OK, so you've decided you need a new something for your camera gear. Perhaps it's a longer or wider lens, a flash, a wee box of filters, whatever. There's a process you should go through.

First, do some research. The very fact that you're on this site indicates that you're probably reasonably comfortable using the internet - so hit Google, and find what products are available. I find googling the phrase "<type of camera> <type of kit> discussion", ie "Nikon D70 Wide Angle Lens Discussion" to be really helpful. If you have a friendly camera shop near by, you might also (or instead) like to drop in and talk to an expert about what you're looking at. Don't let yourself get sold on a particular brand or model at this point, and definitely don't buy anything. "I'm just doing some research at this stage" and "I don't really have the money yet, I'm just window shopping" are good phrases to use.

While googling or talking, make lots of notes. If a sales person offers you a price, make a note of it (and the sales person's name - they're often paid on commission, and I like to send the sale back to the most helpful person if I can).

You should come out of this with a list of suitable pieces of kit.

From there, for each item on the list, google the phrase '"<kit name>" review' - for example, I was recently shopping for a wide angle lens, and one of the options was a Sigma 12-24mm lens, so I googled for '"Sigma 12-24" review' - put the name of the product in quotes, and add the word 'review'.

One thing to remember is that there are folk on the net who will swear black and blue, that if you've got a Nikon (or Canon, or whatever) camera, you should only put Nikon (or Canon, or whatever) lenses on it. Which is fine if you have a mammoth disposable income, and don't care to look outside the range a little and see if there might actually be something better out there. Of course, it does make your shopping a lot simpler.

So, once you've done your reading and reviewing of the reviews and discussions you should have a very short list to work on. Me, I like to be down to two at this point.

Personally, I tend to make purchases like this 'in the flesh', that is to say, in person, from a shop. So, I get to check out the gear before I part with hard-earned cash. I take my camera along, and try out the (hopefully) two options. In this day and age, there's probably not much quality difference between (for example) two $1000 lenses of about the same focal length from reputable manufacturers, so your choice will come down to which one feels better.

Most recently, I was hunting out a new wide angle for my D70. With the 1.6 multiplier from the smaller sensor, the 18mm low end of my 18-70mm lens just wasn't wide enough for some of the tasks I was trying to use it for (notably, real-estate photography, particularly internal shots). My choice came down to between the Tamron 11-22 and the Sigma 12-24 (pictured at the top of this post).

(the first image is taken with the Sigma, at 12mm, the second with the Tamron at 11mm.)

The photos came out pretty similar as far as I could tell on the LCD (I should note that I was on holiday, and this purchase took place over 2 days, so there wasn't really time to head back to the motel room and look at the images more closely), but of the two lenses, I really liked the feel of the Sigma. It has the downside of not really being able to take filters, due to its rather bulbous front element, but it really did feel more solid, more reliable. As I don't tend to make a lot of use of filters, I doubted very much that I'd feel their lack, so the Sigma it was.

So, Andrew's Recommended Camera Purchasing Process is:

• Make a list.
• Check each item on it, to make a short list.
• Trial each item on the short list.
• Make (and buy) your choice.
• Go home happy!