I was flicking through some photos on flickr and started thinking that I wanted to achieve a particular effect - after a bit research I found that what I was appreciating was Depth of Field. Subject in focus with a blurred background.
I'm looking for a new camera and I really like the look of the Pentax x90, however can what I want be achieved with this camera?
The answer is yes you can, but in a more limited set of circumstances.
Depth of field is affected by sensor size, meaning that a camera with a small sensor will have a much larger depth of field (and thus less blur in the background) than a DSLR with a large[r] sensor.
But depth of field is also affected by focussing distance. The closer you focus the smaller the depth if field, giving you more blur. The effect gets stronger the closer you focus so you will be able to get the depth of field effect when doing macro, or close to macro shooting with the x90.
Whilst long zoom lenses don't affect the depth of field (much), they do influence the degree of background blur, meaning you can get the effect you're after by using the longest focal length possible. Given the x90 offers a 626mm (equivalent) focal length this should be plenty long enough.
You can also fake the effct in Photoshop but that requires masking the subject by hand in each photo.
I think you're specifically asking about shallow depth of field, so the short answer is yes, but with any compact camera that has a small sensor, it's harder to do. This won't be specific to the X90, it'll be true of any small sensor camera. There are a number of pretty technical articles on the subject, but some have made it easy to get some ratios such as this Cambridge in Colour article on sensor sizes where they have a handy calculator that you can use to punch in some numbers from some of your Flickr favourites and get the comparison info for the X90 to achieve a similar effect.
You can achieve the DOF effect (bokeh) you're looking for with a compact camera, but you'll have to work at it a little bit because you won't have the really big apertures needed to do this at will. Here are some examples from my Panasonic FX28, which is in the same class as the X90:
Keep in mind that while a DSLR owner can strap on a F/1.8 lens to get shallow DOF, your camera won't be too far off the apertures seen on many "kit" lenses. If you're able to compose your shot to help set up the DOF you want, you should be able to create some nice photos.
