In January 2012 Kodak announced that it was filing for bankruptcy protection, a company with a 133 year history in photography was going out of business. So film is finally dead? I don't think that could be further from the truth. Over the past few months I have been scanning all of my dad's old 35mm slides that he took of us as kids (see my article here) and during this process I have grown to really love the look, feel and quality of film. So much so in fact that I have recently bought a 35mm cameras! Using this cameras has done several things for me. It's made me passionate about photography again, it's taught me a lot about photography, it's changed my view on digital photography in a way I didn't think it would and it's confirmed to me that film is far, far from dead but actually a quietly thriving area of photography.
If you own a Digital SLR at some point you will look at your photos and wonder why there are little black spots in the same position on some of them. Often people think that it's a mark either on or inside their lenses - which it's possible it could be but if you have multiple lenses it's very easy to rule this out, whilst I've even heard of some people thinking that the sensor on their camera has been damaged and have sent it off for repair.
In 99% of these cases the cause of these black marks is simply dust on the sensor. Even if you don't currently have any marks on your photos there is still a very good chance that you have dust on your sensor too. To see if you have try this simple test.