Thanks for the confirmation that it is likely the IS. And dcm, thanks for the link to the Tamron manual. I always wondered why they included these manuals with products.
And jrista with regard to the composites, now you are just showing off. Good work.
Kindest Regards, Lloyd
I suggested VC because the movements look a bit mechanical and 600mm will magnify any movement. I assumed you have taken moon photos with other lenses in your arsenal and not had a similar experience. If you have, then this suggests it is the lens. If not, there are a couple of other things to consider, your base and tripod.
Were you on solid ground or a deck? A deck can impart movement from people walking, even if they are inside the house when the deck is attached to the house. As Neuro noted in some autofocus calibration discussions, his results were affected by movement in the house until he set his tripod on a concrete floor in the basement.
Were you using a lightweight tripod or a tripod with the center column raised? The slightest of breeze can cause movement in these cases. These are two other things to consider.
I'll have to try this out when mine arrives. I haven't experienced anything like this with my 55-250 or 70-200 with extenders.