Camera orientation


#1

Hi, I have posted this in plate solving as I think probably the solution lies there.

I use SGP and Framing & Mosaic wizard. In September I want to capture some images of M31 and to get it to fit the Canon DSLR frame, I need the image to sit across the diagonal of the frame. Common requirement I’m guessing.

Is there a way I can work out from a plate solve (i use local astrometry and elbrus) how much to rotate my camera - I just have the camera attached to the scope - no electronic rotator.

The only other way I can think to do it is to take an image of m31, roughly judge the angle I need to turn it and do that, bit tedious though and would require a number of iterations I’m guessing…

I have read the help file on rotators and didn’t find an answer there.

thanks for any pointers
Paul


#2

Paul, Unless I don’t understand what you want to do, it is very easy,
you want to use a “Manual Rotator”. It is exactly what I do.

Use the Framing and Mosaic wizard to create the new sequence with M31 in
the orientation that your camera needs. Then add the manual rotator to
your equipment in the sequence. See the “Manual Rotator” page in the
on-line help:
Control Panel/Equipment->Other Equipment->Rotators->Manual Rotator

After you add the manual rotator, open the Target Setting panel and
enable “On target start, rotate to:”. That box should already have the
angle populated from the Framing and Mosaic wizard.

When you start your sequence, SGP will use plate solving to find the
current angle and then prompt you to rotate the camera using the popup
described in the manual page, above. It will still likely take 3 or 4
iterations, but you will be told exactly which direction and how far to
rotate.

  • Shane

#3

Shane -thanks for this i will give it a try. Do you have a manual rotator? i.e. a real one rather than rotating the camera on its threaded fitting? If so, can you let me know the manufacturer?

Thanks
Paul

Paul Kirk


#4

The manual rotator is the idea of loosening the camera, rotating it by
hand, and then re-tightening it. SGP will tell you how far and which
way to go and then re-solve and tell you again each time you rotate it.
It really doesn’t take much practice until you can get pretty close in
a few tries.

I have a 2-inch nose piece on the camera in a compression fitting with
thumbscrews on the telescope. If you are actually threaded into the
scope, that would complicate things.

I am working on a bracket to attach an electronic level to the back of
the CCD camera to replace the estimates with an exact measurement. (Saw
that idea on a posting here.) That will let me nail it on the first try.
I already had the electronic angle gauge and a bunch of plastic
scraps, so it’s just a bit of work in the shed …

  • Shane

#5

great idea Shane - I’ll see if I can acquire an electronic angle gauge.
best wishes
Paul


#6

Paul, can you post a pic or link for the electronic level? I would think it would have to be rather small.
I have a inclinometer app on my phone. I hold the phone flush on the camera. Works but not super accurate.


#7

Hi, Here’s one I found but not sure of the magnet bit - this might interfere with camera electronics perhaps?

I’ll probably buy one (perhaps not this one as depends on a little more research). I’ll post my usage findings once I get back to imaging in Aug.
this one is 3 x 5 cms which would work for my setup. Also not sure how easy to see this kind of display in the dark…

just read a review of the item on the Amazon page I posted - someone has used it as an aid to using a telescope…

best wishes
Paul


#8

Thanks Paul. I just wanted to see what to look for. About the battery, I don’t know about interference but most cameras are made from aluminum so the battery probably won’t stick.


#9

I have just downloaded and installed ‘inclinometer’ - it’s free on android. Just tried it and it will be fine for my needs. Illuminated display as well of course.

thanks for the idea - I’m sorted.
best wishes,
Paul


www.mainsequencesoftware.com