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Camera sensor size: Why does it matter and exactly how big are they?

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March 21, 2013

How do different sensor sizes compare with each other?

How do different sensor sizes compare with each other?

Image Gallery (13 images)

The megapixel myth has treated camera manufacturers well over the years, those ever increasing, and often meaningless, numbers have sold millions of cameras. But consumers are getting wise to it. We've all seen dodgy images from high megapixel cameras and know that after a point, megapixels don't matter for most people – a 16 MP compact isn't ever going to be as good as a 12 MP Full Frame DSLR. What does matter is sensor size!

Why is camera image sensor size important?

The size of sensor that a camera has ultimately determines how much light it uses to create an image. In very simple terms, image sensors (the digital equivalent of the film your father might have used in his camera) consist of millions of light-sensitive spots called photosites which are used to record information about what is seen through the lens. Therefore, it stands to reason that a bigger sensor can gain more information than a smaller one and produce better images.

Think about it this way, if you had a compact camera with a typically small image sensor, its photosites would be dwarfed by those of a DSLR with the same number of megapixels, but a much bigger sensor. Able to gain more information, the large DSLR photosites would be capable of turning out photos with better dynamic range, less noise and improved low light performance than its smaller-sensored sibling. Which as we know, makes for happy photographers.

The size difference between a Full Frame and APS-C (DX) sensor

Larger sensors also allow manufacturers to increase the resolution of their cameras – meaning they're able to produce more detailed images – without sacrificing too much in terms of other image quality attributes. For example, a Full Frame camera with 36 megapixels would have very similar sized pixels to an APS-C camera with 16 megapixels.

But I thought megapixels didn't matter!

Megapixels are a passionate issue for photographers; they're up there with the "which is better, Canon or Nikon?" debate. Some argue that no-one needs more than 16 megapixels (a couple of years ago it was eight) while others are of the opinion that the added detail is worth the trade off in terms of noise and the computer processing power needed to handle the extra large files.

The truth is that it's always going to be a balancing act between the efficiency of sensor technology, lens quality, image sensor size and ultimately what you want to do with your photographs. If you're going to heavily crop images or print them very large, extra resolution could be useful, if you're only sharing them online or producing normal prints, not so much. What we can conclusively say is that you can only make a call on megapixels in conjunction with considering sensor size.

What are the other characteristics of bigger sensors?

So larger sensors can help you capture better quality images, but they bring with them a number of other characteristics, some good and some bad. The first, and most obvious impact of a bigger camera sensor is that of size; not only will the sensor take up more room in your device, but it will also need a bigger lens to cast an image over it.

This is why smartphone makers generally stick with very small sensors, they want to keep devices pocketable and not deal with the bulk of larger lenses. It also explains why professional photography gear is still so big and heavy. The cost of producing bigger sensors also means that devices packing them also have a bigger price-tag.

If the HTC One had a Full Frame sensor rather than a 1/3-inch sensor, it wouldn't fit in y...
If the HTC One had a Full Frame sensor rather than a 1/3-inch sensor, it wouldn't fit in your pocket, as this comparison with a Canon 5D Mark III shows

Bigger sensors can also be better for isolating a subject in focus while having the rest of the image blurred. Cameras with smaller sensors struggle to do this because they need to be moved further away from a subject, or use a wider angle (and much faster) lens, to take the same photo. Replicating a Full Frame 28 mm f/2.8 shot on a mobile phone-sized 1/3-inch sensor would take a 4 mm f/0.4 lens!

Angle of view is also something to consider when looking at cameras with different-sized sensors, particularly if using the same lenses between them. Cameras with smaller sensors than Full Frame 35 mm format (seen as the standard) have what's described as a crop factor. So an APS-C DSLR has a crop factor of 1.5x1.6x meaning that it crops into the Full Frame image – using a 28 mm lens on an APS-C giving a view similar to a 45 mm lens on Full Frame.

What different-sized sensors – Full Frame, APS-C, MFT, 1-inch, 2/3-inch, 1/2.3-inch, 1/3.2...

The image above shows what smaller sensors would have captured if using the same lens to take this photo. You can see why devices with smaller sensors use much wider angle lenses, especially by the time you reach smartphones. The lenses on these cameras are often detailed by their 35 mm format equivalent focal length to give a better idea of the angle of view they give.

The trend for cameras with bigger sensors

In recent years, camera manufactures have realized that more and more photographers are wanting the sort of better quality images that only come from having a bigger sensor. As such, we've seen devices (from smartphones to DSLRs) being sold with bigger sensors than in the past.

The Sony RX100 is a compact camera with a bigger sensor than most

Within the smartphone market, Nokia has led the way with larger sensors – currently peaking with the Nokia 808 Pureview, which has a 1/1.2-inch sensor and can produce images to rival many compact cameras. In terms of point-and-shoot cameras, the Sony RX100 brings a 1-inch type sensor to the party, and Canon has released the not-quite-a-compact G1 X with a 1.5-inch sensor.

Mirrorless interchangeable lens systems have also seen small-bodied cameras fitted with larger sensors, typically ranging from Micro Four Thirds to APS-C … which have also made it to enthusiast compacts like the Fuji X100 (now the X100S) and the Nikon COOLPIX A. At the same time, the price of Full Frame DSLRs has also fallen, with the likes of the Nikon D600 and Canon 6D, bringing the affordability of big sensor shooting to a much wider market.

What do different sensor measurements mean?

Manufacturers can sometimes be strangely coy about revealing exactly how big a camera's image sensor is. And even when they do volunteer this information, it's often in a hard-to-understand naming convention … as the last section may have proved. Seriously, how many people would be able to tell you exactly how big a 1/1.2-inch or Micro Four Thirds sensor is without consulting the internet?

Bizarrely, the mostly fractional measurements used to detail sensor size date back to the age when vacuum tubes were used in video and television cameras. But the size designation is still nothing like as simple as the diagonal measurement of the sensor. Instead, it's the outer diameter measurement of a tube needed to produce an image, when the usable image takes up two thirds of the circle. Yes, it's that crazy.

It also doesn't help that different manufacturers use the same title to refer to different sizes, such as APS-C. While a Canon APS-C sensor measures 22.2 x 14.8 mm, the offerings from Sony, Pentax, Fujifilm and Nikon (DX) vary from 23.5 x 15.6 mm to 23.7 x 15.6 mm.

While we'd like to see all camera manufacturers listing the size of their sensors in millimeters, we can't see it happening any time soon. So, in the mean time, here's a couple of graphics showing some of the most common sensor sizes in relation to a Full Frame one.

Different sensor sizes compared with each other shows how big Full Frame, APS-H, APS-C (Ni...
Different sensor sizes from Full Frame to 1/3.2-inch compared with each other

Obviously there are also Medium Format cameras with even bigger sensors than those shown here, but if you're in the market for one of those, hopefully you already know how they differ.

What sized sensor is typically used in different cameras?

The sensor sizes usually used in smartphones are 1/3.2-inch or 1/3-inch, though the Nokia ...

Smartphone Cameras – Most smartphones, including the iPhone 5 use a tiny 1/3.2-inch image sensor. In real terms this measures just 4.54 x 3.42 mm and explains how they are able to keep devices so slim and light, but also why image quality and low light performance suffers, especially when they can have as many as 12 megapixels. The HTC One uses a slightly larger 1/3-inch sensor (4.8 x 3.6 mm) and fewer pixels to combat this. The undisputed king of smartphone sensors, the Nokia 808, has a 1/1.2-inch sensor (10.67 x 8 mm).

Sensor sizes typically used in compact cameras include 1/1.7-inch, 1/2.3-inch and 1/2.7-in...

Compact Cameras – With sensors starting as small as 1/2.7-inch (5.37 x 4.04 mm), it's easy to see why smartphones are making many compact cameras redundant. Budget compacts simply don't have sensors big enough to produce significantly better images. Typical compact cameras such as the Canon IXUS 255 HS and the Samsung Galaxy Camera use 1/2.3-inch sensors (6.17 x 4.55 mm) while more competent ones like the Canon S110, Panasonic DMC-LX7 and the Nikon P7000 come in at a larger 1/1.7-inches (7.6 x 5.7 mm).

Sensor sizes typically used in higher end compacts such as the Sony RX100, Canon G1 X and ...

Higher-end Compacts – With demand growing and the price of producing larger sensors falling, there are a growing number of higher-end compact cameras with larger sensors. For example the Fujifilm X20 has a 2/3-inch (8.8 x 6.6 mm) sensor while the Sony RX100 has an even bigger 1-inch sensor (12.8 x 9.6 mm). The Canon G1 X even boasts a 1.5-inch sensor (18.7 x 14 mm).

Ultra high end compact cameras like the Nikon COOLPIX A, Fujifilm X100S and Sony RX1 use e...

Ultra High-End Compacts – Increasing sensor size again are the growing range of ultra high end compacts. These are cameras such as the Leica X2, Fuji X100S and Nikon COOLPIX A, which all feature an ASP-C sensor (23.7 x 15.6 mm) along with a fixed-focal-length lens. There's also the Sony RX1 which does the same, but with a Full Frame sensor (36 x 24 mm).

Sensor sizes used in mirrorless cameras range from Full Frame to 1/2.3-inch, taking in APS...

Mirrorless Camera Systems – Within the mirrorless camera market, there is a wide range of sensor sizes. The smaller ones include the 1/2.3-inch (6.17 x 4.55 mm) sensor seen in the Pentax Q, and the 1-inch (12.8 x 9.6 mm) sensor used in the Nikon 1 Series. Panasonic cameras such as the LUMIX GF5 and offerings from Olympus (including the PEN series and the OMD EM-5) use a Micro Four Thirds 4/3-inch (17.3 x 13 mm) sensor.

Getting larger still are the APS-C offerings which include the Canon EOS M (22.2 x 14.8 mm) along with the NEX range from Sony and those those from Fujifilm (23.5 x 15.6 mm) … yes, not all APS-C sensors are the same size. Leica rangefinders such as the Leica M have a Full Frame (36 x 24 mm) sensor.

Sensor sizes typically used in DSLRs include APS-C (which varies slightly depending on man...

DSLRs – By the time you get up to DSLRs and other professional cameras, the sensor size has obviously increased. Most DSLRs whether from Canon, Nikon, Pentax or Sony use either an APS-C (22.2 x 14.8 mm Canon and 23.5-23.7 x 15.6 mm for others) or a Full Frame (36 x 24 mm) sensor. While Full Frame DSLRs have been the reserve of professionals for a number of years, more consumer-focused models such as the Nikon D600 and Canon 6D are now being released.

Summing Up ...

It's clear that more people are realizing that bigger image sensors mean better quality photographs (at least as much as, if not more than, megapixels) and thankfully manufacturers are beginning to cater to this demand with cameras like the Sony RX100 and Nikon COOLPIX A, which are presumably just the beginning.

That said, we'd like to see camera and smartphone makers being a bit more transparent about what size sensor is used in different devices and not hiding it away on some spec sheet in a hard-to-decipher format, or omitting it altogether. Retailers also need to step up and start publishing details on sensor size. It's only knowing (and understanding) this information that will allow consumers to make an informed decision on what they are purchasing.

Obviously, not every device can pack a considerably bigger sensor – as other issues such as form-factor and cost come into play – but do the sensors in smartphones and most compact cameras still need to be so tiny? Yes, the bigger sensor on the Nokia 808 added a significant bump, but few users seem to mind when looking back at their photographs, and a bigger sensor doesn't necessarily mean jumping to those proportions.

As sensor technology improves, we're seeing much better performance out of smaller sensors, but bigger will always be better. Does improved image quality justify the bigger device and price for you? Only you know the answer … but we hope that this guide will help you better understand the importance of sensor size when making your next camera purchase.

About the Author
Simon Crisp Simon is a journalist and photographer who has spent the last ten years working for national UK newspapers - but has never hacked a mobile phone - and specializes in writing about weird products and photography technology. When not writing for Gizmag, Simon is often found playing with LEGO and drinking far too much coffee.   All articles by Simon Crisp
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43 Comments

You were doing quite well until this, Simon:

"Think about it this way, if you had a compact camera with a typically small image sensor, its photosites would be dwarfed by those of a DSLR with the same number of megapixels, but a much bigger sensor. Able to gain more information, the large DSLR photosites would be capable of turning out photos with better dynamic range, less noise and improved low light performance than its smaller-sensored sibling".

Photosite size is IRRELEVANT in the context of this discussion. At the IMAGE level, all that matters is sensor size and the technical state of the art of the sensor.

Proof? Well just look at (say) the Nikon D7000 compared to the Nikon D200: the latter has far more, and far smaller, photosites, but kicks the D200 into the middle of next week in IQ terms.

Or how about the 18 mp Canon 7D? It is not only FAR better, in IQ terms (and ESPECIALLY at four figure ISOs) than say, the old Canon 8 mp 30D; but it also handily beats older FF and APS-H bodies like the 1D Mk IIn, the photosites of which are HUGE in comparison to the 7D's.

You seem to be making the funamental error of comparing results at the "pixel" level rather than at the image level. The simple fact is that - right across the board - IQ has improved along with increased pixel count, on same-sized sensors.

Keith Reeder
21st March, 2013 @ 05:22 am PDT

An excellent and informative article.

Thank you.

RJB
21st March, 2013 @ 08:03 am PDT

@ Keith Reeder: I think you have a point, but it only goes so far. You must be into conventional flash and full daylight photography to make the statements you do. I , however, am into astrophotography and the gist of this article is exactly right for that pursuit. As a bonus, my first generation Sony NEX-5 is an excellent low light camera even without its flash as long as the subject is in well balanced light to begin with. The IQ you describe applies to this camera over the 8 Meg Canon EOS20D I started with. Being APS-C format helps too with the limitations of my telescope where a full frame could suffer vignetting. Oh, and the older NEX has a lower pixel count than its successors giving more exposed area to each pixel. There is, I think, a sweet spot when it comes to trade-offs, and there is no substitute for area under low light conditions no matter how good the processing. Garbage in nets garbage out.

Paul Gracey
21st March, 2013 @ 04:29 pm PDT

The other thing is Signal to noise ratio. Packing zillions of megapixels on a pinhole camera is just nuts. The signal to noise ratio is going to be so high that unless you are under ideal lighting conditions, the photo is going to come out with so much noise, it will be useless.

Rusty Harris
21st March, 2013 @ 06:48 pm PDT

16 megapixels in a 2x2 mm sensor results in light hitting more than one "pixel" sensor at a time... You can increase bullshit all you want, but you can't decrease light's wavelength... 16 MP ~= 4000 x 4000 pixels; 2 mm / 4000 = 0.0005 mm / pixel or 500 nm / pixel. If there were absolutely no gaps between light sensing "pixels", you would at this point lose half the red and some of the green light since their length range goes over 500 nm, up to 740 nm.

Tudor Tihan
22nd March, 2013 @ 02:22 am PDT

DSLRs are great, but not for me when going on holiday. Something not mentioned in the article is the lack of zoom when using a large image sensor. With smaller sensors you can get amazing zoom levels - ideal for focusing on that interesting item in a cathedral or something in the distance. Modern high-tech compacts give you (almost) the best of all worlds. My Sony HX9V Cybershot has optical image stabilization and a 16X optical zoom in a small package. And, best of all, it uses image processing to give superb low light shots - it takes multiple short exposures and combines them to give amazing shots in low light. And you do not look like a nerd with all the gear. The ONLY problem is you lose the ability to play with focus, ie. to get the background out of focus.

Franc
22nd March, 2013 @ 02:53 am PDT

Great article.

I wish the cameramanufacturers would take this seriously .The pixelrace we have seen in the past, especially over the last year is just crazy. Why should a regular compact zoom camera have a sensor packed with 16 or even 18 mill pixels, while 10 or 12 mill pixels would in most cases be a much better technical solution both regarding signal/noise ratio and light sensivity as well as better pictures. Nothing but stupid marketing if you ask me.

One thing, why have you overlooked Samsung as to highend compacts and mirrorless cameras? They are definitely in the top quality brand series.

weanor
22nd March, 2013 @ 02:57 am PDT

All very interesting; however, I have a Nikon D2X, D300s, D5200 and a Sony REX100. The two best shots with excellent picture detail come from my Sony REX-100 and guess what, the D5200.

The lens on test with all the Nikon’s I tested was a Nikon AF-S DX 35mm f1.8G. I did this test after taking a shot from the same position with my Sony REX-100 just to compare the shots. I was shocked when I saw the results later. I then bought the D5200 and the extra pixel in my case has made a big difference.

Gerard58
22nd March, 2013 @ 04:35 am PDT

The same as Franc I am also a Bridge camera user. I cannot justify the expense of having a DSLR with 3 lenses, including a 800mm telephoto, which could cost an arm and a leg, and then having to lug all that equipment with you. I have shot everything from a dragonfly to a surfing competition with the same gig. (My brother-in-law has a fancy Nikon, with all the lenses, but could not shoot the dragonfly because he did not have the correct lens with him) - but I do realize that the quality of my images has been compromised by my equipment, but I am not planning on publishing any of my images. (and neiher does my brother-in-law with his fancy kit for that matter, but I had much more fun than him)

Interestingly enough Canon has actually lowered the pixel count in their latest range of bridge cameras from 14mps to 12 mps. It is the Canon PowerShot SX50 with an optical zoom of 50x. (2500mm equivalent?!!?) What would you pay for this size of lens for a DSLR? Would you get the wheelbarrow included in the price?

Thanks for a very nice article.

Riaanh
22nd March, 2013 @ 04:46 am PDT

Whatever combination of sensor size and pixel (site) count, there is a quantum physics fundamental that decides all.

If the pitch distance between two pixel receptor sites becomes less than 1/4 wavelength of the arriving photons, then the information in both sites will be the same, as if the two together came from a single photon wave.

This is a resolution limit no amount of extra pixels can get around without increasing the lens aperture. Bigger lens focused on bigger sensor is more than simply "increasing the amount of light". The size of the available light resolution "mosaic" also gets finer. There is more information in the incoming image.

If you look at two objects on the moon through a telescope so close they can only just be seen as separate, them stop down the telescope by placing a smaller aperture mask in front of it: the image will dim, and the two points will merge into one, still perfectly focused, and any extra magnification will not help. This is why we need optics as big as Hubble and more to go after resolution.

Putting the same number of pixel (sites) on a bigger sensor, and then using optics with a big enough aperture to spread the image over the sensor is what does it.

Complicating things by using only part of the sensor, and rapidly altering the addressing to counter camera shake, or addressing only a bit in the middle to have "electronic zoom", and averaging sites to make single lower noise "new pixel" all cannot get around the fundamental physics of what is "resolution".

Resolution is the number of line pairs/mm of bright to dark transition to an agreed level. It quite hard to do. If it gets close to the pixel spacing, you get interference patterning.

Graham
22nd March, 2013 @ 05:33 am PDT

This discussion is high level, but for us everyday compact camera users, it would be interesting to know what sensor size/pixel count is most effective to 1) send an email of a couple hundred KB without having to go to software to reduce the image size. 2) print the best 4 x 6 or 5x7 picture. I suspect a large sensor and a reasonably lower pixel count would be the best if use is on the low level. My Sony DSC-W650 permits me to take images from 2M to 16M. I am actually surprised how low a pixel count is required to give a "decent" picture for average use. Why then do I feel the need to take all my vacation pictures at 10M when I am lucky to look at them casually more than a few times over the years :)

b2p
22nd March, 2013 @ 10:06 am PDT

I note that there is no mention of resulting file size, depending on the type of camera being used. When I shoot with my Nikon D200, in RAW format, I get between 8 and 9 megabytes per image. A picture taken with the I-Phone results in an image of approximately 8.5 KB, a very substantial difference, implying a huge difference in the captured detail.

Richard Schmidt
22nd March, 2013 @ 10:41 am PDT

the image processor such as the venus V or VI in the olympus cameras has more too do with picture quality than the pixel count...

nice try but you ignored the actual factor that determines image results...

then of course there are the types of sensor array...

do your home work and try again...

Le Ducktor
22nd March, 2013 @ 11:29 am PDT

i designed a smartphone cam with a tiny cmos sensor (even smaller then whats used in smartphones today), but a slight modification, compared to the conventional way of achieving light, but yet would be 3 times better then todays existing technology, in low light conditions. regards, Freelance Eng.

Dave Hargraves
22nd March, 2013 @ 01:52 pm PDT

The one thing you've forgotten is DOF (depth of field), which plays a very big role in choosing the camera sensor size you use for a particular job.

In studios MF (medium format, one step up from full format) dominate, as there a limited DOF is often wanted, - who wants to see the scruffy walls behind the pretty model?!

The majority of classic film cameras were indeed FF (aka 35mm) cameras, just a handful used what we today would call APS-C, or roughly half a FF.

When digital SLR cameras become available they soon settled on the APS-C format, which transformed the lenses the owners had from the film era, by a factor of 1.5, but it also affected the DOF when using those lenses.

And now we have mirrorless cameras with even smaller sensors, like the PEN series, and the Nikon 1 series, and modern mobile phones, with even greater DOF.

There are moments where a restricted DOF is helpful, as I mentioned above, but there is also an up side.

With very long lenses, used by bird photographers with FF cameras, the DOF is very shallow, the only help being using very small aperture, typically 16, or less. Unless the light is brilliant, you need very high ISO, which can lead to noise problems.

But if you use a smaller sensor, like the 1" found in RX100 and the Nikon 1 cameras, you have a magnification factor of 2.7 so first of all you don't need as big lenses as with a FF camera, secondly you'll have much better DOF, which can be much needed - a 800mm lens have a DOF of just a few inches, with normal apertures, while the equivalent 500mm lens will have plenty of DOF.

Same problems you'll experience when doing extreme close-ups: the big sensored cameras need very small apertures, high ISO, and rivers of light, while a 1" camera will be able to use much lower ISO, much bigger aperture, and higher shutter speeds, even with existing light.

So size matters, indeed!

Recently I used a D600 for close-ups of some lovely flowers, with a nice macro lens attached, and needed to use both a small aperture, and a flash, to get enough DOF for a decent shot, while my Nikon V1 did it with ease, as I could use almost fully open aperture, and no flash was needed, plus could use a much lower ISO, thus slightly less noise.

Tord
22nd March, 2013 @ 02:20 pm PDT

@Simon. I have a Fujifilm Finepix HS50EXR point and shoot with a 35 mm lens equivalent to 24-1000 mm, and love it for wildlife photos. The camera's specs say that the sensor is a 1/2" CMOS, but I don't see this size mentioned in any of your graphics. Is it larger or smaller than the 1/2.3" sensor that is shown?

Rick Perez
22nd March, 2013 @ 04:07 pm PDT

Sadly, this article is as misleading as the emphasis on megapixels. While it's true that larger sensors and larger photosites offer advantages, with modern technology those advantages are largely only true at high ISOs when comparing sensors one level apart in size.. For example, at ISOs below about 1600, you'd never be able to tell the difference between an m43 sensor and an APS-C sensor. And barely any difference between m43 and FF.

Articles that focus on "absolutes", like this one, are rarely accurate. The real world is much more nuanced.

bobmeyerweb
22nd March, 2013 @ 05:56 pm PDT

No matter the pixels or image sensor size, pocket cameras will never be able to compete with larger, professional cameras because of lens quality. Over ten years ago I had a Sony that was only 5 megapixels, but it was still able to take better pictures than a 10 megapixel pocket came in large part because of the full-size, very high quality Carl Zeiss lens. There's simply no way a tiny little 3/4 inch lens can compete with a 3 or three inch lens. At least not until they're able to 100% eliminate internal imperfections and smooth the outside of the lens to an atomic level.

At the time I also owned a 54 inch wide format printer. I was able to blow up images from that camera to poster size and have them look great, so how many more pixels do you REALLY need? Even in professional images, it's really not needed.

Unless you're the SUPER rare photographer whose work needs to be blown up beyond the poster size (let's say, 30"x40") and still need the image to be sharp from a foot away, anything beyond a 10mp is a waste.

For even the average professional, anything better is really just ego. There's hardly anyone out there for any reason who needs to make a massive print that still looks photo quality up close.

Dave Andrews
22nd March, 2013 @ 05:58 pm PDT

My old Kodak DC250 easily beats any cellphone camera and many compact digital cameras in image quality.

Zoom way in and the fine details are still clear, unlike the high megapixel images from speck sized sensors. The images they produce are full of noise.

10 year old CCD digital cameras that cost $1,000+ new still take amazing quality images, especially when pitted against cheap (and some not so cheap) CMOS sensor cameras.

How many pixels an image has isn't the whole story on image quality.

Gregg Eshelman
22nd March, 2013 @ 06:15 pm PDT

This was a very informative article. Thanks for writing this.

silentnelite
23rd March, 2013 @ 12:50 am PDT

Simon,

You make some very fundamental mistakes in this article.

The article starts out saying:

"The size of sensor that a camera has ultimately determines how much light it uses to create an image. "

NO! It is the lens that determines how much light gets captured. The whole reason larger sensors perform better is not because the sensor is larger, it is because larger lenses are used to gather more light.

You say:

"a 16 MP compact isn't ever going to be as good as a 12 MP Full Frame DSLR. What does matter is sensor size!"

Again, it is the lens that is the key, not the sensor. The pixel is like a bucket. Given two buckets, a 1-gallon and a 5-gallon bucket, which gets more water. Well, how much water you put in the bucket depends on the the faucet delivering the water to the bucket and the time to fill the bucket. The larger bucket has the POTENTIAL to get more water but only if the faucet delivers that water.

In a camera versus water buckets analogy: the bucket is the pixel, but the faucet and how much water flows through the faucet is like the lens. Turn the faucet on higher is like using a larger lens. (And it is more than just f/ratio--but that is another topic.)

A bigger lens collects more light and that is the

key between different sized cameras. Cameras with small sensors have smaller lenses with shorter focal lengths to get the same field of

view, and it is the smaller lenses which collect less light, not the pixel.

Put the same lens on two different sensors and ignore the field of view difference. Which camera lens will show a better image? For example, a bird that is small in the frame in both cameras? See Figure 2 on the web page: http://www.clarkvision.com/articles/telephoto_reach/

The 5D Mark II is a full frame camera and the 7D is a 1.6x crop. The 7D image is clearly the best.

Bigger is not always better than smaller. You say you like to do astrophotography. The 5D Mark II is regarded as a good low light camera. Would you believe me if I told you the 7D was better?

See Figures 4a and 4b on this page, again with the same lens and exposure time:

http://www.clarkvision.com/articles/nightscapes/

and note how the 7D shows fainter stars.

Figure 5 on the above page illustrates two lenses, both at the same f/ratio deliver different amounts of light to the sensor for a given subject. Thus, it is the clear aperture diameter of the lens that is

important in gathering light, not simply the f/ratio

The Bottom line: choose the lens required to do the job, then the sensor behind it.

Roger Clark
23rd March, 2013 @ 06:07 am PDT

Speaking of sensors, to my knowledge there are only two:

1. The matrix sensor, where the rgb photoreceptor sites are side by side or in a triad (I believe some matrix sensors have an additional sensor for purple, but I'm not sure), and

2. The Foveon (tm) sensor, where each photoreceptor is a stack of rgb, one on top of the other.

Of the two, the Foveon sensor, which has only 3 or 4 megapixels (times 3 for 9 or 12 megapixels total, though overlayed), has the best IQ because light falling on the sensor goes 'through' the rgb layers instead of trying to overlap sensors in a linear or triad layout. The Foveon (tm) sensor, which is still being produced, is used mostly in high end DSLR cameras, such as the Sigma, but at one point in the dim dark past, there was a Polaroid digital camera that used the Foveon (tm) sensor. Unfortunately, it didn't make it to the production stage.

An interesting discussion would be how the Foveon (tm) sensor fits in to the sensor size/pixels debate.

d

Dennis Learned
23rd March, 2013 @ 09:13 am PDT

@Roger Clark,

I was going to take you to task for some fundamental misunderstandings of optics, but I looked at your website and portfolio first. After looking at your work, I've decided that you've earned the right to believe whatever your want. Outstanding imagery!

oldhacker
24th March, 2013 @ 12:42 am PDT

oldhacker said: "I've decided that you've earned the right to believe whatever your want. Outstanding imagery!"

Thank you very much. But regarding optics, I try and not deal in beliefs, but in scientific fact. While much is science is not understood, the science of optics, sensors and pixel sizes is quite well understood in the context of resolution and collecting light. For advanced concepts, look up Etendue, which I try to explain here:

http://www.clarkvision.com/articles/telephoto.system.performance/

Roger Clark
24th March, 2013 @ 08:54 pm PDT

You would be right if you were dealing with emulsion based photographic film where the size of the light sensitive halide was the same. In which case bigger would be better.

Then again the cost of a lens covering 6x6 format with same angle of view as a comparable full frame 35 mm would be prohibitively more. The cost of designing and manufacture of these lenses to compensate for chromatic as well as achromatic aberrations put them beyond the reach of average user.

Correcting for these inb zoom lens is even more difficult. We had 18x zoom lenses for Super 8 cameras some 40 years ago when even a half way decent 3x zoom for 35 mm was almost not existent.

In the final analysis I came to a conclusion that megapixel requirements should essentially be based considering the final image size requirements. If you can get 100 dpi resolution in your final print/image your needs are more than adequately met.

BTW I am originally from the old emulsion/chemical times of Kodachromes / Ektachromes photographic field and have been dealing with digital cameras from the very first commercial offering from Casio, some 20 years ago.

I have produced 4'x4' inkjet prints from 2 megapixel Casio camera images which look razor sharp when viewed from a distance of 3- 4 feet.

pmshah
24th March, 2013 @ 10:16 pm PDT

Here's a couple of other considerations relating to sensor size. One is moment of inertia. It's generally easy for people to physically move most image sensors, but it's quite a job for the sensor-shift image stabilization devices. I think that this is why (to the best of my knowledge) 4/3 is the largest sensor size to use this image stabilization method. Another, as mentioned previously is Dept of Field. Wikipedia has a nice article about this: http://en.wikipedia.org/wiki/Depth_of_field. And finally, there's ergonomics. I experience a special form of joy looking into the viewfinder of my 6x6 format camera, and I continue to wish someone would put a sensor like the Fairchild Imaging CCD 6161 into a camera back allowing me to capture everything I see in the finder.

John Banister
25th March, 2013 @ 10:04 am PDT

""You must be into conventional flash and full daylight photography to make the statements you do.

Absolutely not, Paul - gigs, sport and wildlife for me. Natural light 100% of the time.

I "make the statements I do" because I know what I'm talking about, know how to use my gear, and know how to convert and process my files..

Keith Reeder
29th March, 2013 @ 02:18 am PDT

Overall an excellent article with good information that is unusually well written. Not surprised but still disappointed by the posts that add nothing of value.

Keith Reeder's comments for example show the usual ignorance of digital camera technology by comparing a 2nd generation Nikon camera with a 4th generation one. It is like comparing a 286AT computer to one with a Xenon CPU.

Compare a D300 to a D3 which both use 12MP sensor, but with the D300's being 2/3 the size, and there is a highly visible difference in image quality and tonal range capture with the D3 camera (and this is using the same lenses on both cameras).

What was missed entirely is subject of noise. Noise results from the need to amplify the signals from the sensor in low light situations. The larger the photosites the less the signal needs to be amplified and with less noise there is less heavy filtering and post capture processing needed by the cameras chips.

The problem with the small point and shoot cameras is that with a sensor that is 1/6 the size of the one in a full frame camera the photosites are much smaller and gather a lot less light and the signal even a setting of ISO 400 requires a great deal of amplification. No P&S is good above ISO 400 whereas with a full frame DSLR ISO 3200 is not a problem. The 4/3 cameras that fall in them middle in terms of sensor size (half the size of a full frame) work very well up to ISO 1600.

The ISO limitation is combined with "slower" lenses that let less light through to the sensor. The average P&S lens lets 1/4 as much light through ones made for full frame cameras. So you have 1/4 as much amplification practical and 1/4 as much light coming through the lens so you need 16x as much light.

Flash is a an offset in part with P&S cameras but for quality images in low light in a non-studio setting the camera still needs to be able to capture the subjects using the available light and the flash is used to provide fill, catchlights, etc. and not as a substitute for available light. I know there are those who are intimidated by flash but it is a useful tool and one worth taking the time and effort and expense to become competent in its use for all types of photography.

The comment about using in-camera optical stabilization only in 4/3 cameras due to the size of the sensor is incorrect. The concern is with cost as it is more expensive to provide OS in a lens and the motor drives require a lot more power from the camera's battery. I have a 4/3 camera and the OS is mediocre at best. With the same field of view I need 4x the shutter speed when shooting with the 4/3 Olympus as I need with a DSLR and an OS lens. With telephoto lenses the in-camera OS is worthless. Not all that surprising as my Nikon telephoto lenses with OS cost more than five 4/3 cameras with their lenses. You get what you pay for and that is terms of both dollars and much heavier gear.

All of this information is easily verified with an hours time and some cameras and lenses. I prefer to do my own testing as the information posted on websites is usually based on conjecture and not actual experience much less testing. With digital cameras testing is far easier than in the day of film but it is done no more often which I cannot understand.

Calson
9th April, 2013 @ 03:49 pm PDT

@Simon. I have a Fujifilm Finepix HS50EXR point and shoot with a 35 mm lens equivalent to 24-1000 mm, and love it for wildlife photos. The camera's specs say that the sensor is a 1/2" CMOS, but I don't see this size mentioned in any of your graphics. Is it larger or smaller than the 1/2.3" sensor that is shown?

Rick Perez

22nd March, 2013 @ 04:07 pm PDT

Hi Rick

Am seeking a small(ish) camera with a quality combination of sensor / optics / pixel count / processor.

I looked at Bridge cameras with their staggering zooms, but must admit have been 'put off' by their sensor size.

Your 1/2" sensor is very slightly larger at (6.4 x 4.8 mm) than the 1/2.3" (6.17x4.55mm)

But results are results, and if you are pleased, then good for you.

I am currently favouring the Samsung NX300.

Sensor is a CMOS at 23.5x15.7.

Any advice would be gratefully received by any of you experts out there.

Cheers

Stephen

Stephen Walker
16th April, 2013 @ 10:39 am PDT

Very interesting piece, but spoilt by the author falling into the trap (which is somehow very fashionable these days) of mixing fractions and decimals. Anybody who had done mathematics at grade 5 level should know this !

professore
20th April, 2013 @ 09:54 am PDT

I read from your article, that Canon G1X has the largest size sensor in high end compact camera.

However, i have read that the autofocus speed is somehow slower...

In such case, any camera with about the same sensor size has a quicker autofocus speed ?

Soo Min Foo
8th May, 2013 @ 08:57 pm PDT

Keith is dead wrong in comparing a second generation D200 to a fourth generation D7100. Might as well compare a 8086 equipped PC to a PC with a Xenon CPU. I did a series of test images of wildlife subjects using the same Nikon 70-200mm f2.8 VR II lens and a D300 12 megapixel APS-C sized sensor and a D3 with a 12 megapixel "full size" sensor.

One lens, real world subjects, and two 12 megapixel camers using the same level of signal processing technology from Nikon, shooting in RAW 12-bit capture mode. Both cameras set as ISO 200 which is the base ISO for them. Surpising to me was how much better the images were from the D3. The D300 images showed a compression of the color more like what one sees with 8-bit JPEG images.

There are likely two factors, the D3 with its much larger photosites captured information that the D300 could not, and the D3's processors are more sophisticated in converting the linear output from the sensor into digital data for the CF card.

The difference between cameras has nothing to do with sensor size but rather the size of the photosites and the micro lenses used to enable them to capture as much of the available light as possible. The first ultra high ISO camera to provide excellent image quality was the 12MP Canon 5D.

Now three generations later there are camers like the D7100 and D800 that can produce equally noise controlled images despite using much smaller photosites but manufacturers like Canon with its G12 will still provide a lower megapixel count so as to have as large a photosite on the sensor as possible and with the 14MP G1 X moved to a much larger sensor for this P&S camera.

Calson
20th May, 2013 @ 11:01 am PDT

This article was informative even if some of the other correspondents disagreed with the author. I come from a background with a Pentax SLR. My first digital camera was a Fuji Fine Pix 1400. I do a lot of landscape photography and plants. Some of my pics taken with my Fine PIx 1400 are sharper than my Canon DSLR that I have now. However what digital cameras cant still seem to do is the quality I got from my Pentax mainly when I am taking a picture of a tree. The leaves are just not in focus like the Pentax. Now I don't care what it is whether its Pixels, Sensor size, DOF, or whatever I want something that gives the picture I used to have with a film camera. Back in the good old days the best picture with a film camera was a large negative size. A 21/4 " film gave heaps better pictures than 35mm. So today we can think of the sensor in the same way. But maybe with technology now its not as simple as that. There seems to be a lot of fiddling with the image in comparison to a film camera. Also its unfair to make broad comparisons. One thing I have noticed the light (usually sunshine) makes a huge difference to a picture. Its when we get away from the ideal conditions of a picture that the problems begin. So now we need a remote so I can move the cloud in the sky so the sun can re appear......

Glider47
15th June, 2013 @ 05:09 am PDT

Part of the problem here is that the whole issue gets clouded by mines bigger than yours type drivel. The ultimate quality of the picture taken will depend on a whole range of factors ( lens quality, aperture, shutter speed etc) of which the no of megapixels or the sensor size are just two.

It's also important to note that no amount of technical excellence on the part of the camera can substitute for the skill and eye of the person using it.

tony-k
19th June, 2013 @ 07:40 am PDT

great article for the most of us. Thank you.

Dalton Quigley
7th July, 2013 @ 08:18 am PDT

This is one of the most important articles about digital cameras I've ever read.

Russell Scott Day
14th August, 2013 @ 10:02 am PDT

I always find it amusing how DSLR owners turn a disadvantage into an notional advantage. A loss of DOF becomes "isolating a subject in focus while having the rest of the image blurred". DSLR's often fail at technical photography (my work) because of this loss of DOF. I often get better results out of my old FZ50.

Seems like most DSLR users have forgotten that any sort of selective blur and/or bokeh can be created in image processing starting with a sharp image. Going from blurred to sharp is nowhere near as convincing because blur is a an irreplaceable loss of information. 99.9% of the time you are better shooting a picture in complete sharp focus and post processing to get exactly the blur you want.

Light_Lab
29th August, 2013 @ 06:47 pm PDT

Good article. Explained in easy to understand terms.

Myself, coming from the manufacturing side, there are far more specifications that manufacturers put out so that camera designers can design and build cameras.

Pixel size and dynamic range are important, but also quantum efficiency, spectral response, SNR, PRNU, FPN, Full Well, the Grade of the sensor(bad Pixels Versus Good Pixels), Fill Factor, Global or Rolling Shutter plus a host of other specifications. Maybe some time I will post what camera manufacturers are looking for in a sensor for their target application.

By the way for lowlight, there is nothing available on the consumer market than can compare to an EMCCD or sCMOS sensor. For long exposures in astronomy, most will cool the camera sensor to negative temps.

Current industrial machine & robotics vision applications have been using multi-spectral prism array cameras, with camera lenses that cover from 400-1700nm's.

Added note, this article is about only area scan sensors. There are also line scan sensors.

Facebook User
22nd October, 2013 @ 09:56 am PDT

What do you think of theJVC Everio GZ-EX210. It has Image Sensor 1/5.8" 1.5M Back-illuminated CMOS

Duecking
27th November, 2013 @ 09:15 am PST

Alright, so a smaller photosite has less light-collecting capacity, requiring more noise-introducing amplification. Everybody seems determined to downplay the significance of megapixels, but all I've gathered from the repeated, often conflicting didactic is that resolution is dependent upon megapixels, but other attributes have a greater influence on the amount of detail that's captured.

I've got to be missing something, or else given an unlimited amount of light (say, high noon in Sao Paulo) and/or sophisticated post-processing, wouldn't I prefer my 10mm x 10mm sensor to have more photosites rather than larger photosites?

vaffangool
30th December, 2013 @ 08:32 pm PST

You included the smallest sensors, but not the biggest. Why? Why stop at the small-format 35mm sensor?

Maybe you don't have a proper perspective on photo sensor sizes.

T N Args
14th January, 2014 @ 10:02 pm PST

IMHO the article is misleading. It does not emphasis enough the disadvantage of bulkiness and expensiveness of FF. Let me give an example: FF sensor: Canon 1Dx with EF 200mm f/2.8L II USM lens will cost $7600 and will weight 2100g. MFT sensor: Panasonic GM1 with Panasonic 35-100mm f/2.8 will cost $1800 and weight 560g!!! If you are not doing it for money you wouldnt carry 2kg equipment with you to everywhere you go.

Arkadasim Ciftcibir
31st January, 2014 @ 04:27 am PST

Just one quibble with the article:

"The image above shows what smaller sensors would have captured if using the same lens to take this photo. You can see why devices with smaller sensors use much WIDER ANGLE {caps mine} lenses, especially by the time you reach smartphones. The lenses on these cameras are often detailed by their 35 mm format equivalent focal length to give a better idea of the angle of view they give."

He should have said "shorter focal length" instead of "wider angle".

The whole point is that they are NOT "wider angle" on the smaller sensors. The angular coverage of any lens depends on both its focal length and the sensor size. My EF 85mm f/1.8 becomes the equivalent of a 136mm lens (in terms of angular coverage, but not depth of field*) on my crop-sensor bodies.

* The acceptable blur circle size, which determines DOF scales with sensor size, a point which the author did correctly describe in the article.

rocketride
15th July, 2014 @ 06:17 am PDT
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