Picture Question

comovartia · 10-27-2012, 07:36 PM

I am helping my sister with her son's class picture.
The pic could be sent in on a CD or a flash drive.
One of the requirements was that the picture be 300dpi.
As far as I know dpi has to do with the printer not the picture ie 300 dots per inch.
What would they mean by a 300dpi picture?
Thanks

Lead-Foot · 10-28-2012, 12:42 PM

The parent have to take the kids class picture? Doesn't the school hire a photog?

Are they planning to print a year book or something with the image you take?

ta2maki · 10-28-2012, 01:24 PM

Maybe they are asking that the photos you send in are appropriate for the final picture size. So if you want 5X7 photos, your picture should be 1500X2100. If the photos are tiny 1X1.5, the pics you send in only have to be 300X450.

chopper duke · 10-28-2012, 03:31 PM

Dpi or ppi has to do with the resolution of the image. It's how many pixels are in each inch of the image. Your typical Internet image can be 72 dpi because its on the screen. To print, you want no less than say 240 but typically higher depending on the size of the print.

Lead-Foot · 10-28-2012, 10:54 PM

Quote:

Originally Posted by chopper duke

Dpi or ppi has to do with the resolution of the image. It's how many pixels are in each inch of the image. Your typical Internet image can be 72 dpi because its on the screen. To print, you want no less than say 240 but typically higher depending on the size of the print.

Oh yeah?! Well what about a retina display?

chopper duke · 10-28-2012, 11:19 PM

Quote:

Originally Posted by Lead-Foot

Oh yeah?! Well what about a retina display?

Apple Hype.

dundadun · 10-28-2012, 11:24 PM

Anything you want printed should be 300 dpi preferably. After that the h x w size doesn't matter as much because 300dpi is a large enough resolution that they can enlarge the image to their needs

Luckless · 10-29-2012, 10:29 AM

72ppi hasn't been a standard in a long time. It was somewhat of a standard of a range of equipment, back in the 80s, and early 90s, but quickly shifted away from that.

Due to the wide range of monitors and display styles out there, anything 'per inch' or other real world measurement is kind of useless till you go take that digital data and produce it in some form in the real world.

It isn't even really well understood in some printing companies. I've had to go in several times with a few groups I've worked with and changed the meta data for ppi/dpi values. Exact same photo, and the only difference was the same as if I had taken a sharpie and crossed out something on a shipping container to replace it with another value. "We're sorry, we can't work with this, It Needs to be 250dpi or better for us to print this image for you. You can't print it that large at only 72! Get us another image at a higher resolution..." Change the 72 to a 300, and they're happy as a clam.

There have been a few I've wanted to order a bunch of small posters with the text "My Print Production company is staffed by morons who don't have a clue about what they're actually doing, and could likely be replaced by exceptionally well trained Monkeys", but sadly other people in the group have refused to fund this project.

Rymzor · 10-29-2012, 10:35 AM

Dpi, misunderstandings and explanation, what is dpi

"DPI as DOTS PER INCH (as distinct from PIXELS PER INCH), are the small inkdots (per inch) that come on the paper during the printing-procedure. The DPI (dots/inch) must be larger than the DPI/PPI (pixels/inch), otherwise the result will be a bad print. An example: A print has 300 pixels per inch and 1200 dots per inch. In this case each pixel has the average of 4 (ink)dots"

Dr. PhunkyPants · 10-30-2012, 01:32 PM

This is key...ideally they would tell you the images dimensions (in inches or pixels) AND the dpi. Then you can give them the most perfectly precise image file.

But in the real world, I think whatever you do probably be fine. If you are using a photo editor that allows you to specify dpi at output, but all means do so.

If I were publishing a yearbook, I would be concerned about images coming to me with too little information/resolution...such as some mom using her 2.3 megapixel camera from 2003. In the real world, having enough pixels hasn't been an issue for a long time...Nikon's D40 from 2008 with 6 megapixels had a native image size of 3,008 x 2,000. As you can see, this would support 300dpi images of up to 10" if the image ration of 3:2 was maintained. Consumer cameras these days usually have tons more megapixels than that (let's not get into noise though!

As long as you're starting off with too much data and going down to a smaller size image, you're generally fine for most purposes. It's when you start off with too little and start stretching things that images can start to degrade.

Photoshop and other tools have algorithms that can intelligently fill in the gaps created when stretching pixels. But you do need to know what you're looking for to get best results.

10-27-2012, 07:36 PM	#1 (permalink)
comovartia MCB Member Join Date: Mar 2006	Picture Question I am helping my sister with her son's class picture. The pic could be sent in on a CD or a flash drive. One of the requirements was that the picture be 300dpi. As far as I know dpi has to do with the printer not the picture ie 300 dots per inch. What would they mean by a 300dpi picture? Thanks __________________ comovartia Home Field-http://www.camppaintball.com/ http://www.mayflowerhomeinventory.com/

10-28-2012, 03:31 PM	#4 (permalink)
chopper duke www.Axial-Photography.com Join Date: Jun 2008 Location: Metro ATL	Dpi or ppi has to do with the resolution of the image. It's how many pixels are in each inch of the image. Your typical Internet image can be 72 dpi because its on the screen. To print, you want no less than say 240 but typically higher depending on the size of the print. __________________ My: MCB feedback {total = 275+}

10-28-2012, 11:24 PM	#7 (permalink)
dundadun Boom. Yummy Join Date: Jul 2007 Location: SoCal	Anything you want printed should be 300 dpi preferably. After that the h x w size doesn't matter as much because 300dpi is a large enough resolution that they can enlarge the image to their needs __________________ __________________ Pirate Intimidator and the Most Comfortable Gun Ever Dukie Lever Gun and now Smiley-ized Feedback For sale: k Stock and Random bits for sale as well as items I want to buy!

10-29-2012, 10:35 AM	#9 (permalink)
Rymzor Seasoned Member Join Date: Apr 2008 Location: Ontario	Dpi, misunderstandings and explanation, what is dpi "DPI as DOTS PER INCH (as distinct from PIXELS PER INCH), are the small inkdots (per inch) that come on the paper during the printing-procedure. The DPI (dots/inch) must be larger than the DPI/PPI (pixels/inch), otherwise the result will be a bad print. An example: A print has 300 pixels per inch and 1200 dots per inch. In this case each pixel has the average of 4 (ink)dots" __________________ Arctic Storm. "Everything could have been anything else and it would have had just as much meaning"

10-28-2012, 12:42 PM	#2 (permalink)
Lead-Foot Back from 10day BanCation Join Date: Dec 2011 Location: Florida	The parent have to take the kids class picture? Doesn't the school hire a photog? Are they planning to print a year book or something with the image you take?

10-28-2012, 01:24 PM	#3 (permalink)
ta2maki Yes, that is a joke ----> Join Date: Jan 2007 Location: Sunny Southern California	Maybe they are asking that the photos you send in are appropriate for the final picture size. So if you want 5X7 photos, your picture should be 1500X2100. If the photos are tiny 1X1.5, the pics you send in only have to be 300X450.

10-30-2012, 01:32 PM	#10 (permalink)
Dr. PhunkyPants Yield and Overcome... Join Date: Apr 2008	This is key...ideally they would tell you the images dimensions (in inches or pixels) AND the dpi. Then you can give them the most perfectly precise image file. But in the real world, I think whatever you do probably be fine. If you are using a photo editor that allows you to specify dpi at output, but all means do so. If I were publishing a yearbook, I would be concerned about images coming to me with too little information/resolution...such as some mom using her 2.3 megapixel camera from 2003. In the real world, having enough pixels hasn't been an issue for a long time...Nikon's D40 from 2008 with 6 megapixels had a native image size of 3,008 x 2,000. As you can see, this would support 300dpi images of up to 10" if the image ration of 3:2 was maintained. Consumer cameras these days usually have tons more megapixels than that (let's not get into noise though! As long as you're starting off with too much data and going down to a smaller size image, you're generally fine for most purposes. It's when you start off with too little and start stretching things that images can start to degrade. Photoshop and other tools have algorithms that can intelligently fill in the gaps created when stretching pixels. But you do need to know what you're looking for to get best results.