Your first three lenses, in the order that gets you shooting

The order is: the zoom that came with the camera, then a fast standard prime at €220 to €280, then one lens chosen from your own photographs rather than from a list. The first is already in the bag. The second is the cheapest large improvement in photography. The third is the only one that needs thinking about, and you cannot think about it usefully until you have taken a few thousand frames.

The usual advice is to buy a wide, a standard and a telephoto and call it a kit. That works, and it also means two of the three sit in a drawer for a year while you discover you are a 35 mm photographer. Buying in response to a shortage you have actually felt wastes less money.

For scale: this catalogue holds 65 lenses between €220 and €3,100. The 28 primes have a median of 700 and the 37 zooms a median of 1,300. That gap is why lens two is a prime. If you have not yet bought the body, read lenses before bodies first: the mount decides which of these lenses you can ever own.

A kit zoom typically covers something close to 28-85 mm in full-frame-equivalent terms, at a maximum aperture that starts around f/3.5 and closes to about f/5.6 as you zoom in. Most of the criticism it attracts misses. Stopped down to f/8 in daylight it resolves more than a phone screen or a 30 x 20 cm print will show, it is light, and it almost always has stabilisation.

It is also the only instrument you own that can tell you which focal lengths you actually use. A prime cannot collect that data. Shoot the kit zoom for a few months and it will hand you the specification for lens three.

What it genuinely cannot do

• Work in dim light without a high ISO. At the long end, where a kit zoom is f/5.6, you are about three and a third stops behind an f/1.8 prime; at the wide end, f/3.5, it is about two. That is the difference between ISO 6400 and roughly ISO 640 for the same picture.
• Throw a background out of focus at normal distances. At two metres on full frame, a 50 mm lens at f/5.6 has around 54 cm of depth of field. At f/1.8 it has around 17 cm. Those figures assume the usual full-frame standard for how much blur still reads as sharp, so treat them as the shape of the difference rather than a measurement. Both are physics, and no setting on the camera changes them.
• Hold its aperture across the zoom range. The f/3.5-5.6 marking means the aperture closes exactly as you zoom towards the portrait end, where you most wanted it open.
• Focus close enough for real macro. Kit zooms get you a large flower; they do not get you an insect eye.

The honest summary: a kit zoom is a good lens in good light and a weak one in bad light. If the photographs you are failing to take are indoors, at dusk, or of something that moves, that is an aperture problem. If they are failing because of shake or blur, read exposure basics first.

A prime has one focal length, so it has fewer elements, no zoom mechanism and one set of aberrations to correct instead of a range of them. That is why an f/1.8 prime can cost a fraction of an f/2.8 zoom and still out-resolve it wide open. Every major mount has one, and they are the cheapest lenses here.

Stops are what you are buying, and stops decide whether a picture exists at all. Indoors in the evening, f/1.8 is the difference between a shutter speed that freezes a face and one that does not. It is also the first time most people see a background genuinely dissolve, which is the effect they thought needed a more expensive camera.

One caveat. On APS-C a 50 mm prime frames like 75 or 80 mm, which is a short portrait lens rather than a standard one. For the standard view on APS-C look nearer 30-35 mm, or take the Sigma 18-50mm f/2.8 at €450, a constant-aperture zoom that does the job of two primes.

Here is where lists stop being useful. The standard third recommendation is a telephoto, or a wide, or a macro. Each is right for somebody, and none is derived from anything about you. The 65 lenses here fall into six roles: 18 standard, 13 telephoto, 10 portrait, 9 all-round, 9 wide and 6 macro. Only your own frames can say which role you are short of.

Experienced photographers genuinely split on the shape of lens three. One camp says buy a fast constant-aperture zoom and stop, because a lens change costs you the picture at a wedding or a street corner. The other says primes weigh less, cost less, and teach you to see a focal length before you raise the camera. Both produce good work.

What lens three should not be is a second zoom that overlaps the first. If you already cover 28-85 mm, a 24-105 mm adds almost nothing at a zoom-class price. Reach outwards, or for an aperture the kit zoom cannot give you, or for a focusing distance it cannot manage. Otherwise wait.

Half an hour, and it replaces every opinion on the internet with your own data.

1. 1

   Gather a year of keepers

   Open everything you kept from the last twelve months, not everything you shot. The keepers are the evidence: they are the pictures you wanted, so they describe the photographer you actually are.

2. 2

   Group them by focal length

   Every cataloguing application can sort or filter on the focal length recorded in the file, and so can the info panel of most operating systems. You want a rough histogram, not a spreadsheet.

3. 3

   Convert everything to full-frame equivalent

   Multiply by 1.5 for most APS-C bodies, 1.6 for Canon APS-C and 2 for Micro Four Thirds. Without this step you cannot compare your figures with any lens specification or with anybody else.

4. 4

   Look at the ends of the range, not the middle

   A pile of frames at the widest end of the zoom means the lens was stopping you getting more in, and you want something wider. A pile at the longest end means you were cropping later, and you want reach. A flat spread in the middle means the zoom is doing its job and the answer is an aperture, not a focal length.

5. 5

   Read the rejects as well

   Sort the year by what you deleted. Blurred frames at slow shutter speeds point at a fast prime, frames binned because the subject was a speck point at a telephoto, and frames binned because you could not get close enough point at a macro.

6. 6

   Turn the role into a shortlist

   Once you know the role and the budget, the lens finder ranks all 65 against those two answers and shows why each one moved. Buy from the shortlist, not from a review of a lens for a different job.

Lens one is usually bundled. Lens two is 220-€280 on any of the big mounts. Lens three is the variable: the prime median here is €700 and the zoom median 1,300, and telephoto reach is what pushes a lens to the €3,100 top of the range. Budget for the role, then look.

• Skip a filter set. A polariser earns its place for water and foliage; coloured and graduated filters do not.
• Protective filters on the front element are a real argument with two reasonable sides: a filter is cheaper to replace than a front element, and it is also another air-glass surface in front of your most expensive optic. The rule that settles it: fit one on a beach, at a gig or anywhere with blowing grit, and take it off otherwise.
• Skip a teleconverter until you own the telephoto it sits behind. It costs light and a little sharpness, and it fits a short list of lenses.
• Skip any lens for a mount you are not sure you will keep. Bodies get replaced every five to eight years and lenses outlive several of them, which is why choosing a camera is really a choice of system.

After that the limiting factor stops being equipment. What changes your pictures is where you stand - focal length and framing - and whether the kit survives the trip, which is camera care and travel .