Recently, I’ve received some questions from readers regarding the recommended resolution for photos when making photo books. It’s a good question and I’ve decided to add this post into my “how to” series on making photo books. This is post number 6 in the series!
The best advice I can give you on this point is: “Don’t sweat it.”
Really? Really. I’ve never really worried about photo resolution in the past, and my photo books have come out with high quality results. Really. (Especially with the advent of camera phones with ever-improving picture quality, it’s even less of a worry now.)
Now I know that for some of you, that answer may be good enough and you’re off to make your photo book without a second thought, but for those of you who actually like my verbose and sometimes rambling posts…don’t worry I didn’t forget about you! I did a lot of reading over the last couple of days and I will tell you, the information out there is conflicting and confusing, and every other article says other articles have it wrong.
Oh, and advance warning folks – we will do some math, but I hope that after reading this post, you will come away with a greater understanding of the topic.
Q: What is the right resolution or dpi for photos when making a photo book?
A: The recommended dpi from the photo book companies is generally 300dpi.
Pixel – the smallest element that makes up an image (generally the more pixels the better the image quality)
Resolution – the number of dots or pixels that make up an image
DPI – dots per inch (used when discussing print resolution)
PPI – pixels per inch (used when discussing screen resolution, like on your computer screen for example)
Oh no! My photos are only 72 dpi! If I try to make a photo book with 72 dpi photos and the printers recommend 300 dpi, won’t my photo book turn out bad?
The above is a screenshot from Adobe Photoshop. This photo was taken with my 5 megapixel Sony Cyber-shot T7. If you look at the box marked “Resolution” you’ll see a number of “72”. Similarly, when I open up a photo taken by my brand new Nikon D90 DSLR shot in RAW format (the format that allows you to capture the most pixels, preferred by pros), I get 240 dpi.
How can it be that a quality 12.3 megapixel DSLR at it’s highest setting, can’t take photos acceptable for photo books?
The 72 dpi, 180 dpi, or 240 dpi that shows when you open the photo in Photoshop or a similar photo editing program is not relevant at all. It’s a made up number. It’s easy to see why this may mislead you to think your photos are not good enough to put in a photo book.
What we need to pay attention to is the photo’s pixel dimensions.
The photo below was taken with my 9.1 megapixel Panasonic Lumix camera.
Don’t have Photoshop? You don’t need it to check the dimensions of your photos. You can right click on the photo and select “Properties” on a PC or “Get Info” on a Mac. The following window opens (or very similar window on a PC) and it will contain the data you’re looking for. I believe you can even hover over a photo on a PC and its pixel dimensions will pop up.
Now armed with that information, if you want to know the maximum recommended print size for your photo, you have to do a little math.
So, if the photo book printers recommend 300 dpi and your photo is 2592 x 1944 (about 5 megapixels), divide each dimension by 300. You get 8.6 x 6.5 inches. So, that means you can safely place this photo in a container or photo box in your book layout of that size (or less). I have read that you can safely stretch that further to as low as 225 dpi (resulting in a size of 11.5 x 8.6 inches) and the result will still be fine.
According to a post written by a Blurb user, that warning symbol that pops up to tell you your image is not of sufficient resolution doesn’t trigger until you get down to 150dpi. Therefore, that user doesn’t recommend that you trust the warning symbol. Note that we’re only talking about Blurb, and not necessarily for other companies. If you follow my tips however, you shouldn’t see the warning symbol pop up.
(UPDATE 1/16/2015) On the rare occasion I want to use a photo with small pixel dimensions (maybe a friend’s Facebook photo that wasn’t uploaded at high quality or a random screenshot), I personally haven’t had an issue going along with the warning symbols in any photo book software. If I still want to use that photo, I just reduce the size of the photo box until the symbol disappears and maybe a small touch more for peace of mind.
Below is a chart I created showing some typical cameras covering a range of megapixel outputs. You should be able to pick one that’s similar to your camera. Note that I recently updated this post to add the details on the iPhone 6 and iPhone 6 Plus – phone camera have come a long, long way since my original post!
||Pixel Dimensions||Max. Recommended Print Size (300 dpi)
||Acceptable Print Size (225 dpi)
|Sony 5.1MP||2592 x 1944||8.6 x 6.5||11.5 x 8.6|
|Panasonic Lumix 9.1MP||3456 x 2592||11.5 x 8.6||15.3 x 11.5|
|Canon (used in AdoramaPix wedding book)||3861 x 2574||12.9 x 8.6||17.2 x 11.4|
|Nikon D90 12.3MP||4288 x 2848||14.3 x 9.5||19.1 x 12.7|
|NEW* iPhone 6 and iPhone 6 Plus 8MP||3264 x 2448||11 x 8.2||14.5 x 11|
If you want to see a sample of how my photos printed out, let’s look at the third row – the photos taken by the Canon DSLR, provided by my wedding photographer. Although at the recommended 300 dpi the maximum size is about 12.9 x 8.6 inches, I successfully used these photos to do full two-page bleeds in an 8 x 10 portrait book. Therefore, I stretched the photos to fit a spread of 16 x 10 inches without any problems, which as you can see from the chart, falls within the “acceptable” range. You can see that book in my review of my lay-flat AdoramaPix photo book.
On a not-so-successful attempt, I made a very large 15 x 11.5 book and stretched the photos taken with the 9.1 megapixel Panasonic to a whopping 30 inches across and surprise – those didn’t come out as clearly as I would like. There was definite pixelation and the lack of resolution is noticeable. Note that the chart above tells me that my image should work as a full-page bleed on a single 15 x 11.5 page of that size book, but 30 inches across was definitely getting greedy. So, unless you’re making a super huge book, you’re images are going to be fine 99.99% of the time!
(Image of the large book to come – I didn’t get a chance to photograph it yet…)
Note in many cases, even though you’re making an 11 x 8.5 photo book, you’re probably not making every page a full-page bleed. On some pages, you may have 4 or 5 photos. So, even if you are using photos taken with an older 5-megapixel camera like my (now ancient) Sony point-and-shoot, you should have no problem using them in an 11 x 8.5 photo book (the most common size offered by the photo book companies). Lots of my photobooks have images (including full page bleeds) that were taken with that camera and they came out great. (Notice that the calculations show that an “acceptable” print size for the Sony is 11.5 x 8.6. A surprising “real world” application for math!) Check out the photos and images of my photobooks using images taken with the Sony 5 megapixel camera.
- Don’t pay attention to the dpi numbers (commonly 72 dpi, 180 dpi or 240 dpi) out of context – they don’t mean anything on their own;
- Also look at the corresponding pixel dimensions (i.e. 2592 x 1944 or 3861 x 2574);
- Divide the each measurement by 300 to get the maximum size in inches recommended as the print size for your images.
- Bottom line, if you’re concerned about print quality, get yourself a 16GB memory card (even I can’t fill one of those on a single trip), shoot your photos at the highest possible setting allowed by your camera and don’t worry about it!
Links to some articles I read that helped me understand these concepts better:
PPI / DPI / Pixels / Resolution / Scanning / Aspect Ratios…Explained! by Blurb member lkb-28
The Myth of DPI by Ken Watson