Tonight I aligned my d6 enlarger (neg stage and lensboard) for the first time with a laser alignment tool. I inserted the piece of glass that came with it in a 4x5 glassless neg carrier and aligned without problem. Did the same for lensboard, no problem.

Then I got to thinking(always dangerous) and inserted my new used 4x5 glass carrier and rechecked alignment. I was surprised to find that alignment had changed about 1/8" on the target somehow.

Is this normal? How much error in alignment would call for an adjustment?

Thanks for your replies,