This unique manual is better than the manual that comes with your camera in several important ways:

• It’s organized according to efficient workflow, so you can get the most out of your Sony A100 quickly and with the least amount of bother. You can find what you’re looking for interactively: by using the interactive Table of Contents, choosing one of the questions in the Quick Answers section, or by following any of the convenient links we’ve placed throughout the document.
• It’s not a book (unless you want it to be). It’s a PDF that you can read on your computer or on a PDA that fits into your camera bag. It is laid out on an 8.5 x 11-inch “page” so if you want to print, you won’t have to waste paper or spend time configuring your printer.
• Because it’s a PDF, you can find subjects you’re looking for by searching electronically. Typing Cmd/Ctrl-F brings up the familiar search dialog. So all you have to do to jump straight to all the references to a particular part or feature is to enter its name. (No reliance on a mindreading indexer.)
• The PDF is photographically illustrated so you can see exactly which combination of buttons, knobs, wheels, and menu choices will help you make the magic you are hoping for.
• In addition to teaching technically correct procedures, this document offers valuable hints for taking photographs in some of the toughest situations.

Website : Sony Alpha DSLR A100: A Better Manual at $9.99

NeoCamera did a great comparison between the two camera. The Sony Alpha A100 and the Pentax K10D compete head-to-head with the most similar feature set among 10 megapixels DSLR cameras. These two digital cameras share the same image sensor, built-in stabilization and dust-reduction. Besides the lens mount, the most prominent feature difference is the Pentax K10D’s weather-sealed body. Note that weather-sealing is only truly effective when using weather-sealed lenses. The first two such lenses, the 16-50 F2.8 and the 50-135 F2.8, are expected to ship in May 2007.

The remaining differences between the Alpha A100 and the K10D can be spit into performance features and usability features. Since these camera’s share the same sensor, performance differences were not expected to be significant. Here are the relative advantages of each camera over the other:

Sony Alpha A100: 

• Greater sharpness
• Better automatic white-balance
• Superior image stabilization
• Easier to use with gloves
• More usable status screen
• Eye-start sensor efficiently controls status display
• Keyed ISO settings help with high-contrast subjects
• DRO optimizes image tonality directly in-camera
• Wider range of image parameters, although with larger increments
• Customizable EC and AEL behavior
• Eye-start auto focus
• More lenses currently in production

Pentax K10D:

• Lower image noise
• More image details
• Better color accuracy
• White-balance preview
• Greater accessibility of features
• Larger and brighter viewfinder
• Top-mounted status screen
• Unique exposure modes
• Customizable Auto-ISO and Program line
• Finer control of image parameters including white-balance
• Weather sealing with applicable lenses when they become available
• In-camera RAW development

Website :  Pentax K10D vs Sony Alpha A100

Nikon took the D40 which is a very successful beginners DSLR and equipped it with a sensor to compete against the Canon 400D / XTi. But the D40x also inherits several weaker aspects of the D40 which stand out now it’s virtually the same price as the Canon. Here’s the conclusion from the review:

“The D40x may have a better kit lens, but the Canon 400D / XTi has far superior auto focus, anti-dust features, depth-of-field previews, greater support for older lenses and comes with RAW processing software not to mention a TV cable. Then there’s the Sony A100 which again costs roughly the same and features built-in anti-shake facilities. Both it and the Canon are technically superior and better-featured cameras.

…So ultimately if you’re a beginner who loved the D40 but wished it had higher resolution, then go for the D40x. If however you want a technically more sophisticated DSLR for roughly the same money, then the Canon 400D / XTi and Sony A100 have more going for them, although if you can stretch a little further, Nikon’s own D80 offers even more still. Indeed the D40x does a great job of up-selling potential buyers to Nikon’s higher-end model.”

Website : Nikon D40x Review by CameraLabs

Sony’s DSLR-Alpha 100K–or Alpha 100–is a full-featured, 10.2-megapixel digital SLR with built-in shake reduction technology. Here’s the conclusion from the review by PCWorld: “The Alpha 100 has a sensor-based stabilization system, which Sony claims yields 3.5 stops of stabilization. I found the number of stops to be closer to 1.5 or 2–not as impressive as on cameras with lens-based stabilization. The stabilization system also functions as a dust-removal system, but the dust-removal cycle runs only when you power the camera off, for faster startup times.

The Alpha 100 delivered high image quality overall. In shots taken at ISO 100 to 400, image quality was very good–comparable to that of other entry-level SLRs. At ISO 800 to 1600, however, the Alpha 100 got noisy.

The Sony DSLR-Alpha 100K is a very good but somewhat pricey camera. Despite feeling clunkier than its competitors, it delivers good image quality and a full feature set, plus some nice extras such as image stabilization.”

Website : Sony Alpha DSLR-A100 Reviewed by PCWorld

The Pentax K10D is based around an APS-C sized CCD imager with an effective resolution of 10.2 megapixels. It uses a 22-bit Analog-to-digital converter, and a new processing engine dubbed “PRIME” (Pentax Real IMage Engine). The K10D has a dust-proof, weather resistant body with a stainless steel chassis and some 72 seals that allow the camera to be used in dusty and/or rainy environments. The sensor sits on a free-floating electromagnetically controlled platter that can move horizontally, vertically, and even rotationally. Here’s a brief look at how it compares against the nearest competition from the Camera Labs:

Nikon D80 - “Arguably the biggest rival for the K10D is the Nikon D80. At first glance the K10D appears to thrash it in terms of features including built-in image stabilisation, dust removal, environmental sealing and impressive RAW capabilities; the K10D’s also cheaper. But in our view, the D80 simply out-performs the K10D in day-to-day use. We shot with a D80 throughout the entire period of this review and saw first-hand how it handled exactly the same situations as the K10D. There were many occasions when the K10D required exposure compensation, while the more sophisticated metering of the D80 remained un-phased. We also preferred the output from the D80 using the default settings, although to be fair this is subjective. See our Nikon D80 review and video tour for more details.”

Canon EOS 30D - “Canon’s mid-range DSLR is an interesting rival for the K10D, and like the D80, it initially appears to come-off badly in terms of features. The K10D boasts slightly higher resolution, built-in anti-shake and anti-dust, environmental sealing, the chance to swap focusing screens and impressive RAW capabilities. Look a little deeper though and the 30D has several aspects in its favour including a magnesium alloy body, 5fps continuous shooting, superior metering and again more consumer-friendly output using the default settings. That said the K10D’s cheaper than the Canon 30D, so unless you need 5fps and aren’t willing to tweak image settings, the K10D represents much better value. See our Canon EOS 30D review for more details.”

Sony Alpha A100 - “The Sony Alpha A100 is a natural rival for the K10D as both are 10 megapixel DSLRs featuring in-camera stabilisation which also doubles-up for anti-dust duties. In practice we found the Sony A100’s Super SteadyShot proved slightly more effective than the K10D’s Shake Reduction, although neither were as effective as lens-based solutions at longer focal lengths. In its favour, the K10D’s anti-dust was more effective in our tests and while its default output wasn’t as punchy as the A100, it did boast lower noise levels at higher sensitivities. The A100 may be cheaper than the K10D, but if you’re willing to learn how to tweak the settings, it’s worth spending the extra on the Pentax. See our Sony Alpha A100 review for more details.”

Website : Pentax K10D compared with Nikon D80, Canon 30D, Sony A100

PopPhoto did a comparison of Nikon D40x, Canon XTi and Sony A100. Here’s the conclusion:

Canon EOS Digital Rebel XTi: With 18-55mm f/3.6-5.6 Canon EF-S lens ($770, street):

The Nikon D40x produces Image Quality a bit higher than Canon’s mighty lightweight, notably in better noise control throughout the ISO range, and it has an ISO 3200 setting, which the XTi lacks. But the XTi remains a potent competitor, with faster and more sensitive AF using a sophisticated nine-point AF array that can track across the frame. The Canon takes a RAW file simultaneously with a highest-quality JPEG, not lowest. While we’d rate the build quality about equal, we’d trust the Canon more in dusty conditions, as it has both self-cleaning sensor and software dust deletion (the D40x, just the latter). And the Canon has no AF lens limitations — all EF and EF-S lenses have built-in focusing motors.

Sony Alpha 100: With 18-70mm f/3.5-5.6 Sony Zoom DT lens ($710, street):

The Sony’s singular advantage over both the Canon and Nikon models is its sensor-based Super Steady Shot system, which provides image stabilization across both the Sony and the discontinued Konica Minolta Maxxum lens lines. Canon and Nikon make you pay for stabilization with every lens. The Sony has faster and better-tracking AF than the Nikon D40x, a self-cleaning sensor, and innovative dynamic-range controls. We also think it’s a better-built camera than the D40x. The Nikon wins on Image Quality, with somewhat higher resolution but, more important, clearly superior noise control. The Sony lens line is smaller than Nikon’s AF-S lens catalog, but not by much.

Website : Nikon D40x Compared with Canon XTi and Sony A100

Macworld has posted a great six-page article entitled “How to buy: DSLR cameras” written by Ben Long, author of “Complete Digital Photography” that gives a fantastic overview on what to look for and how to buy a digital SLR. Here’s a summary of the article:

“Camera manufacturers now recognize that hobbyists and other nonprofessional shooters have become more serious—and more skilled—at producing a wide variety of photographic images and are demanding more-affordable DSLRs to help them do it. While the $1,000 DSLR price barrier was broken several years ago, lower-priced cameras with more-extensive features have been released in the past year. If you’ve thought of switching to a DSLR, considered upgrading from the one you already have, or wondered what all the DSLR hoopla is about, read on to learn the differences between SLR and point-and-shoot cameras and to check out our reviews of five of the newest DSLR models:

• Canon Digital Rebel XTi; ; (Best Current Price: $649.00)
• Nikon D40; ; (Best Current Price: $519.95)
• Nikon D80; ; (Best Current Price: $909.99)
• Pentax K100D; ;(Best Current Price: $535.00)
• Sony Alpha DSLR-A100K; ; (Best Current Price: $641.00)

Macworld’s buying advice

Both the Nikon D40 and the Pentax have excellent lens selections, and both are fun and comfortable to use. The D40 wins the contest because of its many fine features and strong battery life.

Should I keep my point-and-shoot?

If you already have a point-and-shoot camera and are planning to buy a DSLR, you may be considering selling your current camera to help finance your new purchase. A better option, though, is to keep it. Point-and-shoots are smaller and easier to carry, so they’re ideal for situations in which carrying a DSLR is not possible or necessary.

Also, almost all point-and-shoot cameras provide excellent macro features for extreme close-ups. If you’re interested in macro photography, you’ll find that working with a point-and-shoot is usually easier and cheaper than investing in a DSLR macro lens. Finally, many point-and-shoots now include excellent movie modes, which make them a great resource for taking short video clips, something you can’t do with a DSLR.”

Website : MacWorld - How to buy DSLR cameras

In 2006, five 10MP cameras hit the U.S. market, all packed with high-end features and priced at $1,000 or less (street) — including, in four cases, a kit lens: Canon EOS Digital Rebel XTi 10.1MP, Nikon D80 10.2MP, Pentax K10D 10.2MP, Samsung GX-10 10.2MP, and Sony Alpha 100 10.2MP. PopPhoto compared the models head-to-head on performance and features and the conclusion is:

1. Nikon D80
2. Canon EOS Rebel Xti
3. Pentax K10D (tie)
3. Samsung GX-10 (tie)
5. Sony Alpha 100

There has to be a winner, and, given its image quality and near-pro-level feature set, the Nikon D80 was hardly a surprise. We’re more than happy, though, to use any of these superb cameras.

Website : Comparing 10MP DSLR Camera from PopPhoto