Content Comparison

...

The higher the better, anything above 14+ mega pixel , must be taken by a DSLR and not using iPhones/mobile devices with very importantly a good lens.

Automatic Turntable

It might help you to purchase this Turntable that uses an app on the iPhone to rotate the table by X degrees, it can also work with DSLR

Foldio360: Amazon.de: Electronics & Photo

JPEG MINI Application

Use JPEG mini to reduce the photo sizes with-out loosing any quality. 

http://www.jpegmini.com/app

Scan UPC barcodes to Excel sheet

Use an app on an iphone/android
Scan to Spreadsheet on the App Store (apple.com)

Or better is to simply buy a UPC scanner:

Tera Wireless Barcode Scanner Wireless 1D with Stand 2.4 GHz and USB Cable Handheld Scanner 100 m Range 3 Mil Resolution 32 Bit Decoder P54 with Instructions in German : Amazon.de: Stationery & Office Supplies

To track all the products been photographed.