how to set ppi settings on a digital camera NOT dpi

JustPassingBy

darich wrote: »

If the image is 2400 x 1200 (for round numbers) and the ppi is 100 then on the screen, the image will be 24inches by 12inches.
By changing the ppi to 200 that becomes 12inches x 6inches.
By changing the ppi to 300 that becomes 8inches x 4inches.

If you are reporting something you have carried out and what you saw on the screen I'd suggest you take a look at what your software is doing to the image. Please see post #10.

I just tried to be certain. my 5123x3410 image at 300 ppi was resaved at 72ppi without being resampled and the file size was unchanged - both images are 9.2mb.

Screens only care about pixel dimensions. An 800x600 image at 200ppi looks the same on the same screen as an 800x600 image at 500ppi.

I take it you have examined the properties (pixel dimensions and ppi) of both images and displayed both using an image viewer.

darich

darich wrote: »

Basically the arguements about ppi v dpi v 300 v 180 are irrelvant. The original camera isn't even 6mp.

As I stated - all discussions about pixels adn dpi etc are irrelevant - the OP's camera doesn't take pictures of a high enough quality to to be accepted by most printers/agencies.

No amount of manipulation/enlargement/photoshopping will change that.

Scrilla

For anyone who may into similar problems regarding their camera megapixels and their printing needs at a desired resolution, the following chart (based on 300 dpi) may help:

Megapixels vs. Maximum Print Size Chart
Megapixels	Pixel Resolution*	Print Size @ 300ppi	Print size @ 200ppi	Print size @ 150ppi**
	3	2048 x 1536		6.82" x 5.12"		10.24" x 7.68"		13.65" x 10.24"
	4	2464 x 1632		8.21" x 5.44"		12.32" x 8.16"		16.42" x 10.88"
	6	3008 x 2000		10.02" x 6.67"		15.04" x 10.00"		20.05" x 13.34"
	8	3264 x 2448		10.88" x 8.16"		16.32" x 12.24"		21.76" x 16.32"
	10	3872 x 2592		12.91" x 8.64"		19.36" x 12.96"		25.81" x 17.28"
	12	4290 x 2800		14.30" x 9.34"		21.45" x 14.00"		28.60" x 18.67"
	16	4920 x 3264		16.40" x 10.88"		24.60" x 16.32"		32.80" x 21.76"

*Typical Resolution. Actual pixel dimensions vary from camera to camera.
**At 150ppi, printed images will have visible pixels and details will look "fuzzy"

The above is taken from http://www.design215.com/.

I'm still not convinced by everyone's assertion that dpi and ppi are the same thing. They are similar, but not the same from what I gather and my further reading still suggests this. I'm trying to learn, so can anyone shed any light on this (web-links preferred to save you typing). Thanks.

darich

Scrilla wrote: »

I'm still not convinced by everyone's assertion that dpi and ppi are the same thing.

They're not the same thing.
ppi is related to the image
dpi is related to the printer.

check out http://www.tildefrugal.net/photo/dpi.php for an explanation of each

Scrilla

darich wrote: »

They're not the same thing.
ppi is related to the image
dpi is related to the printer.

check out http://www.tildefrugal.net/photo/dpi.php for an explanation of each

Yep, first link in google for a "dpi ppi" search when I tried to read on a bit more.

One more thing if I can bother you darich. You said earlier?

darich wrote: »

Resolution is not connected to dpi or ppi.

Surely it is? I mean, my implication was in my post, if you wanted to print an image at a set size and your camera resolution was too low to give you the desired ppi, then your would indeed need a camera with more megapixels to give you that result. I wanted to give a quick run down of options for the OP without going into details to be concise and also due to lack of time for typing on my part. Megapixels is surely a factor to consider if your end result is to be achieved in print, is it not?
Megapixels -> image resolution -> printed image size at desired ppi

JustPassingBy

Scrilla wrote: »

I'm still not convinced by everyone's assertion that dpi and ppi are the same thing.

The image file stores the information 150 ppi. The image itself has no use for this information. It could be removed from the file or altered to 150 pixels per kilometer and there would be no difference between screen displays of a before and after image. However, no respectable printer driver will accept the image file unless it is told the ppi.

The image viewer sends the file to a printer driver saying "put every 150 pixel's worth of information in 1 inch. How you treat or manipulate the information is up to you but it has got to occupy 1 inch on the sheet of paper".

It's not unusual for a piece of software to call pixels "dots" so 150 ppi is written as 150 dpi. Perhaps it shouldn't and it might be better if it didn't, but it happens and does not affect the previous two paragraphs.

The printer receives the information in 150 pixels after it has been processed by the printer driver settings and puts it on paper. So many dots in an inch.

But these dots don't have the same significance or meaning as the ones understood by the image viewer. But it's a wonderful world! Everyone can be right. ppi is the same as dpi and ppi is not the same as dpi.

darich

Scrilla wrote: »

Surely it is? I mean, my implication was in my post, if you wanted to print an image at a set size and your camera resolution was too low to give you the desired ppi, then your would indeed need a camera with more megapixels to give you that result. I wanted to give a quick run down of options for the OP without going into details to be concise and also due to lack of time for typing on my part. Megapixels is surely a factor to consider if your end result is to be achieved in print, is it not?
Megapixels -> image resolution -> printed image size at desired ppi

Resolution is the amount of information that your camera can capture. So a 3mp camera will capture less information or less detail than a 12mp camera.

ppi is not a setting you can adjust within a camera and "in camera" it is irrelevant because there are a set number of pixels to record the scene, whether it's a 3mp or 12mp camera. My camera is a Canon 5D 12.8mp with full frame sensor - it's among the best cameras on the market and when it was released it was around £2000 yet images from my camera are only 180ppi. It can still produce good quality prints at 30inches x 20inches.

Larger resolution means the image can be printed larger because there is more information to be "spread out" on a larger piece of paper.

Printing can be done at 72dpi or 300dpi on any image regardless of the resolution it was captured at. Higher dpi means higher quality but any image can be printed at any resolution and the more pixels there are at the start to capture the scene, the larger the final image can be printed.

Scrilla

Thank you, both. I think my understanding is decent, but you've now cleared things up about the relationship of bits of terminology for me.

I hope the OP has got the answer he/she wanted as I've inadvertently hijacked the topic