Crop Factor / Sensor Size

[compleks]

Alright, my brain is hurting again.

I just came across a discussion on 'crop factor' which lead me to read some articles on sensor size and such...

I'm having a hard time making sense of it all. I understand that D-SLR cameras will have different size sensors, but what are the implications in terms of actual photography?
How does sensor size impact the photographer?

From what I read, I got the impression that having a smaller sensor would be advantageous when shooting with a telephoto lens. Seeing as though the crop factor would increase the practical focal length of your lens.
Am I on the right track? Is there a loss of image quality or any down side to this?

It appears as though full frame photography (or full frame cameras) are really geared towards studio/portrait photographers. Is that correct?
I assume that is because they are likely to be shooting at the lower end of the focal range and probably from a closer range?
Am I way off here?

Please enlighten me on the topic!
Is sensor size a serious consideration when shopping for a camera?
How does sensor size impact the various stages of photography?


Cheers

[OsmosisStudios]

Essentially, youve got it right.

Smaller sensors are better for telephoto use because they effectively give a longer lens and have a higher pixel density for those shots.

Full-frame sensors are better for wide-angle because they dont have the crop factor and thus you dont end up with a 14mm lens being a 21mm lens, or your 24mm lens being a 36mm lens.

The other advantage (and the biggest one, in my book) to full-frame is the effective increase in ISO range. This is slightly less true of Canon cameras, but it's very true of the NIkon FX cameras (D700/D3). Because they have the same amount of receptors in a surface twice the size, each sensor gets effectively twice the light. This makes shooting at 6400 ISO possible (without it being totally noticeable). Try doing that on any crop body!

[dcclark]

Osmosis got it. To add one thing, "full frame" has the advantage AND disadvantage of working well with "regular" lenses -- that is, good old fashioned film lenses. Small sensors (1.5 or 1.6 crop factors) work fine with "regular" lenses too, but now that there are "DX" lenses (Nikon's term) which only work correctly on cropped sensors, we have to worry about what type of lens we have, and whether it will work right now, or on your future cameras. If you buy "FX" lenses (again, Nikon's term for regular old lenses), you'll never have to worry about them working on future cameras. However, their focal lengths will be a bit weird on your DX body. So, not having to think about that is a small advantage to having full-frame all of the time.

[compleks]

Ah, that headache is returning...

Thanks for the help, it's slowly starting to make more sense now. Appreciate it!