Unless you are a photographer yourself, then like most people you will naturally turn to the stock photo websites where you can buy royalty free professional images. The most well-known stock photo website of them all is iStockphoto which is an excellent but fairly expensive source. However, iStockPhoto is certainly not your only option as there are many others...

Starting with iStockPhoto, and ending with some less well-known stock photo websites we explore a few which might be of assistance to you...

istockphoto.com is an amazing website loved by site owners around the world. It quickly changed the way that people buy and sell photography and illustrations online. However, prices for the best photographs are on the rise and sometimes you just want something different. So, here we present a selection of alternative premium stock photo sites, plus some useful tools for finding free photos.

Getty Images was set up in 1995 by Mark Getty and Jonathan Klein. Getty images offer the industry's best and broadest collections of imagery and footage - including award-winning news, sport and entertainment content, plus rare and contemporary archival imagery. Getty provide images for multi-million-dollar advertisers.

Dreams Time is a relatively new player that's built up a great reputation. It is a member of the Picture Archive Council of America and is a popular source of photographs for many advertising agencies, magazines and media companies. Like iStockphoto, images are sold on a credit system with subscription options. A selection of over 220,000 free images are available under a Limited Royalty Free License, which restricts you to using the image no more than 10,000 times. All free images are donated by photographers.

123 RF is another American based website which delivers a refreshing change and has a great image search engine. Again, images are purchased using credits; although credits can be a little more expensive than some other options. Many of the images are free for the lowest resolution or smallest size, and there's a broader range of categories than some other sites.

Shutterstock offer a monthly subscription based service (which allow you to download up to 25 images per day) or an 'Images on Demand' plan which simply allows you to download images anytime for up to one year. Shutterstock offer more than 24 million royalty-free stock images and vector illustrations.

Stock Exchange is owned by Getty Images but it offers a totally free stock site. SXC has a long history and a great community although it lacks choice.

Big Stock Photo has a set price based on the size of each image and offers credit packs. If you are after one or two photos, then this is a good way to shop since you don't need to remember how the credit system works. They have a very wide selection of photographs, and although it's not the cheapest, the ordering system is slick.

Deposit Photos is another competitively priced stock photo business. Individual images can start at about 30 pence, but having a subscription brings the cost of images down to as little as 7 pence each. They have many illustrations, vectors and backgrounds in addition to images. There's also a greater depth to some categories, for example their medicine and health section contains over 1,000 photos of operations alone.

Fotolia is a London-based business with stock photos starting from 7 pence each. Fotalia describes itself as the first worldwide social marketplace for royalty free stock images and illustrations. They emphasise that the site is as much for designers and illustrators as for photographers so, if you are looking for illustrations this should be the first place you visit. They also have a small selection of free images.

Can Stock Photo boasts 4.5 million stock photos and is one of the few sites where no membership is required. Many of the images are also available on previously mentioned stock photo sites. They also have a large collection of vector images and illustrations.

Alamy boasts 24 million stock photos with a whopping 15,000 new images added every day. You can tell from the start that they offer a much higher quality of photography than other sites. Images are often very well composed, artistic and dramatic. On their homepage they showcase some of their top photographers. You can search specifically for model-released images too, which is something few sites provide. They also have a 'creative' filter which includes more abstract images and some illustrations.

Vector Stock offers Royalty Free Vector Art and a handful of Stock Images at some very low prices. If you looking for a logo design or some scalable vectors, this is one of our favorites.

Flickr offers a vast amount images which are uploaded by users. Many Flickr users have chosen to offer their work under a Creative Commons license, and you can browse or search through content under each type of license. The 'Non-Commercial Share Alike License' will allow you to copy, distribute, display, and perform the work so long as you give the original author credit, and not use the image for commercial purposes. The 'Share Alike' license allows you to alter, transform, or build upon the work but you may only distribute the resulting work under an identical license.