The Best Resolution (DPI) for Scanning Film

Optimal Settings for Web/Social, Print, and Archiving Film Scans

7 min read by Dmitri.
Published on June 7, 2021. Updated on July 3, 2024.

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35mm film is estimated to have about 20 megapixels worth of visual data¹ which requires scanning it at around 4,000DPI. However, your goals for the image and the tools you have available will determine the best scanning resolution for your project.

In this guide: The best scan resolution for the Web. The best scan resolution for making prints. The best scan resolution for archiving film negatives. Glossary. Book reference. Support this blog & get premium features with GOLD memberships!

A 400% crop from a CineStill 50D scan at 75DPI (left) vs. 5,000DPI (right).

This guide should lay your options out in detail so that you can make the best possible decision for your film scans. I will go over three scanning scenarios, each with distinct requirements: the Web, print, and archiving.

DPI isn’t the only value you’ll need to consider when scanning nor is it as straightforward as some may think. Here, you will find a full explanation of what it really means, as well as other important attributes like DMax and bit-depth.

✪ Note: To get acquainted with the terms used in this article, have a look at the glossary below.

If you’re looking for quick answers: read the first paragraph of either Web, print, or archiving sections.

Don’t forget to bookmark!

The best scan resolution for the Web.

35mm film will work best on the web when scanned at 2,700DPI and saved as a JPEG file with compression set to 80. Medium format will produce a similar file when scanned at just 1,200DPI. 4x5 only needs 650DPI, and 8x10 will do fine at 320DPI.

This website features some of the highest-resolution images on the web at 3,000 pixels wide. Instagram downsizes everything to 1080 pixels wide. Other sites like Twitter, Flickr, or photographer portfolio websites may allow higher-res scans; however, that isn’t always a practical resolution for casual viewing.

Web browsers can resize huge images to fit on the screen, but the weight of the image file will affect their performance. In my experience as a web designer, developer, and active sharer of images online, photos that are 2,500 pixels wide tend to work best for most web or app uploads. Many websites and apps have a cutoff of 5MB for image uploads, making that a good target maximum.

Your image’s height, compression, and content can dramatically affect the file size. I found that 2,500-pixel-wide images saved as JPEGs with the quality set to 80 usually fit well within the 5MB.

Assuming that 2,500-pixel dimension is the minimum for the sake of vertical image scans, we are looking at 2,500 / 0.94” ≅ 2,700DPI for 35mm film (where .94” is the frame height, converted from 24mm — 35mm includes borders and sprocket holes that we discard). Using the same formula of 2,500 / frame height in inches, we get ≅ 1,200DPI for medium format, ≅ 650DPI for 4x5 large format and ≅ 320DPI for 8x10.

If you’re scanning 110 film and looking for the same 2,500 pixels on the short side, you’ll need to scan it at nearly 5,000DPI.

✪ Note: Keep in mind the differences between the interpolated and optical scanner resolutions. Consider saving your scans as TIFFs or other non-lossy formats at 16-bit per pixel (if you have that option) in addition to your JPEGs — this may help you get better results if you plan to edit your scans or invert the negatives by yourself.

The best scan resolution for making prints.

35mm film should be scanned at 2,700DPI for 8x10” prints and saved as a TIFF file. Medium format will produce a similar file when scanned at just 1,200DPI. 4x5 only needs 650DPI, and 8x10 will do fine at 320DPI.

There’s barely any limit to what you can do with print, so I’ll focus on 8x10”-sized paper, which fits perfectly on the standard A4/Letter paper. The scan file that works for 8x10” will do even better for smaller print sizes. Assuming that you’ll be printing at 300DPI — perhaps the most quoted recommended resolution for print.

Turns out that an 8x10” print at 300DPI will need 2,400 pixels on the short side, which is almost the same as the 2,500 recommended for the Web above. But instead of a JPEG, I suggest you save your images as TIFFs for optimal print quality.

Other formats also have similar requirements for 8x10” prints as they do for the web.

✪ Note: If you’re planning to crop your images, you may want to scan at a higher resolution. Larger prints at the same pixel density are easy to extrapolate from the above figures.

The best scan resolution for archiving film negatives.

If you plan to archive your film digitally, scan it at the maximum optical resolution and save it in uncompressed TIFF or RAW files. Consider other constraints, such as storage space and your time. Limit large format scans to 2GB for practicality and device compatibility.

You may want to scan once to keep a future-proof digital copy of your film. For this, you will obviously want the highest resolution possible so that your file may be good for the enormous prints and ultra-high-resolution displays of the future. However, you will still be limited by the amount of storage space you have available and some false promises written on the box of your scanner.

A single 16-bit TIFF file scanned at 5,000DPI from 35mm film can take up to seven hundred megabytes of disk space. On my machine, I have nearly 6,000 scans which weigh close to 1.5 terabytes.

If you are prepared to invest in digital storage, top-resolution scans are what you want. But make sure that you figure out your scanner’s optical resolution and use that as the max to avoid wasting your space on interpolated pixels.

4,000DPI, according to one estimation, is the maximum visual resolution an ISO100 film may carry. This, of course, does not take into account slower speed films and the value of grain detail. However, you will need to consider the trade-offs when scanning large format film at 4K+ DPI, which can easily swell to over 1,280MP (≅ 3.5GB+) with an 8x10.

Mind that your scanner resolution and bit-depth aren’t the only factors in the scan quality. A higher DMax resolution will do a better reading of highlights on your negatives; the software and the scanner hardware may also play a role.

You may also want to consider making backups and/or paying for cloud storage service as a failsafe for failed hard drives and general data loss.

☝︎Further reading: “How to Store & Organize Film & Film Scans” — useful advice for digital and physical film archival techniques.

Glossary.

Bit depth (image) — a number of bits of colour assigned to a single pixel. All JPEG images are 8-bit per channel (red, green, blue) or 24-bit in total. TIFF and RAW images can have 16-bit per channel or 48-bit+ in total. A higher bitrate will provide greater flexibility when editing images and a larger file size. The total number of colours in 1-bit is 2 (2¹), 2-bit is 4 (2²), 4-bit is 16 (2⁴), 8-bit is 256 (2⁸), 24-bit is 16,777,216 (2²⁴), etc.

DMax — a maximum density of silver halide crystals that the scanner can distinguish. Higher DMax scanner capability will let you preserve more detail in your negatives’ highlights.

DPI, dots per inch — a number of pixels assigned for a single inch of an output of an image. 1MP image can be printed at 3⅓ ✕ 3⅓ inches at 300DPI. Note that the same 1MP image can be printed at 10 ✕ 10 inches at 100DPI.

JPEG — the most popular image encoding format, particularly on the Web. All JPEG images are 8-bit per channel (red, green, blue). They are compressed with some data loss.

MP, megapixel — one million pixels. An image measuring 1,000 by 1,000 pixels is 1,000 ✕ 1,000 = 1,000,000 (1MP).

PPI, points per inch — this is a print resolution. A printer may print an image set at 300DPI at a resolution of 1,200PPI — in which case 4 dots of printer ink will make up a single pixel.

Scanner interpolated resolution — total pixels/dots per inch (DPI) the scanner can generate from a single inch of film after computationally increasing that number using an algorithm. For example, when you resize your 1,000 ✕ 1,000 pixel image to 2,000 ✕ 2,000 in Photoshop, you are interpolating a 1MP image into a 4MP image, but you are not adding any real-world data.

Scanner optical resolution — total pixels/dots per inch (DPI) the scanner can generate from a single inch of film.

TIFF — is a popular format for lossless image storage with applications in print, image manipulation, and archiving. TIFF images may be compressed (without data loss), and they may be 16-bit per channel.

Book reference.

1. Langford, Michael (2000). Basic Photography (7th Ed.). Focal Press.

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jmbehave Dec 16, ‘22

nice to meet you dimitri, (ala the web) I am a film photographer who has experimented with making digital negs from numerous film sources including 35, 6x6medium, 4x5 an antique glass negs some as large as 8x10 .I am new to the primefilm xas. I appreciate your review as I have over 5-7 k negs I need to “digitalize”.I prefer the cloud BUT size may force me to external drive.(or justmake jpg untilI need to print and then make TIFF.

BTW check out if you haven‘t already the SilverFast 9 update . It is much better than the 8 which I hated also. thank you

Dmitri Author Dec 16, ‘22

Hello!

Good luck with your project, and I’ll check out SilverFast 9 if I get a chance. 👍

Nageswararao Yakama Sep 17, ‘23

i want positive film (like movie film). i want to make view master reels. my own reels. can you give me idea.

Dmitri Author Sep 17, ‘23

Hi Nageswararo,

I’m not an expert on moving picture film but as far as I know, there are three ways of doing this:

1) Shoot and develop a positive. For colour, you can use Ektachrome E100 — which is an excellent film that’s been recently revived and is produced new. I have a review of it here: analog.cafe/r/kodak-ektach…

You will need to develop your Ektachrome in E-6 chemistry. You can also develop some black and white films as a positive (a different process) — but that depends on the lab and whether that film has a clear enough base.

2) Shoot negative, scan, then transfer to positive film. This may be expensive. Essentially, you’ll shoot, develop, scan, edit, and then use a machine that can transfer your digital images onto positive film and then develop that. This method also gives you a lot of flexibility when it comes to image quality, effects, etc. Some modern Hollywood films are made this way.

3) Shoot negative and then directly transfer to positive. Essentially, it’ll be your developed negatives that will be projected on suitable emulsion using a machine. I know the least about this method other than it’s common in the industry.

I hope this helps!

The best scan resolution for the Web.

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Dmitri