Full Frame Sensors

[PnwGuy]

I was reading about the Canon 5d and it has a full frame sensor. Is that really an advantage? Do I have to worry about lenses I buy for my 400d not working with a full frame model if I upgrade in the future?

I found some complex explanations about full frame sensors but I just need the basics. Anybody?

[Saralonde]

Going from a Rebel XTi to a 5d will give you a "wider" field of view with all the lenses you put on it as compared to using them on your XTi. It will give you a smaller portion of the same image. For example, an 18mm wide angle become 28.8mm (multiply the 18 by the 1.6 crop factor).

Larger sensors such as on the 5d can deliver better quality images because they collect more light which can make a difference with a higher ISO. Here are some sites that may explain this all better.
http://www.cambridgeincolour.com/tutorials/digital-camera-sensor-size.htm
http://www.luminous-landscape.com/tutorials/understanding-series/dslr-mag.shtml
http://www.photo.net/equipment/digital/cameras/basics/
http://www.photo.net/equipment/digital/sensorsize/

EF-S lenses work only on crop cameras (Rebels, 20D, 30D), EF lenses on crop and full frame.

[PnwGuy]

Saralonde, Thank you!!! That's exactly what I was looking for. I do appreciate it!!

[sdjl]

When I got my 5D, I found one lense of mine would have vignetting. This is where the lenses aperture is too large for the sensor. It basically created a nice black halo around the image, which isn't too great to look at!

David

[sdjl]

I forgot to mention, with the full frame sensor, your lenses will be the magnification that they say. i.e. 70 - 200mm will be 70 - 200mm, whereas on the 400D for instance that lense would have an effective focal length of 112 - 320mm.

So if you're used to a APS-C sized sensor, you may find some of your lenses don't go as far on a full frame sensor. :)