Here you will find some FAQs which will definetly help you in understanding photography better than ever.

1. Where's a good place to buy camera gear?
2. Can I trust these on-line sites with incredibly low prices?
3. Should I trust camera advice from somebody whose photos I admire?
4. Should I buy from a particular manufacturer because my cousin/local cameras store guru/professional photographer friend/brother in-law/etc. says that this manufacturer makes the best film cameras?
5. Where can I find good camera reviews?
6. Where can I find ratings of different lenses?
7. Should I purhcase an extended warranty for my camera?

1. What is a "35mm equivalent" focal length?
2. What's the relationship between focal length, subject distance, aperture, image size, and depth of field DOF)?
3. Does depth of field really extend 2/3 behind the subject and 1/3 in front?
4. How is the circle of confusion (CoC or CoF) determined?
5. What is diffraction and how does it affect my photos?
6. The corners of my images are darker than the center at the telephoto end of my zoom's range. Is my lens defective? (vignetting)
7. Do Japanese cameras with German labeled lenses (e.g., Zeiss, Schneider, Leica) really have German made lenses, or are the German companies just renting their names?
8. What are those red and green color fringes in my images?
9. How do I avoid chromatic aberration (CA)?

Where's a good place to buy camera gear?

Shop around. I like using pricegrabber to get prices from a large number of retailers at once. Pay careful attention to the merchant ratings column! Also check reselleratings.com.
I've noticed that Canoga Camera tends to have very competitive prices on Canon lenses. B & H Photo seems to be well liked by camera aficionados for their good prices and good return policies. Note that some have complained about uneven service and poor packaging, so be sure to read the most recent merchant ratings.

Check their ratings at pricegrabber. You'll find that the least expensive merchants often do one or more of the following tricks:

Should I trust camera advice from somebody whose photos I admire?

Not necessarily. A person who has taken some good photos has demonstrated some skill with photography and most likely knows more than a person randomly selected off the street. However, a good photographer will figure out how to take some good photographs with almost any gear. Consumers should be interested in cameras that it will make it easy for them to take good photos in the widest variety of situations. Just because a person can take good photos, doesn't mean that he has insight into this question. Indeed, he may lack insight because he has become so skilled at working around limitations that he has forgotten what issues concern a beginner.
People sometimes comment that only serious photographers need especially good cameras. This was certainly true when "good" meant rugged. If good means that it can be used in a wide variety of situations without heroic efforts or special skill, then beginners need good cameras even more than pros.

Should I buy from a particular manufacturer because my cousin/local cameras store guru/professional photographer friend/brother in-law/etc. says that this manufacturer makes the best film cameras?

You must be joking. First off, the camera market is extremely competitive and with the exception of esoteric, high end gear, it's not reasonable to expect that any one manufacturer will maintain a consistent edge in consumer gear for many years without being challenged in some way. People who say, "Always buy brand X," are generally people who don't know what they're talking about but bully others into following their lead becasue they're good at sounding very confident when they speak.
Second, digital cameras are a new ballgame in countless ways. Critical parts of the camera, such as the sensor, typically are not made by the same company that puts its name on the camera. For example, Sony makes the CCDs inside the cameras of many competing manufacturers. The cameras themselves are often contract manufactured (Sanyo is a big player in this market), so cameras with different labels may be coming out of the same factory. Finally, one of the most important parts of a digital camera is its electronic innards and image processing algorithms. This is a relatively new product area and there's no reason to think somebody's old prejudices about film cameras are relevant to this in any way.

Where can I find good camera reviews?

My favorite place is dpreview. While they don't hit every model, the cameras they do review are covered in a thorough and objective manner, and they offer a clear statement of the strengths and weaknesses of each model. You should keep in mind that the camera market changes rapidly, and that a camera that was "highly recommended" in 2002 may not be a super performer by today's standards. Other good sites:

Where can I find ratings of different lenses?

The most widely cited place appears to be photodo, which is sadly out of date. photozone also has lens reviews.
A note about lens reviews: There is often significant variation between samples of lenses. Reviews typically consider just a single sample, so you may not get the full picture from reading just a single review. See also:

Should I purchase an extended warranty for my camera?

The thing to remember about extended warranties is that salesmen push them because they are very profitable on average. This means that on average you will lose money with extended warranties. However, there are a few cases where extended warranties can be wise decisions:

What is a "35mm equivalent" focal length?

Every lens has a focal length, which is a physical property of the lens. Once the lens is made, this cannot be changed. The field of view associated with a lens will be a function of the area projected by the lens that is captured by the camera. For 35mm film photography, this area is 36mm by 24mm. Note that if you change the area captured, the field of view also changes. For example, using a 50mm lens on an APS format camera yields a very different field of view than using 50mm lens on a medium format camera.
For many years, amateur photographers who used 35mm film and no other systems became accustomed to associating particular focal lengths with particular fields of view. When these photographers moved to other systems, such as medium format, or digital, it was sometimes convenient to think about lens focal lengths in terms of the equivalent field of view they offered in the more familiar 35mm film world.
Note that the 35mm equivalent focal length of a lens is simply a way of relating field of view of a lens attached to a new camera, to the field of view of a different lens attached to a more familiar camera. There is no deeper connection than this.

What's the relationship between focal length, subject distance, aperture, image size, and depth of field (DOF)?

If you want to check the math on this, I suggest you visit Andrzej Wrotniak's site, which also has some nice tables comparing DOF for different imager sizes. I'll briefly summarize the key points you need to remember:

Does depth of field really extend 2/3 behind the subject and 1/3 in front?

This often cited rule of thumb cannot possibly be right in general, as a simple thought experiment proves: When you have focused your lens at the hyper focal distance, depth of field extends infinitely far back. If the 2/3 rule were true, then depth of field would need to extend infinitely far in front as well (since 1/3 of infinity is still infinity), and objects behind the camera would need to be in focus. This is obviously ridiculous, so the 2/3 rule cannot be right in general.

How is the circle of confusion (CoC or CoF) determined?

For depth of field calculations, the circle of confusion (CoC) is the smallest acceptable amount of blur in the image plane. To determine the CoC, you must do the following:

What is diffraction and how does it affect my photos?

Diffraction is an optical effect that occurs when light passes through a very small opening. Instead of producing a bright, clear image on the other side, it produces a blurry, disc shaped image. (Click here for a more detailed description of the physics behind this.)
Diffraction can reduce the quality of your images when you use very small apertures. Many people think that images always get sharper as you decrease aperture size. This is true up to a point. Beyond this point, they start to get softer due to diffraction.

The corners of my images are darker than the center at the telephoto end of my zoom's range. Is my lens defective? (vignetting)

Probably not. This effect is called ‘vignetting’ and it is common in consumer quality lenses. If the effect is not equal in all corners, then something may be misaligned and you should return your camera or lens for service.
Some models have been particularly prone to uneven vignetting. For example, a batch of Sony DSC-F707 models had uneven vignetting on their left side, leading to the acronym DLSS (dark left side syndrome). Many owners with this problem ultimately returned their cameras to Sony for service.

Do Japanese cameras with German labeled lenses (e.g., Zeiss, Schneider, Leica) really have German made lenses, or are the German companies just renting their names?

From what I have heard, Zeiss people were involved in the design of Sony's Zeiss lenses and they are involved in the manufacture of the lenses too, though the lenses are made in Japan. The extent of the involvement is not clear.
The relationship between Panasonic and Leica seems somewhat different. It is described as a collaboration, although Panasonic's version of events seems to suggest Panasonic engineering and Leica enforcement of quality standards.
If you have information about the operation of other Japanese-German partnerships, please let me know.

You are most likely seeing classic chromatic aberration (CA), the details of which are explained in beautiful detail by Van Walree. (See also HyperPhysics or Wikipedia) In short, chromatic aberration results from the fact that different wavelengths of light refract slightly differently when passing through your lens. This causes some wavelengths to be misfocused or misrouted, have different magnification and/or get shifted laterally in your image.
See also: How do I correct for chromatic aberration (CA)?

How do I avoid chromatic aberration (CA)?

If you don't know what I'm talking about, see: What are those red and green color fringes in my images?
With the lens you currently have, you can reduce CA by stopping down. You may also find that some focal lengths are more prone to CA than others. For zooms, CA is typically worst at one or both of the extreme ends of the range.
Another way to avoid CA is to switch to a different lens. In general, extreme wide angle and extreme telephoto lenses are more prone to CA than "normal" lenses. Zooms are typically more prone to CA than fixed focal length lenses. Lenses with exotic elements (fluorite, high index or low dispersion glass) are less prone to CA. Such lenses are often labeled as "UD" or "ED" lenses. Apochromatic lenses also minimize CA. These are usually labeled as "APO" lenses.
See also: How do I correct for chromatic aberration (CA)?

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