04-13-2017 09:11 PM
Firstly, I know this is a long post, but it was necessary.
I am making a website where images will be available on web, but they can also be saved by users and printed. So I was wondering how much DPI should I choose.
I decided to google it out. But I am super confused right now, because I am getting completely different answers to this question.
Use Case:
- Adobe photoshop file (.psd)
- High resolution photograph
- 1000 px by 1000 px
- Saved as .jpg
- Upload to website as well (file size not an issue)
- Photo can be saved via website and printed
There are 4 different websites I found giving me 4 different answers.
Website 1: 300 DPI
Print - 72 DPI < 300 DPI
URL: http://www.vsellis.com/understanding-dpi-resolution-and-print-vs-web-images/
"Print: 300dpi is standard, sometimes 150 is acceptable but never lower, you may go higher for some situations."
With examples of 300dpi and 72dpi.
Website 2: 72 DPI
Web - 72 DPI = 300 DPI
Print - 72 DPI > 300 DPI
URL: https://daraskolnick.com/image-dpi-web/
This author shows an example of how 72 DPI and 300 DPI look when printed. And guess what, the 72 DPI image looks bigger. How???
Please search for:
"Remember the three images I showed you above with different DPI values that look exactly the same on the web? Here’s what they’d look like printed:"
72 DPI - https://daraskolnick.com/daraskolnick/wp-content/uploads/2015/03/72-231x300.png
300 DPI - https://daraskolnick.com/daraskolnick/wp-content/uploads/2015/03/300-232x300.jpg
Website 3: 300 DPI
Print - 72 DPI < 300 DPI
"300 DPI is usually a good rule of thumb."
URL: https://graphicdesign.stackexchange.com/questions/95/what-dpi-should-be-used-for-what-situations
Website 4: 72 DPI
412 x 324 pixels, 7 dpi, prints 58 x 46 inches
412 x 324 pixels, 72 dpi, prints 5.7 x 4.5 inches
412 x 324 pixels, 720 dpi, prints 0.57 x 0.45 inches
URL: http://www.scantips.com/no72dpi.html
Sorry, but I don't understand what is going on here. Someone please care to explain??
Thanks in advance!
PS. Researching about this confused me even more. Haha. 😱😁
04-18-2017 05:06 PM
This is a hard concept for most people to realize. It is made even more confusing when PS and/or LR has them listed usually in a place that compounds the confusion. Plus folks all over the place (the web!) talk dpi when they really don't mean dpi or don't know what they are talking about.
Photos DO NOT have dpi. Printers have dpi.
04-18-2017 05:20 PM
No, but scanned images have dpi which is where that comes from.
04-19-2017 07:42 AM
@ebiggs1 wrote:This is a hard concept for most people to realize. It is made even more confusing when PS and/or LR has them listed usually in a place that compounds the confusion. Plus folks all over the place (the web!) talk dpi when they really don't mean dpi or don't know what they are talking about.
Photos DO NOT have dpi. Printers have dpi.
OK, fine. But as long as major competitions continue to express their size constraints in DPI, we'd better at least understand what they're saying.
04-19-2017 10:36 AM
"...scanned images have dpi which is where that comes from."
Actually they don't. They have PPI. It is just another confusing point in all of this.
"..we'd better at least understand what they're saying."
Wouldn't it be better to do it correctly? Understand it correctly?
Camera images mostly have no resolution assigned to them. When you open the file in most image-editing programs, such as Photoshop, a resolution is assigned to the file. Photoshop, uses 72 ppi as a default resolution. It is incorrect to say that digital camera images have a resolution of 72 ppi since it is the software program assigning that number.
Monitor resolution is measured strictly by pixel width and height.
Though the terms DPI and PPI both describe the resolution of an image, they’re not the same thing. PPI describes the number of square pixels that show up in an inch of digital screen. DPI is a printing term referring to the number of physical dots of ink in a printed document. Photos DO NOT have dpi. Printers have dpi.
04-19-2017 05:00 PM
@ebiggs1 wrote:...
Though the terms DPI and PPI both describe the resolution of an image, they’re not the same thing. PPI describes the number of square pixels that show up in an inch of digital screen. DPI is a printing term referring to the number of physical dots of ink in a printed document. Photos DO NOT have dpi. Printers have dpi.
A distinction without a difference. An inch is an inch. What a "dot" or "pixel" physically is, is irrelevant.
04-20-2017 10:29 AM
Whatever! Have it your way.
Exactly why this confusion remains. It becomes impossible to pull people into the facts when they resist all efforts at learning.
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