jcarlosjr Loc: Orange County

For years I have heard, and passed on, the rule, "to save for the web use 72ppi (or dpi)." But after some experimentation and research this rules seems to have no basis.

An image to fit a given opening on an html page is simply a matter of pixels. For example, a 300x400 image will ALWAYS be 300x400 if properly prepared for the web. It does not seem to matter if the image has been "coded as 72, 180 or 300 ppi", it will be 300 pixels wide and 400 pixels high - PERIOD!

Now, I have tried to share this with some photographer friends and they look at me like a hieratic.

Any discussion - pro or con?

MWAC Loc: Somewhere East Of Crazy

you use 72dpi not for the web viewing quality but more for if/when someone makes the choice to print your picture without your permission and "borrows" it off the web, printing at 72dpi will result in a low quality print.

You won't see much difference between an image on your monitor that is 72dpi or 300dpi but you should when you try to print those same images.

Does that make sense?

dirtpusher Loc: tulsa oklahoma

dang MWAC; you know all the good answers

jcarlosjr Loc: Orange County

MWAC, I hate to differ, but an image in my example of 300x400 would make a perfectly good postage stamp.

Nikonian72 Loc: Chico CA

Postage stamp? Who wants a postage stamp size print?

Why not "make a perfectly good" 8x10-inch, or even a 4x6-inch print from a 72dpi image? Because the resolution would suck!

dpullum Loc: Tampa Florida

OH!! MR. N72!! Is this why you shoot Nikon and Not Canon.. (not really a question) The superior DPI of Nikon is why all Canon factories have shut down and Canon no longer sells cameras!! No did not happen. Canon can not achieve the 300 figure because engineering there is not capable? No. Is DPI confused with resolution? Yep, Hokus Printus one and all. For good reading...

"The Myth of DPI - the term DPI (dots per inch) is misinterpreted by some to be a measure of digital image quality - but it has absolutely nothing to do with the quality of a digital image. Learn about what really makes up the quality of a digital photo." Source below:

http://www.rideau-info.com/photos/mythdpi.html
http://www.rideau-info.com/photos/index.html

Roger Hicks Loc: Aquitaine

You're doing the same as I do for the web (and indeed for e'books -- see http://www.rogerandfrances.com/e-books.html ): saving as dimensions in pixels. I can't really see much reason to do it any other way. Likewise, for photomechanical repro (where 300 dpi is the standard) I just multiply the image size in final repro by 300; which is, of course, the same as dividing the image size by 300. Thus 4x6 inch image needs to be 1200 x 1800 pixels, while a 2100 x 3300 pixel image = 7x11 inches. This makes the slightly sloppy assumption that ppi (pixels per inch) and dpi (dots per inch) are interchangeable, but in the real world, they are.

For ink-jet printing, 200 ppi is widely regarded as standard, though some reckoning you can go as low as 150 ppi. These values are NOTHING to do with the dot size of the printer head.

Cheers,

R.

Terry Scott Reed Loc: Reading, PA

I was taught that 72 DPI is the maximum res of your monitor, so any DPI above that doesn't enhance the view on the screen. However, 72 DPI is lousy for printing at any reasonable size. (Don't lose any sleep over that postage stamp...I don't envision that hanging over anyone's fireplace mantle...)

Trial-n-Error Loc: Tacoma, Washington

Most computer monitors will only display 72 DPI because that is all they are capable of. Some newer do 96 DPI.
So no mater what resolution your image is, the monitor can only display 72 dots per inch, That's why you hear about 72 PDI for web use. It is a limitation of the computer monitor and has nothing to do with camera or computer video card capabilities.

dpullum Loc: Tampa Florida

Guys & Dolls, it does not matter what you were taught by your great grandfather (since I am a grandfather I go back a generation to great grandfathers... who lived with DPI 9-pin printers, and scan sheets that had dots, lithography, screen printing and CRT screens,,,etc).. we live in a modern world,,,, The Conservatives(still using dos and playing with Romnie's Etch-a-Sketch and doing away with woman's health.. having 7 children.. conservitive...???) well any way, we old fogies need to revise our thinking to the modern world... how foolish to be concerned with dpi and please do not use a microscope to prove your 6 color printer better than my award winning photos using a 4 color... please shake the Etch-a-Sketch brain and start anew!!! Read some more and stop arguing... pointless non facts... from http://www.signindustry.com/outdoor/articles/2001-03-19-viewingDistance.php3 I quote: "Did you know that the average size of a billboard is 14 feet in height by 48 feet in length and that the resolutions of a billboard print ranges between 2 to 20 dots per inch (DPI)?"

aaah, so we can keep our Canon's because Nikons 300 dpi is not needed... humm perhaps both should drop dpi in their specifications...

Viewing Distance: The Misunderstood Concept
http://www.signindustry.com/outdoor/articles/2001-03-19-viewingDistance.php3
"Did you know that the average size of a billboard is 14 feet in height by 48 feet in length and that the resolutions of a billboard print ranges between 2 to 20 dots per inch (DPI)?

More interesting stuff here!! http://www.photokaboom.com/photography/learn/printing/resolution/1_printing_ppi_flow_chart.htm

So guys, if the print company smokes unfiltered Joe Camel cigarettes and wants to print files on 3.5" disks in dos and shipped in pink envelopes... hay, if they do good work humor them. BUT, do not delude your self or others and go on for 10 pages beating a hoarse that we have killed in many other blogs... just shoot, print, enjoy, do not get too involved in buying a 300 dpi Nikon and trashing your 72 dpi Canon... buy Qimage and let it work magic and know that god is looking out for you and your printer... Use 300, 150 and 72 to make # combos for betting the Lotto...

PS monitors LCD can see 2272 PPI, but your eye can only discriminate at max 300,,, 72 monitor std is for you " Conservatives" still using CRT Monitors ... and Dos of course... Hay, occasionally, I use a green screen to recall what it was like back then.. http://en.wikipedia.org/wiki/Pixel_density

Ronny Loc: Netherlands

I take pictures of homes for Realtors. The ones that goes on the MLS internet are all 720 x 480 and 72 dpi.
I also give them a few in the size 1800 x 1200 and 180 dpi to make flyers.
Above experience gives a very good result and happy clients.

dpullum Loc: Tampa Florida

Hello, boys and girls photographers one and all. This is your old pals, Ren & Stimpy. This is a song about a photo client. No! This is a song about being happy! That's right! It's the Happy Happy Joy Joy song!
Happy Happy Nikon Nikon Happy Happy Canon Canon
Happy Happy Nikon Nikon Happy Happy Canon Canon
Happy Happy Joy Joy Joy!
I don't think you're happy enough with 72 dpi! That's right! I'll teach you to be happy with few! I'll teach your grandmother to suck eggs til pixels flow! Now, boys and girls, let's try it again!
Happy Happy Nikon Nikon Happy Happy Canon Canon
Happy Happy Nikon Nikon Happy Happy Canon Canon
Happy Happy Joy Joy Joy!
If'n you aint the grandaddy of all liars them specifications people say! The little critters of nature... They don't know that they're ugly ugly hedgehog! That's very funny, a fly marrying a bumblebee! I told you I'd shoot at 25 megapix for to see! But you didn't believe me with your cassic canon 5 @ 72! Why didn't you believe me?! With references yet. Numbers and studies scientific they bee numbers and proof for to see.
Happy Happy Joy Joy Happy Happy Joy Joy
Happy Happy Joy Joy Happy Happy Joy Joy
Read, read read read technical stuff to see confusion abound but happy in myth we be, happy and joy happy and joy.

Photo and basis for song from my favorite guys Ren and Stimpy
http://www.bitstorm.org/happyjoy/

Ren Shoots Nikon, Stimpy Canon

MWAC Loc: Somewhere East Of Crazy

You asked why 72 dpi, I gave you the reason why. It's to stop people (clients if you have them) from stealing an image off your blog/website and printing an 4x6, 5x7, 8x10, etc. Believe it or not people will images off the web, copy it and attempt to print and frame it. Most photographers I know don't make their living off sitting fees but off print orders, so they want to protect their potential profit from very session.

jerryc41 Loc: Catskill Mts of NY

I know nothing about this topic, so I might as well give my opinion. On second thought, let's check what the Internet has to say.

https://www.google.com/search?q=why+use+72dpi%3F&rls=com.microsoft:en-us:IE-Address&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7IRFC_en#hl=en&rls=com.microsoft:en-us:IE-Address&rlz=1I7IRFC_en&sa=X&ei=if2BT8m9D-by0gGh4MH1Bw&ved=0CBoQBSgA&q=why+use+72+dpi%3F&spell=1&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.,cf.osb&fp=b207a2b4bbd5c6f4&biw=1680&bih=915

dpullum Loc: Tampa Florida

Right on Mad-Wac.... the debate is well documented in scientific studies and generally speaking dpi in modern equipment is a worthless hang over form the old. Dpi is a number that confuses issues.

Eventually the old guys at printers will retire and the new guys will smoke a joint and forget what they were told that had nothing to do with the new electronic equipment that is all automated anyway. Dpi was only significant to the stuff retired in late 1990s and people who should have retired before that.

And considering MLS books and most real-estate clients, they are hardly authorities on photography. Good that they are happy happy and filled with joy joy, but they would probably be happy with a Canon 5 mpix G-2 camera for most work. Good Real-Estate photography requires not dpi, but rather requires LIGHT - GREAT LIGHT and better light and good staging.. crazy stuff like wetting drive ways, cloning a tree away. 72-150-300-1000 dpi not the make/break factor.