pancakes

MicrostockGroup Sponsors


Author Topic: generate JPG as 300dpi  (Read 10297 times)

0 Members and 1 Guest are viewing this topic.

« on: August 29, 2010, 04:45 »
0
Hi all,

I happened to read that there is an agency moodboard that needs a JPG which is 300 dpi, to my understand dpi is dot per inch that means it is a printing resolution?

I am not sure how to generate a 300dpi jpg, i notice my jpg file from camera is 240 ppi, that's pixel per inch? so does it matter?

and i am doing illustrations too, so when i generate jpg from eps vector using photoshop software, i can choose the number of ppi i need to generate, by default the value is 72 ppi. i had tried to generate 1 vector jpg as 300 ppi, but i can't see the difference too.

so what should we do with all this ppi and dpi?

can we set the resolution from our camera?
is it best to generate a 300ppi jpg from our vector?


microstockphoto.co.uk

« Reply #1 on: August 29, 2010, 05:01 »
0
Hi,

you're right: dpi is printing resolution, but sometimes it's used - incorrectly - as a synonym for ppi;

I submit photos to all top and middle tier agencies on the right and I am pretty sure ppi/dpi doesn't matter as long as total size of picture is at least 4 MP (or as required) - just leave it as it comes from the camera;

If that agency actually requires 300 ppi, I suppose you must change resolution in your editing software.

Not sure about illustrations, as I don't submit many.
« Last Edit: August 29, 2010, 05:07 by microstockphoto.co.uk »

« Reply #2 on: August 29, 2010, 05:14 »
0
I have a video for you in a few seconds but really it is just a setting in Photoshop you have to set it really has nothing to do with the quality of the image.  I don't know why some agencies require images to be set at a certain dpi.

« Reply #3 on: August 29, 2010, 05:18 »
0
here is a little photoshop tutorial video

Photoshop Tutorial : How To Change the DPI [60 Seconds] Beginner

« Reply #4 on: August 29, 2010, 05:54 »
0
Any agency worth its salt ought to know better than to have that as a requirement.

« Reply #5 on: August 29, 2010, 10:01 »
0
shoot with nikon, they allways recording images in 300DPI... ;)

« Reply #6 on: August 29, 2010, 10:37 »
0
if you shoot in RAW you can set what you what DPI you want the raw processor to use as well.

« Reply #7 on: August 29, 2010, 10:37 »
0
here is a little photoshop tutorial video
You can also do it batch in the Thumbs screen of Irfanview. Much faster.

« Reply #8 on: August 29, 2010, 10:53 »
0
To my knowledge, 300dpi equals to 150lpi (simply divide it by 2), so your file exceeds what they require.

edited 150ppi into 150lpi, thanks for great explanation, cuppacoffee.
« Last Edit: November 20, 2010, 18:09 by photosoup »

« Reply #9 on: August 29, 2010, 11:45 »
0
To my knowledge, 300dpi equals to 150ppi (simply divide it by 2), so your file exceeds what they require.

That makes no sense.  dpi can be set to anything. 1dpi, 10000 dpi.

red

« Reply #10 on: August 29, 2010, 18:15 »
0
photosoup may be thinking of lpi (lines per inch or halftone dots per inch). All photos are screened or turned into halftones for print on paper. This happens after the images are sent to a printer who prepares them for the printing plates, using software called a rip (raster image processor). In the old days ppi was controlled by the scanner settings as most imagery was converted from color transparencies and stripped into films.

But, the same principle applies to today's digital images. For printing it was a "rule" that lpi doubled equaled the best ppi. And, this isn't quite right either as good printers usually asked for images to be scanned at up to 2.5 times the lpi. In some ways this was equivalent to sharpening in photoshop - a higher than needed ppi usually led to a crisper image. The chosen line screen depended (and still depends) on the type of paper an image is printed on. Newspapers require a lower lpi then magazines which require a lower lpi than fine art books. So, if a magazine is printed at 133 lpi (a typical line screen for this type of use) the image should be saved at 266 ppi if it is placed at 100% in the digital file (InDesign, Quark XPress, etc.) which is then "ripped" and turned into a printing plate.

As a general rule, most images for print are saved today at 300 dpi (or ppi - somewhat interchangeable except in the purist sense) which is about 2.2 times the typical lpi (133 being typical). It gets murky because dpi is a printing term and ppi is a measurement term for when an image is displayed on something like a monitor or when it is scanned.

As clear as mud.
« Last Edit: August 29, 2010, 18:19 by cuppacoffee »

« Reply #11 on: August 29, 2010, 19:01 »
0
Oooh I cant tell you how much 300dpi has driven me mad over the years! I know why moodboard do it (tho they should accept images regardless of the DPI setting and change it to something consistent themselves) its because a few years back designers were completely obsessed with having images that were '300dpi', try telling them to change it in photoshop and they would tell you something like "i can't do that because if I up-sample it in photoshop it will go all blocky" arrrggghh. as cuppacoffee says it's all to do with what happens when you import the images into a publishing software that's why they like images that are set to 300dpi

shoot with nikon, they allways recording images in 300DPI... ;)

it wasn't for me, if you shoot raw then the default (at least for my setup) in ACR was to bring them in at 240dpi (not exactly nikons fault), just change it in the raw converter 300dpi and the problem is solved for every image you process. Leafs video is the work around for images that are already in jpg format

not sure how we ended up on lpi-dpi here, that general rule depends on what the output is, a 300dpi monochrome laser printer can resolve about 133lpi when printing its screen (halftone or whatever), but can resolve 300lpi when it prints just black and white text that is not screened

yes indeed - clear as mud lol

« Reply #12 on: August 30, 2010, 01:03 »
0
oic, so is it because designers few years back is obsessed with that setting. I think in photoshop, it is used as 'ppi' for jpg.

it seems it is not a 'real' resolution, but just an adjustment of resolution calculation.

anyway, i think moodboard had accepted other ppi nowadays, as i saw in their faq something like prefered 300 dpi but other dpi is also okay.


Oooh I cant tell you how much 300dpi has driven me mad over the years! I know why moodboard do it (tho they should accept images regardless of the DPI setting and change it to something consistent themselves) its because a few years back designers were completely obsessed with having images that were '300dpi', try telling them to change it in photoshop and they would tell you something like "i can't do that because if I up-sample it in photoshop it will go all blocky" arrrggghh. as cuppacoffee says it's all to do with what happens when you import the images into a publishing software that's why they like images that are set to 300dpi

shoot with nikon, they allways recording images in 300DPI... ;)

it wasn't for me, if you shoot raw then the default (at least for my setup) in ACR was to bring them in at 240dpi (not exactly nikons fault), just change it in the raw converter 300dpi and the problem is solved for every image you process. Leafs video is the work around for images that are already in jpg format

not sure how we ended up on lpi-dpi here, that general rule depends on what the output is, a 300dpi monochrome laser printer can resolve about 133lpi when printing its screen (halftone or whatever), but can resolve 300lpi when it prints just black and white text that is not screened

yes indeed - clear as mud lol

« Reply #13 on: August 30, 2010, 03:50 »
0
oic, so is it because designers few years back is obsessed with that setting. I think in photoshop, it is used as 'ppi' for jpg.

it seems it is not a 'real' resolution, but just an adjustment of resolution calculation.

anyway, i think moodboard had accepted other ppi nowadays, as i saw in their faq something like prefered 300 dpi but other dpi is also okay.


Thanks cupacofee and microstockinsider, very well put.  It is nice to hear a little more indepth explanation of things

@mtkang Yeah, DPI is just a resolution calculation if you want to put it that way.  It has nothing to do with the quality of the digital image.

And that sounds right that moodboard will accept other DPI settings.  At PhotoPlus last October I asked them about their DPI requirement and they said they were dropping it.


 

Related Topics

  Subject / Started by Replies Last post
0 Replies
2870 Views
Last post August 11, 2008, 09:03
by johngriffin
4 Replies
2859 Views
Last post June 04, 2009, 11:41
by madelaide
6 Replies
4143 Views
Last post October 19, 2012, 13:30
by sweetgirll
5 Replies
2911 Views
Last post October 30, 2013, 06:25
by cathyslife
6 Replies
2330 Views
Last post September 29, 2023, 05:49
by waitingonthestuff

Sponsors

Mega Bundle of 5,900+ Professional Lightroom Presets

Microstock Poll Results

Sponsors