The processor speed is the least important factor. I have the same software, Lightroom 3 on my wife's computer (2.7 GHz) and my computer (3.2 GHz). Guess what, the speed of her's beats mine by a mile. Reason, bus speed. Wait until Windows 8 is out, get a desk top instead of a laptop because you will need to replace the monitor anyway.

Raw is:
A) 12 bit vs 8 bit, or 256 shades of red, blue and green as opposed to 4000 shades of each.
B) Allows for correcting white balance, exposure, clarity.
C) Has a greater dymanic range.
D) Is not lossy (not compressed).
E) Has not been processed by the camera, you make the decisions.

JPEG is good for:
A) Taking you card directly to WalMart for printing.

A while back, Popular Photography gave the Nikkor 18-55 VR an A+ rating for images up through 8X10". The main reason I switched was it was too confining, had nothing to do with image quality. Now shoot with Sigma 10-20 and Nikkor 18-105.

I totally agree, the difference is the one without the filter is overexposed, hence the colors lack punch. Personally, I'd eat dirt before using a UV filter. For protection, I store the camera, and use a lens cap when not shooting.

I have given them to a local thrift shop run by a hospital. I also keep the most recent old camera in the car at all times in case I come across a scene.

I prefer an ultrawide angle lens to a fisheye, because by design there is minimal distortion with the ultrawide. To be classified as an ultrawide, the lens has to offer a field of view of over 100 degrees, as well as having a corrective element for the distortion. Fisheyes intentionally leave out the corrective elements, hence the barrelling. I use my Sigma 10-20 mm for most landscape shots and love the results. Sharpness from one foot to infinity at f/13.

A tripod is a MUST. The exposure should be between 1/2 and 2 seconds. Also, I typically use an f/stop of f/16, as well as a circular polarizer to further reduce light and reduce any glare. I set the ISO to 100-200. Avoid sun light, it is a killer. Dawn, dusk overcast and even rainy days are the best times to shoot. Finally practice, practice, practice. Good Luck.

Good explanation, but you left out the most critical part of the equation, the focal length of the lens. If I am shooting at 12 mm @ f/11, I manually set my focus to 3 feet for maximum depth of field. Changing just the focal length to 35 mm, I would know have to focus at a distance of 19 ft for maximum DOF.

I use a Sigma 10-20 mm on a D5000 for most of my landscapes. I normally set it for 12 mm @ f/11 and focus manually for 3 feet. This gives my a depth of field of about 18 inches to infinity. Great for getting low and adding depth to the image. As a side note. do not use a circular polarizer with the lens, it will create very unnatural results.

The exposures from the 5100 are over exposed, which results in a loss of high light detail. Also, the white balance is set too cool causing the color to be off.

I am sick and tired about getting private messages from Tomphenox about my response to "no one offered the asked for advice". My post was an hour earlier, so it was clearly present for all to see and read, if they know how to. Even the others who posted offered solutions they thought were best, were blasted by someone who did not even ask the question, let alone offer a valid solution. Why is it all right to trash me, and everyone else who posted, yet when I point this out they are in error, I am the villian. It is apparent, that there are those on this site who just like to bad mouth people. I left this site for a couple of weeks because of idiot posts like this, hoping it would get better, but it has not. I am busy enough teaching those who are willing to put the effort into learning photography, than to deal with "it is okay not to read the manual and ask stupid questions", or have those who trash comments, when it is not even their post. Beam me up Scotty, no intelligent life here.

I have had one in my bag for several years. While it is to my go to lens, it does provide very good images if used properly. By that I mean either with a tripod, or if hand holding, and exposure of 1/300 sec or faster.

I use a digital recorder to state location, weather conditions, filters used, which images for HDR set, which are bracketed. The rest of the data I get after downloading.

It appears you do not know how to read, as I gave three, count them 3, options to use in the field to avoid blown out skies. By the way, exposure compensation is not one of them, as it will also darken the shadows. So get off your mighty throne, and go back and read. Sound out the words if you are having problems, before you blast people's responses. Also try prune juice, it will help your disposition.

I have a white balance lens cover that fits on my 18-105, and i use two layers of coffee filters of my 10-20 mm, as it requires a larger filter (google coffee filer for white balance). I calibrate every time I change locations. The calibration takes only a few seconds, so it is well worth the effort. But, I still make adjustments in Lightroom to better set the mood I am looking for, as often I want a warmer scene. Digital offers this flexibility, I do not understand why so any look down on it. Every great photographer, film and digital, post processes. This is what separates a photography from a picture taker.