The DPI You Should Be Scanning Your Paper Photographs

by | Last updated Sep 12, 2019 | Featured Post, Scanning Photos | 204 comments

Scanning DPI list of values - Epson Scan (graphic)

One of the most important decisions you face when scanning anything with your scanner is choosing what dpi (“dots per inch”) to scan with. 

And specifically for this post, what is the best DPI to use when scanning and archiving your 8×10″ and smaller paper photographic prints — which for most people, make up the majority of our pre-digital collection.

Making this decision was very challenging for me and certainly a huge part of my 8-year delay. The reason for this is that dpi (sometimes also interchangeably referred to as ppi for “pixels per inch”) is the critical variable in determining several important outcomes for your scanned digital images:

  • Detail – how much image detail you will extract from your photograph
  • Image Size – how much resolution in pixels you will have to work with (e.g. 2400 x 3000 pixels)
  • File Size – how large the file size will become (e.g. 64.9 MB or 64,878,462 bytes)

It's definitely a decision you want to make before you complete your very first scan. Trust me, you don't want to get halfway through your collection and realize you scanned too high, and your computer is running sluggishly and your image quality looks weird — soft and pixelated. Or worse, you find out you could have been extracting more image detail from your prints if you had just chosen a slightly higher dpi, to begin with.

Finding a Manageable Scanning DPI Game Plan

When trying to decide which dpi to scan and archive your photos with, the “big picture” that you want to keep in mind is the following:

What dpi should we scan our paper photographs with that will capture as much detail stored in them as we possibly can, will create a manageable file size, but will also produce enough image resolution should we choose to do some radical cropping, print them out to an average-sized enlargement on photo paper, or display them on high-definition monitors and televisions.

If you study the routine of a professional photo restorer, you will learn they tend to see each photograph as a separate unique challenge — like a doctor attending to an ailing patient for the first time.

It's a laborious investigative process for them. They may even scan each print several times with varying dpi's, carefully comparing each image until they find the most appropriate dpi for the photo's personalized workflow.

Because you probably have anywhere from hundreds to thousands of photos in your family's collection, it's not practical or even reasonable for me to suggest we would ever want to attempt such perfectionism. So, to make things manageable, I wanted to come up with scanning dpi values that we could all use that would be easy for all of us.

The Best Scanning DPI for Your Paper Prints

Most everything you will need to know to decide which DPI to scan your photos with, including my recommended dpi value(s) you should use, is discussed in the special video right below here.

The video is a section taken from one of my lessons on scanner settings in my video training course on scanning and organizing photos. Until now you needed to be a Member, but for a limited time, I've made this particular section on “The Best Scanning DPI for Paper Prints” available for you to watch too.

Think of this as a Mini-Lesson on learning the the best way to set your scanner DPI setting for your photo collections!

Start Here With This Mini-Lesson

Additional Information:

And here are some other important points that aren't mentioned in the video above that will also help you understand how your scanner works and how the dpi selection will affect your family's photo collection.

Problems When Choosing a DPI Based on the Time Required to Scan

One of the biggest mistakes I find people make when choosing the dpi is allowing the length of time it takes to complete the scan influence their decision. Those new to scanning may be surprised to learn that the higher the dpi, the longer it takes for the scanner to make its capturing pass and for the computer the process the information. I've recorded for you the time it takes the Epson Perfection v600 flatbed scanner to complete scans with various dpi's set.

Scanning Photos DPI - Five Women imageScanning Times for a 3.5×3.5″ Print on an Epson Perfection V600
DPI 150 300 400 600 800 1200 2400 3200 4800
Time Elapsed (mins:sec) :11 :12 :14 :18 :31 1:02 2:34 3:53 6:37

You can see there is, in fact, a vast difference in the amount of time required to scan at one of its lowest settings (150 dpi) and scanning with one of its highest (4800 dpi). But more importantly, I want you to notice the time it takes to scan between the range of 300 dpi through 800 dpi. It's relatively almost the same length of time. On this model, we are only talking about a difference of 19 seconds. And specifically between 300 and 600 dpi, it's only a measly 6 seconds.

If you're about to purchase a new scanner, and you're looking for an affordable flatbed scanner, I would highly recommend either the Epson Perfection V550 or the Epson Perfection V600.

Epson Perfection V550 Photo Film and Document Scanner Epson Perfection V600 Photo - 530x500

Epson Perfection V550

Epson Perfection V600

Check Price

Check Price

All scanners scan at different speeds so your scanner may or may not be slower than this model. But if it is, chances are the percentage of time between each of the dpi settings will be very similar. Regardless, if you think you are going to be one of the ones waiting impatiently for your scanner to work its magic on a higher dpi, I would like you to remember this. Scanning and archiving your family's photo collection is an investment. It's going to be an investment of your time and energy, and for that reason, more than likely, you will only want to do this project one time.

I believe it's worth a few extra moments to ensure your image quality isn't being compromised by rushing the process. Open wounds need time to heal, baking dough needs time to rise, and photo scanners need time to scan. See where I'm going here?

To fill the extra time, consider taking an extra long sip of your nonfat mocha latte, play solitaire, have a television on next to your scanner, or better yet – lightly dust off your next photo to be scanned with a lint-free cloth!

Are You Looking for the Fastest Flatbed Scanners?

However, if you are shopping for a new scanner, and you really want the fastest model, then I would recommend either the Epson Perfection V800 or the Epson Perfection V850.

Photo scanner with lid open - Epson Perfection V850 Pro

Epson Perfection V800

Epson Perfection V850

Check Price

Check Price

Optical Resolutions vs. Digital

The really high resolutions, however — 2400, 3200 and 4800 dpi — are really intended for capturing really small and highly detailed sources like film negatives and slides.

If you want to experiment with these resolutions, just make sure you stay away from the “digital” ones. On the box your scanner or printer/scanner combo came in, you will see a rating with two numbers. The Epson Perfection v600, for example, is rated for 6400 x 9600 dpi of resolution. The first number is the highest “optical” resolution your scanner is capable of, and therefore the highest dpi you should ever scan with. The second number is often the highest resolution it's capable of scanning digitally — faking the results by interpolating the data. Thankfully, some scanning software now won't even let you select the digital dpi's from the list.

In the case of the Epson Perfection v600, the maximum “digital” resolution is actually 12,800 dpi, much higher than the second number given. So you may need to consult your specifications printed on the box or find it in the printed or .pdf manual if you are curious about your scanner's digital capabilities.

Epson v600 Scanner dpi ratings on outside of box

The Advantage of Having All of This Archived Image Resolution

In the end, there won't be any benefit to having our entire collection in a digital format if we aren't able to make paper prints from them like we can with our film negatives. Just like we need a certain amount of “dpi” to capture images into the computer, we need a certain amount to print them back out to paper. The larger the piece of paper you want to print on, the more image resolution you are going to need in your digital files.

Printers today need on average between 200 and 300 ppi (dpi) of image resolution information to print a high-quality image on high-quality paper. And I am going to make the assumption that most of us seldom print out a photograph larger than 8×10 inches. Which is good, because almost all of the printers out there won't even print larger than 8×10 inches!

I know you probably hate math as much as the next person, so don't worry – I'll do it for you. What this means is that in order to print out a photo on an 8×10″ piece of paper, we need up to a 2400 x 3000 ppi (dpi) image. Here's my work:

(8 inches  x  300 ppi)  x  (10 inches  x  300 ppi)  =  2400 pixels x 3000 pixels

Given a choice, without a doubt in my mind, it's better to scan too high than to scan too low.

And if you don't want to take just my word for it (grin), when I started learning all about scanning years ago, I found great comfort in this quote from Wayne Fulton of scantips.com and kept going back to it:

It is true that if the image might be resized after the scan, it's always much better quality to resize to reduce the image size rather than to resize to increase the image size. If you aren't sure what your future intentions for the image might be, and won't be able to scan it again, then it's probably best to err on the large side (if storage space allows, up to reasonable amounts anyway). Resizing to be smaller discards excess pixels. But resizing to be larger must create (or fake) new interpolated pixels which were not in the original scan. There is no additional detail possible in interpolated pixels, even if the image is larger. The results are not at all the same as scanning at the higher resolution.

Conclusion

Alright, again, if you haven't watched the special video above, I would highly recommend you watch it. Most of the information you need to know is in this easy to follow mini-lesson.

After watching the video and reading this article, has this made you change your mind one way or the other? Tell me what you think about all of this in the comment section below. I'd love to hear your thoughts.

Related Posts

Aiming for the Stars to Hit a Cowpie — My Enlightening Scanning Journey

Aiming for the Stars to Hit a Cowpie — My Enlightening Scanning Journey

As a Wyoming farm gal, I was raised with the phrase “It’s better to aim for the stars and miss than to aim for a cowpie and hit.” Well, that’s great advice … unless your goal actually is to hit the cowpie.

My scanning goal really was that simple, but for some reason, aiming at the cowpie just wasn’t working. So I changed strategies and aimed for the stars. The result? Read on to find out. And hopefully, by sharing my scanning journey, it will help you on your scanning journey.

Scanning All of Our Family Photos … What's the Actual Point?

Scanning All of Our Family Photos … What's the Actual Point?

For anyone with children, or with other family members such as nieces or nephews, the answer to whether or not we should scan our old family prints, slides and negatives may seem quite obvious.

But, when I received this email from Jennie, asking me why she should go through all the trouble of taking on such a big scanning and organizing project when she doesn't have younger family to pass it on to, I was struck with the thought that many of you might be asking yourselves the same question. Maybe even for some of you who actually do have family to pass your scanned collections on to!

If you don't have or know anyone that will truly cherish your scanned photo collection once you've passed, is there even a single reason to scan any of your old family photos?

A 70-Year-Old Silver Surfer Scans Her Entire Life!

A 70-Year-Old Silver Surfer Scans Her Entire Life!

Being a man of action as well as words, my son Mark bought me a slide scanner and taught me how to use it. I scanned in the slides of the Holy Land without much difficulty. I was delighted to be able to view them on my computer with the same ease as I could view the digital photographs that I had started taking in 1999.

The remainder of the slides came first. Then I started work on the prints in the photograph albums that I had lovingly curated over the decades. The physical albums had started to deteriorate to the extent that some of them were falling apart. Scanning the prints was an ideal way to remedy this. I also scanned in all the prints that had not made the cut for the photograph albums but I had kept nevertheless. I also spent several months scanning in approximately 4,000 negatives. All in all I must have scanned nearly ten thousand photographs in one form or another.

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Henry
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Henry

Hi, thanks for all the information here. I have an Epson Perfection V600 Photo, but I can't get to scan my photos beyond 2400 at 48 bit because a message would pop up asking me to reduce resolution. According to the EPSON website: “EPSON Scan Professional Mode has a maximum pixel count of 21000 x 30000”. Is there any way around this so hat I can scan at 4800 with 48-bit? Maybe another software? In case there isn't any, I guess is better to reduce resolution than to switch to 24-bit, correct? Thank you in advance!

Joette
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Joette

I want to scan some old photo's and I scanned them at 600 dpi on my HP photosmart premium printer/scanner. the picture sizes range from 2×3 upo to 5×7., and just a few at 9×10's.
I this a good setting. I don't expect when reprinting the photos to enlarge them beyond 5×7's in the future.
Secondly, I have some very very old photos dated back to 1800's and early 1900 and I am having a problem scanning them in with reasonable quality,

Pete A
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Pete A

Looking at a slightly different problem. My mother has 15 print albums, each with at least 50 pages. Each page has a variable number of pictures on it. They are glued in place, and encased in a plastic overlay. It is impractical to remove the pictures and scan each individually. The WHOLE PAGE scans well even with the plastic overlay.

BUT, I then have to crop each individual picture into its own file, and “blow it up” to a reasonable print size. For example, one page might hav3 3 2×2 pics and one 5×7. Other pages might have 6 2×2's and another might have one 8×10.

So far, I've experimented with 1200ppi and the cropped images work out reasonably well. BUT, as you note, the scan time and the file size are long/large.

I'm thinking there is no general solution, but I'm loathe to set & forget at 1200, and MORE loath to analyze each of the 750 pages I need to scan. I think the quality loss at 600 is too much for the smaller pictures, unless I just abandon ever expanding the small ones into bigger prints (or monitor displays).

Any ideas?
Pete A

Cormack
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Cormack

Are you using the scanners supplied software to scan? My HP scanner has an option to scan multiple photos on one page and crops them itself – it first of all scans a quick preview image and then suggests photos it has found – you can edit the areas or add new areas to any photos it hasn't detected correctly, it then scans each individually. This scanner is about 10 years old and the software of similar age, so I would of preumed new scanners have such a feature?

Hope this helps

michael parle
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michael parle

very helpful thanks

Emile
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Emile

Thanks this was helpful

Chris
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Chris

Dear Curtis,

Hello! I found your article above to be very helpful…Thanks! But I had a question I was hoping you could help me with before I invest in a photo scanner (I'll probably buy the one you use).

After scanning in slides and negatives, will they appear as a regular photo and much larger on the computer screen, or will the images remain super tiny, true to life size? My family primarily wants to just view photos, slides, & negatives on our computers.

Thanks so much and have a great day!

Sincerely,

Chris

David
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David

You are right – you are terrible at math. You have a units problem in you calculation. You calculate the total number of pixels, NOT dpi or ppi. The “i” (inch) in dpi/ppi goes away when you multiply by photo size in inches. But you lead the reader to beliece that is the resolution they should scan at (i 2400 x 3000).

It would be helpful to relate the various scan resolutions to equivalent megapixels. For your example, the scanned 2400×3000 pixel image is equivalent to taking the picture with a 7.2 megapixel digital camera. People can relate to that better

Axel
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Axel

Curtis,
Thanks for a fantastic post. Over the past few years, I have been thinking about this project, scanning old photos & capturing over 25 years of family activities. Now that I am ready, I had several wondering thoughts and questions, and this post just put all of them to rest. I also wanted to let you know of the good scanner I found, plustek ePhoto, 600PPI that is reasonably fast and easy to use.
Axel.

Anne
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Anne

I noticed that you only use flat scanners. Have you ever used a self feeding scanner? I don’t want to sit by my scanner all day. Please reply!