No image.

denababy

Hi, I have a Sharpstar94 scope with an asi 2600 camera and an am5 mount. The clear nights this year are few and far between but I have a couple of problems.
Although there are in excess of 5000 stars my ASIAIR plus will not polar align, I hit the sky map on the bottom of the page and go to Polaris, the mount hardly moves, then I slew to firstly Orion’s nebula, then the Horsehead nebula and various bright targets but none of them show up on my tablet only a screen full of stars! I have tried different ISO settings as well as exposure lengths. Is there an issue with the plus? The skies are really clear. Guiding was ok and focus was good. I’m really struggling as this is the second night where I’ve had these issues. Anyone help and advise please. When I imaged Orion previously I could see on my screen what I was imaging but not now.

johnpd

What error message are you getting when the polar alignment function fails? At what point does it fail?
Do you {Home} the mount before polar alignment?
When you start polar alignment function (PA), does it initially take an image and then requests the mount to be slewed 60 degrees?
Do you then OK that and the mount slews 60 degrees?
Does it take another image and give you how far off you are?
Then you make appropriate adjustments to the mounts Alt and AZ knobs.
7 Once you do get polar alignment to complete, do you {Home} the mount again?

JohnD

denababy

Hi, I don’t get any error message it just keeps solving, as I said there are over 5000 stars detected but the solve reaches over 100 then starts again from 0, I waited ages but it never gets to the point of the mount slewing it just keeps solving over and over. Yes I always send the mount to the home position, it’s set in the app that when I finish the imaging session both the mount goes home then the aap switches off. Everything has worked ok before. To answer your point three there is an image taken then it solves over and over, even though the sky is very clear.
Everything is just as it was when working but it has been a few weeks due to cloud. I have two Jackery batteries and one powers the mount whilst the other powers the aap. I checked that both had good charge, one at 87% and the other at 92%.

johnpd

You need to send the mount to the {Home} position before you do anything else. The ASIAIR is assuming that the mount is sitting there before you do any alignment or initial GoTo functions.

There are several things that can affect plate solving.

If you have a FOV under .2 degrees. But since you have a rather short focal length scope and high resolution camera, that should not be an issue. You should be getting a pretty wide FOV.
Have you checked the focal length that has been set for your telescope? This must include any reducer or Barlows that might be in the imaging train. That could contribute to plate solving not working.
If you don't have good focus on your camera, plate solving might not work.
One dumb question, but I have to ask. Are you sure that the cap or anything like a Bahtinov mask is not on the end of the scope? You can actually get a star count with the cap on as your camera may have a number of hot pixels.

JohnD

denababy

Hi thanks for your reply. I have a Sharpstar94 and a field flattener / reducer, that unit is specifically for the Sharpstar94, I’ve just asked if introducing that unit into my imaging train would need me to change the focal length numbers in the aap. Still waiting for a reply unless you know the answer.

MarcK

denababy
Hi
You can also enter 0 and the ASIAIR will then calculate your correct focal length.

If you use a reducer, your focal length will of course change.

But there are currently many people with plate solving problems. Including me, I always have problems after GoTo towards the south. And there seems to be no solution except to wait for a new update.

denababy

Hi and thanks for your responses, I have been investigating the focal length of my scope and adding a field flattener/ reducer, the focal length has gone from 532 ish down to 414 so on the next clear night I’m going to put in that new focal length figure and hope everything works ok.

johnpd

Correcting for that reducer should get you back on track.

JohnD

denababy

Hi everyone I’ve just finished imaging and I’m happy to say that after I put in a corrected focal length everything went ok. Thanks to everyone your input is invaluable.

johnpd

You are most welcome. Enjoy your imaging.

JohnD