Doing multiple nights

[Anthony1979]

I am thinking of doing 2 nights on same target tonight and hopfully tomorrow but never tried it.... What do i need to do... Do i just leave my camera on the scope and continue tomorrow night... Does taking it down and then setting back up affect anything

[alacant]

10 minutes ago, Anthony1979 said:

Does taking it down and then setting back up affect anything

Hi

Yes. It makes it more difficult. It's easier to...

Leave it set-up and plate solve one of your existing images. Most decent capture software will then synchronise the mount exactly to where the image was taken. Then it's just a case of taking more frames where you left off.

Tell us what you'll be using and we'll no doubt be able to be less general.

Cheers.

Edited June 23, 2020 by alacant

[Anthony1979]

I cant really keep it setup... Not where i live

[ollypenrice]

Can you at least leave the camera on the scope and take the lot off the mount as one unit? That means one set of flats will be OK, almost certainly, and your camera angle won't change.

Another good practice is to have your camera orientated along RA and Dec. Take a (say) 10 second sub while slewing at a slow slew speed on one axis. You'll get trailed stars. The angle of the trail is the angle of the camera. Get the trails horizontal or vertical and then you can easily replicate that camera angle. A random camera angle is very time consuming to replicate. Don't do it!

Olly

[Anthony1979]

Yes i can take the whole lot off the mount

[tomato]

Leaving the scope attached to camera is a good approach if this is practical. I could not do this as my scope and camera had to go back in their cases in between sessions.

For a one off it depends how big your target is in the Field of View. If there is ‘clear’ space around your target just get it in the centre of the sensor, your stacking software will align all the images but you will need to crop the edges. This won’t work if your target is an extended nebula that goes all the way out to the edge. If your camera screws onto the focuser it won’t end up in exactly the same place, but if you can rotate your assembly then make a pointer to show where the camera is pointing on night #1 and realign to this on subsequent nights. Olly’s alignment  method is very precise, it just takes a bit of time to set up.

[ollypenrice]

There is another way to orientate a camera. First use a spirit level to set your counterweight bar to the horizontal and lock it. Then set the OTA to horizontal as well. (By eye will do for this.) Finally use the spirit level to set the camera to horizontal. DSLRs and square bodied astro cameras make this easy. You just hold the level agains the flat part of the camera. If you have a round bodied camera you can use the method I first described to set the camera angle to orthogonality with RA and Dec and then set the mount axes to horizontal. Put a piece of masking tape almong the back of the camera, hold the spirit level against it horizontally and draw a line on the masking tape. You can then hold the level against this line at any time in the future. This method is not quite as precise as the camera slew method but it's not at all bad.

Olly

Edit: this only works for refractors, Maks, SCTs etc which have a linear light path from objective to camera.

Edited June 24, 2020 by ollypenrice