More resolution = less noise

Most photographers realize that the more resolution your camera captures, the better. How does that relate to noise in your image? Especially when it goes to print. DxO Labs has the answer. They did an independent complete analysis of signal-to-noise ratio (aka SNR) with two Canon model cameras. The results might surprise some people.

DxO is a free resource that offers non-biased in-depth technical analysis of RAW-based image quality. There is a wealth of data on their site. They are highly recommended by places like Popular Photography.

Contrary to conventional wisdom, higher resolution actually compensates for noise

This Insight uses currently-available DSLRs to demonstrate the technique for objectively comparing noise for cameras with different levels of resolution. Such comparisons conclusively show better results overall for high-resolution sensors, despite the increase in noise.

You like the look and feel of your old camera, but you want to upgrade it to a higher resolution. If you keep the same optics, the same sensor size (and therefore the same field of view), what will be the result? Basically, the same amount of light captured by the optics will be shared by more pixels, and since each individual pixel will receive less light, the signal-to-noise ratio (SNR) will be lower. In short, you will end up taking photos with more noise.

Two questions naturally arise:

• How can the noise from two cameras with different levels of resolution be fairly compared?
• Which is better, a low-resolution camera with less noise, or a high-resolution camera with more noise?

...Suppose now that the images have exactly the same field of view (by changing the lens focal length) and are printed on 30x20cm paper with the same 300dpi printer. Because of the very high resolution of the 1Ds Mark III, the printer will downsample the image and decrease the noise, giving a clear advantage (about 3dB) to the 1Ds Mark III.

Imagine a low-resolution sensor. A higher-resolution sensor can be obtained by cutting each pixel of the low-resolution sensor into four smaller pixels.

For a given exposure time, each smaller pixel receives four times less light than a large pixel-the equivalent of reducing exposure time by a factor of four. So to get the same sensor response, exposure time needs to be multiplied by four, which means that the ISO sensitivity of the high-resolution sensor is four times less than the low-resolution sensor.

Take better pictures with your phone

Many people have already converted to one unit for all their audio and visual communication needs. Cameraphones have improved dramatically over the past couple of years. Companies consistently add cameras with larger megapixels and better lenses to their latest models. I recently saw an image by an amateur astronomer of Jupiter taken with an iPhone. Granted, it is not the most detailed shot, but still a big leap for the capabilities of a cameraphone.

If your phone has also become your camera Photo Industry Reporter has some tips on how to capture better shots.

10 Tips for Taking Better Cameraphone Photos:

Middletown, CT— Wireless Zone reports that cameraphones are increasingly becoming the picture-taking device of choice. According to a recently published study, the company says about 1 in 5 consumers already use a cameraphone as their primary camera.

Mark Asnes, vice president and COO of Wireless Zone (wirelesszone.com), shared some wireless wisdom that can help consumers take better cameraphone pictures.

1. Good lighting is key. The ideal is natural light, but you can still get good results inside by turning on a few lights.

2. Adjust the white balance. Select your setting based on the type of lighting. If the lighting is mixed, stick with the auto setting.

3. Just say no to digital zoom. The picture quality will be reduced drastically. Optical zoom is OK if the phone has it.

4. Get ready for your close-up. In place of digital zoom, get the cameraphone closer to whatever you’re taking a picture of.

5. Stay very, very still. To prevent blurring, hold the cameraphone with both hands and brace your arms against your sides or lean your elbows on a stable object.

6. Get accustomed to the shutter lag. For better timing, get a feel for how long it takes between the moment you press the button and the moment the picture is captured.

7. Don’t get trigger-happy with the delete button. An image that looks grainy on your phone could look just fine on your computer screen.

8. A clean lens takes clean pictures. Use a glasses or lens cleaning cloth to avoid scratching the lens.

9. Turn up the resolution unless the sole purpose is for picture messaging.

10. If at first you don’t succeed . . . just keep experimenting with different angles, lighting and settings.

Get the "big" shot in a big crowd

Unless you are a press photographer with clearance, most likely when attending a sporting event your seats are not front row. Or say a parade, graduation, red carpet, really any situation where you are trying to photograph around something blocking your view. Sure you can use a monopod to elevate your camera above the what is obstructing your shot, but how do you know what you are getting? The Argraph Corporation launched a product called Zigview that can help. It is a real time digital viewfinder for DSLRs that allows for a lot more freedom when shooting. The company also has a site where fans of the product can share their images of once "impossible to get shots" called How Do You Zigview? Now you don't have to miss the "big" shot when stuck in a big crowd.

"Impossible" Becomes Possible with Zigview: Picture Business Magazine May '08 issue

Talk about having fun with a product launch – Argraph Corporation has never stopped having a blast with their unique Zigview product, launched last year. The product, rotating, tilting real-time digital viewfinder for DSLRs, was well received in the imaging industry and the company has run several interesting promos around the p[product since its launch. The most recent marketing commotion is the response Argraph has gotten from asking Zigview users to send in some of the more interesting images the product is allowing to capture. The company claims, “Photos are pouring in from enthusiastic photographers around the world. They’re taking shots they never thought were possible. And they’re posting the incredible results on the “How Do You Zigview?” page of the Argraph Corp. website.”

A wealth of digital photography tutorials

I quite literally Stumbled Upon this website today. Sean T. McHugh on his site, Cambridge in Colour, posts a quite and extensive and comprehensive list of digital photography tutorials. He covers topics from understanding your camera, to Photoshop techniques, to how we perceive color, and many more. Lots of technical data, but written in a way that is easy for users at any level to understand and apply. A great resource!

Here is a little background on Sean:

To provide some background, much of this work was conducted while pursing my PhD in chemical engineering at the University of Cambridge. I have previously conducted undergraduate studies at the California Institute of Technology in Pasadena, California, also in chemical engineering. My doctoral research focused on understanding reactive flow in multiphase plumes (applications to carbon dioxide sequestration, cloud growth and volcanic eruptions).

As a scientist by training, I am fascinated by the interaction between technological developments and the range of creative options available to photographers. Improvements in sensitivity, ex post facto white balance control and real-time feedback from digital imaging are providing photographers with unprecedented low-light capabilities. Much of this fascination has been channelled into finding unique times, perspectives and techniques for capturing many of these low-light scenes in Cambridge.

As part of the Cambridge University Photographic Society, I conducted student workshops relating to general camera and SLR technique, photographic post-processing and low-light photography. These included participants ranging from those with their first camera, to more seasoned users wishing to refine their techniques. I encourage you to contact me if you would like further information about joining the society.

Lightroom tutorials

Staying in this weekend? Maybe you can spend your time trying out new techniques in Adobe Lightroom. Jack Nack on his blog has posted links to "a wealth of" Lightroom tutorials from the Adobe Design Center. Check them out. It should keep you busy this weekend.

Speaking of Lightroom, Stephen Shankland of CNET reports that Adobe has plans to support HDR image creation and panoramic image stitching in future versions of their software. More on that here.

Print a 30x40 from your cell phone

Well, not quite yet. Researchers in the UK and Jordan have been working on a new method of image enhancement using the Swarm approach. PSO (Particle Swarm Optimization) uses a computer algorithm that can intelligently boost contrast and detail in an image without distorting the underlying features. The current application being to help those pesky traffic cameras read your license plate better. If the technology ever disseminates to consumer cameras and printers, like our LightJet, the possibilities could be endless.

Swarm Approach to Photography Improves Contrast and Detail in Digital Photos; Science Daily

There have been several approaches to image enhancement developed by image manipulation software companies and others. However, none comes up to the standards of the kind of image enhancement often seen in fiction, where a blurry distorted image on a screen is rendered pin-sharp at the click of a mouse. PSO, however, takes image enhancement a step closer to this ideal.

PSO is based on a mathematical model of the social interactions of swarms. The algorithm treats each version of an image as an individual member of the swarm and makes a single, small adjustment to contrast levels, edge sharpness, and other image parameters. The algorithm then determines whether the new members of the swarm are better or worse than the original according to an objective fitness criterion.

"The objective of the algorithm is to maximize the total number of pixels in the edges, thus being able to visualize more details in the images," explain the researchers. Such enhancement might be useful in improving snapshots of CCTV quality for identification of individuals or vehicle number plates, it might also have application in improving images produced with lower quality cameras, such as camera phones, that are required for use in publishing or TV where image quality standards are usually higher.

The process of enhancing step by step is repeated to create a swarm of images in computer memory which have been graded relative to each other, the fittest end up at the front of the swarm until a single individual that is the most effectively enhanced.

"The obtained results using grey scale images indicate that PSO is better than other approaches in terms of the computational time and both the objective evaluation and maximization of the number of pixels in the edges of the tested images," they add.

This research was published recently in Inderscience's International Journal of Innovative Computing and Applications.

Holiday digital camera buying guide

The holiday shopping season is upon us. A new digital camera is on many people's wish list. If you are thinking of buying a new camera for yourself or a photo fanatic in your family and are not sure where to start Yahoo! has posted a shopping guide by David Elrich of DigitalTrends that can help. The most sensible advise is to be purchase a camera that most fits your needs. If you plan on making big prints make sure you buy a camera that is 8 megapixels or larger.

Digital Cameras: Buying Made Simple

You've decided to buy a digital camera - or upgrade to a newer, more powerful one. You're not alone.

According to industry experts, close to 30 million digital cameras will be bought this year. And these hefty figures don't include the millions of camera-phone owners who take zillions of snapshots every day.

When you're researching different cameras, manufacturers will state the maximum file (or picture) size you can take. In the case of a 6 megapixel camera, it's 2816 horizontal pixels x 2112 vertical pixels, with 7MP it's 3072 x 2304 and so on. Simply multiply the numbers and you get the effective resolution of the imaging device. We suggest you avoid anything less than 6 or 7MP at this point unless you're looking for an inexpensive camera for the kids.

Pros have access to 21-megapixel imagers in very expensive D-SLRs. You don't have to go this route or spend that much money for great everyday photos, but 6MP should be your minimum. If you plan on making very large prints, such as 13x19s, or you think you might experiment with imaging software, consider 8 or more megapixels. There are no hard-and-fast rules, since so much depends on your final end use.