This lesson shows you how various camera sensor sizes (35mm, APS-C, Micro 4/3, etc.) affect lens focal length, f-stops, resolution and noise. There's a great spreadsheet included that makes doing conversions easy which is useful when comparing different camera and lens combinations.Note: The downloadable spreadsheet that comes with this lesson has been compressed into a .zip archive. That means you'll have to double-click on it after downloading to extract its contents before attempting to view the spreadsheet. The file that ends in .numbers can be opened using Apple's Numbers spreadsheet, while the file that ends in .xlsx can be opened in Microsoft Excel. If you have neither of those programs, then you should be able to import the Excel file into Google sheets online spreadsheet. A quick google search should be all that's needed to figure out how to open the excel file in that online program.