# It depends.

The numerous options available today can be overwhelming, furthermore, entire publications dedicate themselves to talking about the necessity of the latest camera gear. However, digital cameras starting from 2012 and lenses from at least 1893 are able to produce top-quality results, that easily find themselves on large posters, magazine front covers and much more. Knowing what to buy and what will serve you well, will protect you from overspending.
If you are seriously interested in photography and just starting out, you are generally best served with a camera with an interchangeable lens. In photography, the lens is the most important factor for technical image quality, the camera is secondary. Furthermore, optics have had minor developments for more than 100 years, so you have a massive catalogue of affordable, high-quality optics, even more so in the used market.
As for the camera itself, it should be“RAW capable”, that is the most important aspect of the camera body. “RAW capable” means that the camera can output the unaltered sensor data to a storage medium, this will open an entire world of new creative possibilities for you and can even save shots you thought you missed.

## All that glitters is not gold

Pure technological capability is meaningless, if your audience cannot enjoy it. It does not matter if a camera is able to produce 20 % better results than the average, if the “worst” model already far exceeds the capability of the human eye. If you buy a camera that is above the average, do it, because you like it, or you need that model’s capability for a specific application, not because it is so terribly useful everywhere. Photography is a social art-form and not the technophilic science of ever increasing capability or quality.

### In defence of small cameras

A camera is worthless if it is being left at home.
Small cameras, such as compact digitals and especially cell phones, have smaller sensors than DSLRs/MILCs or digital medium format, and therefore produce worse photographs and at that increasingly with less light, since a higher gain “ISO” needs to be used to have a properly exposed picture. However, they are much more portable, since they retract their lens into the body, they are about as small as a phone, while still having massively improved quality over one. For casual photographers, who would rarely if ever lug around a DSLR/MILC, a small camera may be the ideal choice.
Further, used properly, a small camera can produce quite good photographs, particularly at low ISO speeds and if one does not plan to enlarge it too greatly – for posting on the web, for instance. Many serious photographers carry around a small camera whilst about casually, and reserve DSLRs for specifically photographic expeditions or the studio.

## Introduction to camera classes
### Compact Digitals

These are for casual photographers: "point & shoot"
If you do not want to dedicate much time or money, want a camera that fits in a pocket or purse, and just want to easily take photos to view on computers or small prints, compact digitals are ideal, and the choice of 100 million people per year. Conversely, they are generally of lower quality than more advanced cameras, their automatic operation takes control of the image away from the photographer and they lack interchangeable lenses, although, they retract the lenses into the body, which gives them a tiny foot print, more akin to a phone, rather than a camera.

### 35mm Digital Single Lens Reflex (DSLR) and Mirrorless Interchangeable-Lens Cameras (MILC)

The ideal choice for hobbyists and professionals alike.
35mm cameras are suitable for all purposes, they can provide excellent quality and are reasonably portable and affordable. New cameras start from below € 500.00 and used ones are even cheaper. 35mm cameras today are all mirror-less, they show you a video of what the sensor is seeing. Therefore, exposure, compositional aides, remaining shots and much more is being presented to you as it happens in real time. Preferably, choose a mirror-less camera, as they have adapters to almost all lens mounts that were ever created and therefore have superior lens choice. Digital Single Lens Reflex (DSLR) cameras do not have these two benefits, other than that, they are identical. Over 5 million bodies are sold per year.

### Digital Medium Format (> 35 mm)

Top quality, at a high price.
Digital “Medium Format” cameras are designed to achieve optimal image quality, at the expense of everything else. While nowadays most medium format cameras are as portable as 35mm cameras, they are expensive, significantly slower and strict in their workflow. They are meant to be used on high-end commercial sets or in the studio, where you have controlled lighting and actors. While the price hike from high-end 35mm to medium format is manageable, as your first, or hobby camera, they are a bad choice.
That being said, they have the highest image quality of any digital camera by far. Their optics are second to none, due to sensor size, they have significantly more resolution, better tonal reproduction, higher dynamic range, superior accuracy in colour reproduction and much more. If you pursue a career in art, high-end advertising photography or scientific imaging, they are the tool of choice.

### Large Format (≥ 9 x 12 cm)

Unique images and unique baggage.
Large Format refers to any sensory medium that is at least 9 x 12 cm large. They are specialised cameras, most of them need a tripod to be even properly used. They are heavy, bulky and the by far slowest, many of them even require their own suitcase to be transported. They are exclusive to film, as a digital large format sensor costs about € 375,000.00; needs to be cooled with liquid nitrogen and is only custom manufactured for high-end telescopes.
Their benefit however, is that the position of the lens and the film cassette can be freely changed, this allows you to manipulate your image in ways the other formats cannot natively do. Digital cameras can do some of their perspective correction, but that requires a high-resolution image and even then, is only an approximation of this effect. The larger your sensor or film, the more natural the perspective of your image will be, as this is a side-effect of magnification. Spaces and objects will look more like they do to normal human vision and naturally, large format has the this effect to the strongest extent. Lastly, if loaded with the right film, they will surpass the resolution of even high-end digital medium format significantly.

## Sensor size

The key reason that compact digitals are disdained by serious photographers is that the sensors are small. All else equal, a bigger sensor is better – the typical compact digital sensor size is 25 mm$^2$, while the smallest DSLR sensors are 9 times bigger, more typically 13–15 times bigger, with the biggest DSLR sensors being over 34 times bigger. This results in a major difference in quality, but an increase in cost and size – bigger sensors are harder to make, and require bigger (and heavier) lenses.
The larger sensors in DSLRs provide very significant advantages in low-light sensitivity, dynamic range and image noise.
Sensors have a “crop factor”, which derives magnification, the lower the crop factor, the larger the sensor and the less the magnification of said sensor; the reverse applies. This means wider lenses are needed for general use, hence the added magnification of the sensor needs to be offset by the lens. An all-rounder camera should have a crop factor of at most 1.5, smaller sensors than that will have degraded performance in all situations, adding to that is the severely limited lens choice, as you will need extremely wide lenses to accommodate the massive magnification of a small sensor.
Common crop factors are:
| Sensor Class | Size | Crop Factor |
| Micro Four Thirds | 17.3 x 13.0 mm | 2 |
| APS-C | 23.5 x 15.6 mm | 1.5 |
| 35 mm | 36.0 x 24.0 mm | 1 |
| Common smaller Medium Format | 43.8 x 32.9 mm | 0.8 |
| Digital 645 Medium Format | 53.4 x 40.0 mm | 0.644 |
Focal length in a lens, which is printed on the lens tube in millimetres, together with the crop factor of the sensor, will both influence the field of view. Human vision is similar to a 42 mm lens on a Crop Factor 1 camera. If the focal length is longer than 42 mm, the more an object will be magnified; the reverse applies again. If the same 42 mm lens were mounted on an APS-C (Crop Factor: 1.5) camera, the field of view will be equal to a 63 mm lens (63 mm = 42 mm x 1.5) on a Crop Factor 1 camera.
A crop factor of 1.5 is still manageable, has increased reach and can be beneficial for optical quality, as it will only use the centre of the lens, which is its best part. If you were to mount a 600 mm lens for wildlife photography on an APS-C camera, you will actually have a 900 mm lens, for sports/action/wildlife and macro photography an APS-C camera is especially beneficial. The quality gap between APS-C and 35mm sensors is minor. The most commonly manufactured lenses have a focal length of 50 mm and thus are very close to natural human vision. APS-C cameras will enhance the optical quality of those lenses, but they will be effectively 75 mm, which could be limiting, depending on the application.
A Crop factor of 2 is more akin to a compact digital camera, since the sensor will have significantly degraded performance and to get a workable field of view, extreme wide angle lenses need to be used, which is detrimental in all applications, considering that extreme wide angle lenses (< 35 mm focal length) add a high amount of extension distortion, which cannot be removed. Close objects seem closer, than they are and far objects seem farther than they are. You can photograph your own face closely with your phone and see how distorted especially the nose, cheekbones and chin will be.
For starting out, both 35 mm or APS-C cameras are a good choice, choosing a system depends on what you want. You can either go with the extremely flexible 35 mm sensors, or the slightly more inflexible APS-C sensors, which enhance optical quality, at the cost of higher magnification.

## Compact digitals

Compact digitals vary greatly in appearance, interface, and features, and substantially in price, but rather little in image quality. Specific models are hard to recommend because of the rapid replacement cycle in this category.
Biggest issues (beyond price) are generally portability (does it fit where you want to carry it?) and usability: does the interface work for you?
Auxiliary camera. Compact cameras are widely used and recommended as auxiliary cameras – a camera is no good if it is at home – and thus many photographers will carry around a pocket or purse-sized camera when not on a specifically photographic expedition.
Ignore pixel count. At these sensor sizes, higher pixels yield higher noise which swamp the higher resolution and instead yield worse image quality, not better.
* The Best Digital Cameras, by Philip Greenspun
These have caused some measure of excitement, as they allow high quality images in a camera that can easily be carried around and thus are suited as an auxiliary camera for when one does not wish to carry around a DSLR.

## Bridge cameras

Bridge cameras — cameras between compact digitals and DSLRs — form an amorphous category, which has become essentially obsolete. If quality is a concern, buy an entry-level DSLR or MILC; if budget is a concern, buy a compact digital and play to its strengths.

### Usual meaning

They generally mean "a small sensor with a big lens" – thus a style similar to a DSLR, but with a small sensor and hence relatively poor image quality. By comparison with compact digitals, they have bigger and faster lenses – hence can take photographs in lower light and of moving objects – while by comparison with DSLRs the lenses are much easier to make, and hence are generally super-zoom.
These fill a niche which is increasingly small as the price of DSLRs has come down, and one is almost always better served by an entry level DSLR or mirror-less camera. Currently in the US entry DSLRs (with kit lens) retail for $375 (Nikon D40) to $600 (Canon Digital Rebel XSi), while bridge cameras are in the $250 to $400 range.

### Micro Four Thirds System

The “Micro Four Thirds” system is a joint standard of Panasonic and Olympus, which feature a small sensor and were targeted primarily at the video-market; before media processors were capable enough for that application. Cameras with this system have both interchangeable and fixed lenses, although, they posses a Crop Factor of 2, which means that all regular lenses are effectively unusable.
To get usable lenses, you will be locked in to the manufacturers of the Micro Four Thirds system and the only other lens choice you have is the “C-Mount” system, which is a special system of interchangeable lenses designed for machine vision tasks, microscopes, surveillance cameras and extremely compact television cameras.
While they used to have their niche, since a smaller sensor enabled manufacturers to build a smaller camera and made high-speed processing applications, such as quality video recordings, cheaply possible, they have developed into the missing middle, that no one asked for. Hence media processors, together with the larger APS-C, 35 mm and even medium format sensors, are nowadays superior in the only niche that the Micro Four Thirds system excelled at, there is no positive aspect left, that would offset the system’s massive flaw – the Crop Factor of 2.

## DSLRs and MILCs

It used to be that if you were buying a camera, you were primarily buying into that manufacturers system, however, thanks to mirror-less cameras and their enabling of lens adapting, that is largely false nowadays. Largely false, since modern lenses are electronically controlled, meaning when adapting lenses manufactured after ~2017 to a different mount, you would lack control over it. More on adapting lenses in the chapter “Adapting Lenses”.
Since about 2012, it is basically impossible to buy an APS-C or 35 mm camera with bad image output. All APS-C and 35 mm cameras output RAW data and are fully capable of producing professional results. While there are minute differences between cameras, such as in gain behaviour (“high ISO” capability), signal-to-noise ratio, colour reproduction, or others; they are often times negligible for professionals and hobbyists alike.
The largest differentiator between models is how “fast” they are. In sports/action/wildlife photography, a camera with quick auto-focus capability and a high number of frames per second taken (≥ 7 fps), is useful. On the other hand, if you were to frequently make large prints (> ISO A2), a higher resolution camera will be useful. Any camera in this class can do anything and everything, again, it depends on what you primarily need and is therefore better for your application.
As for camera systems, there are many to choose from. Bellow are the most common and notable ones.

### Fujifilm

Fujifilm manufactures APS-C and medium format cameras. They are renowned for their quality native optics.
Their APS-C cameras feature a variation of the usual “Bayer” colour filter array, Fujifilm claims that this “X-Trans” arrangement enhances colour reproduction and resolution, while minimising moiré and therefore eliminate the need for an optical low-pass filter. Their medium format cameras use a conventional Bayer colour filter, this is because of the increased processing requirements for X-Trans, according to Fujifilm.

### Nikon

Nikon is known for having the largest lens product line of any camera or optics manufacturer.
Their catalogue includes many extremely high quality lenses, which are perfectly adapted to other cameras, thanks to their long standing tradition of purely mechanical control. Their “Nikon F” bayonet was introduced in 1959 and up until about 2016, all Nikon F apertures were controlled exclusively mechanically. Even if their pre-2016 lenses lack an aperture ring, as long as there is a slit with a small lever sticking out of the mounting bayonet, it can be controlled via the adapter on a non-Nikon camera. Nikon themself sells the “FTZ” adapters, such that Nikon F DSLR lenses can be mounted on their newer “Nikon Z” mount MILCs.

### Sony

Sony is responsible for kicking off the transition from DSLR to mirror-less cameras, at the time they were at the cutting edge for professional video. Their native optics range is considered subpar, it is best to adapt other manufacturer’s lenses to Sony cameras.

### Panasonic (35 mm product line)

Panasonic used to be the primary manufacturer for Micro Four Thirds cameras, nowadays they almost exclusively manufacture 35 mm sensor cameras, their mount system is the Leica L mount system, which shared by multiple other manufacturers and therefore has the most natively supported lens mount.

## Lenses

Lenses are the number one aspect that changes your images and at that irreversibly so. One lens might have better resolution, the other better inter-tonal detail and another might render the out-of-focus blur significantly better than both. All optical designs have their negatives; there are no lenses which are “perfect” and in optical design there is always a price to pay. That is exactly what makes lenses interesting, every lens has unique characteristics which permanently imprint themselves onto every image they create.
As explained previously, lenses have a focal length, which together with the crop factor of your camera dictate the field of view. 42 mm on Crop Factor 1 is almost perfectly natural human vision. Additionally, lenses have an aperture, the lower the number is, the more light it lets into the camera and the less the area of acceptable focus (depth of field) is. The higher the number, the more light is needed to achieve a normally exposed picture and the larger the area of acceptable focus (depth of field) will be. The aperture of a lens is printed on the lens tube as well; a 50 mm F2.8 lens will have 50 mm focal length and a maximum aperture of 2.8, maximum meaning wide-open. Most lenses have their highest resolution, when making the aperture smaller, usually between F8 to F11.
As a first lens, it is recommended to buy a professional standard zoom lens, native to your camera mount, as this will give you the usual luxuries such as autofocus, automatic aperture control and more. Most professional standard zoom lenses have the 24-70 mm focal length and a fixed aperture of 2.8. If a professional lens is outside of your budget, use a Nikon F adapter to use the “Nikkor 28-85 mm f/3.5-4.5 AF”, which is extremely affordable costing < €100.-, it has a macro-switch to focus very close and the quality is good, with the price in consideration however, the quality becomes astounding.
Frequently, camera manufacturers bundle lenses with their camera bodies (called "kit lens"). Indeed, many people use no other lenses, and thus reap relatively little of the flexibility and especially benefits that a DSLR/MILC affords. Others decry this practice and suggest instead that one use a (prime) normal lens. Kit lenses are poor quality zoom lenses, having low Image Quality and a low F-number (hence needed lots of light and not being capable of Depth of Field effects), because of lens adapting, they are often times a bad value for money.
Some common recommendations follow.
* Canon Lenses Overview by Bob Atkins, especially for APS-C (Rebel, 20D/30D/40D)
* General Purpose Canon Lenses (from The-Digital-Picture)
Sample professional collections:
* Canon lenses
* Nikon lenses

#### Canon

Photography Equipment/Lenses/Canon standard

##### Standard Zoom

* kit lenses: Canon EF-S 18-55mm: considered very soft
* Canon EF-S 17-55mm ($1,300) excellent general-purpose lens

##### Standard Prime

* Sigma 30mm f/1.4 for Canon ($400)

#### Nikon

Photography Equipment/Lenses/Nikon standard

##### Standard Zoom

* Kit
** Nikkor 18-55mm (various versions)
** Nikon 18-70mm f/3.5-4.5
* Nikkor 28-105mm f/3.5-4.5, ~$325
* Comparison of popular Nikon zoom lenses
* Nikkor 28-115mm

##### Standard Prime

* Sigma 30mm f/1.4 for Nikon ($400)

## Medium Format

Medium format may be the most vague sensory medium category, as it starts from the nameless 0.8 Crop Factor, purely digital Medium format up until 6x9 cm, exclusive to film, it even includes special formats like the 24x65 mm format, shot by the Fujifilm TX panorama cameras. Medium format has one thing in common however, very high quality with a very slow workflow. The quality is one of the main reasons as to why it is so slow. When you have a 16 Megapixel sensor on APS-C for example, errors in focus, sensor dust, or other defects, will not be recorded since the resolution is to low, that changes when your sensor is more than 60-100 Megapixels, while still having massive photodiodes. Every small error in tonality, focus, or others will be recorded perfectly well. Since focus is now critical, Medium Format cameras need to precisely focused, either manually, or with autofocus, which will take much more time, adding to that, are their lenses, which have a significantly reduced depth of field since they are longer focal lengths and being used closer to a subject, than on cameras with smaller sensory mediums.
Medium Format cameras find themselves on high-end advertising sets, or with professional artists needing to make very large prints, or in scientific imaging applications. There are nowadays only a few manufacturers of digital medium format cameras.

### Phase One

Phase One A/S is truly embracing the mantra of quality, at the expense of everything else. Even in the Medium Format class, their optics are significantly ahead in terms of quality, compared with the competition. A single lens costs between € 6,000.- and € 12,000.-, with one camera body about € 10,000.- and finally a digital back costing between € 40,000.- and € 50,000.-. Although, in the used market, it is a different story, a camera body can be had for about 10-30 % compared to the new price, their newest generation digital back for about 50 %, or an older “CCD” generation, with almost identical specifications and performance, for < 10 % of a new digital back. The lenses are the most affordable, since the newest “blue-ring” generation is just a product line consolidation after their acquisition of Mamiya, another Medium Format camera and optics manufacturer, the blue ring lenses being equipped with a leaf shutter and autofocus for the two optically identical Mamiya 645 AF lenses, while all "Silver Ring" series lenses had both from the start. All Mamiya 645 AF lenses are compatible with the XF camera body and the older film lenses are compatible with the predecessor model “Mamiya/Phase One 645 DF”. To make the XF camera accept older film lenses, refer to the chapter "adapting lenses". Below is a table outlining their lens product catalogue and which optical formula is identical and therefore yields equal performance, at a fraction of the price:
| Modern "Blue Ring" Lens | Optical Formula Identical to Predecessor “Silver Ring” Series? | Optical Formula Identical to Mamiya 645 |
| Schneider Kreuznach 40-80mm LS f/4.0-5.6 | Yes | / |
| Schneider Kreuznach 75-150mm LS f/4.0-5.6 | Yes | / |
| Schneider Kreuznach 35 mm f3,5 LS D | No | / |
| Schneider Kreuznach LS 45mm f/3.5 | No | / |
| Schneider Kreuznach 55mm LS f/2.8 | Yes | / |
| Schneider Kreuznach 80mm LS f/2.8 (MK.I) | Yes | / |
| Schneider Kreuznach 80mm LS f/2.8 (MK.II) | No | / |
| Schneider Kreuznach 110mm LS f/2.8 | Yes | / |
| Schneider Kreuznach 120mm LS f/4.0 Macro | / | Mamiya 645 120mm f/4.0 Macro MF |
| Schneider Kreuznach 150mm LS f/3.5 | Yes | Mamiya 645 150mm f/3.5 AF |
| Schneider Kreuznach 150mm LS f/2.8 IF | / | / |
| Schneider Kreuznach 240mm LS f/4.5 IF | Yes | / |

### Fujifilm

Fujifilm is the manufacturer responsible for making digital medium format affordable for the mass-market. While still more expensive than professional APS-C and 35mm, the price gap is rather manageable. Fujifilm medium format “GFX”-series cameras have the smaller and nameless 0.8 Crop Fact sensor format, meaning they are 43.8 x 32.9 mm large.
Their lenses are extremely flexible medium format optics, as most of them have usual 35 mm niceties such as linear autofocus motors, image stabilisation and some feature very large apertures. If there were a middle-ground between traditional medium format and 35 mm, it would be the Fujifilm GFX product line.
It’s Fujifilm G mount also has a range of adapters available for it, even for 35 mm mounts and although it is mechanically possible to mount lenses intended for smaller formats on a GFX camera, it should be avoided, as the image the sensor is now receiving will be far outside it’s intended image circle and therefore the quality will be severely degraded or the image will be even missing entirely. In the menu it is possible to tell the camera, to only use a 36 x 24 mm centre crop of the sensor, although if you were to primarily use small picture lenses – and there are very good reasons to do so for most applications –, a GFX camera would be a waste of money. If you adapt lenses, it is recommended to exclusively adapt other medium format lenses, such as:
* Mamiya 645
** No control over modern, electronically controlled lenses.
* Hasselblad V
* Contax G
* Contax 645
* Pentax 6x7
* Bronica ETR
* ARRI PL
** Medium Format lenses are extremely rare, but available, for this bayonet.

### Film

* Choosing a Medium Format Camera, by Philip Greenspun
* Choosing a Large Format Camera, by Philip Greenspun

### Digital

MF backs exist that are similar to DSLR sensors: a full sensor. These are extremely expensive, but can be rented.

## Large Format

LF backs are scanning backs: a sensor the size of a LF image would be prohibitively expensive, so instead one uses a row of sensors which scans across the image, with exposures measured in minutes. They are thus only suited for photography of static objects.

## What about Film?

With two exceptions, digital imaging is far superior to film, signal-to-noise ratio, colour accuracy, dynamic range, gain, flexibility in post-production, ease of use, reproducibility and many more. The exceptions, where Film is still heralded as superior are: sensor size and resolution.
Sensor size is quite evident, it is possible to make a film plane as big, as it is possible to make a black box containing it.
Digital and analogue resolution are measured differently, but achieve the same. Digital cameras have Pixels, a square unit, which holds a certain mathematical value, while analogue cameras have microscopic dye clouds, with a certain saturation, inside the photosensitive emulsion. There is a simple test, in which both formats can be compared: how many increasingly small, black lines on bleached white paper can a recording device capture? A black line, together with one adjacent white line is called a line-pair and the unit is line-pairs per millimetre (lp/mm). If it is assumed, that regular black and white film can cleanly resolve 45 lp/mm, it is possible to calculate its equivalent “digital” resolution. If the same lens is used for both technologies during the test, one line-pair can be cleanly represented by two pixels, since one pixel should be white and the other black. Thus, this black and white film has an equivalent resolution of 90 pixels/mm and on a usual 36x24 mm camera that would be 6.9984 Megapixels (10⁶ Pixels). If the same camera would be loaded with 110 lp/mm colour reversal film, the resulting image would be 41.8176 Megapixels. There are cameras, with significantly bigger film planes, than any digital sensor, the largest standard format being 10.16x12.70 cm (8x10”), which with the same given colour reversal film from the previous example would have ~ 624.51 Megapixels.
If it is of interest as to why film has it’s unique look, refer to the chapter “recording technologies”.
For certain purposes, notably non-destructive testing or high-quality landscapes, film remains the medium of choice. Similarly, others enjoy its look, as well as the process and tradition of film.
Lastly, when using radioactive lenses, there is no need to worry about the sensor being damaged by them. It is recommended that you buy a cheap digital camera for using radioactive lenses, since the sensor is guaranteed to fail at a later date, depending on the radiation dosage.

## References

* ↑ R. N. Clark (2008-12-26). "Digital Camera Sensor Performance Summary". ClarkVision.com.
* ↑ (2009-APR)
* ↑ http://photo.net/equipment/building-a-digital-slr-system/
* What Camera Should I Buy?, by Philip Greenspun