Monday, October 7, 2013

How To: Finding the best camera on a smartphone for you

There was a time when smartphones didn't have cameras, and if they did, they were crap. The most you could do with that camera is take a crappy photo and send it through email or maybe MMS. There was a place for the point-and-shoot camera, with its 6 or 8 megapixels and its 6x zoom lens.

That place reserved for the point-and-shoot doesn't exist anymore. It's been crowded out from the bottom by ever improving smartphone cameras, and from the top by more accessible and affordable interchangeable lens cameras.  
Smartphones are better than ever. Faster than ever. Smarter than ever. These days, almost everyone has a borderline magical computer in their pocket, and every smartphone has a camera. It's one of the last remaining features with which a manufacturer can truly distinguish itself, so I decided to help out those looking at smartphone cameras as one of their deciding factors in choosing a smartphone by breaking down what makes some cameras better than others.

Common Features of Smartphone Cameras

Perhaps the most important consideration for any smartphone manufacturer is size. If a component is too large to fit in a phone comfortably, it needs to be miniaturized or digitized. This emphasis on miniaturization has led to the near-universal adoption of complementary metal-oxide semiconductor (CMOS) image sensors for smartphone cameras. CMOS sensors are significantly smaller than the other main type of image sensor, charge-coupled devices (CCDs), and they use less power.

Advantages and Disadvantages of Smartphone Cameras

The development of camera phones has in large part kept pace with the development of digital photography technology as a whole. Smartphone manufacturers have been able to take advantage of developments in CMOS sensors, which have significantly improved picture size and image resolution. In addition, most modern camera phones are able to record video in addition to still shots, though at the expense of reduced quality and megapixel count.

Overall, most smartphone cameras are built simpler than standalone digital cameras as a concession to size considerations. In addition to the image sensor, which is the heart of any digital camera, camera phones usually feature fixed lenses and have no physical shutter. These factors limit their usefulness in low-light conditions and contribute to their long shutter lag in older smartphones (pre 2011).  However, some newer smartphones have taken advantage of recent advances in miniaturization to create phones with better flashes, high-quality optics, and autofocus lenses.

Megapixels Needed for Common Tasks

Many camera users look solely to megapixel counts when comparing cameras, as manufacturers have attempted to make pixel counts something of a benchmark. However, an image sensor’s megapixel count only describes the maximum size an image can be viewed at without a loss of image quality. While good digital cameras require more than just a large megapixel count, a camera’s pixel count is important, especially for smartphone users but only to a certain extent. Recently with more and more people only concerned about image quality for showing pictures on their phone or posting them to social media, 8 megapixels (MP) appears to be a great sweet spot. Smartphones often feature somewhat smaller image sensors than digital cameras, as manufacturers have to fit more components in a smaller space.

Displaying Pictures from a Smartphone

Simply put, any smartphone with a camera, regardless of its megapixel rating, will be able to capture an image that will appear sharp on other phones and on computer displays. That is because even the largest computer monitor resolution of 2560 x 1440 pixels yields a megapixel count of only 3.67 megapixels. All modern smartphones can capture images at a higher resolution than 5 megapixels, which means that any image displayed on a monitor is automatically compressed and scaled down to fit the display.

Maximum Effective Print Size

If a user wishes to print out any pictures he or she has taken, however, then that user will have to take the time to compare the desired print size and the phone’s megapixel rating. A larger megapixel rating allows users to print their pictures at larger sizes without a reduction in image quality. This chart details the differing sizes and resolutions each pixel rating allows.


 Size at 150 dpi (inches)

Size at 200 dpi (inches)

 Size at 300 dpi (inches)

1 MP
5 x 7
4 x 6
2 MP
8 x 10
5 x 7
4 x 6
3 MP
8 x 10
8 x 10
5 x 7
4 MP
11 x 14
8 x 10
5 x 7
5 MP
11 x 14
11 x 14
5 x 7
6-7 MP
16 x 20
11 x 14
8 x 10
8 MP
17 x 22
16 x 20
8 x 10
10 MP
20 x 30
17 x 22
11 x 14

It is important to remember, though, that megapixel rating is not always the best indication of a camera’s capabilities, especially for smaller image sensors like those used in camera phones. A larger image sensor allows for more efficient light collection, leading to sharper pictures with less noise. Regardless of the size of the image sensor, however, trying to pack more megapixels onto the same size image sensor will result in grainier images.

When explaining how megapixel ratings and image sharpness go hand in hand, industry experts use the image of water buckets. Think of the image sensor as an expanse of asphalt and the pixels as empty buckets. The buckets are placed to cover the entire surface in order to catch any water (which takes the place of light in this exercise) that falls on the surface. Adding more buckets to the rig requires reducing the size of each bucket. While this will prove beneficial up to a certain point, as having smaller buckets allows them to catch more water overall, there comes a point where each bucket is too narrow to catch water effectively. In the same way, cramming too many pixels onto a small image sensor causes a reduction in image quality as digital noise interferes with image capture.

Megapixel Ratings of Common Smartphones

As mentioned above, the megapixel and resolution ratings of smartphone cameras have kept pace with developments in standalone camera technology. For instance, Samsung recently developed small form-factor CMOS image sensors that can capture images at 8 and 12 megapixels. In addition to this high megapixel rating, both lines of sensors can capture video at a resolution of 1080p, comparable to high-end digital cameras. Each of the most popular brands of smartphones provides its users with different features, which must be considered before purchase.

The aperture on your smartphone camera has a lot to do with the way your photo will ultimately turn out. Here’s the breakdown on apertures, iPhones, and Android phones.

What is aperture?

Simply put, the aperture is the hole that light must travel through in order to make an image on your camera’s sensor. Your eyes have apertures but we don’t call them that. We call them your pupils. As your pupils dilate, you can see more light. When they tighten, you see less. The exact same thing happens with camera apertures.

There is a certain benefit you get from having a camera with a big aperture. The camera will work better in low light situations without using a blinding flash because it can allow more light in. One of the big selling points of the recent iPhone 5S is its F2.0 aperture. It is the largest aperture ever released on an iPhone, making it the best iPhone for photography to date (when you couple that with an 8 megapixel sensor, you can clearly see that this is a phone built with photography in mind). Other smartphones have cameras with similarly amazing apertures. The Samsung Galaxy S4 gets F2.2, and the HTC One goes all the way down to F2.0 as well but only has a 4MP sensor. Just for reference, a lower f-number is a good thing. F-numbers are weird. They go down as the aperture gets physically bigger.
The other advantage of a large aperture (small F-number) is portraits. The large aperture helps to isolate your subject by blurring the background.

Why don’t I see any aperture settings on my phone?

Why don't most smartphone manufacturers give you access to these controls? It’s hard to say, but it probably has a lot to do with design philosophy. Then how can I see which aperture my camera picked after I’ve taken a photo?

The nice thing about smartphone photos is that they still contain the EXIF file with all the information about your exposure. If you ever want to see which aperture your camera picked, simply right click on an image you’ve imported and choose “get info.” If you’re using a Mac, you’ll see this information under the “more info:” section. Look right under F number, and you can see the aperture your phone used. It’s handy to know this kind of stuff because it teaches you things about your camera. By studying these numbers, you can learn how your smartphone interprets light.

Just one quick word on apps like Instagram. If you want to look at the EXIF file, make sure you take two photos, one with the native camera app and another with Instagram. Instagram photos have no data on the aperture or shutter speed. The data only gets preserved when you use the native camera app.

Make your camera pick the right aperture

When your smartphone knows what you’re trying to do, it tends to pick an aperture more suited to the job. That’s why the best thing you can do to get the right aperture every time is to focus on your subject by tapping the screen (at least that’s with the iPhone). Smartphone cameras can gauge the depth of field, so they know when you’re trying to isolate your subject for portrait or macro photography. That’s it. Tap to focus and then double check to make sure your camera is still focused on the main subject. Always do this, and you’re bound to get something very close to what you want.

Some phones have a great ‘scene mode’ feature, usually represented by the letters SCN. Tap that and you’ll see options like Landscape, Portrait, Action, Night, Sunset etc. Choose the one that best fits your photo and your camera will choose the correct settings and aperture for the scene.

You may not have control over the aperture on your phone’s camera. That’s okay. As long as you give it the right instructions, you’ll do fine.

Optical Image Stabilization

An optical image stabilizer, often abbreviated OIS, IS, or OS, is a mechanism used in a still camera or video camera that stabilizes the recorded image by varying the optical path to the sensor. This technology is implemented in the lens itself, or by moving the sensor as the final element in the optical path. The key element of all optical stabilization systems is that they stabilize the image projected on the sensor before the sensor converts the image into digital information.

The BIGpixel approach

One big weakness of traditional approach is low-light photography. More pixels on a small image sensor - there is not enough space to put big image sensors in a phone - means the pixel size is small. And as companies increase the number of pixels, it is getting smaller. This means in low light, there is likely to be lots of noise in images. There are two smartphone companies that are trying to tackle this problem by opting for bigger pixels - HTC and Apple.

With HTC One, the Taiwanese company introduced an image sensor that would take photos only in 4 mega pixels size (. HTC argued that this size is big enough for photos that would be shared digitally or posted on social media websites. At the same time, low number of pixels allowed HTC to use bigger pixels (they are calling them Ultrapixels) - 2 microns (a unit of length equal to one millionth of a meter, used in many technological and scientific fields, in this case measure light) which could capture more light to aid a user in low-light photography. In comparison, the pixel size used by the Samsung Galaxy 4 camera is 1.1 microns.

Theoretically, HTC One should capture better images in low-light conditions and decent images in proper light. But in actual use, HTC One camera falls a bit short, mostly because it can't capture enough detail with its 4MP camera. Yes, it does click better pictures in low light than most of the other smartphone cameras but overall it has an average camera compared to what you get with the Samsung Galaxy S4 or iPhone 5c.

With the iPhone 5S, Apple is following in the footsteps of HTC, but with caution. Apple increased the size of image sensor in iPhone 5S but without increasing the amount of pixels. iPhone 5S shoots images in 8MP just like iPhone 5 but the size of a pixel is bigger at 1.5 microns. Apple believes this should provide the right balance between the amount of details and amount of light that iPhone 5S will capture. For now, it looks like Apple has the right balance by making sure there are enough megapixels for image quality, enough light coming into the lens with a high f/2.0 aperture, and a better than average image sensor to allow more light onto each pixel used.


In this age of photos every where of our daily lives, I believe its important to have good ones. Obviously no one wants terrible ones and great ones can sometimes take to long to set up. Since most of us rely on our smartphones to capture our daily lives in photos, good photos will be able to show our kids, grandkids, and even great grandkids what we randomly did as friends or family on a Saturday afternoon or a Friday night.  So on top of making sure we feel comfortable with the size of the smartphone, the weight of it, the operating system that is on it, we also make sure that the camera is the best we can too, so that we aren't dependent on filters to fix under or over processed moments in time.

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