Image size vs resolution?

[om-cdt]

My coworker asked me for a logo with a 600px height and 300dpi. I made this and sent her the jpeg. She then comes back and says that it's the wrong size. I was confused, because I made it the exact size that she requested. She then said that it was 2000+ px tall. At that point I realized she was talking about the resolution (I think that's the right term) rather than the file size itself. I shrunk the photo down to 600px in Photoshop image size and it worked fine for her. I just had the exact same scenario happen when another coworker requested a "size" that turned out to be the resolution. Are they confusing image size and resolution or am I? I am the only designer at my company, and I'm doubting myself now. I don't want to make a mistake and I want to make sure that they understand how to tell me what size they need.

Please help!

[Monika Gause · Accepted solution]

The problem is that when you export in a size of 600 px and the  300 ppi you will always enlarge the graphic.

Illustrator always calculates with a resolution of 72 ppi.

You need to first export the image at the 600 pixel size. Then open that in Photoshop and set it to 300 ppi without resampling.

But actually what do your colleagues need the specific resolution for? 600 pixels is too small for high quality printing and since they tell you the size in pixels I assume they need the logo for Power Poont or the web and both don't care for resolution.

[Mike_Gondek]

Open the image i photoshop. Image >> Image Size. These are the 2 values which must match to fulfill the request.

Play around with the image size, this is the best way to learn, and you will never doubt yourself again.

[S_Gans]

One way I look at it is that 300dpi is a print measurement, so when someone mentions that, I expect height and width measurements in inches (here in the U.S.). If they want pixel measurements, I usually assume they're talking about something for screen usage (like web). So, then the resolution only needs to really be 72ppi (generally).

So - you'll likely need to send them 2 of the same item - one for print at the right H (in) x W(in) x 300ppi, and one for screen at the right H(px) x W(px) x 72ppi.

I think if you tell your colleagues to specify inches for print and pixels for screen, you'll maybe help them to tell you what they need...

[Monika Gause]

S_Gans  schrieb

I usually assume they're talking about something for screen usage (like web). So, then the resolution only needs to really be 72ppi (generally).

On the web resolution doesn't matter at all. It can be 1 ppi or 18000. The browser just doesn't care. All that matters is pixel dimension that is set up on the web page in the HTML.

[S_Gans]

Except that it matters for file size/download size. Although the browser doesn't care and will only display any image based on the code for the frame size, if one resizes the resolution and height and width to an optimal size, the download will be faster with a clearer image. Nowadays, with people accessing the internet on devices, using available bandwidth that may be limited, this can be a huge timesaver. I used 72ppi as an example - a general basic size. Nowadays, with different monitors capable of much higher resolutions, it's just a rule of thumb. but file size still matters. Ask anybody who pays for their cellular data.

Back to @katv6352670's point, they can make the choice whether they wish to optimize for download speeds, I was suggesting a method to clarify what her coworkers can use to distinguish what they want.

[Monika Gause]

S_Gans  schrieb

Except that it matters for file size/download size.

There's no difference between a 600x600 px image at 72 ppi and a 600x600 px image at 300 ppi.

[S_Gans]

I'm very familiar with the "Resolution Myth", but in explaining these concepts to a newer user, I find that breaking it down to these concepts help people start to grasp the idea of pixels for web vs print, and I believe that using that analogy will answer the OP's question of how to clarify for her coworkers.

If you have a cleaner way to answer her question, please do offer it, so she can work more easily with her coworkers, with less confusion.

While it's true that a browser will interpolate an image to any view size it needs, by simply displaying pixels themselves larger and smaller, it's good practice to optimize image size/quality/compression.

[Monika Gause]

S_Gans  schrieb

it's good practice to optimize image size/quality/compression.

Sure it is, but resolution just doesn't matter when doing graphics for a web page.

The only thing you need to make sure is that the pixel dimensions are matching the intended layout.

Something you don't have to worry about causes no confusion.

[Jacob Bugge]

kat,

My coworker asked me for a logo with a 600px height and 300dpi.

That is a bit like a conjuration, which works against the purpose. Taken literally, she actually asked for 2500 pixels.

If she wants a specific pixel (by pixel) size, it is completely sufficient, and safer, to just ask for 600px.

You can get the exact pixel size straight away if you use Save for Web, now hidden away in File>Export>Save for Web (Legacy), and set the size, even simpler than setting the resolution to 72 for Exoprt.

And, for losslessness and crispness/clearness (and possible transparent parts), PNG24 (PNG24/32) is a better choice.

[Monika Gause]

https://forums.adobe.com/people/Jacob+Bugge  schrieb

kat,

My coworker asked me for a logo with a 600px height and 300dpi.

That is a bit like a conjuration, which works against the purpose. Taken literally, she actually asked for 2500 pixels.

No, she didn't.

Only when working in Illustrator you will get that result, but a pixel as such has no physical size.

The 72 PPI Web And Screen Resolution Myth

[Jacob Bugge]

Monika,

Only when working in Illustrator

which is what kat is.

And otherwise, the request seems rather meaningless: if you simply ask for 600 pixels you will get that; if you ask for it with the 300 dpi added, which should have been PPI since it is web use, it would be an additional requirement that the image should be 2" in the direction in question, which would seem rather strange/impossible for a web image and hardly possible for kat to supply/ensure in any conceivable way, but of course it might give the additional thrill of having the image blurred by having the resolution changed to fit.

[Monika Gause]

https://forums.adobe.com/people/Jacob+Bugge  schrieb

Monika,

And otherwise, the request seems rather meaningless:

Yes, that's what I already mentioned in #1. But maybe you didn't notice?

[Jacob Bugge]

Indeed, Monika, and posts #5&7.

Rereading, I see nothing in my post #10 to contradict or question any of your statements in any of the posts.

[om-cdt]

I tried duplicating the error today and the same problem in AI was revealed, and I also did the same thing in PS with no issue. Monika and Jacob seemed to hit the nail on the head as far as the problem and a potential solution. If I make an image 600px tall @300 ppi and export it from AI, it is much larger at the end. if I go into PS and create the exact same file of 600px tall @300 ppi, I can save it as a jpeg and it will have those exact dimensions. I evidently missed this export issue in my rush to deliver the logo. What I will likely do is just use PS from the beginning next time, since the desired result was achieved the first try. Silly me.

Does this seem like the issue then? I missed/wasn't expecting the changes that AI makes to exported jpegs?

[Jacob Bugge]

kat,

For a logo, and especially if there is the slightest possibility that it may ever be used for something outside web/screen use, I would suggest your using AI, and just creating it at the 600 px, then (legacy) Save for Web with no need to do anything about the size, or eport at 72PPI if you must.

I still think your coworker should just give you the pixel size, and know why. You can let her read this thread if you like.

[om-cdt]

One of the problems I have is people misrepresenting what they need me for, or not explaining until partway through. I'm the only designer, so I get pulled in a lot of different directions and don't always have time to ask the same questions of everyone as they contact me. I've considered making a form that everyone must fill out to help with the burden. For example, one of my coworkers said he needed some help with PP graphics, and within a day it was revealed that I was making graphics for a prototype that had nothing to do with PP - he was just showing me his personal mocks up in his presentation to the company. It's frustrating to say the least.

In this example related to the thread, she later told me that it was for print only and needed the logo to place on a greeting card.. In that case, needing 300ppi, you say I can create the file with 300ppi to start and export it via legacy even at 72ppi? I do love AI (it's my primary tool for this job), so I wouldn't object to doing that first, but I want to make sure it's still ok for print since I have just encountered this problem for the first time.

[Jacob Bugge]

kat

If it is for print only, if possible (depending on the way she wants/insists upon), it would be better to create it at the desired final size as vector artwork, then save as PDF, keeping everything vector; not least with any text (live Type can be used), the quality will be much higher.

If it is for both web/similar and print, you can create it at the desired final print size, and deliver it in two versions: a PDF as above and a PNG24 using the legacy Save for Web and setting the pixel x pixel size in the Image Size window.

[om-cdt]

She needed either a TIFF or JPEG specifically - PDF wasn't an option in this case.

[Jacob Bugge]

kat,

I was editing post #17 when you posted #18.

Here is the edited version (ignore the PDF bit):

kat,

you say I can create the file with 300ppi to start

No, forget about PPI/DPI when you create the artwork.

If it is for print only, if possible (depending on the way she wants/insists upon), it would be better to create it at the desired final size as vector artwork, then save as PDF, keeping everything vector; not least with any text (live Type can be used), the quality will be much higher.

If she insists on something with 300 DPI for print, get the actual print size in the real print unit, inches/mm/cm/whatever, then export to a raster format at 300PPI.

If it is for both web/similar and print, you can create it at the desired final print size, and deliver it in two versions: a PDF (or raster format) as above and a PNG24 using the legacy Save for Web and setting the pixel x pixel size in the Image Size window to be the exact size for the web/screen use.

[om-cdt]

Awesome, thanks!

[Jacob Bugge]

You are welcome, kat.