It appears that full frame cameras have reached a level of maximum pixel counts, or at least have considerably slowed in being offered with ever increasing resolution. It used to be that the industry was doing a great job in convincing the general public that the higher the number of pixels, the better the camera. This was definitely the case when we had to deal with 1 or 2 megapixel cameras. But those days have definitely gone, and manufacturers have put more effort into improving sensors other than just increasing the number of pixels offered. We now have cameras with incredible ISO sensitivities, low noise, great color accuracy, high res video capability etc.
So the question is, how big an enlargement one could one possibly make with a high quality, full frame sensor. I researched the topic and wasn’t able to come up with anything definite.
Being that today’s full frame sensors use the same image dimension as 35mm film, I included 35mm in the equation. That doesn’t mean that we can simply equate a 35mm negative with files obtained from a full frame sensor, as a mater of fact, there are several factors that lead to a slight image degradation with film that do not exist with digital sensors. Based on that, one can reasonable expect that a high quality full frame sensor can deliver a sharper image than a 35mm negative.
Ernst Haas image chosen for the Kodak Colorama
The biggest enlargement ever made of a 35mm photograph was the one for the Kodak Colorama at Grand Central Station in New York in 1977. The original picture was taken by Ernst Haas with a Leicaflex SL and a 50mm Summicron-R lens on Kodachrome 25. The finished Colorama consisted of 20 vertical panels of 3 feet width and 18 feet height for a total size of 18 x 60 feet This was the first time a 35mm picture had been used for this project. It presents a 508 times enlargement to achieve the width of the image. It was a definite testament of the quality of the film and that of the Leica camera and lens.
Based on modern sensor technology, we can reasonably expect enlargements of the Kodak Colorama size to be as good or better than what was done back in 1977.