For travel, you want a camera body plus a set of lenses that covers most or all of the types of photo you want to take at a price that does not break the bank and a weight that does not break your back. This is often achievable, though usually some compromises are involved.

We cover simple systems that will suit many travellers in the main travel photography article. This article gives suggestions for a more elaborate system based on a camera with interchangeable lenses. Take these suggestions a bit sceptically since all the choices here depend on your personal preferences and priorities in rather complex ways.

An old saying is that to get the best system, you should spend around two thirds of your budget on glass and only about a third on the camera body. Many users today, though, do more-or-less the opposite, buying a good body but, initially at least, getting only the cheap "kit lens" that comes bundled with it. Most are quite happy with such a purchase, but many will later get more lenses.

Certainly lenses are a better long-term investment than digital bodies. Plenty of lenses made in the 20th century are still giving fine results, many could still be sold for a large fraction of their original price, and a few classics fetch more today than they sold for new. However, while older digital bodies may still give good results, they usually sell for far less than their original cost. Semiconductor technology changes fast; newer bodies will generally have both better sensors and better in-camera image processing.

Size and weight have a sort of compounded effect. A larger heavier camera/lens combination is harder to hand hold so more likely to need a tripod; it also requires a larger sturdier tripod. Then you may need a larger carrying case; the combination is more of a problem for airline baggage allowance, and less likely to fit in hand luggage. It is also more strain on you, especially if your style of travel involves a lot of walking or difficult ground. Because of this, heavier stuff is much more likely to be left at home or in your hotel, so not available when you actually need it; any camera in the hand is worth two Hasselblads in the hotel. On the other hand, some photographers find a larger camera easier to handle and a heavier camera may be more stable.

Bodies

The first thing to choose is the body; that will constrain all the later choices of lenses. Of course, one factor in choosing the body is what lenses are available for it, and body choice may be dictated by a desire to use existing lenses or because you want a particular lens so you get a body that supports it.

There is a wide choice of interchangeable-lens bodies available, sometimes described as "consumer", "enthusiast" and "professional", though the categories overlap. Features that appear mostly on the higher-end bodies include:

• larger sensors
• more flexible controls
• weather-proofing
• more bits of color information for each pixel
• more measuring points on the sensor for better control of exposure and autofocus
• larger battery and/or an external battery grip, good for a long day of heavy shooting
• dual memory cards, not so much for extra capacity as for backup so a card failure cannot wipe out hours of work
• higher frame rate for bursts of shots
• larger buffers and/or faster transfer to memory cards, so they can take more shots in a burst

A pro may need all these features, and be able to justify paying for them, and an "enthusiast" may want some. The rest of us do not need most of them and should not pay for them.

Depending on your interests and budget, you might consider used equipment. For any brand, a used high-end body often gives a better feature/price trade-off than a new body, and older low-end or mid-range bodies may be quite cheap.

Sensors

A key design decision for a digital camera is the size of the digital sensor. See the main travel photography article for a description of common types of digital camera, with some mention of sensor sizes.

On the left is a full-frame sensor
On the right is a sensor of a size typical for a cellphone or webcam.

Sizes in common digital cameras range from 48 mm² in some compacts, through micro four thirds (μ43) at 243 and APS-C at 300-odd, up to 864 mm² in a "full frame" camera (sensor is 24 by 36 mm, same as a 35 mm film frame).

This article does not attempt to cover medium format digital cameras. Those have sensors 33 by 44 mm (1452 mm²) or larger, and are for expert photographers with a large budget; bodies are $4500 and up, and the lenses are not cheap either. Few travellers need them, and any that do probably know more about photography than most of our writers. Medium format film cameras are discussed in our Travel photography/Film article.

At any given sensor size, the designer makes trade-offs between more pixels for better resolution versus larger pixels. Large pixels give better dynamic range (the range between the dimmest shadow and the brightest light where they can show any detail) and they require less light, which is essential in low-light situations and useful when you want to use a fast shutter speed for a stop-action effect.

A larger sensor allows any of:

• more pixels of any given size — giving higher resolution
• larger pixels for any given resolution — giving better dynamic range and better low light performance
• compromise solutions — giving more modest improvements in both resolution and pixel size

It can safely be said that a larger sensor gives better performance, other things being equal. However, other things are rarely entirely equal and there are trade-offs. There are pros happily working with everything from μ43 to medium format.

The costs of large sensors are significant; they are more difficult to manufacture, so usually more expensive, they require more power and produce more heat, and moving the sensor for image stabilisation is harder. They also give less depth of field for a similar image and aperture. Perhaps most important, they need lenses that can cover the bigger area, and those lenses are significantly heavier and more expensive. Higher-resolution images also need more memory, more storage space and more processing power, often both in the camera and in a computer used for later processing. Large images may also mean transfers from sensor to buffer and from buffer to storage are slower. These difficulties can all be dealt with, but not cheaply.

An alternative is to use film instead of a digital sensor. See Travel photography/Film for discussion.

Image stabilization

Many newer cameras have a feature which vendors call image stabilization, vibration reduction or shake reduction. This automatically moves some part of the camera system to partly compensate for camera movement; it can give a large improvement for hand-held shots, but is of little or no value if you are using a tripod. It is most useful for telephoto lenses since those are more sensitive to camera movement.

Some vendors (Olympus, Pentax) put this feature in the camera body; this saves on weight and cost compared to having it in multiple lenses. and it means you get stabilization with every lens, even older ones that you might pick up cheaply. Others (Nikon, Canon, Fuji) build it into their lenses, which they claim is more effective since it can be tuned for the individual lens. Still others (Sony, Panasonic) put it in both some lenses and some bodies. Nikon's full-frame Z-mount mirrorless cameras (but not its APS-C mirrorless, at least at present), and some of Canon's RF-mount mirrorless cameras, have in-body stabilization but will also work with the corresponding company's stabilized lenses.

If the camera can move the sensor for stabilization, that mechanism can be used for other things as well. Most sensors use the Bayer pattern for pixels; each group of four has two green, one red and one blue pixel arranged in a square, there are color filters so each pixel gets mainly one color of light, and software constructs a full image by interpolating missing information. This works fine, but resolution and light sensitivity are lower than with a monochrome sensor, as used in Leica's M Monochrom, where every pixel gets all the light. Many Pentax bodies have a "pixel shift resolution" mode that takes four shots moving the sensor by one pixel each time, then combines them into a single image so each pixel location gets information for all colors. Results are often good, but the sensor movements are slow enough that it requires a tripod and does not work well for moving subjects.

Anti-aliasing filters

Some photos have an effect called a moiré pattern, as shown in the photo of parrot feathers below. Moiré can appear for any subject with repeating elements: fabrics (especially densely textured ones like tweed), cornfields, brick walls, ... It is caused by an interaction between the pattern in the subject and the pattern in the sensor.

Moiré pattern in photo

Moiré is always unrealistic and in most cases it is quite undesirable, though it can sometimes be used for artistic effect. A polarising filter on the lens or various tricks in post-processing can reduce the problem, but often they cannot eliminate it entirely.

Most cameras have an anti-aliasing (AA) filter built into the sensor to reduce this effect. However, this reduces the effective resolution; the filter eliminates moiré by blurring the image slightly. Some vendors therefore offer cameras without the filter, sometimes even a pair of models that are identical except one has the filter and the other does not.

Pentax leave out the AA filter and emulate the AA effect when needed by vibrating the sensor to blur the image slightly.

Lenses

Lens focal lengths In discussing focal length, we assume a 35 mm film camera or "full frame" digital camera. For other types of camera, the actual numbers are different but the "35 mm equivalent" is often quoted.

For cameras with interchangeable lenses, the choice of lenses to bring along becomes important, though having a large range of lenses is not nearly as important as the eager salesperson at the camera store wants you to believe. Some of the world's most famous photographers used only one or two lenses for much of their career.

The next few sections discuss specific types of lens, later we give suggestions for choosing the right combination for travel.

Wide-angle lenses

A wide-angle lens will let you get a broad panorama in landscape photos, or fit all of a city square into the frame. For travel, an important use is for interior shots where you cannot back up enough to cover the whole scene with a longer lens. They can also be used for artistic effect; getting close with a wide-angle lens can give a photo with high visual impact.

An observatory in Chile. Depth of field is huge; everything is in focus

Wide-angle lenses give greater depth of field than longer lenses; that is, objects are in reasonably good focus over a greater range of distances so small errors in focusing do not matter and a complex scene with objects at different distances is more likely to look good.

One way to use a wide-angle lens is to focus to the hyperfocal distance for some aperture; everything from a few meters to infinity will be in focus. Set the camera for aperture-priority exposure (it will automatically set shutter speed), set the aperture and focus once, and it is sometimes possible to shoot all day without ever needing to adjust anything.

Typical wide-angle lenses are in the range 20 to 35 mm; even wider lenses are sometimes used, but less common. Some general-purpose zooms go wide enough to handle this and there are wide-angle zooms, but many photographers prefer to carry a compact lightweight lens such as a 24 mm 2.8.

For APS-C, zoom lenses around 10 to 20 mm (15-30 mm equivalent) are a common choice. For full-frame, there are attractive choices among used lenses; neither autofocus nor image stabilization is much needed for wide angle, so lenses from the film era work fine.

Telephoto lenses

Lion, 500 mm lens. Depth of field is small; things both in front of and behind him are out of focus

If you intend to photograph far-away objects – especially wildlife, for example going on safari or birdwatching – you will need a telephoto lens. Pros use quite long lenses, often 400 mm or more, for wildlife, or for things like photographing a surfer from the shore. For some shots, such as photographing bighorn sheep in mountainous terrain, an even longer lens may be needed. For others, such as photographing performers at a concert, a milder tele such as a 70-200 mm zoom is typical.

Really long lenses are both heavy and expensive and the depth of field is narrow so a small error in focusing can ruin a shot. A traveller might just choose a zoom that goes to 300 or so, or look for a 200 mm prime (common and often fairly cheap on the used market) which acts as a 300 mm equivalent on an APS-C camera or 400 on μ43. If you expect to shoot a lot of wildlife, consider a 300 mm prime; these are heavier and generally more expensive but there are some bargains on the used market if you do not need a fast lens or newer features like autofocus and vibration reduction.

Sigma 200-500mm f2.8 zoom

If you are going on a safari, consider renting a lens. Bought new, the high-end lenses that are best for this start around $900, many are priced far higher, and they are neither common nor cheap on the used market. The Sigma shown is an extreme example, about $25,000 and 16 kg (35 pounds).

For anyone except a pro who specializes in wildlife, rental often makes more sense. Cost for a two-week rental is typically about 10% of the cost of the lens; a few hundred dollars for that is reasonable in the context of a safari budget, where a few thousand to buy such a lens is not unless you are quite well-off and expect to use it a lot.

800 mm f8 mirror lens

Mirror lenses are lighter, more compact and usually cheaper than refracting lenses; most of them are between 400 and 1000 mm. These are the only lenses with zero chromatic aberration; a refracting lens bends different colours of light differently, but a mirror reflects them all identically. However, they have odd bokeh (the quality of out-of-focus parts of an image), the aperture cannot be adjusted, and they lack autofocus. Professionals typically prefer refracting lenses because they need absolutely top-quality results, but a traveller might choose either; except for bokeh, the results can be just as good.

A teleconverter fits between lens and camera and increases the effective focal length. They can be useful if you do not want the weight or cost of an actual lens, but they often degrade the image quality somewhat and they make the lens slower by the same factor that they increase the focal length. For example, if you use a 2x converter with a 200 mm f4 lens, that gives you in effect a 400 mm f8 lens. Using a 1.4x converter with a fast high-quality prime lens will almost always give good results, while using a 2x converter with a cheap slow zoom will usually be highly problematic. Between those extremes, some combinations work well while others do not.

A small-sensor body may be an alternative. Suppose your main rig is full-frame digital and you have a 200 mm f4. All full-frame vendors also offer APS-C bodies; your 200 will fit on one of those, giving the angle of view of a 300 mm lens on full frame, features like autofocus will still work, and lens speed will not be reduced as it would be with a teleconverter. This will not be the cheapest or lightest solution, but it also gives you a back-up camera. Or get a μ43 body and an adapter to use your lenses on it; that will make your 200 act like a 400 mm f4 and some of those bodies are very compact, with weight not much more than a teleconverter.

There are also adapters for mirrorless cameras (μ43, Sony E-mount, Fuji X-mount and a few video cameras) called speed boosters. These are sort of reverse teleconverters; instead of making a lens act longer and slower, they make it act shorter and faster. With multiple adapters a lens can become quite versatile; for example a full frame 200 f4 on μ43 acts like a 280/2.8 on a speed booster, 400/f4 on the normal adapter, and 560/5.6 with a 1.4x teleconverter.

Tripod required!

The longer the lens, the more likely you are to need a tripod, both because the lens is heavy and because the magnification of the image increases the adverse effect of any camera movement. A rule of thumb is that you need a tripod if shutter speed is slower than one over the 35mm equivalent focal length; for example, with a 200 mm equivalent lens you need a tripod if shutter speed is slower than 1/200 s. A lot of practice or a good image stabilisation system in either camera or lens may let you hand-hold a bit beyond this.

There are alternatives to hauling a heavy tripod along, including small tripods for use on a tabletop or on top of a wall. A monopod is sometimes enough, is lighter, and can also be used as a walking stick. Various other things may also work; there are camera mounts that clip on a vehicle door, and sometimes just resting the camera on a beanbag is enough.

Macro

Close-up shot of a rose

A macro lens is designed for photographing small things. The traditional definition is that it allows a 1:1 ratio of object size to image size so that, for example, a flower with 24 mm (about an inch) diameter gives an image that just fits on a full-frame sensor or film negative, as in the image at the right. Marketers, though, apply the rather saleable term "macro" to any lens that can get somewhat close. Another confusion of terms comes from Nikon; their line of what everyone else calls macro lenses are designated micro-Nikkor.

Not all travellers need this, and many of those that do can get by with less than the full 1:1 ratio. It is common, though, to include one lens with macro capability in your arsenal. Generally this will be a telephoto lens since shooting macro with a shorter lens requires getting extremely close to the subject; this makes lighting difficult, and if the subject is a small creature you might scare it away.

Most macro lenses also work fine as general-purpose lenses — though they may be a bit slower or more expensive than a non-macro lens — so it is possible to choose one that can be used both ways.

Lens features

Most photographers want some of these features on some of their lenses:

• Fast lenses let a lot of light in. You can tell how fast a lens is by checking the aperture numbers printed on it, the lower the faster. One stop of aperture changes the number by the square root of two (about 1.4) and the amount of light admitted by a factor of two. For example, going from f2.8 to f2.0 doubles the light intake; you can get the same exposure with a shutter speed twice as fast.

Fast lenses allow shooting in lower light or using faster shutter speeds, and they make it easier to get good bokeh, that sexy expensive-looking background blur. The differences can be large; consider a typical kit lens at its long (f5.6) end versus an 85 mm f2 lens. The difference is three stops, so the fast lens admits 2³ or eight times as much light. The fast lens may be shooting at 1/200 second, easily hand held, while the slow one needs 1/25 which requires a tripod and is likely to produce blur if the subject moves.

To some extent, the high-ISO capability of digital cameras compensates for this; just crank the ISO up by three stops and you can shoot at 1/200 with the f5.6 lens. Fast lenses are therefore less important now than they were in film days. However raising ISO gives more noise in the photo, and for really dim light or for stop-action shots that require high shutter speed you need both high ISO and a fast lens.

Fast lenses also have disadvantages. Moderately fast primes in the 35-85mm range are generally reasonably priced, but if you want an ultra-fast lens, a fast zoom, or a fast lens outside that range, then the price will be stiff. Shot wide open, fast lenses have less depth-of-field so they require precise focusing. Also, weight increases at approximately the same rate as light-handling capacity — for example, an f1.4 lens gathers twice the light that an f2.0 lens gets, and weighs about twice as much.

• A zoom (variable focal length) capability is certainly convenient and nearly all photographers today use at least some zoom lenses, though many prefer prime (fixed focal length) lenses for some applications. Prime lenses are less flexible, but generally faster, lighter, and more compact. They are also often sturdier, both because zooms have more moving parts and because many useful primes are older designs with all-metal construction rather than the plastics in newer lenses.

Consider a 70-200 mm zoom vs an 85 mm prime. The prime may be sharper; the design problem is much less complex for a prime than a zoom. For the photos where you want a longer lens, you can switch to a longer prime, use a teleconverter, or just shoot at 85 and enlarge it more. The prime user takes a considerable penalty in convenience, and sometimes in quality if the shot really needs a longer lens, but is better off in terms of weight, reliability, and low light performance. The zoom user, though, may get shots while the prime user is busy changing lenses.

• Autofocus is convenient anytime and really useful when tracking a moving subject (e.g. animal or athlete). However, it is not necessary for a static subject (e.g. cathedral or landscape) and for some subjects (e.g. portrait or crowded square) manual focus may give better results because it gives the photographer more control. For most macro shots, manual focus is essential.
• Image stabilisation is more useful for longer lenses, especially when shot handheld. It is less valuable for standard or wide-angle lenses and of almost no value when a tripod is used.
• Macro capability is useful for photographing tiny things, but not for anything else.

You may need each of these on at least one lens, but you do not need all of them on all lenses.

General rules

Owning a lot of lenses may make sense, since each has different strengths and may be ideal for different situations, but for travel carrying all of them generally does not. You want to keep your carry-all-the-time kit down to two or three lenses, and some people do fine with only one. On the other hand, it is fairly common to bring along a few specialized lenses that are not part of the everyday kit; they stay in the suitcase or the hotel safe most of the time and go into the camera bag only when they will be needed.

The best weight/coverage balance involves avoiding duplication and keeping roughly a 2x difference in focal length between adjacent lenses. It used to be quite common to choose a pair of primes around 35 and 75 mm (or three around 25-50-100) as a lightweight travel kit. This is still a viable choice for some travellers, but zoom lenses have improved greatly and they are now the most common choice.

The same principles still apply. If you have a kit lens for the 28-85 range, think about whether to add lenses around 28/2=14 or 85*2=170 mm; you might end up with a 16 or 20 mm wide angle or a 135 or 200 mm telephoto.

In most cases it makes little sense to duplicate focal lengths, for example to carry a 24, 50 or 105 mm lens along with a 28-85 kit lens. Of course there are exceptions; you might want a fast 50 for night shots or a 105 for macro. However, it is worth thinking about how to reduce the kit and 'travel light'; for example, if you will be carrying the 50 and 105, can you leave the kit lens at home? Would you then need the 24 as well? Or would a fast 35 let you do without the 24 and 50? Should you buy a high-grade mid-range zoom to replace the kit lens, perhaps fast enough you would not need the 50 and able to get close enough you would not need the 105 macro?

Lenses for a pro shooting sports
Most travellers would not want to carry even one of these

Another good principle is to avoid extremes unless you have a specific need for them. For example an ultra-wide lens such as 16 mm can be useful, and some travellers even find a 16-35 mm zoom worth carrying, but many have a mid-range zoom that goes wide enough for them. Most of the rest will be fine with a 20 or 24 mm prime, which is likely to be lighter, cheaper and faster than the 16 mm prime, let alone the zoom. Similar considerations apply for extremely long lenses.

This also applies to ultra-fast lenses. For example, Canon's 85mm/f1.2 gives famously good but not perfect performance at f1.2, so in many situations it will be stopped down to f.1.8 or so to eliminate distortion. The 85/1.2 is two-and-a-half times the weight of a Canon 85/1.8 and nearly five times the price. Every vendor has at least one fast lens in the 75-105 range and many pros consider those lenses ideal for studio portraits, but even they might choose not to carry one for travel, especially if they will be carrying a 24-70 or 70-200 zoom.

Another extreme to consider avoiding is high-ratio zooms which cover a large range of focal lengths. The designer can achieve a high ratio only by trading off something else; you lose some image quality or speed, and often some of each. Most pro zooms have a ratio between 2:1 and 3:1, but consumer zooms with higher ratios are common; for full-frame Nikon have a 24-120 (5:1), a 24-105 (4.5:1) is among Canon's best sellers, Panasonic have a 24-105 for their L mount cameras, and several vendors have 70-300 (4.3:1) lenses. These are convenient, and most users are quite happy with them, but every user pays a price due to the design trade-offs.

You may even be tempted to go for a superzoom lens with a zoom ratio up over 10:1 such as 18-200 mm; these give an enormous advantage in convenience and may be the only lens you need. However, picture quality may suffer noticeably and you'll be stuck using a physically big lens all the time. There may be some exceptions; for example, Olympus have a 12-100mm (24-200 equivalent) f4 lens for μ43 which they claim is pro quality and which has had excellent reviews. On the other hand, it is bulky, heavy (560 g, 19 oz) and expensive (around $1300).

Modern pro zooms get close to primes in both speed and image quality and usually have constant aperture across the zoom range, but they are heavy and expensive, and often have a smaller zoom range than consumer-grade zooms. These are a common choice for professionals but much less so for amateurs. For travellers, an f4 zoom may be a good compromise. For full frame Canon, Nikon and Pentax all offer an f4 lens around 70-200mm which is lighter and cheaper than the f2.8 pro model but faster, more expensive and perhaps better quality than the usual consumer model. Pentax have a 60-250 f4 (90-375mm equivalent) in their DA* line of high-end lenses for APS-C. Several vendors also offer f4 zooms for the 16-35 or 24-70 mm ranges.

Mixing systems

An advantage of most DSLRs is that they use the same lens mount as older cameras so they can use older lenses. For most users, an old film camera does not make much sense today, but see Travel photography/Film for discussion. However, using fine old lenses on a new digital body is a far more attractive proposition. Current Pentax or Nikon DSLRs can use most lenses back to about 1960, and Sony Alpha DSLRs can use Minolta lenses back to 1985. Current Canon DSLRs can use most lenses back to 1987 when they changed their mounting system. New Leicas can use lenses all the way back to the 1930s.

Complications Many companies make both full-frame lenses (Canon "EF", Nikon "FX", Pentax "FA" and "D FA", Sony "A" and "FE") and lenses designed to cover only the smaller APS-C sensor (Canon "EF-S", Nikon "DX", Pentax "DA", Sony "E"). Most of the APS-C cameras will accept lenses designed for full-frame systems without an adapter, though Sony needs an adapter. Not all lenses designed for APS-C will mount on full-frame cameras and those that do will often vignette (take pictures with the corners darkened). Some full-frame cameras will automatically crop images taken with an APS-C lens. Some bodies (e.g. Nikon D3xxx and D5xxx) do not have autofocus motors. With those, autofocus is only available if the lens has a built-in autofocus motor ("AF-S" or "AF-P" for Nikon-brand lenses, though the latter will not focus at all on 3- and 5-series bodies made before about 2013). In-body stabilization systems need to know the lens focal length; recent lenses tell them that but older ones do not. For a prime, just set the focal length when you mount the lens. For a zoom lens, you need to set it every time you zoom, and some cameras let you set it only at startup so you have to power the camera off and restart it to do that. The best solution may be to disable stabilization when using an older zoom lens. In 2018 both Nikon and Canon introduced full-frame mirrorless cameras with a new lens mount, Nikon Z series or Canon RF, and a new line of lenses. Nikon now also offer an APS-C mirrorless camera with Z mount. Both companies offer adapters that let the new cameras use their older SLR or DSLR lenses, but the new lenses will not mount on any of their older cameras.

Older bodies or lenses from any manufacturer may lack features that are common in later models, most notably autofocus and vibration reduction. If you want to mix and match across generations various restrictions apply; the boxed text to the right describes some of the common ones but is not an exhaustive list. If you are considering a large investment in equipment — and especially if you will include some older items — it is almost certainly worth doing considerable research first; you might start by looking at the online forums for the brand of interest.

MILCs (mirrorless interchangeable lens cameras), also known as EVIL (electronic viewfinder, interchangeable lens) cameras, have a short register distance (sensor to lens mount) so with an appropriate adapter they can use any lens designed for a longer register distance. This includes almost all available lenses — any new DSLR lens, any Leica rangefinder lens, almost any SLR lens including pre-1987 Canon FD lenses that do not work on current Canon cameras and older Minolta lenses that do not work on current Sony models.

However, there are restrictions. All adapters allow the lens to physically plug into the body, but many do not provide any other interface (levers or electrical contacts) so features like autofocus do not work. In some cases, even automatic aperture control — you compose the shot with the lens wide open for good viewing then when you hit the shutter the lens stops down to shoot — is not available. There are a few exceptions if camera, lens and adapter are all the same brand.

People with several interchangeable lenses may carry two camera bodies, or sometimes even more. In film days this usually meant two with different film; today it may mean two digital cameras or a digital and a film body.

A camera body that uses film, or has a full-frame sensor, can be an advantage for wide-angle lenses, because the larger format widens the angle that lens captures. On an APS-C camera, a 24 mm lens gives an angle of view equivalent to 36 or 38 mm; on μ43, 48 mm. Why not load some film into another body and use the lens as the 24 mm device it was designed to be? This may give pictures that your small-sensor rig can't capture.

On the other hand, some people take advantage of the effect of sensor size differences on telephoto lenses, making them act like longer lenses.

Putting a system together

A common approach to assembling a good system is to pick one type of lens you really need, then choose other lenses to go with it. Here we discuss options with different choices for the first lens; of course you might choose to start with two or more of these.

Start with a standard lens?

Arguably the most important lens is the standard lens, around 50 mm. For most of the 20th century, nearly every camera sold came with one, and they give an undistorted perspective, close to that of the human eye. Henri Cartier-Bresson — who is often credited with inventing modern photojournalism and whose classic photos of Paris now appear in poster shops everywhere — did nearly all his work with just one lens, a standard 50 mm.

There are variations. Some photographers prefer to use 35 mm as their standard lens, and someone used to smartphones may consider a 28 mm equivalent to be a "normal" perspective. Some claim that the least distorted perspective comes from a lens whose focal length equals the sensor diagonal, 43 mm for full frame. Pentax makes a 43 mm full-frame lens which is very highly regarded, a 28 mm lens on APS-C gives a similar perspective, and Panasonic has a 20 mm f1.7 (40 mm equivalent) for μ43.

One could build a system starting with a high-grade 35 to 50 mm prime. Most vendors offer f1.8 or f2.0 lenses in this range at moderate prices, and often f1.4 for not much more; these are among the easiest lenses to design and manufacture since they do not need to zoom, to be remarkably fast, or to handle extreme focal lengths.

For example, one might put together an interesting system for any brand of APS-C system starting with the camera vendor's 35 mm (50mm equivalent), 28 (42) or 24 (36). For full-frame, one might start with one of the camera maker's primes, but the manual focus Voigtlander 40 mm f2 is an interesting alternative; it is extremely compact and gets excellent reviews.

Start with the kit lens?

The lens most commonly sold with a camera today is the kit zoom. Cost is usually low; a body with the kit lens is generally not priced much above body alone. These lenses vary in coverage; nearly all cover at least the 28-70 range and many go a bit beyond that. They also vary in speed (most are quite slow), weight and image quality. Many users will be quite happy with a kit lens, and some vendors offer different bundles so a buyer can choose a different kit lens.

Most manufacturers offer a consumer-oriented 70-300 mm zoom, not topnotch quality or very fast but lightweight and moderately priced. That is a very popular add-on; with the kit lens it gives quite a versatile two-lens system. Some vendors even offer two-lens bundles along those lines. For some users it is also worth considering a higher grade tele-zoom.

A prime telephoto lens would also make a good pair with most kit lenses. Most kit lenses go up to about 85 mm equivalent, so they pair best with something well above that, near 200 mm equivalent. For many brands high-grade used manual focus lenses are available in this range at moderate cost. You might also choose a new lens; for example Olympus μ43 lenses include a 60 mm (120 mm equivalent) f2.8 macro and a 75 mm (150 equiv) f1.8, and either might be a good choice.

Start with a high-end mid-range zoom?

Another way to build a fine system is to replace the kit lens with a high-grade wide-to-tele zoom. For some pros, especially wedding photographers and photojournalists, this is their most-used lens; it is fast, high-quality and very versatile. However, other pros may have a wide zoom and/or a long one, but do not feel they need this one.

Pros who do have mid-range zooms often use top-of-the line 24–70/2.8 full-frame zooms which are quite heavy and expensive, not suitable for most travellers. However on μ43, Panasonic offers a 12–35 (24–70 equiv) f2.8 and Olympus a 12–40 2.8. For APS-C, Fuji and Sony have 16–55 (24–85 equiv) 2.8 lenses, and Pentax have a 20-40 f2.8-4.0 in their top-of-the line "limited" series. These are not cheap either but are quite a bit lighter than the full-frame lenses.

Lesser lenses might be better for travel. For full-frame, Canon have a 24–70/4.0 and Nikon a 24–85/2.8-4.0. For APS-C or μ43, all the main vendors offer cheaper and lighter mid-range zooms; these might be just the thing for some travellers. Others should save money by just sticking with the kit lens, or by using a prime as their standard lens.

If you plan on doing a lot of low-light shooting and have an APS-C body, consider Sigma's fast zooms; they have an 18–35 mm f1.8 (about $800) and a 50–100 f1.8 (about $1100). While the focal length ranges may not appeal to everyone and these lenses lack image stabilization, the maximum aperture is the fastest found in any zoom lens available (as of 2020); an f1.8 lens lets in three times as much light as f2.8.

Taking an APS-C system with the Nikon 17–55 as an example, one wants the next lens up to be around 55*2 = 110 mm. The Nikon 105 f2.5 is readily available on the used market at moderate cost and has a fine reputation; that is the obvious choice, but there are many other possibilities. Some users may find the 26 mm-equivalent end of the zoom range wide enough; if not the obvious choices would be the Nikon 10.5 mm or a 10-20 mm zoom.

Start with a tele zoom?

Another approach is to build a system starting with high-grade tele-zoom. This can work with a kit lens rather than replacing it, so in one sense it is a better buy than the wide-to-tele zoom; whether it is more useful depends on your style of photography.

The approach is tried and proven. Well-known outdoor and travel photographer Galen Rowell did most of his work with only two Nikon lenses, a 24/2.8 wide angle and a 75-150/3.5 zoom. Buying used from a dealer one can get exactly those manual focus lenses today for around $350; the nearest current Nikon equivalents, a 24/1.8 and 70-200/f4 with autofocus on both and vibration reduction on the tele, would be $1600-odd new. On APS-C the Sigma 50-100mm f1.8 would give you a much faster 75-150mm equivalent lens.

For full-frame, the obvious choice for travel is an f4 zoom around 70-200 mm. Nikon, Canon, Sony and Pentax all offer one, and they are both cheaper and lighter than the pro 2.8 lens but faster than the other consumer zooms. Another alternative for Nikon or Canon shooters only is Tamron's 70–210 f4, which is cheaper than the camera vendors' lenses and according to many reviews sacrifices very little in image quality.

For a μ43 system, Panasonic have a 35-100 mm (70-200 equivalent) and Olympus a 40–150 (80–300 equivalent); these are about the same price and weight as full-frame 70-200 f4s, but faster at f2.8. These are heavier and more expensive than most µ43 lenses but may be rather an attractive option, especially since the camera bodies are lighter and cheaper as well. Of course, there are trade-offs here too. In particular, these systems use far smaller sensors than full frame cameras; see above for discussion.

APS-C shooters are less fortunate in this respect. The full-frame 70–200mm zooms will work, but on APS-C they act like longer lenses, and they are heavier than an APS-C lens needs to be. Those who want a high-quality tele-zoom designed for APS-C can face a difficult search. Of the main players, only Pentax offers a lens that gives a 35mm equivalent range of 70–200, a 50–135 f2.8. Another option is the Sigma 50–100 f1.8, available for Canon, Nikon, and its own bodies. Fuji offers a 50–140 f2.8 for its X-mount bodies. None of these are cheap; the Pentax and Sigma lenses are a bit over $1000 and the Fuji about $1600.

There are many choices for lenses to pair with a tele-zoom; the commonest are a prime in the 24-35 mm range, or a wide-angle zoom.

Start with a wide zoom?

Another approach, perhaps the best way if you shoot a lot of architecture or landscapes, is to start with a high-grade wide zoom; this can also lead to a versatile two-lens system. For example, for full-frame Canon's 17-40 f4 or Nikon's 16-35 f4 plus an 85 mm prime or a tele zoom might be all you need. Add a 35 to 50 mm fast prime if you need it for night shots.