On this page, I collect questions regarding digital cameras and photography in general. Please note that some users may laugh at some of the questions...
I was asked this question again and again by people who wanted to buy a camera. The simple answer is, "I don't know." And this is the correct answer for at least, four reasons. I do not know...
Let me expand a little on items two to four...
Purposes or motifs vary largely: landscape, people (friends and relatives, children, street photography = unknown people on the street), close-ups of flowers and animals, flowers in general, animals in general, wild animals or birds far away, sports, architecture, cars, night shots, holiday photos of all kinds, diverse stuff - the list of motifs is endless... Not all of these subjects require a different camera, but some of them call for very different requirements (speed, focus speed, close-up facilities, long focal length, high sensitivity, water resistance, and so on). And since most people want to take photos of several different subjects, they may be forced to search for an "optimal" compromise, if possible. Some photographers, by the way, prefer not to compromise but to have different cameras for different purposes (sometimes even for the same purpose so that they need not change lenses o films...).
All in all, before the question can be answered, it is important to get an understanding of the purposes (or subjects) for which a camera will be used. Then it is much easier to scan the market for possible candidates.
Shooting style or habits may be a little bit surprising in this list, but there is a reason for this. Let my explain this using an example: Friends told me that they want to take photos "spontaneously". Therefore they set their camera to the "all-inclusive" automatic, that is, to the automatic that automatically selects the appropriate automatic or scene program. That is, they do not want to think about how to take a photo, they just want to take it. That's OK, but this excludes any camera for them where you have to care a bit for the camera settings.
"Habits" might also be described by the following example (in can also be put in the "size" category): My wife accepts only a camera that fits her trouser pocket. Any camera that is larger and therefore does not fit her trouser pocket is excluded this way, irrespective of how good it may be.
All in all, these arguments can - sometimes surprisingly - exclude a lot of cameras from the candidate list.
Size, type, weight, look (yes, even this...) can also be arguments for excluding certain cameras from the candidate list. Here are a few anecdotic examples:
You may ask yourself, why I do not mention image quality, speed, zoom range, test results, or other technical data. Aren't they important? They are, but I found out that these are often quickly pushed aside by other arguments, such as the ones I mentioned above. Thus, before you inspect test results, make sure that you know all these arguments. Otherwise, these may quickly kick out the "top-camera" that you, after laboriously studying the literature and the Web, selected because of its outstanding image quality or the brilliant test results...
Usability and design guru Alan Cooper used to show two pictures of a car: The first was the one that was built according to the customers' requirements and looked like a craftsman's truck. The second was the one that they actually had in their minds - a classy sports car. This seems sometimes also be true for cameras...
I was asked this question again and again by people who wanted to buy a camera. The simple answer is, "I don't know." Déja vu? Definitely, but the arguments are a little bit different...
Like any other industry product, a camera and its design are the result of a multitude of compromises. These compromises are weighted or biased in one or the other direction (quality, price, user type, ease of use, universality, weight, size, appeal to certain age groups, ...), but they remain compromises. Cameras are meant to take photos. Thus, image quality is an important, perhaps the most important, factor when debating "the best" camera. But handling, the ability to carry it everywhere, and many other factors also contribute to what we mean by "best". I often read in forums the saying, "The best camera is the one that you have with you." This is meant to say that people often leave their "best" camera (equipment) at home because it is too bulky, too heavy, or both. Sometimes, they take a smaller and/or lighter camera with them instead, which is, of course, not as good as the one they left at home. Sometimes, they take no camera with them at all and regret this later...
Image quality is also a "multi-dimensional" problem, so even in this respect you rarely find that people agree on it. In forums, you often find that someone reports that he or she just sold a camera, whereas another poster just bought it - and sometimes even vice versa. Of course, both blame the image quality of the camera that they just got rid of... On the other hand, there are some overall agreements on image quality and quality in general that can be trusted. But then the price may be prohibiting...
I think that it is nevertheless possible to narrow down the number of possible candidates when you know what camera type you want and what is important for you. But you can only be sure of your judgment about these cameras if you had and used them all... And others, see above, may well disagree with you.
Sometimes, you may be lucky that you can narrow down the number of candidates to "one" - as I was able to do with my Leica M (Typ 240). But this is not at all the best camera in the world. It only seems to be the best fit for my lenses, other aspects were more or less neglected... And then the price may be so high that even this "one and only" candidate may not be a valid choice...
On the other hand, I often meet people having a camera (mostly compact ones with some zoom range), who tell me how content they are with their camera and the pictures it takes. This is really the "ideal" camera for them and they are proud to have made such a brilliant choice. In the end, this is what they want to tell me: How excellent their choice was. As I have become older and wiser now, I do no longer contradict, but nod my head instead and tell them that I am glad that they are so happy with their camera. Maybe, I take a look at the test results afterwards, but I will never give away what I read there...
This is a question that is probably the least relevant for those people who should be interested, namely those who are using small-sensor cameras, including smartphones and who are not much interested in camera technology. Therefore, I should better withdraw this question... There are, however, also some "serious" photographers who favor small sensors, but they know already the answer. That would be another reason to withdraw this question...
But I decided not to withdraw the question and answer it briefly in my favorite data format, a table:
|Characteristic||Small Sensor||Medium-Size Sensor||Large Sensor||Comments|
|Sensor Size||1/2.3" ... 2/3"||1" ... 4/3"||APS-C ... Full-frame Format||One might debate the classification of APS-C as a "large" sensor...|
|Crop Factor||5.6 ... 4||2.7 ... 2||1.5 ... 1||This factor relates primarily to the equivalent focal length of the lens but also has an impact on depth of field|
|Depth of Field||Large||Medium||Narrow ... as narrow as with 35 mm film||Users of small-sensor camera might already struggle with 1" camera because of their smaller depth of field...|
|Relevant -Number for DOF||Multiply f-number by crop factor||Multiply f-number by crop factor||APS-C: Multiply f-number by 1.5||If you multiply your f-number with the crop factor, you get the equivalent
f-number for full-format to compare depth of field.
See table below.
|Useful Highest f-Number||f/4 ... f/5.6||f/8 ... f/11||f/16 ... f/22||This limit is given by the fact that at and above a certain f-number diffraction sets in and makes images more and more fuzzy. See here.|
|Useful High ISO Limit||400 ... 800||1600||3200 and above||Smaller sensors (or pixels) exhibit more noise than larger sensors; therefore higher ISO numbers are less useful at these cameras, even though they offer these. See here for details.|
|Zoom Range||Large zoom range possible with relatively small lenses||Only low zoom ranges (1:3) possible for fixed lenses if the lens is to be not too large||Only low zoom ranges (1:3) possible for fixed lenses if the lens is not to be too large||This information refers mainly to fixed lenses. Cameras with larger sensors may support exchangeable lenses, which offer larger zoom ranges, but are usually also much bulkier (depending on their characteristics, e.g. zoom range, light gathering power).|
|Close-up and Macro Shots||Large DOF, large magnifications, at small distances possible (often
at the wide end);
|DOF narrower, lower magnifications at somewhat larger distances
(often at the wide end);
not as easy as with compact cameras
|Shallow DOF, larger distances or special macro lenses needed; challenging but can be rewarding...||This refers to shots without additional macro lenses, extension tubes, close-up lenses, etc.|
|Camera Size||Can be small and pocketable with smaller zoom range (1:10...1:20); bridge cameras with larger zoom range (up to 1:50) are bulkier||Small only with fixed lens or zoom lens with small range; larger and heavier than small sensor camera, but for 1" still pocketable||Large up to very large, pocketable only with fixed wide angle lens.||Depending on your pockets, even an APS-C camera with a fixed wide angle lens (e.g. Ricoh GR) may fit your trouser or jacket pockets...|
The most important aspect from a photographic point of view is probably the difference in depth of field for the small and large sensors. The following table serves to to illustrate how the "DOF-effective" f-number increases with decreasing sensor size (or increasing crop factor) for different sensor types and exemplary cameras (most of which are/were owned by us):
|Leica M (Typ 240)||Full format||1||identical with nominal||identical with nominal|
|Leica X Vario||APS-C (DX)||1.5||3.5 (28 mm)||5.6 (28 mm)||6.4 (70 mm)||9.6 (70 mm)|
|Panasonic GM5 (Kit)||MFT||2||3.5 (24 mm)||7 (24 mm)||5.6 (64 mm)||11.2 (64 mm)|
|Sony RX100 M1||1"||2.7||1.8 (28 mm)||4.86 (28 mm)||4.9 (100 mm)||13.23 (100 mm)|
|1"||2.7||2.8 (25 mm)||7.56 (25 mm)||4 (400 mm)||10.8 (400 mm)|
Ricoh GXR S10
|1/1.7"||4.5||2.5 (24 mm)||11.25 (24 mm)||4.4 (72 mm)||19.8 (72 mm)|
Ricoh GXR P10
|1/2.3"||5.6||3.5 (28 mm)||19.6 (28 mm)||5.6 (300 mm)||31.36 (300 mm)|
*) All focal lengths are given as 35 mm equivalent values.
I would also like to add that most small-sensor cameras one have two "real" f-stops, the remainder is created by applying neutral density filters. This makes it also difficult to estimate the effect of aperture on DOF for these cameras. Note that a huge DOF range also makes life easier for the autofocus system: small errors are usually not relevant. All in all, for people who like it "sharp from here to infinity", a huge DOF and a small-sensor camera can just be what they need. Photographers who like to play around with DOF are, however, best served with a full-frame format camera, but the chance of setting the focus at a wrong position is high, as my own experience shows...
For more information, see page About Focal Length, Aperture, and Depth of Field for Different Sensor Sizes.
Note: The light gathering ability is not affected by the crop factor (or sensor size). That is, an f/1.8 lens on a small-sensor camera is as fast as a full-frame format camera with such a lens.