[TYPO3-mvc] imageViewHelper: "Could not get image resource for ..."

[Henjo Hoeksma]

Hi list,

I am new to ExtBase / Fluid and am intrigued :-)

I run into a fluid issue though when trying to use images. I get the 
error: "Could not get image resource for " followed by the filename.

My Fluid looks like this:
<f:image src="{product.image}" width="50" alt="{product.name}" />

My Model uses:
	/**
	 * Image of the product
	 * @var string
	 */
	protected $image;

What am I missing?

Is there a way to provide a 'if no file show custom error msg' option?

Thanks!

Henjo