To help make your visit from the Image Bot go as well as possible, you need to know that it relies on several factors to figure out what an image is about. Those factors include: the file name, the alt text, the surrounding text, the page title, the page theme, and links. The alt text and file name are the most important in the Bot's determination of what an image is about. You should be descriptive, but you don't have to go overboard with it. Choose a description that represents what you would be searching on if you were looking for that image. Leave out words like "the, or, and, are, we" and similar ones. They'll do little but take up space that better descriptors could be using. In other words, you should use something like "horseshoe crab Seabrook Island South Carolina" rather than "the horseshoe crab I found that time."

The same principle applies to your image file name. Don't call it pic081204.jpg. Call it horseshoecrabseabrook.jpg. Keep the file name either the same as or similar to the alt text. Cramming different keywords into the alt text and file name will not help you rank higher. It will only confuse the Image Bot. If you can (and sometimes you just can't), put your keywords into your page title and your page meta description. The more consistent the data that Google gets concerning your image, the better the indexing will be. This applies to your regular page optimization as well as that for images, and it will also result in more pertinent Adsense ads if you participate in AdSense.

When it comes to images and to your site's pages in general it's best to keep every page relevant to its own theme. In other words, leave your images and text about wildlife photography techniques on its own page rather than mixed in with your image and description of the horseshoe crab.

If you have a page for each topic and optimize each page, you can then use the trick of placing Adsense ads on the page to see if Google "gets" what your page is all about. Even if you don't want to participate in AdSense, you can try this as an indicator of what your site is perceived by Google as being about. As with your regular pages, back links help your image rank higher as long as they were obtained in an organic and honest manner. If you use text links with anchor text, use your key phrase as the anchor. In other words "click here to see horseshoe crab from Seabrook" is much better than "click here to look at a cool picture I took". And, as usual, the more descriptive your URL, the better.

One final tip is to be aware that Google wants to provide unique content in image form just as it does with web pages. To do this it tries to match up the image file size, dimensions of the image in pixels x pixels format, and the image file name. Therefore, if you get an image from another site (with permission of course), you should alter the file name, file type, file size, or image dimensions so that Google doesn't flag it as duplicate content. As you can see in the screen shot, all these front page results are different.