Model builder obvious question

Hello all,

So I have been getting to grips with model builder, and I have a few key questions;

1. I am trying to process each band of a raster image the same way - is there a way I can split a raster into it's bands and then iterate over them to do processing? I've looked at the iterators but none of them seem to do what I'm after.

2. How can I default my "field" parameter in the featureToRaster tool? I am not guaranteed that my input file will have any specific field, so I can't hard code it, but if I don't hard code it, it the process doesn't work.

I'm sure there will be lots more questions but these are keeping me from the rest of the flow..

Thanks for any advice,

Toby