Camera Buying Guide
Lately I've been answering many posts on which cameras people should buy, explaining the differences between them, and listing the pros and cons of each. I therefore thought it would be a good idea to make a thread about this so that anyone who wants to buy a camera could read it and get a basic understanding.If people wanted to read it, notify me of any errors or wrong info (I don't profess to be the guru of all things camera related), or add any vital info that's missing, and then hopefully make it into a sticky?
Key
DOF- Depth of Field; area of the image in focus
IQ- Image Quality
FF- Full frame; referring to the size of the sensor (part of the camera that captures the image). FF sensors are equivalent in size to the old 35mm film
APS-C - APS-C sized sensor, smaller than FF but still with excellent publishable IQ.
Smaller sensors have what is called a crop factor, please read here for more info.
For the purpose of this article I am not going to discuss medium and large format cameras as these are still a niche market. When I compare IQ across the cameras they are not compared to medium or large format.
Camera Buying Guide
Before we get started I think it’s important to remember a few things. Getting good pictures is primarily about the person behind the camera knowing what to do, don’t expect that buying expensive equipment automatically gets good pictures.
After technique, and of course light, arguably the two most important factors in getting the best images are the lens and the sensor (the part of the camera that captures the image, ie does the job that film used to). Generally the better the lens the better the image quality (IQ), and the bigger the sensor the better the IQ. Also the larger the sensor the better the low light performance in terms of the image looking less noisy/grainy, and the more control of depth of field (DOF) you will have (the amount of the image that is in focus). See this link for more info on sensors, including a diagram showing the relative difference in sizes. In recent years the gap between the IQ of the different sized sensors has been bridged and in certain situations it can be difficult to see the difference in IQ between a FF sensor and crop sensor for example.
You will see a lot of camera specifications having a ‘second’ 35mm specification listed. This refers to the old 35mm film cameras and this ‘second’ listing refers to how the camera would ‘behave’ if it were the old traditional 35mm film cameras. When making comparisons between cameras it is probably best to compare the 35mm equivalent listing as this is standard across all cameras. The most common 'equivalent' specifications are focal length (how much 'zoom' the lens has) and aperture, expressed as f-number. The larger the aperture, the more light is let into the camera and so the better it will perform at low light. Aperture will also affect DOF, but I'm not going to discuss this here. Just to confuse matters large apertures have small f-numbers, therefore a f2 lens will have a larger aperture than a f8 lens.
When buying cameras there can be a lot of brand ‘snobbery’ and personal preferences, therefore when buying a camera it is important to look with an open mind and decide what functions of the camera are more important to you. Layout of the controls and buttons vary dramatically from camera to camera, as do menu systems, screens, and also something that is often overlooked but very important, ergonomics. For these reasons it is always best to go to a store to try the camera before you buy.
How many Megapixels do you need? Don't be fooled by thinking the more MP you have the better the IQ will be as this is not necessarily the case. MP count is a bit of a contentious issue, but forcing too many MP onto a sensor can be detrimental to IQ and can introduce noise (used to be called grain in the film days). High MP count can be useful if you want to print very big, and/or you intend to crop the image heavily.
Right then, onto the cameras. This is not exclusive, but I’m going to cover the most common.
Compact Cameras
Most often we think of consumer compacts here. These are generally cheap, small, portable cameras that can offer quite large optical zooms. Generally they have the smallest sensors and so image quality is going to be at the low end, as is low light performance. That being said, in the right conditions they can still provide very good images indeed. Typically consumer level compacts have a sensor size of 1/2.3", but some offer slightly bigger sensors such as 1/1.7" and so will give marginally better IQ and low light performance.
Mobile phones can fit into the category of consumer compacts too, although zooms tend to be limited. Consumer compact cameras offer full automatic control, but only tend to offer limited manual control. Another thing to consider is that the majority of compact cameras do not have viewfinders, having an LCD screen only.
Recently compact cameras have been released that are aimed at the high-end amateur market sporting much bigger sensors (some have a full frame (FF) sensor which is approximately the same size as a 35mm film) and full manual control. These will produce much better image quality and low light performance. However, they tend to cost significantly more money, and zoom is limited. A very good compromise between size, cost and image quality is the 1" type compact cameras such as the Sony RX100 range and Canon G7x range.
Bridge Cameras
Bridge cameras are essentially consumer compact cameras in a different form, looking and feeling more like a DSLR camera. As they generally share the same sensors as compacts (1/2.3”), image quality and low light performance tends to be similarly at the low end of the spectrum. Other than the form of the camera, the other main differences between bridge cameras and compact cameras is that they can offer bigger zooms, allow full manual control and have viewfinders.
Recently bridge cameras have been released with larger sensors, such as the Sony RX10 which has the same 1” sensor as the RX100 mentioned above. However, once again they tend to be considerably more expensive.
Compact System Cameras (CSC’s), commonly referred to as Mirrorless Cameras.
These are cameras that fit somewhere between DSLR’s and compacts. They have interchangeable lenses like DSLR’s and some are much less bulky having a body not much bigger than a compact camera, whilst some have a body that looks like a smaller DSLR. They tend to have large sensors and so image quality can be very good indeed. CSC’s have varying sensor sizes, including the Micro Four Thirds (MFT) with a 4/3” sensor (Olympus and Panasonic G-series), APS-C sized sensor (Fuji and Sony A6xxx/A5xxx series) and more recently FF sensors offering outstanding IQ and performance. Sony have been leading the way with FF mirrorless but Nikon and Canon released FF mirrorless in 2018 and are set to produce some really good systems. Panasonic have also recently entered the FF mirrorless market but initial response is mixed.
Apart from form factor, CSC’s differ from DSLR’s in that they don’t have mirrors. Because of this they use a different focusing system than DLSR’s which has tended to be slightly slower, although some of the latest generations are said to match DSLRs, and some say some have surpassed DSLRs. CSC's also have other focussing tricks up their sleeves like eye autofocus where the camera can automatically detect and focus on a person's eye(s) in portraits etc. They also have manual focus aids such as peaking and zoom magnification.
A large number of CSC’s have a viewfinder, and tend to be electronic (EVF) rather than optical (OVF). Both EVF’s and OVF’s have pros and cons and is really down to personal preference. The main advantage of EVF's is that what you see if what you get, ie the image in the viewfinder is exactly the image that you will get. Also, you get focussing aids as just mentionedOne issue with the EVF is that there is a lag, meaning that it can be more difficult when panning. With the latest generations of CSC's the lag is minimal to the point you don't really notice it, and for most people it won't be an issue. With an optical viewfinder you are looking through the lens and not seeing the final image, however you are getting a 'real' image (as opposed to looking at a small LCD like EVFs) and as a result there is no lag.
DSLR’s
Primarily there are two types of DSLR cameras, APS-C and Full Frame. APS-C DSLR’s have large sensors (typically in the region of 23.5mm x 15.6mm), whereas Full Frame DSLR’s have Full Frame sensors and, as already mentioned, are the equivalent size of the old 35mm film (approx. 36mm x 24mm). For this reason FF DSLR’s can provide the best image quality and have the best low light performance. Up until recently FF DSLR’s were primarily reserved for ‘pros’ or the very wealthy, but they are now becoming more affordable for the enthusiast to be able to afford them (although still a lot of money). Both APS and FF DSLR’s have their pros and cons.
FF DSLR’s , as already stated, can provide the absolute best in IQ,low light performance, and control of DOF. Also, when you get into the more expensive FF cameras they tend to have more features, have better focusing systems and better quality sensors providing even better IQ. The problems with FF DSLR’s are that they are expensive, bulky, heavy, and have less reach (think zoom) than APS-C DSLR’s and other cameras with smaller sensors. The reason for not having as much reach is that there is no crop factor (see this link for explanation of Crop Factor) so a 300mm lens will give a 300mm reach. Compare this to a 300mm lens on an APS-C Nikon which gives the effective reach of 450mm due to the 1.5x crop factor of Nikon APS-C (1.5 x 300mm = 450mm)
APS-C DSLR’s have a smaller sensor than FF as already mentioned, but can still produce outstanding IQ and low light performance. To the untrained eye there is little to no discernible difference in IQ between APS-C and FF. They have the advantage over FF in that they are cheaper, less bulky, less heavy, and have a longer reach due to the crop factor as already mentioned. This is advantageous for those who want a long reach but without the weight and expense of very long telephoto lenses. There are APS-C DSLRs available that provide the 'pro level' features and build of the higher end FF DSLRs. The Nikon D500 is arguably the best example of this currently (true as of June 2019).
All DSLR’s have viewfinders, with most being OVF. Sony broke the mould by introducing EVF’s into their DSLR’s, which was made possible by their different mirror technology, at the expense of introducing a bit more noise. These cameras are actually called DSLT's rather than DSLRs but other than the tech behind the mirror they can be considered the same.
Sensor Size Comparison
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camera-sensor-size-12 by TDG-77, on Flickr
Useful Links
Learn About Camera Equipment
Digital Photography Review
Welcome to Photozone!
Digital camera reviews, photography techniques, photography gallery and photography forums
KenRockwell.com: Photography, Cameras and Taking Better Pictures
Compare digital cameras - Snapsort
Here's some good links for guides into photography for those wanting to learn the basics.
Understanding ISO, Shutter Speed and Aperture - A Beginner's Guide
Understanding ISO - A Beginner's Guide
Understanding Aperture - A Beginner's Guide
Understanding Shutter Speed - A Beginner's Guide
Understanding Metering and Metering Modes
Cambridge in Colour - Photography Tutorials & Learning Community
Understanding Digital Camera Histograms: Tones and Contrast
Understanding Digital Camera Histograms: Luminosity and Color
Understanding Camera Metering and Exposure
Making the Most of Natural Light in Photography
The Basics of Light for Photography - Pinkbike
Ultimate Exposure Computer
Also, this book is good. Goes over a lot of the stuff from the links above, but nice to have as reference. I got it for a tenner off amazon so worth looking to see if it comes up on offer.
Understanding Exposure, 3rd Edition: How to Shoot Great Photographs with Any Camera: Amazon.co.uk: Bryan Peterson: Books
P.S. Zone, I don't know if you could bump this up so that it follows the first post? Looks pretty good and thanks for taking the time ot do this.
minor typos - braket and carriage return missing in the FF para and i'd reverse the sentence "best images are the lens and the sensor " to "best images are the sensor and the lens" int he 4th para to be consistent with the info in the following brackets.
May also be worth adding a paragraph about lens aperture numbers and what to look for (amount of light and depth of field) and may be an additional para in the compacts section about the mid range 1/1.6" and 2/3" being a good compromise especially when combines with an f2ish lens. Also may be worth adding a note about Mpix not being a big differentiator once you get above about 10Mpix for most amature applications. Another thought may be to add a para in about thinking about what type of photo you want to take and therefore what to look out for in a camera/lens. And finally may be useful to add a link to the wiki page on camera sensor sizes (has the picture you added) and also the various review standard sites dpreview, photozone, ephotozine, the-digital-picture, ken rockwell, snapsort etc.
Hope these comments are useful and I'll leave it to you to include/discard as you see fit. Thanks for the feedback. Have made a couple of alterations to my original post based on this. I will dig out a link re sensor size later. Nice one Snerks data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 Image sensor format - Wikipedia, the free encyclopedia Thanks, added this link to the original post and removed the diagram (as this link has it) Excellent guide data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 @Snerks - PM Zone and get it added as a Sticky Thread to make it easier to point people at if they don't spot it themselves data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 Will do, was just waiting to get it 'finalised' first. I think the recent alterations have just about completed it though? It's useful as it is - getting it stickied won't stop you adding to it as new ideas come along....