How will I see my image rotation.

[bomberbaz]

Hello all.

I have a SW 130 P-DS and I am using a ZWO 224mc camera to do some basic unguided EV type imaging. (I am really enjoying it too)

Anyway, on stellarium when I use the ocular (eyepiece) view to look at an object it shows an view as I would expect, rotated 180 degrees.

However when I click on the image sensor frame it shows it unrotated, that is to say how it is seen in the sky, is this right.

I would have expected to have an image exactly the same as my eye see's it, rotated 180 degrees. Am I missing something here.

EDIT. Come to think of it, the moon was unrotated when I imaged it, now I am confused. (from 25/11/2020 - slightly out of focus)

[symmetal]

It  depends on how you set up the camera orientation when you attach it to the scope. If you set the camera's longer axis parallel to RA movement direction (for an EQ mount) or horizontal for an Alt/Az mount and the image is upside down compared to how you visually see it,  just rotate the camera 180 degrees and the image will be right way up.

Some manufactures mount the sensor rotated 180 degrees compared to the writing on the camera case so that if the camera writing is the right way up, so is the image. Others don't, so you only find out when using it. The image data in the camera memory could easily be read out in reverse order to effectively rotate the image so it could be done then, rather than physically rotating the sensor.

With an EQ mount doing a meridian flip rotates the image by 180 anyway, so you have to choose which side of the meridian gives you the right way up images. 😀

Alan

Edited November 29, 2020 by symmetal

[vlaiv]

Not sure what are you asking?

Image orientation depends on how you rotate your camera with respect to telescope and also what type of telescope you are using. Some telescopes invert both axis - thus creating effect of 180° rotation, while some invert only one axis (or invert both and then additionally invert one axis one more time - thus returning it to "normal").

You can set all of that in oculars plugin when you define scope and sensor.

Additionally you have this popup menu accessible via ALT+O:

[bomberbaz]

I am aware of rotating the camera and also about the settings in stellarium but something didn't seem right.

I will look again tonight with bins, visual through scope and then with camera to see if I can replicate what I think is happening.

Sorry for vagueness but now i am not sure myself.

regards

[vlaiv]

Adding diagonal for visual in Maksutov and Refractor type scopes will change orientation of one axis (left to right usually, but it depends what is your observing position with respect to optical axis).