Question

TaylorGraphics · Apr 27, 2009

I own a FujiFilm A850 Digital Camera...it takes excellent picture but the problem is i cant figure out how to make it better then 72 DPI..like the dimensions of the photo is like 35 IN by 45 IN but the DPI (Dots per Inch) or PPI (pixels per inch) is only 72...Can anyone help me to set it to 300?

Big Mike · Apr 27, 2009

I posted this in your into thread...so I'll just copy it here.

As for your PPI question. (note I say Pixels Per Inch, not Dots Per Inch). It's simply a number that tells the computer how large to display the image on screen. You can change the PPI from 72 to 300 (without re-sampling) and it won't change the actual image at all. Just the size of it on the screen.

TaylorGraphics · Apr 27, 2009

we use 300 DPI photos in class. they look better when printed for our stuff..thats why I was wondering whether or not i could change it..Thank you for the information. I'll remember as part of being a Photographer.

farmerj · Apr 27, 2009

There is no way to change it. It's how the camera is programmed in the firmware. I had a similar issue with my Sony H9, which is why i bought the Nikon D90.

You're pretty well restricted just by having bought it. One of the things I look at on ALL cameras I buy now. Less than 180 DPI, I walk away from it.

TaylorGraphics · Apr 27, 2009

okay well.. I didn't buy it, my Gma did for a graduation from College/Bday.... So for a camera that takes those big of pictures for free...i can work with the 72 DPI setting...and I'll look at the Nikon D90

dcclark · Apr 27, 2009

Typically when you print out a photo, you choose the printed size (such as 4x6 or 8x10). That, together with the number of pixels in your photo, determines the resolution (DPI) of your printed image.

You can also "set" the DPI in Photoshop, but it is rather irrelevant -- that only tells your computer what size to display the image onscreen.

Garbz · Apr 28, 2009

farmerj said:
You're pretty well restricted just by having bought it. One of the things I look at on ALL cameras I buy now. Less than 180 DPI, I walk away from it.

Can't figure out if you are joking or don't know what you are talking about. The DPI of an image has no effect on it what so ever till you print, and even then you select it yourself. It doesn't matter what it's set to when you save the file or take it on the camera.

TaylorGraphics said:
we use 300 DPI photos in class. they look better when printed for our stuff..thats why I was wondering whether or not i could change it..Thank you for the information. I'll remember as part of being a Photographer.

Yes upping the DPI resolution would lower the dimensions without resampling. It's just that "Dots Per Inch." If you take the resolution of your image, say 4000x2700 and divide it by the dots per inch, say 300DPI (or rather PPI, Pixels Per Inch to use the correct terminology), then you get the final print size of 13"x9"

farmerj · Apr 28, 2009

Garbz said:
Can't figure out if you are joking or don't know what you are talking about. The DPI of an image has no effect on it what so ever till you print, and even then you select it yourself. It doesn't matter what it's set to when you save the file or take it on the camera.

Sony H9 is 72 DPI .
Dad's Panasonic is 180 DPI.
My D90 is 300 DPI.

All resolutions are set BY the manufacturer. I would constantly look at my images at 100% and could not figure out why the resolution was not as good as a picture taken by a friend who was using a D70.

H9 is a SLR like Point and Shoot.

We set the camera identical one day. Same manual settings everything. Put them up on a tripod and took pictures. His images were much sharper than mine.

Only difference we could see between the two was the camera resolution of 72 vs 300 DPI.

Same difference between the Panasonic vs D90 vs H9.

It makes a difference.

dcclark · Apr 28, 2009

... they were on different cameras, with different lenses. That will vastly overshadow the DPI settings, which affect NOTHING except for changing a value in the metadata.

Dwig · Apr 28, 2009

farmerj said:
Sony H9 is 72 DPI .
Dad's Panasonic is 180 DPI.
My D90 is 300 DPI.

All resolutions are set BY the manufacturer. ...

Not always. Sometimes they are set by the software. Abobe's Camera RAW doesn't respect any PPI (the correct term is PPI for Pixels Per Inch and not DPI for Dots Per Inch) recorded in the RAW file. It assigns a value set in Camera RAW's preferences with the out-of-the-box default being 240ppi. Also, may JPEG images lack any PPI specification. It is conventional to treat such images as if they are spec'd at 72ppi. Photoshop will do this, along with most high end image apps and vector drawing apps. If you don't alter the value in PS, any resulting Save (but not "Save for Web") will be spec'd at 72ppi in the file.

The thing that must be kept clear is that the PPI setting in a digital file has absolutely nothing to do with the resolution of the file. It is, as I said in another post that was quoted above, merely a note attached to the file that informs the application how to display and/or print the image by default. A 2400x2400 pixel image spec'd at 72ppi and a 2400x2400pixel image spec'd at 300ppi will be equally sharp is printed to the same size. The difference is that the print and sometimes display default size of the 72ppi image is larger by default (33.3" square) than the 300ppi image (8" square). If they are both printed 8"x8" that will appear identical as they are both in effect 300ppi on the print.

Knowing the PPI of an image is valuless until you go to print it. Only then do inches figure into the equation. Without inches, pixels per inch is meaningless.

Garbz · Apr 28, 2009

farmerj said:
Sony H9 is 72 DPI .
Dad's Panasonic is 180 DPI.
My D90 is 300 DPI.

All resolutions are set BY the manufacturer. I would constantly look at my images at 100% and could not figure out why the resolution was not as good as a picture taken by a friend who was using a D70.

H9 is a SLR like Point and Shoot.

We set the camera identical one day. Same manual settings everything. Put them up on a tripod and took pictures. His images were much sharper than mine.

Only difference we could see between the two was the camera resolution of 72 vs 300 DPI.

Same difference between the Panasonic vs D90 vs H9.

It makes a difference.

You're getting your resolutions mixed up. The difference in these cameras, other than the quality of the sensor and the lenses is resolution of the sensor in megapixels. The Sony H9 is an 8.1mpx and the D90 is a 12.3mpx. This would account for a difference in image size on the screen, but again has zero to do with the sharpness or overall image quality.

Now say you take you Sony H9 8.1mpx image (which is 3264x2448 and you:
- Print a 6x4" standard frame: The image will 3264 / 6 or 2448 / 4 dpi or 544dpi to print. Set in software before it's sent to the printer.
- Print a 8x5" large frame: The image will be 3264 / 8 or 2448 / 5 dpi or roughly 408dpi to print.

Do you roughly understand now that the DPI means nothing to the quality of the camera, and only something to the quality of the print, and that it is user selectable with zero effect on quality?