Understanding PPI

kitkatdubs

TPF Noob!
Joined
Oct 5, 2015
Messages
152
Reaction score
2
Can others edit my Photos
Photos OK to edit
I am trying to understand PPI but still struggling. I am shooting in RAW but when I open the photos in Photoshop, the ppi for all my photos is 72. Shouldn't they be higher? When I give people their photos, do I need to go in and change every single photo to 300ppi before giving to a client?
 
You might consider taking a course in digital photography to learn all this before you try to do this as a business. It sounds like it might be the way you have it set, and it could depend on how a photo will be used to determine what settings would work best.
 
You can set the PPI to any value you want. That value is meaningless until you print.

In Photoshop, open the image. Click (from the pull-down menu along the top) "Image" -> "Image Size..."
Important! UNCHECK the box that says "Resample" (if it is checked.)
Type in the box that says "Resolution" the new value that you'd like (e.g. 300) and make sure you've selected "pixels/inch" (usually that's the default anyway.)
Click "Ok"

That's it... you're done.

What did this do to your image? Absolutely nothing! Not a single pixel was harmed in this process (because you disabled "resample"). All it really did was change a meta-data label that used to declare that you had a 72 dpi image to declaring that you now have a 300 dpi image. But did you really change anything.... nope!

That's because "pixels per inch" is a printer term. If I want to print a 4x6" print (and I physically want it to be 4x6" and not any other size) AND my printer is set to print at 300 dpi, then I need a pixel with dimensions 4" x 300 pixels per inch for a total of 1200 pixels in that dimension and 6" x 300 pixels per inch for a total of 1800 pixels in the wide dimension and I'll get the exact output size I want.

But sometimes a publisher says 'I want your picture to fit in a 3" x 4" spot on the page and I'm printing at 300dpi.' What that means is they want YOU to work out the math to realize that your image needs to be 3" @ 300 ppi (900 pixels) by 4" @ 300 ppi (1200 pixels) and in that case you would tell Photoshop to "resample" the image to a new resolution of 900 x 1200 and you'd set it to 300 ppi and when it goes to the printer it will exactly fit in the space they want. The resampling process will cause Photoshop to eliminate (or add) pixels (make sure you save your original image because Photoshop is a "destructive" editor.)
 
You might consider taking a course in digital photography to learn all this before you try to do this as a business. It sounds like it might be the way you have it set, and it could depend on how a photo will be used to determine what settings would work best.


So I am currently not running a business... I am taking photos for friends and family to build my portfolio. I am learning as I go. Nothing wrong with learning as you go. Are there any photography classes you would recommend that talk about this specific area? I feel like I have the basics down but now I'm getting into editing and need some guidance.
 
You mentioned giving photos to clients, that seems to be doing photography as a business. The questions sound like you need to learn more photography skills, then consider business possibilities, to enable you to be successful with this.

I'd look for classes in your area - try a community art center, a community college, or a university that offers continuing education classes (for adults that aren't part of a degree program but for personal enrichment). In my area the public library offers classes.

There will be the business aspects of it to learn too. For that I'd take a look at American Society of Media Photographers or PPA to get info. from pro photographers organizations to get an idea what will be involved.
 
Clients at this point are friends and family.

Does anyone know if photoshop defaults to a certain ppi?
 
Setting the PPI for an image is one of the critical settings you selected in ACR when you got set up to process raw files.

Joe

acr.jpg
 
Setting the PPI for an image is one of the critical settings you selected in ACR when you got set up to process raw files.

Joe

View attachment 112180

That was INCREDIBLY helpful! So for example, I just randomly picked a photo and uploaded to photoshop and the PPI was 240, is that the default setting? It gave me the option to change it but I don't want to have to manually change every photo to 300....
 
Setting the PPI for an image is one of the critical settings you selected in ACR when you got set up to process raw files.

Joe

View attachment 112180

That was INCREDIBLY helpful! So for example, I just randomly picked a photo and uploaded to photoshop and the PPI was 240, is that the default setting? It gave me the option to change it but I don't want to have to manually change every photo to 300....

There is no default or if there is I'd guess it's 72 -- it stays wherever you set it and applies then to all additional photos. The most important thing to remember about it is what Tim said: It has absolutely no effect on your photo. You can change it 100 times to 100 different values and not one pixel of your photo is altered in any way. It's informational for your benefit but doesn't do anything. If you change it the information it gives you remains the same.

Joe
 

Most reactions

Back
Top