Seems that $image is not the name of my image field.
Sorry, maybe my comment in line 2 is a bit misleading. Instead of if your image field is named 'image' it should read if your image field is named 'field_image'.
how does one find the name of this field
The name of your image field is what you set for the Product content type under admin/content/types/product/fields (in mykz' tutorial above it's 'field_image_cache').
could cart, category, product be used as these are the existing choices?
Absolutely, you may use any existing imagecache presets for the large and small images on your product page. 'large' and 'small' in my sample were just meant as placeholders for your actual preset names.
Joined: 08/08/2007