As i am hopeing to create a brand with on half being a retro version of the other i thought i would look at how well know brand logos have changed over the years to give me an idea of how different my two logos should look. I found this website that shows a few logo evolutions. http://www.hongkiat.com/blog/logo-evolution/
From looking at these i have noticed that there is usually an element of the logo which is consistent even over many years of change, whether it be colours used of certain pattern or shape. For example if we look at the pepsi logo, from 1950 up to today the logo has kept the same rounded shape with the three colours red white and blue with some kinds of wave in the centre. There is a consistency in the design which allows the public to instantly recognise the logo as pepsi even if was from the 1950 or today. The logos seem to become more simplified over time. This is somthing i need to take into account when creating my logos, they will both have to be recognisably the same brand even though one is vintage in style.