But which came first?
Nicephore Niepce invented the first form of negative photography in 1826. It would take over a century before slides came onto the scene.
Negative photography quickly progressed over the decades as more scientists experimented with different chemicals and exposure times. In 1935, color photography for negatives was invented by Kodachrome.
Negative photography uses a reversal process in the photo development. In the 1940s, Ektachrome started producing slides (originally in the E-1 and E-2 format) that used positive transparencies in color photographs.
So what exactly is the difference between negatives and slides? Film slides show a positive image on a transparent base, whereas nagatives have a darker appearance that is reversed during scanning. Basically what this means is you can see the photo on a slide very well. But on negatives, it can be hard to tell what you’re looking at and the final appearance of the photograph is unclear because of the reversed colors.
Ektachrome first came out with E-1 roll film in the late 1940s. Their process started to advance until they invented the current format used today – E-6. E-6 slides were made in 1975.
E-1 through E-5 slides were invented first, but E-6 proved to be far superior because it was easier to process and didn’t require hazardous chemicals.
In the photo development world, slides are now universally referred to as E-6 and negatives are known as C-41. E-6 and C-41 can both be processed using the same equipment, but a lot of film developers prefer E-6 slides.
C-41 (negatives) is more likely to degrade and fade at a faster rate than E-6 film.
E-6 slides have a finer grain, higher resolution, and more pronounced sharpness.
On the other hand, negatives are easier to work with because they have a wide range of ISO speeds and exposure. But slides typically have more vivid colors for photographers who prefer vibrant images.
Long story short, negatives were invented in the 1830s and slides were invented in the 1940s. Both films have advanced greatly over the generations and have become exceptional mediums for producing photos. The two formats are quite different, so make sure to consider these distinctions before choosing your preferred film type.