Guiding issues!

[mbalkham]

Second time out with the guidescope and I think i've done everything I am supposed to this time!!  Happy with the PA and done a couple of align master 2 star adjustments. Happy with scope balance etc.  Let PHD calibrate properly this time (last time I did not!!).

I keep getting a warning along the lines of PHD not being able to make large enough adjustments. Even when set to max (2000) on Dec Duration and RA Duration (which I am aware I shouldn't be needing or using).  I've read a guide to guiding (http://www.rosecityastronomers.org/resources/pdf/GuideToGuiding.pdf) which has helped me try to understand things but I'm not sure what I'm doing wrong (though I fear it could be overloading the mount which sounds expensive!).

Any other ideas?  Happy to try to post log once I've stopped imaging!!

[Carina Lass]

I doubt you'll do any damage.

Could be that your PA is a little too far off and PHD is having difficulty keeping up - turn on the graph and see what it looks like when it starts guiding after calibration.

If it is during calibration, the only thing you're going to be able to do is do a really good PA and see if it makes a better attempt

[mbalkham]

It all seemed to come good after a prolonged period of guiding. Does PHD2 improve it's accuracy as it goes?

Then I moved to another part of the sky, recalibrated (not sure if I needed to!) and had a different problem. This time after things settled down the RA was pretty good but the DEC showed a trend of increasing slowly and then decreasing quickly before repeating.

On another note any idea how to capture the graph? Can you recreate it from the log?

Thanks all

[Carina Lass]

Haven't tried that.Sorry can't help.

You could alwaus print screen

[Shiinsuh]

I would be willing to say you could be way past your EQ5 mount weight limit. With a SW 200p at 8.8kg, auto guider and a heavy DSLR, plus all the extras. Its going to be way over the 6.5kg imaging limit and over it's visual limit at 9kg.

I had a similar problem as I have the Celestron CG-5GT (which has a slightly higher weight limit but is just a re badged EQ5 with better motors) I had to get a lighter scope for imaging. The best i can put on it with guide scope and DSLR is a SW130PDS and even then its probably over the imaging limit.

Hopefully you could get away with it with really good PA and balancing but you might be looking at needing a new mount (HEQ5 might still be at the top end of the imaging weight limit with a 200p) or get a smaller imaging scope.
Shedding other weight might help too, if you have a lighter DLSR use that, if your using a guide scope, attach the guide camera to the finder scope and do away with the guide scope. Also ensure the centre of gravity is is good (following is just speculation and you might have already done this), have the tube rotated so the focuser is in towards the centre of the mount and the DSLR is pretty much at the centre of the mount axis, but also slight off centre to counter the weight of the finder scope. Also with such a big scope it will catch wind easily so if you are out in the open, even the slightest breeze will push the scope off and the guiding with it.

[mbalkham]

Thanks Shiinsuh. I concur and have just picked up my NEQ6! Hopefully that'll do the trick!

I figured out the point the DSLR down bit myself and it def helped (a lot).  Why did no one say that before!!  Balance was pretty good (so I thought).  I also did away with the finder scope to try to lighten the load.

Prob ought to write something summarising my learning as it's been a steep learning curve with software, dirvers, new terminology, cables, etc. etc. etc.!

[Shiinsuh]

I'm sure a NEQ6 will be perfectly fine to image with your set up. I wish I had one my self!

I learnt balancing the DSLR on the centre of gravity from watching a polar alignment video. Otherwise it seems to not to be very well documented. Nether the less even with the EQ5, I would think. if you get everything perfect, it would be usable, but probably find more frustrating getting it perfect then simply changing the gear.

Notes are always good iv found. I haven't been an astrophotographer for very long so I'm still learning most of the terminology, how to use software and how best to set up the mount and scope and using notes helps a lot!