Not so Secret Digital Photography Tricks

By Russell Roberds

Have you ever desired to improve your photo taking skill, yet did not know where to to start? Well, what if I told you that in just a few minutes, you could be using some fantastic digital photography tricks that will take your photos from okay to incredible!

If you are anything like me, you have thrown away a lot of time and some cases a lot of money taking photographs, that are, well, not that great. After several years (too many to reveal), I finally decided to do something about it. I read a couple of books, magazines and took a couple of classes to advance my digital photography skills. What I learned is that there are a tremendous amount of digital photography tricks that are so easy, I picked them up in nothing flat and discovered sensational results.

I will not pledge that you will be a superstar from these digital photography tricks, but you will identify results from your very first picture.

1. Fill the frame: One of the most basic digital photography tricks to grasp, but harder to put into practice. When you shoot a picture, how small is your subject in the view finder? When I look at old pictures I took, the subject invariably seemed to be tiny. Well, by filling the frame you highlight the object better. Also, whenever the subject takes up most or the entire frame, you are "removing" objects from the picture that might have appeared beside or around the subject. By getting rid of the "clutter", the viewer then focuses more on your subject. The practice that I now put to work is if you conclude you are close enough, your not. If you conclude you are too close, then you are probably the perfect distance, so take the picture.

2. Would you repeat that?: An easy to grasp digital photography trick is repetition. Repeating arrangements, colors or textures make fabulous photos! You can find many repeating patterns in nature. One way to enhance a pattern picture is to find a pattern and then an object that defies the pattern, like a carton full of red apples with one yellow one. The odd man out pulls the viewer's eye into the picture and moreover composes a contradiction.

3. One of the digital photography tricks used in many pictures is reflection: The earth is chock-full of reflective objects and faces; water, glass, chrome, waxed cars and mirrors to mention a few. They alter our natural awareness by twisting the original. Whenever you take a photo of the reflection rather than the original, it will engage increased interest to your photo.

4. Last yet not the least of the digital photography tricks is to construct a frame within the frame. I am not saying a photo frame, I am talking about generating a frame encompassing your principal object using objects in the area around your subject. One idea is to locate yourself on one side of a door frame and your subject on the opposite side. Shoot the photo so that the door frame is around the edges of the view finder. The picture will pull the viewers eye to the interior of the frame and to your subject. It may also construct extra depth in the photo.

These are a few of the simple techniques that skillful photographers put to use to attain those awesome photos in magazines, books and on the web. My desire is that you will employ these digital photography tricks to enhance your picture taking talent. Happy shooting and say cheese (make mine white American)

About the Author:

Russell Roberds is an novice photographer living in Georgia. He has been snapping pictures for over three decades. He has used a multitude of cameras from film to digital, but his preferred is the Nikon D60. Click here digital photography tricks for more information and more tricks to improve your photography technique.

Lecia 35mm: The Pioneer

By Yars Revenga

Photography has developed rapidly over the years with equipment and film working in tandem to pioneer new methods of taking pictures.

The 35mm camera was introduced to the public in 1934. It gradually began to find favor amongst the masses and became one of the best selling cameras by the late 1960s.

The typical number of exposures on a roll of 35mm film is 36. However, the number of exposures can vary depending on the needs of the photography and cost constraints. Disposable cameras can be found in 6, 8, 10, or 15 exposure quantities.

In 1913, the American Tourist Multiple was released to the public. Inaccessibly expensive, photography enthusiasts would have to wait until 1925, when the 35mm Leica camera was released at a more affordable price.

The Germans produced the 35mm Leica which took the world by storm. It has since taken over the world of photography as the standard in cameras. Outfitted with a superior lens in addition to its compact size, it's no wonder the 35mm Leica has its world class reputation.

In 1934, the Kodak Company launched the German built Kodak Retina, the first 35mm camera to use the modern film cartridge, familiar to camera users today. The next important innovation took place in the 1960s when Nikon introduced the Nikon F SLR.

This was the beginning of the Single Lens Reflex system, a technology that went on to dominate photography. This type of camera proved more user friendly with functions such as a viewfinder, focusing screen and motor drive to automatically move the film on.

Digital SLRs are currently on the evolutionary crest of cameras. Will they ever compare to film is a question that many photography enthusiasts ponder. The digital SLR appears to have secured its place in the foreseeable future of photography.

Canon, Nikon, Olympus, Fuji and Ilford are the leaders of the camera making world. These visionaries have all contributed to the evolution of photography and will undoubtedly be a part of future advancements. The traditional 35mm film camera will never be forgotten and has played an integral role in the popularization of photography on all levels.

About the Author:

Film vs. Digital Find out which format prevails at Digital Camera Reviews

Buy Spy Cameras To Protect Your Home And Office

By Jason Frehly

When we buy spy cameras to protect our home and office we have take the offensive in our own personal security. We actively put an end to the the days of 'passive' protection. By taking the important first step of buying a spy camera, we actually put the bad-guys on defense - right where they belong!

But to buy spy cameras is the easy part. To know 'which' spy cameras to buy may be a bit more difficult. There are some simple questions that need to be answered at the very outset of our investigation in order to be sure that the spy cameras that we purchase are exactly what we need.

First and foremost we need to know where the spy cameras will be located. The location of the spy cameras is important due to the fact it will reveal much to us about the type of spy cameras we're going to need. Will they be located inside or outside? Will the location have low-light or normal lighting conditions? Will it be a hidden location? Will it be a location conducive to wired cameras? Or will wireless models be necessary?

After answering the question of where, we'll need to answer the question of what? What are we going to film on our home spy cameras? If we need to record a particular person or situation, than we'll need a particular type of camera. If we need to record a perimeter or multiple rooms, than we're going to need an entirely different type of spy camera.

The third set of questions has to do with the viewing and storage of our chosen capture device. Will we need to immediately view the evidence captured on our spy cameras? Will we need to record the data? If we need to record and store the data, how much storage will we need? What type of storage devices will we need to implement with our home spy camera system? These questions will help us to best decide on the type of monitor and digital video recorder (dvr) we will need to better implement our home spy camera system.

Of course we have to consider the cost - unless we have unlimited budgets. Even with an unlimited budget it is not a good idea to buy something simply because it is the most expensive - OR because it's the cheapest. We need to first answer the previous three sets of questions - and then proceed to deal with our budget. We first need to learn what type of spy cameras that we need. We then decide which are the best spy cameras to buy within our budgetary constraints. The budget question should not be a concern at the beginning. First learn what you need to buy, then search within your budget.

We buy spy cameras to protect ourselves or to catch someone in the act of doing something their not supposed to do. By reading and then acting on what we learn in this list we put ourselves in the best position to be protected. But the important thing to realize is that we must ACT! We must go from reading to action!

The decision to buy spy cameras may cause some of us to worry - but this is due only to a lack of understanding and knowledge. This is second nature to others. But the key to being successful when we buy spy cameras is to follow the steps in the list and then to act on these steps. Good luck! I hope that this has set you on the right path to helping you make the best decision available when you buy your spy cameras.

About the Author:

Jason Frehly is devoted to helping you learn how to Buy Spy Cameras for your home, office, and personal protection. To find out more on how to Buy Spy Cameras - please visit his site.

Gigabit Ethernet: Coming to a Camera Near You

Gigabit Ethernet:
Coming to a Camera Near You

by George Chamberlain, Pleora Technologies

An AOI application based on GigE connectivity opens up a whole new range of configuration options.

For want of lower cost, more flexible alternatives, the automated optical inspection (AOI) industry has been designing its high-performance applications around short-reach, point-to-point image transfer protocols like Camera Link™ and low-voltage differential signaling (LVDS).

LYNX GigE Camera Courtesy of Imperx

Perhaps that explains the buzz in the machine vision world over new application configurations that leverage the economy and agility of standard Gigabit Ethernet (GigE). In GigE, the industry finally has found an inexpensive, standard transport platform that goes long distances, supports all sorts of networking and processing options, and perhaps most importantly, delivers the high bandwidth needed to stream imaging data from cameras to host PCs in real time.

One measure of the momentum behind GigE is an initiative by the Automated Imaging Association (AIA) to define GigE Vision. It is an open standard that will enable seamless interoperation over GigE between cameras and applications software from different vendors (see sidebar).

Pleora Technologies provides a range of stand-alone products that allows existing camera link, LVDS, or analog cameras to stream data in real time over GigE. In the past year or so, many camera companies, including DALSA, Imperx, JAI-Pulnix, Tattile, and Toshiba-TELI, have unveiled their first GigE camera offerings.

If you're shopping among these wares, it's worth taking a hard look at what's inside. Not all GigE interfaces are created equal. The techniques used to grab, packetize, queue, and transfer image data over the GigE link have a significant impact on the reliability and quality of the image stream.

Instead of a frame grabber, GigE applications use a standard network interface card/chip (NIC) to route image data to PC user memory. To improve NIC streaming efficiency, many GigE cameras come with a special driver. These drivers operate with varying degrees of effectiveness and merit careful inspection.

Another key consideration: If your application has to synchronize and trigger multiple system elements, ensure that these traditional frame-grabber functions are adequately met by internal camera circuitry.

The GigE Interface
The GigE interface sits behind the camera head inside the enclosure. Its main job is to acquire image data, convert it to IP packets, queue it for transfer, and send it over the GigE link. It also must deliver control signals from the GigE link and other inputs to the camera head and handle network functions such as boot-up and packet resend.

Two classes of interfaces are offered in today's new GigE cameras: those made from purpose-built hardware and those derived from a software application on an embedded processor. Table 1 summarizes the relative benefits of each approach.

Table 1. Performance Trade-Offs Between Different Classes of GigE Camera Interfaces

In general, purpose-built hardware yields higher performance, more reliable GigE interfaces that are capable of processing and transmitting image data at the full 1-Gb/s GigE line rate. They easily meet the real-time throughput requirements of most AOI applications including those involving high-resolution cameras with fast frame rates.

Hardware interfaces operate with deterministic, clock-cycle accuracy suitable for even the most demanding AOI applications. This helps them deliver the low, consistent latency required to achieve superior system-level performance and improve the quality of AOI application results.

Hardware interfaces are compact, which minimizes camera size. And they are power efficient, drawing as little as 2.0 W regardless of how much data they pump out.

GigE interfaces derived from software can achieve deterministic operation at accuracies suitable for many AOI applications as long as they use a real-time operating system (RTOS) and a processor with decent clock speeds. However—and this is a key point—the power consumption of these interfaces is directly related to how much image data they process.

Analyses indicate that, even with a power-efficient processor, a software interface would draw up to 25 W to drive the throughput of a 1,600 × 1,200 sensor operating at 50 f/s. This is just not practical. Cameras for imaging applications operate at well below 10 W.

Furthermore, the heat generated from this much power would degrade sensor efficiency. Power consumption imposes a ceiling on the data throughput a software interface can handle and explains why GigE cameras using this technology are packaged with sensors operating at lower data rates.

Performance at the PC
AOI systems with GigE cameras don't require a frame grabber. Instead, data is brought into the PC using a standard low-cost NIC. However, the drivers supplied by NIC manufacturers use the delay-prone Windows or Linux IP stack to transfer data into memory. They can handle high-bandwidth image data but not in real time.

Some camera companies ignore this issue because their cameras are aimed at applications where real-time operation is not critical. Others include a more efficient NIC driver with their camera.

A few of these drivers are top-notch software that stream image data directly to user memory, in real time, at the kernel level of the system, bypassing the Windows or Linux IP stack process. Since they don't engage the IP stack and use intelligent direct memory access (DMA) transfers, these drivers need almost no CPU capacity from the PC.

This is important for demanding AOI applications that need the CPU to analyze image data as it's streaming into the computer and, depending on the analysis result, trigger a subsequent event in the system. If the CPU is busy managing data transfer, it's not available to the application, making real-time processing impossible.

More typically, drivers included with GigE cameras improve NIC streaming efficiency but still use elements of the IP stack for some processing. These drivers can't guarantee real-time operation and use more CPU time in the PC than some AOI applications can tolerate.

Higher performance drivers often perform another critical function: helping to ensure the recovery of packets dropped by the network. These drivers guarantee data delivery by implementing a sub-millisecond data resend protocol in conjunction with the GigE camera interface. This ensures data is never lost.

The GigE Vision standard will support data resend but will not define the implementation method or maximum response time. Establishing the time required to generate or respond is left to the camera manufacturer. AOI applications that require real-time performance will need to validate that the packet resend capabilities of the chosen camera are sufficient for their application.

Triggering and Synchronization
Many AOI applications need to synchronize, trigger, and coordinate the operation of cameras with encoders, light sensors, motion detectors, conveyor belts, and other system elements. In the past, this job has fallen to frame grabbers.

In systems with GigE cameras where no frame grabber is required, camera companies need to offer these functions inside the camera. Lower-end GigE cameras usually, but not always, include a couple of I/O ports that support basic functions such as external sync.

At the other end of the spectrum are richly featured GigE cameras with I/O capabilities that rival or exceed those of the most sophisticated frame grabbers. These cameras include a flexible signal matrix that allows signals from the I/O, GigE, and camera connectors to be interconnected in hundreds of ways. Any input can be mapped to any output, activities can be chained where outputs are fed back as inputs, and I/O signals can be combined in classic Boolean logic operations.

Using a look-up table, specific relationships can be built between different system elements. Triggers range from a simple external sync to intricate interoperations. Image capture, for example, can be initiated, interrupted, or aborted by triggers from a single encoder or by combinations of triggers from encoders, light sensors, and motion detectors.

These higher-end I/O systems also include control circuits such as delays, rescalers, and counters for fine-tuning system operation in numerous ways. Images can be tagged with timestamps and system actions triggered based on time intervals.

Signals also can be delayed by specified time intervals or have their frequency scaled up or down. Actionable interrupts can be generated from the PC host, and all system elements can be reset simultaneously.

Triggering From an Application
In some vision systems, in-camera I/O activity must be complemented by commands from PC-based applications software. If, after analyzing the image of a product, the software detects a fault, it may have to activate a push arm to remove the product from a conveyor belt.

In the past, frame grabbers handled this trigger. With GigE cameras, such triggers can be problematic because vision application software usually runs on Windows or Linux. Trigger requests can be stalled in OS queues, interrupting real-time signal flow.

Figure 1 shows how GigE cameras with fully featured I/O capabilities can bypass this limitation. Each image is timestamped by the in-camera I/O system, and the timestamp correlates to an encoder count.

Figure 1. Some GigE Cameras Can Support Real-Time Triggering From a PC Application

The encoder count gives the I/O system the precise location of the widget on the conveyor belt. Through system design, the push bar is located far enough away from the camera to accommodate the maximum possible variability from the OS scheduler and any other network equipment.

The PC-based AOI application sends the in-camera I/O system the timestamp of the exact moment the defective widget will pass the push bar, and the push bar is triggered accordingly. This allows applications to precisely time trigger events and synchronize system elements independent of latency variations in the OS and changes in conveyor speed.

Matching Cameras to Applications
Regardless of which camera is used, the mere fact that an AOI application is based on GigE connectivity opens up a whole new range of configuration options. For the first time, applications can leverage the long-distance reach, networking flexibility, scalability, and low-cost equipment that have made Ethernet the reigning global LAN protocol.

If you need real-time end-to-end performance, high-resolution imaging, or sophisticated I/O capabilities, look for a GigE camera with an interface based on purpose-built hardware. If your AOI application is less demanding, then a product with a processor-based interface might suffice. In the end, as always, application needs and business priorities will dictate which GigE camera best fits the bill.

About the Author
George Chamberlain is president of Pleora Technologies and serves on the AIA GigE Vision Committee. He has been involved in the design of communications, networking, and imaging products since the late 1980s. Before co-founding Pleora in 2000, Mr. Chamberlain worked for companies including Semiconductor Insights, Mitel, and Bell-Northern Research. Pleora Technologies, 359 Terry Fox Dr., Suite 230, Kanata, Ontario, Canada K2K 2E7, 613-270-0625, e-mail: info@pleora.com

GigE Vision a new camera interface standard

GigE Vision™ is a new camera interface standard developed using the Gigabit Ethernet communication protocol.  GigE Vision™ is the 1st standard to allow for rapid image transfer using low cost standard cables over very long lengths.  With GigE Vision™, hardware & software from different vendors can interoperate seamlessly over GigE connections.  The standard was developed for industry, by a selected group of companies representing every sector of the vision industry. The Automated Imaging Association (AIA) oversees the ongoing development and administration of the standard. GigE Vision™ offers lots of benefits including: High bandwidth (1000 Mbps) allows large uncompressed images to be transferred quickly in real time Uncompromised data transfer up to 100m in length Standard gigabit Ethernet hardware allows single/multiple camera connection to single/multiple computers Low cost cables (CAT5e or CAT6) & standard connectors Highly scalable to follow the growth of Ethernet bandwidth. As 10GigE becomes mainstream, GigE Vision™ will be the fastest connection in the industry Standard hardware, cables allow easy, low cost integration