Known Participant

Question

why does photoshop export 300 ppi image as 72 ppi?

Forum|Forum|9 years ago
November 13, 2016
18 replies
75825 views

why is it if i open an image in PS which has a dpi of 300 (image sourced from Shutterstock), work on the image and then use Export As JPG, the resulting ppi is 72 according to PS. I checked my Export Prefs and they are set to JPG and 100 for quality, so why does it export as 72 and not 300? I need to supply images in my document at 300dpi not 72dpi

This topic has been closed for replies.

Show previous replies

P

pasane

Inspiring

I'm having the same problem - only discovered it when I went to my online printer and asked for a print using image size and it was 41"!! It was then I discovered that the "Export As" was changing the ppi. I tried to use the "Save As" put the online printers didn't like that format...? So, I "Export As". Open the JPEG in photoshop, change the image size and ppi back to 300 and save - a bore to be sure but at least I end up with what I want.

I personally don't see the point of Adobe having a function like the "Export As" that doesn't save the settings prescribed - maybe they should fix it!

D Fosse

Community Expert

Re-reading this old and lengthy thread, it certainly took its time to get to the heart of the matter. But it finally did.

So again: Export is for web/screen/mobile. Pixels per inch does not apply for screen viewing. Since it is not needed, the ppi value is stripped from the file.

And in case you're wondering where the 72 number comes from, it's the Photoshop default when there is no resolution metadata present. Photoshop needs to have some ppi number for other unrelated reasons, but any number will do. Most native Windows applications will assign 96.

So you see, pasane, there is nothing to fix. This works entirely as intended.

O

Olga5DE5

Participating Frequently

Photoshop's online help does not mention anywehere that "Export is for web/screen/mobile". I think this was true with the legacy 'save for the web', but not for the new 'export as' anymore. So, I do not consider this the correct answer (anymore). In addition, I think a dpi setting is actually missing and Adobe should have add this to the export settings. A workaround is given by lesnicole and williamting below.

L

Lumigraphics

Legend

PPI data is saved in the TIFF metadata namespace. The pixels on disk do NOT change regardless of this setting.

If you save with a method that doesn't write that metadata, some programs default to 72ppi.

rob day

Community Expert

Here are the Save As formats that include the PPI resolution and print output dimensions:

L

Lumigraphics

Legend

ONLY if the tags are present in the proper namespace and if the viewer supports it.

This is like talking about color management. Lots of formats support color profiles, IF the creating program writes a profile tag and IF that is not deleted from metadata and IF the viewer also supports profiles.

J

juliana.alonso.art

Participant

Hi! You've posted this a long time ago, so I hope this helps you because I had the same problem.
Starting with a file set at 300 PPI with multiple layers I needed to export individually at 300 PPI. Using the Export/Layers to Files script gave me images at 72 PPI on JPG or PNG (so I could trim layers, otherwise all I needed were the JPGS). My work around this was to create a new file with the option for Artboards checked in, set to be 300 PPI. I dragged all the layers from the other file into the new one and individually converted each layer to an artboard. Each dartboard kept the size of each layer independently.

Then I went to File/Export?Artboards to files, chose the Export content only option, unchecked the "include background option" and my files were perfectly exported at 300 PPI and at the dimension of each individual artboard (no white background included).
I tried it to export dartboards as PNG files and it still saved them all at 72.

I hope this helps you!

L

LA7283

Participant

OMG I just read all of the posts and am worse off than when I started. I need to save 300 DPI files for an ETSY store to be downloaded for printing by the customer. They keep changing to 72 DPI. I "export as" and get it that I should use "save as" instead? So like the person who started the thread, I would like to understand why but think it might just cloud the issue more.

So is everyone SIMPLY saying that all I have to do is SAVE AS instead of EXPORT as?

Conrad_C

Community Expert

https://forums.adobe.com/people/rob+day wrote
HTML and CSS code has no ppi resolution property,

Yes & no. The W3C web standard for images is 96 pixels per inch, not 72. And it has been that way for many years. To illustrate my point, I prepared a little CSS pixels per inch test. No matter which display you use -- high res, low res or something in between -- 96 CSS pixels = the same length as 1 CSS inch. See screenshot taken from Firefoxr.

For anyone interested, I used the following HTML & CSS code.

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>CSS Pixels Per Inch Test</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<style>
body {
background: #555;
color: white;
width: 50%;
margin: 5vh auto;
}
.css-box > span {
display: inline-block;
height: 2rem;
border-right: 2px solid red;
}
.px72 > span {
width: 72px;
background: pink;
}
.px96 > span {
width: 96px;
background: aqua;
}
.inch > span {
width: 1in;
background: gold;
}
</style>
<body>
<h1>CSS pixels per inch test</h1>
<div class="css-box px72">72 pixels<br>
<span></span></div>
<div class="css-box px96">96 pixels<br>
<span></span></div>
<div class="css-box inch">1 inch<br>
<span></span></div>
</body>
</html>

The 72 ppi screen res was an Apple-only standard that didn't last long. Its origin dates back to the mid 1980's when Apple released its first Macintosh computers. The early Macs included a built-in 9 inch display with a screen resolution of 72 pixels per inch. Why 72 pixels per inch? Because the Mac screens were specifically designed to work with Apple's ImageWriter printers, which had a print res of 144 dots per inch - exactly twice the res of the screen. This made it easy to scale the screen display to the printed page for WYSIWYG rendering of graphics and text. Later on, as Apple began making larger displays for Macs, they made sure to keep the screen res set to the same 72 pixels per inch so users would always see an accurate on-screen preview of the printed document (as long as they were using an ImageWriter printer). Meanwhile, Apple's competitors had no reason to stick with 72 ppi res.

Today, 72 ppi screens are long gone. But for some strange reason, Photoshop still clings to this woefully outdated number as if it were the gold standard. And what's worse, the developers and some PS experts would like us all to believe that ppi is only relevant in print which is ridiculous. When I export 96 ppi images, I need the ppi setting to remain unchanged. The Export As feature used to work correctly. Now it's as badly broken as legacy Save For Web <shaking head>.

This is only going to add to the confusion, but it's important. When we say the CSS standard is 96 pixels per inch, it must be emphasized that does not mean 96 screen pixels. It means 96 CSS pixels. This is because a CSS pixel is not defined by any hardware. This is intentional, so that when a mobile/web designer specifies 96 pixels (or one inch) in a vector graphics program, it will appear more or less the same size whether the screen hardware itself is 100 ppi, 220 ppi, or 356 ppi.

It's because the CSS pixel is defined as a specific angle of view. That angle resolves to different numbers of pixels depending on the combination of screen resolution and typical distance to the screen. (By the way, this is why Apple correctly does not provide a single number for what Retina resolution is. That number is, and must be, different for phones, laptops, etc.)

Device screens are categorized as 1x, 2x, 3x etc. depending on their pixel density, and this helps viewing software (like web browsers) correctly adjust the size of a web graphic. It is why, when you draw a 800-pixel-wide rectangle in Photoshop and put it on a web page, the rectangle size is relatively consistent when viewed on an old 110-ppi screen (1x), a Retina/HiDPI screen (2x), or a high resolution phone (2x or 3x). It is also why Export As has 1x/2x/3x options.

Photoshop doesn't do that compensation in the document window, which is why a common forum question is "how come my web graphics look too small in Photoshop at 100% compared to the browser?" Because the browser compensates for CSS pixels, and Photoshop does not. Photoshop 100% magnification always maps one image pixel to one hardware pixel (not CSS pixel).

My point here is just that when we talk about ppi for web/mobile screen graphics, we have to make that distinction between hardware pixels and CSS pixels.

T

Test Screen Name

Legend

I didn't say resolution was irrekevant for JPEG and PNG. If these are to be printed or placed it's very relevant. What I said is that (1) it's irrelevant for web work and (2) export is for web work.

Either er if these statements might be wrong. (1) some people assert that ppi is important for web graphics. I've never understood the arguments here. (2) Some people might argue that the name of the Export function suggests it's for more general use. I have sympathy for that argument, but what do Adobe say?

ShipsAhoy

Participant

Hi Craig,

I understand and sympathize with your "Export As" frustrations and its inability to keep the original resolution. The workflow for our files requires creating a transparent PNG at 300 ppi (I'll explain why below.) We start with a native CMYK photoshop file at 100% size @ 300 ppi. The file gets reduced by 50% at 300 ppi. In previous versions of photoshop (CS4 or CS6?) "Export As" retained the original ppi. This made it perfect for our workflow, and everything could be done in one click. It reduced the file by half, changed it to PNG, changed it to RGB, retained transparency, and kept it at 300 ppi--all without having to make a single change to my native CMYK PSD. Unfortunately, newer versions of PS now change the resolution to 72 regardless of the original ppi. This adds a whole additional step when using "Export As" (changing the resolution back to 300 ppi) to the workflow, which is frustrating.

Other commenters have suggested simply using "Save As" but in my case, a 50% reduction still needs to be done, as well as converting to RGB before I can save it as a PNG. So this adds two additional steps to my process, plus it means I have to make sure NOT to save changes to my original PSD file. So "Save As" is a worse option for my workflow. When we are talking about a large team using this workflow daily, adding any additional steps is never good. And even more frustrating since we used to be able to do this without an issue until Adobe made the default resolution 72 ppi upon export.

For those that are suggesting that resolution doesn't matter because it's screen--you're right as long as it's being ONLY used on screen. For our workflow, the PNG files go on to a digital asset management library which is also the back end for our website. So resolution doesn't matter there. However, these same PNG files also get used for print. Yes, that might sound heretical to some of you, but an RGB lossles PNG can be used just fine in certain print processes. Every once in a while we do get a bit of a color shift from the original CMYK PSD on certain images, but it's a sacrifice we easily made in order to reduce the number of files and amount of time to have and manage 2 different file types. When you're dealing with hundreds of thousands of files like this, a little color shift is perfectly acceptable for images that are merely product representations anyway--especially when it means not having to double our time and number of assets to accommodate both web and print scenarios. Since the DAM software requires a transparent PNG as the "original" source file in order to serve as the back end for the website, we are stuck with using transparent PNGs in our workflow for both web and print--and it has worked nearly perfectly (except for the "Export As" hiccup.)

I get that "Export As" is designed with web only use in mind, but it could be a much more powerful tool if resolution could be controlled, and maybe even some additional file types added. The workflow I've described maybe isn't typical, but for some of the reasons I've touched on it's the workflow we have to use. "Export As" used to meet our needs perfectly, but no longer does now that it changes the default resolution to 72.

For now, the best workaround is to change the resolution back to 300 ppi after export. I've considered using the "Generate Assets" feature, but it's a bit overkill with only one export happening per file. We do use that for some of our files where we have to generate many assets at 50% from one layered PSD. I've also considered setting up an action, but from a procedural perspective, I'd prefer our staff not have to rely on actions if they can accomplish it through simple menu commands (which used to be the case before Adobe changed the default to 72 ppi.) One additional step might not sound like a big deal to some people, but for those who work with large teams and workflows with many steps, one additional step makes a big difference.

Appreciate all of the ideas. But for now, the only answer to the OP is what Barb said: "while the dialog box should have a way to set the ppi, it doesn't." We all have different workflow requirements, and this would be a lifesaver for our team if it kept the original resolution instead of changing it (after all, if it's for web it doesn't matter, right?!) or if there was an option to set the ppi. I'll keep exploring the best workaround for our team.

T

Test Screen Name

Legend

I see the statement over and over that Export changes the resolution to 72 ppi. I don't think it does that, though the effect may seem to be. If I am right, these Q&A explain why it's wrong (but largely unimportant) to say that Export changes the resolution to 72 ppi.

Q. Do JPEG files have to contain a resolution (ppi value)

A. No, it's optional.

Q. What happens when an app opens a JPEG without a resolution (ppi)?

A. It's entirely up to the app what it does. Some apps will remember that there is no resolution at all, or ask for one. But most apps will set a default resolution.

Q. Ok, what happens when Photoshop opens a JPEG without a resolution (ppi)?

A. Photoshop assumes 72 ppi, and you cannot tell whether this came from the file or was used because the file said nothing. Many other apps do exactly the same thing.

Q. So, does Export set 72 ppi?

A. No, export sets NOTHING because it is for use with web graphics, where resolution (ppi) is irrelevant.

Q. How does that go again?

A. The export sets NO RESOLUTION (ppi). When an app reopens the JPEG, Photoshop (and many others apps) assume it was 72 ppi. So it's exactly as if the resolution was set to 72 ppi and impossible to tell without a detailed analysis of the JPEG internals.

ShipsAhoy

Participant

Thanks for sharing this, TSN, it's an interesting thought. As you know, resolution does have meaning for print, and while the resolution may seem irrelevant since the pixel count doesn't change, it does change the size that the image prints. What I find strange--especially given your proposed explanation of how "Export As" supposedly treats resolution--is that it's different than the behavior of "Save As" which allows users to set the resolution--which in turn sets the image dimensions.

Because PS allows all kinds of file types to be saved out from the "Save As" dialog box, it makes sense that resolution would just be a parameter for all of them regardless of whether it's relevant or not to the specific file type. And if you hold to the idea that resolution is irrelevant for png and jpg, then being able to set it in the "Save As" dialog box is extraneous, and being able to set it in the "Export As" dialog box seems unneeded.

I hold a different perspective, which is that resolution--and by extension the corresponding image width and height--has great relevance in certain situations for png and jpg. Maybe it's not your situation nor is it a common situation, but nonetheless it is the situation I'm in and have no choice but to work with. Based on the fact that many people seem to be asking this question, I would guess the OP and I are not the only ones who see a use for the function.

I'm also pointing out that this behavior for "Export As" (whether warranted or unwarranted) was not always like this, and previous versions of Photoshop DID retain the starting resolution for jpg and png. It no longer does, and for most people that might be insignificant. For me, it's significant and I'd love to have an option to set the resolution on export. Since noticing the change after upgrading and the consequences on my workflow that I didn't have before, I've been wondering the same thing that the OP was asking. Your explanation makes sense (even though I disagree with the premise that resolution is irrelevant for jpg and png.) Unfortunately, it doesn't solve my particular issue. But it's helpful to understand the behavior and the apparent thinking behind the behavior.

Thanks for considering the question and sharing your knowledge. It's great to be able to discuss such nerdy details like this!

Barb Binder

Community Expert

I need to supply images in my document at 300dpi not 72dpi

And you need to supply them as JPG? You can't supply native PSD files?

~Barb at Rocky Mountain Training

C

craigriches66Author

Known Participant

yes, in theory the images could be supplied as native PSD files, but in my case the images need to be 300ppi used within an InDesign document as a whole. And I dont see that i should have to use native PSD's for every image i use in an InDesign document destined for professional print.

Derek Cross

Community Expert

The advantage of using native PSD files in InDesign is that you can round-trip to adjust them.

By the way, I assume you know that you supply a PDF to your (commercial) printer from InDesign, probably PDF/X-4.

Silkrooster

Legend

To add to Derek's response, save as allows you to specify the ppi, whereas save for web assumes it will be on a screen where ppi is irrelevant.

C

craigriches66Author

Known Participant

Hi Silkrooster, thx for the added comment, but my question is related to why when using "export as" for an image that is 300ppi, PS seems to export and save it as a 72ppi resolution image by default?