Apple told me the mid-2012 model Macbook Pro can't take more than 8GB ram. Is this true?

I would like to purchase the 500gb Macbook Pro but they told me that it can't accept more than 8GB ram. Is this true?

I use the laptop for editing wedding photos because I'm a wedding photographer. Large raw files from my Nikon d810 will be used.

Or should I go with the retnia display… Does it make a difference when editing photos? I don't feel like I'm sold on it… Unless someone can explain the benefits to me.

Mid-2012 Macbook Pro non-Retina can swap the ram for 2x8gb
https://en.wikipedia.org/...acBook_Pro
http://www.crucial.com/...9-mid-2012

Apple makes their Macbooks less and less upgradable so they can make the profit at time of purchase.
Retina models are soldered ram and not upgradable. You may find a 15 inch used 2012 Retina with the 16gb ram option.

The Retina display is higher resolution, so if photos are high resolution certainly fully displaying the pixels is useful.