Photographic Drift Align Help (DSLR)

[Serotonin]

I'm not sure if I'm posting this in the right place or not (moderator please move if incorrect).

I an new to all of this and I am struggling with polar aligning. I do a rough alignment on polaris and try to tweak the azimuth/latitude adjustments. I am trying to use the DSLR to perform a drift alignment. I start with the drive motor off during the exposure (30s). I make a second exposure with the drive motor in reverse (8X - 30s).

By comparing the angle made between the motor-off and motor-on of the star traces shouldn't I be able to tell if I'm polar aligned or not? Shouldn't I abe able to adjust the scope until the angle is zero? Am I going about this wrong?

Motor off:

Motor on (8X reverse):

Merged in order to measure angle:

Red arrow denotes the angle between the two photos star traces.

Thanks.

[davew]

I've never used this method but this is how I understand it.

Star your exposure with the mount motor off and the star at or near the edge. Allow the star to trail across the photo. When it has reached the other side, switch the motors to 2x sidereal and give it the same exposure. The angle = drift.

Have I made myself clear ? If not say and I'll try again.

Dave.

[Serotonin]

Ahh, ok. That makes sense. Im going to try this tonight.

I'm using a equatorial mount. Should i be able to tell from the drift direction if i need an azimuth or latitude adjustment? Or both?

[davew]

The simple answer is yes. But don't ask me Maybe try it and see or read up on drift aligning for the ups and downs, left and right.

I think you will need two runs at least, just like the visual method. One East or West and one South.

Dave.