I’ve worked with many developing labs that use a variety of machines to scan their negatives. It was only when I finally decided to print my own images that the quality of the scan became important to me. Luckily I now understand where to get the best quality scans and how large those scans can be printed. I’ve put together my own research and chatted with experts to give you the answers you need.
The resolution of 35mm film is around 50MP if scanned by some of the top scanners. Drum scanners could produce a much bigger resolution but after 50MP there isn’t much to gain from 35mm. As most developing labs scan at a maximum of 25-35MP, you could print up to A2 without losing quality. Going beyond A2 will mean grain will be more visible and the quality of your image will start to suffer.
The ‘resolution’ of 35mm film isn’t exact and can depend on a few important things, over the rest of the article I’ll explain what else affects the resolution of your image and how large you can go with print sizes.
How large can the resolution of 35mm get?
I wanted to make this article as easy to understand as possible for beginners by trying to use less jargon than I saw while doing research. Most of the information available is somewhat out of date due to the machinery that’s currently available and most people just seem to want a simple answer.
I got in contact with the people at take it easy to see what they had to say on the matter.
It seems that most developing labs don’t use things like ‘drum scanners’ or ‘pro flat-beds’ because they’re incredibly expensive and much more specialized. As I checked myself, I saw the cost of a drum scan of a single 35mm image was $35 with an overall file size of 700MB. This may be a very high-quality file but for most of us, we’ll simply never need such large files for our images. I can only see that it might be useful for professionals that want to print their images at A0 or larger, in which case you might expect that they’d be.
So most 35mm film can be scanned at 100MP if you have the machinery for it however, most top labs could potentially get 50MP out of your 35mm film and that depends on a number of things which I’ll cover in a moment. At 50MP you’ll probably have all of the information that you could want. Even at 18-25MP you still have a very high-quality image.
What Else Affects The Resolution?
Although the capabilities of the scanner of obviously important, it seems that there are some other aspects that add to the final quality of your negatives.
- One of the key things that impact your final scan is the ISO of the film, low ISO film will allow you to take a much larger final scan than high ISO film due to grain. So your Ektar 100 will allow you a higher quality scan than Portra 400.
- The quality of your lens can also be an impact, a lower quality lens will mean lower resolution and ultimately a lesser image.
- The taking of the image. If it’s shot well.
- Shutter speed. Higher shutter speeds can effect grain.
- Film age/quality (out of date film will usually be worse)
- Film processing and handling
This could seem like a complicated list of things to look out for but it really depends on what your overall goals are. If you actually want the clearest, highest quality image you can get, then don’t shoot 35mm, shoot with a medium format camera. If you want better quality 35mm images then look for lower ISO film, get a better lens and take your time while shooting, then ask your lab to scan at the highest quality, if their highest quality doesn’t cut it then shop around for somewhere that scans at higher res.
How Large Should I Be Printing 35mm?
The size you decide to print 35mm shots is really up to you, if your scans are around 30-40MP then your final print could happily be A2 without losing much quality and showing too much grain. After A2 it depends on your own personal preference, most of us that currently shoot film enjoy the look of grain and the loss of quality beyond A2 might actually suit our personal aesthetic choices.
Kodak famously produced a 40ft x 60ft image using Kodachrome, this is an extreme example but it demonstrates how far an image can be pushed, especially if the viewer is far away from it.
How Do I Calculate The Megapixels Of My Film Scan?
You can easily work out megapixels, most developing labs will show what their low, medium and high-resolution pixels will be. For instance, you may see it written as something like ‘6774 x 4492 pixel’, you will multiply those two numbers, then divide that number by 1,000,000, in this instance the scan will be 30.42 Megapixels.
I think that this information gives us a good understanding of what kind of quality we need from film scans and how we can affect the overall quality ourselves. Really, a good 35mm camera can still stand up to many DSLR’s and even if the quality isn’t quite as good, we still love film.