Image sizes - What's the best size to use?
A question we commonly receive is what image sizes should be used with our themes. In most cases it will depend on the theme itself, but for full screen themes like Bold Reloaded, or Venti, the best route to take is to size images accordingly to what screen sizes the majority of your visitors have.
How do you find this info? Analytics.
Google analytics provides data on resolutions and browsers which can be helpful in determining the sizes you need. You can find this info under: Audience->Technology->Browser & OS in your analytics dashboard. If you look above the default list at the bottom you'll see a line of links titled 'Primary Dimension', clicking on the 'Screen Resolution' link will bring up the data you're looking for. Once you have that info, see what top 3 resolutions are and use this as a basis for resizing your images. In general most traffic will be in the 1280 x 800 - 1440x900 range, for these sizes a good starting point for image sizes is 1500x1000, which gives you wiggle room for larger sizes. One Important thing to remember and keep watch of is image file size , you'll want to keep the images ideally less thank 200kb in size to prevent long page load times, as each image has to be downloaded by your visitor before the page is displayed. Large image files can significantly impact the speed of your site and loading times, so it's also a best practice to keep galleries to a reasonable number of images 20-30 to help avoid long load times as well.
For themes that are not fullscreen, we've built our themes to automatically resize and use the best possible image size in places throughout the theme, so in many cases this will be automatic. Unless you'd like the images to be cropped in a specific manner, the theme should handle resizing for you in most instances.
Please Note: Uploading too large of images may cause the resizer to fail on some webhosts. This is because many hosts set a limit to how much memory a script can use at any given time, this is generally set at 2mb. So if an image's filesize is larger than 2mb the resizer is not able to resize the image since it is not able to put the image data into memory in order to create/manipulate the image. If your images are not being resized, make sure the filesizes of your images stay below 1.5mb (ideally you should be uploading images much lower in size than that).