The Creative Mom

How do I make my digital photos smaller?  How do I make them bigger? These are two of the most common questions I get asked.  Usually I walk them through the process using whatever image editing software they have (See the instructions for reducing image size in Adobe Photoshop below.) And then I usually have to go through the image size verses image resolution speech.  So, here it is in brief in case anyone out there is a little confused.

First, some digital image facts.  Image resolution is given in pixels.  Image size is given in inches (or centimeters if you’re into the metric fad.) File size is given in bytes (usually the Kilo, Mega or Giga variety.) Screen resolution is 72 dpi (dots per inch.)  A good quality print resolution is 300 dpi.  That means that an image on screen, say from the internet, looks great on your computer, but when you go to print it out it looks a little fuzzy or pixilated at the same size. Your eyes can see more detail on printed images than on screen. 

So, lets say you have an image of your baby that you want to email to your entire address book.  Since screen resolution is 72, and you don’t want to alienate all of your friends by filling up their inboxes, you, as a courteous e-mailer, reduce your image resolution to 72 and your image size to around 5 by 7 inches.  Now your baby photo will delight your friends instead of infuriate them.  But, let’s say you also want to print this photo out for yourself.  Do not try and increase the resolution.  IMAGE RESOLUTION CANNOT BE INCREASED.  I know they can enhance the reflection on someone’s contact lens on CSI Miami to see the license plate of the bad guy, but in the real world that would take some kind of magic spell or a deal with the devil.  So, always keep a copy of your original photo if you reduce your image size for email or web.  Now, go back to your full size photo of that baby of yours and print from that.  Keep in mind that anything under 250 or 200 dpi will start to look pixilated.  Don’t try and blow up a small digital image to an 11×14 to hang on your wall.  It’s better to have a good quality small photo than a large crappy one.

There are many image organization programs out there now that will not only organize but resize and do minor edits such as cropping and red eye reduction. I highly recommend iPhoto or Picassa. 

How to Reduce Image Size in Adobe Photoshop…

So, you have the industry standard, top of the line image editing software, and you have no idea how to use it for the simplest task.  Don’t show fear! Click like you know what you’re doing.

1. open your photo
2. go to file -> save as  and save this image under a new name. I like to add simply “sm” at the end of the files I am shrinking (ex. baby_sm.jpg . Now you won’t shrink your original image.
3. go to image -> image size.  Make sure that the box marked “resample image” is checked.  This allows you to alter resolution independent of size.  
4. Enter 72 in the box marked resolution.
5. Now enter a new height or width, something around 6 or 8 inches wide is ideal for most emailed photos. Notice that your height and width are connected so you only need to enter one, the computer will calculate the other. 
6. click okay. Go to file -> save.   See, it’s simple!