting point, which is the 5 second exposure of your bright star. Then view your star trails on your camera's LCD. If your alignment is out you will end up with a sideways V. The aim is to get that V to be a flat line and to increase the exposure time to 2 minutes or more with a straight line. All the other principles of polar alignment are needed, lowish star on the equator East or West and a star near the meridian on the equator. If you Google something like "polar alignment with a DSLR" you should find some tutorials on it. If you have no joy pm me and I will get some links for you.

As far as not controlling the mount using Starry Night. Did you have the correct COM port selected? If you are unsure use device manager to find the correct one.

Good luck with it and I hope you are up and running soon, you sound like the bug has caught you too ;).

Regards
Wayne

[Scooter]

Thanks for the response madwayne

It’s all learning so no complaints – could have done with some more sleep but (my boy gets up bloody early everyday and he only wants his dad to deal!!)

Regarding doing the drift using the DSLR, the camera is connected to lappy and I am using the Camera Control Pro 2 software to show the Live View (I should have explained myself a bit better instead of saying LV) on the laptop screen. Works really well and magnification is plenty (12” newt using a 2x Barlow so 3000FL). Might investigate other software options later but for now Live View is all I need as I can use the zoom for focus (actually last night picking a double worked well for focus as I had the two side by side) and at the normal view I can orient the camera to the mount axes and use the grid lines for E/W and N/S. You can see movement of the star in seconds and the process worked well last night (adjust mount – move star back – rinse/repeat - only worked on azimuth) it’s just a pity it never resolved (i.e. the star just kept drifting down until I ran out of mount movement which had been huge so something was not right – thus the request to clarify camera orientation and movement needed.

Regarding tracking in sidereal – I am assuming it was (as I used goto to get to the drift star and it was tracking – sidereal is the normal tracking type yeah?). The drift at the 3000FL in live view was pretty obvious whereas say in the finder it took awhile for the star to move off center. I have trees to the North so was using a star a little to the east so not sure if that makes a difference so maybe next time I will use a higher (clear the trees) north meridian star.

Regarding Starry Night not sure, I am very PC literate (yeah a nerd) so I did all the usual thing (update ascom, celestron drivers, reinstall com drivers etc.) but nothing. Will try the mount from the main PC at sometime as well as using some other software on the lappy to see how I go.

Last night was a bit of bugger really – lots of time spent and it seems I didn’t actually do anything.

Early days…… :thumbsup:

[JohnG]

Sounds like you are a fair way off alignment.......

First off, ditch the camera, use an illuminated X-Hair eyepiece for your initial alignment....

During daylight, identify, with your mount setup, True South using a compass, align the mount roughly on that bearing, adjust your altitude using an inclinometer or make up a latitude gauge (do a search on IIS, there are a number of articles), set the mount at your latitude.

Forget about East/West/North/South directions in the eyepiece, you only want up/down and left/right. Pick a star either in the East or West about 20 or so degrees up and near the Celestial Equator, Alpha Can Minor is good at the moment, just identify the left right movement, turn your tracking off and align the X-Hair to this movement, turn back on your tracking and recenter the star, watch the star, any movement, up or down, will become apparent almost immediately, if it moves down, aggressively move the mount in altitude, re-center, if the star moves up, you know then that the mount has been moved to much, just go back halfway, if the star then moves slowly up or down, your close, adjust accordingly.

The same with azimuth, pick a star overhead and close to the Celestial Equator, once again, just watch the star going up or down and move the mount accordingly.

Intial close alignment with the Pole is done with aggressive movements, you want the star to move in both up and down directions, don't worry about left/right, that is just PE and tracking errors.

When you have the star staying in the center with just a small amout of drift, either up or down, then use a camera if you wish, you should be able to get around 15 minutes or so with the star in the center of the X-Hairs, with an appropriate mount that is.

The trick is, be aggressive with your first couple of moves.

Hope that helps....

Cheers