howto How Big is my Photo?

[bradl]

As you may have noticed, we love photos of Cairns and their companions on CairnTalk. If you haven't used a forum before it can sometimes be a puzzlement when trying to upload your first photos. If you tried to upload a photo direct from your camera or phone, you probably got a message saying it was too big. Since the web uses lower resolutions than printing photos, the number of pixels in the average camera image are far too many to display on a screen. So in most cases you will be resizing your images to be smaller in order to display well on a forum. But how big ARE you photos?

It's often useful to know how big a photo is. Sometimes we want to know the size in pixels so we know how big it will appear on-screen and sometimes we want to know how big it is in file size so we know if it will fit in our allotted  disk storage space.

File Size: Whenever you are uploading an image, there will be fine print on the upload dialog box with the file size limit, if any. The limits vary depending on your use (user avatar photos are small, profile cover images are bigger, photos for posts and gallery albums are typically biggest). The file size will be listed as KB or MB. For example, .5MB is the same as 500KB. 

Pixel Size: For a forum post a good image size in pixels that will display nicely for a majority of users (who may be using phones or tablets or desktops or desktops with Really Big Displays)  is somewhere between 500 and 1024 pixels wide. I frequently choose 800 pixels.  Not so small as to be a postage stamp on a big monitor, but not too big for lower resolution displays. The forum software may size down your image slightly if it's larger (say 1024 pixels wide) so as not to break the page layout, but we can usually view your image in all its full sized glory by clicking on it. 

But, you ask, how do I know how big the photo is? Here are some instructions I found from a google search results on that very question, courtesy of the folks from Constant Contact.  I've edited it slightly. Errors are probably mine, not CC's. 

Using Your Web Browser

To find the file size and dimensions of an image that is currently on a webpage:

1. View the image URL in your web browser.
2. Place your cursor over the image, and right-click (PC) or Ctrl-click (Mac).
3. If you're using:
   • Internet Explorer - Choose Properties.
   • Firefox - Choose View Image Info.
   • Safari - Choose Inspect Element and then click on Images on the left-hand side. Click on the image and view the properties in the Styles section on the right-hand side. 
   • Note: Safari doesn't display the image file size, but you can typically Ctrl-click to save the image and view the properties on your desktop as described below.
   • Chrome - You can install an app that lets you view the properties within the browser.
4. Locate the "Size" line that shows the image's file size  and the "Dimensions" line to see the height and width in pixels.

You may also be able to drag the image off the screen and onto your desktop where you can examine it as a file on your computer as described below.

A Saved File on Your Computer

To find out the file size and dimensions of an image that is stored on your computer (generic insructions):

1. Open the file where the image is saved.
2. Place your cursor over the image icon, and right-click if you are using a PC or Ctrl-click if you are using a Mac.
3. Choose Properties.
4. Click the Details tab.
5. Scroll down to the:
   • Image section -  To view the image dimensions.
   • File section - To view the image file size.

The exact procedure may vary slightly depending on operating systems and whatnot, but these tips should give you an idea of how and where to look to discover the file size and image dimensions of your photo. For example, here are the file properties of an image on a Mac, found by highlighting the image on my desktop and clicking CMD-i (command-i) to get file information.