How annoying is it when pictures don’t load fast enough on the web? If your buyers are on dial-up they may even hit the back button and search someone else’s listings if your photos are too slow. There are three things to consider:

The dimensions of the final image in your eBay listing
The number of pixels (the detail of the image)
The speed of loading

So how do you keep the pixel size down?

Crop your shot
Resize the image
Compression

The better shot the image is the less time wasted editing it. The higher the resolution, the better the picture so set your camera to the highest image quality possible (typically this is “Fine”). This will make for a good Master. Save the Master as a JPEG. Don't be tempted to set the camera to highest file compression so you can fit more images on your memory card, once lost you can't get the image quality back. You can always bring the picture down in pixels, but not up. So it is better to start with the best resolution, especially if you intend to do a lot of editing with software later. Remember you can compress the image later after a Master image has been saved.

Transfer the image to your computer to use your picture editing software.

1. Crop your shot, so buyers can focus on the item you have for sale. Remember to only include the item for sale in the image - you can use a backdrop to isolate your item when taking the shot. Cropping is the first step to reducing pixel size.

Correct the lightness/darkness/contrast if necessary - correct lighting at the time of shooting will minimise the need for this step.

Correct the colour cast - the image may have a yellowish or bluish cast depending on the way it was lit. (See our guides to using Flash and Daylight).

2. Resize the image - the ideal pixel number for eBay is 40,000. A dark image, of a black leather belt for example, uses a higher number of pixels than a lighter image. All picture editing software should have a command called Resize or Image Size or Sample. Alternatively, if you create your listings using an HTML generator like Microsoft Frontpage you can resize your images by right-clicking on them after copying and pasting from your image hosting space. Go to Picture Properties where you can enter the exact pixel number you want to use - for a square image 200 x 200 is a good size. Play around a little but try not to exceed 40K. Remember digital photos can be stretched and distorted - keep "aspect ratio" or "constrain proportions" active so that by entering the height value, the width one will be entered automatically.
Plan the layout of your eBay listing and try not to exceed 100K for the whole page. You can also resize by highlighting the image and dragging from one of the corners - dragging from the top or bottom will distort the image. After re-sizing check Picture Properties to see how many pixels you have.

3. Compression - reducing the size to take up less storage space. This step is optional - it is the way to get images with a larger than normal dimension on the web page load quickly.
JPEG is what's known as a "lossy" format - It allows for compression by losing data. The higher the compression the greater the loss of quality, the lower the compression the more like the original. With high compression when you publish your image on the web you lose quality and the image will break-up, on the other hand the lower the compression the longer it will take to load.
To give you an idea: if any of your buyers are on dial-up with a speed of 57.6Kbps an image of 40K will take 45 seconds to load. Optimising your photo for the web reduces the size of the image further without significantly changing the viewing experience - it makes it possible to have a larger image within your eBay listing.

If you were using Photoshop for example, click on File > Save for Web which gives you options to further compress your images: Choose an option from the Quality Level menu, or specify a value in the Quality text box.
The higher the Quality setting, the more detail the compression preserves. However, using a high Quality setting results in a larger file size than using a low Quality setting. View the optimized image at several quality settings to determine the best balance of quality and file size. You can have up to 4 images on screen displaying the different resolutions of the image and different loading speeds. Then choose the best compromise between dimension and picture quality for your listings.

Naturally not everyone has access to Photoshop but luckily the excellent and FREE Gimp enables you to compress your images.  Save images as JPEG then open the "Preview in Image Window" and adjust the image quality slider and compare with the original.  The dialog box will tell you the file size.