Any added glass will degrade the image, but usually only very slightly. It is hard to see the difference without zooming in to the pixels in the corners were the difference is the greatest. The thicker the glass, the more chromatic aberration and possible distortion will be seen. That is why most photographers buy the thinnest glass. But if it means that I will get a better photograph with a filter than without, I have no qualms with put a filter on my lens.

I have Olympus equipment. All the advice dealing with sites has been good. Some of the simple things to remember are 4/3rd lens are, for the most part, interchangeable between manufactures. If you do not see the lens you want on the Olympus site and see it on the Panasonic or Tamron sites, they will work on your camera. Soon Olympus will soon offer the ability to go from 7mm to 150mm at f2.8 (14 to 300 in 35mm terms).

Actually the digital sensors will see UV but not as easily as film does. It also sees less of the UV spectrum than film sees. Usually the use of a UV filter is more called for out here in Colorado with 5000 to 14,000 feet of altitude and less atmospheric absorption of UV.

amfoto1's advice is quite accurate. When I started I only used an A1 filter for protection. Now I only use a polarizer when necessary and specialty filters on rare occasions. I have used mostly Hoya filters, but have started including B+W. If you cannot afford either of the two, there are other manufacturers that make good filters. The trade off is usually fewer coatings and/or less optical flatness. The fewer coatings affects flare and light transmission while the flatness affects image quality and the ability to filter stack. As amfoto1 states, avoid single or non-coated filters. They are a waste of your good money.

Scott, I never said that the focal length of the lense actually changed. Every site that I know for APC or 4/3rds states that their lenses are "35mm equivalent focal length". In fact, the Olympus 60mm macro lense is stated as "Focal Length 60mm (35mm equivalent focal length 120mm)" in their technical specifications. My statement was "this amounts to" which I thought everyone would take as meaning "equivalent". And as far as DOF, for the same image size relative to the film/sensor, a full frame with the 90mm at f2.8 and focus at 10 feet has a DOF of 0.62 feet while the 4/3rds with the same 90mm at f2.8 (35mm equivalent focal length 180mm) must focus at 20 feet (remember, same image size relative to the sensor) has a DOF of 1.26 feet (http://www.dofmaster.com/dofjs.html). In other words, for the same image size relative to the sensor, focal length, and aperture, the smaller the sensor size will have a larger relative DOF. Everything around the subject will appear to be more in focus in the 4/3rds image than in the full frame image. This is why Olympus advertised its XZ-1 and XZ-2 with the f1.8 as being one of the first compact cameras to be able to blur the background. I can promise you, it is not that blurry at f1.8 - we have one.

I use the MMF-2 adapter and my older OM 90mm f2 macro. This amounts to a 180mm macro on my E-M5. Per Olympus literature, the f2/f22 aperture range is best cut down to f4/f8. But I have shot with f2 and f2.8 and find the images to be more than acceptable. I even have a photograph in the Olympus photography gallery that was shot with this combination at f2.8. The problem with using full frame film lenses is they were designed for a different format (full frame versus 4/3rds), the thickness and uneveness of film, and film's ability to be more accepting of light at an angle in the film corners. This does not mean film lenses cannot be used, just that they have limitations. Olympus has a chart that can be found as a link in the information on the MF-1 adapter as to OM lenses and usable f range(s). Also check the other 4/3rds sites since their lenses will fit all 4/3rds cameras. Hopefully this information will be of some use to you.

You are about to learn about what it is like to be the fox in a very crowded chicken coop! There are many places and views that require little or no walking at all. You will want to keep water available both in the car and if you are on one of the longer hikes in to some of the places. Bring bring lots of film or memory cards to fill up. You can go to the National Park Service web site and it will provide you some of the details and maps and descriptions of hikes and requirements. And the NPS site will also provide information on Canyonlands and other national locations in the area. Check the individual states for their sites to the state parks. Some of them are as spectacular as the national parks. Be sure to check out other photographers' photographs for techniques and ideas. Even from the same spot that they took a photograph, you will have different lighting and weather that they didn't have. And as always, be sure to enjoy the views both with and without the viewfinder. Have a great trip.

I use both Hoya and B+W. HOYA makes a lot of glass and individual lens elements for a lot of lens manufacturers. B+W will not make a second rate filter. It really comes down to the thickness and features of the lens first and cost second. Since any "extra" glass will alter the lens image ever so slightly, the best glass alters it the least. But if one cannot afford the absolute best, at least buy the best you can afford. When one needs a filter like a polarizer to cut reflected light or darken skies, almost any filter is better than no filter at all.

If you want to keep the price at or less than $400 and a lens length of between 24/28 to 140/1200, you have 12 choices from seven manufacturers. All of the cameras will capture your images very well in program mode while not weighting you down. I suggest program mode over auto since most, if not all the cameras, allow one to change aperture and/or shutter quickly with the turn of a dial.
My wife and I cruised the inland passage in 2001 with my Hassy and Canon. On our trip, I needed nothing less than 28mm or over 135mm long for all my shots. But the other contributers would agree that my trip was the exception and not the rule. A 200 or 300 length lens would increase your odds for pictures. Not everyone will be less than 100 feet away from a whale breeching. A 300 telephoto lens will do one no good at that distance. Whatever you decide to buy, be sure to enjoy the view without the camera as well as with the camera.

Lizzy, I think you can see that there is, and probably will always be, very diverse opinions or thoughts on this subject. I think SharpShooter says it best in that, film or digital, it the results that count in the long run.

My SP-550 went five years in my hands and is now taking pictures for my second oldest son for the last two years. We must have latched on to a good one since the only pictures lost are due to the photographers, not the camera.

If you have somewhat big pockets, you might want to look at the Olympus Stylus 1. It has a 28mm to 300mm (35mm equivalent) f2.8 lens, internal stabilization, and I think it is a 2.4 million pixel electric viewfinder. There are some other cameras similar to the Olympus but I think the Olympus P&Ss are very well thought out.

I bought a E-M5 and use some of my older OM system lenses with the E-M5 using the micro 4/3rds adapter. But there are limits on the older film lens' abilities to shoot digital. The film lenses were designed with the optics for full frame. Some optical defects that are acceptable at the full frame level become unacceptable or limiting at 4/3rds frame level. The sensor is cropping from the full frame coverage. I have used my 90mm f2 macro lens (180mm f2 in 35 equivalent) with very sharp photographs from f2.8 to f11 because it was an extremely sharp lens as a 35mm lens. But my 75/150 lens is only useful between 100mm and 150mm at f5.6. Olympus puts out a listing of the OM lenses and their compatible with 4/3rds. It would be useful to compare the list to what you have and see how useful each lens is to you before spending money for an adaptor.

I have had several Olympus cameras for my wife or myself. My first digital camera was the SP-550. I had to buy it for our trip to Italy since the car our friends had rented would not handle all four of us, luggage, and my 35 pounds of Hasselblad and Canon. It was quite advanced for its time and worked quite well. Everything that I have read about the SP-100 indicates that as long as you understand its limitations as a point and shoot, it should allow one to travel without being weighted down and without losing too many shots. Be sure to go to a camera store and see if it fits your needs.

I agree with one of the previous comment about the Olympus XZ-2. I bought the previous model of it, the XZ-1, for my wife and she is not even thinking about trading it in for the slightly newer "bells and whistles" of the XZ-2. Do get the electronic viewfinder and eyecup for it. It helps my wife in bright sunlight. Also there are other P&Ss similar to the Olympus. It is just that the XZ-1 has made my wife very happy about taking pictures without having to worry about lens settings. It can also double as a backup for you in a pinch.