The merits and flaws of the two cameras have already been discussed in detail,

http://forum.southerndownhill.com/index.php/topic,81258.0.html

http://forum.southerndownhill.com/index.php/topic,78267.0.html

As has the meaning of photographic technical terms questions. Aperture, Shutter speed, ISO, metering, exposure etc.

With regard to how many photos a card will hold, it depends entirely on the size and format you tell your camera to shoot in. My 1gig card will hold say 100 RAW files, but over 1000 small medium quality jpeg files. There are other factors that effect storage aswell.

cheers ady, have read those threads and can see that perhaps it really is down to personal oreferance, it seems that spec wise the canon is a step better than the nikon but the nikon appears perhaps nicer to use and is larger (doesnt really effect me, im only little and i thik both me and my dad would prefer as small a camera body as possible)
will have to get to a shop and try each one out in the flesh it seems.

have looked at other threads and have a kind of understanding of shutterspeeds and aperture etc but if someone could give a set in stone definition of shutter speeds, aperture and the other slr basics; and when and why to change them (lighting, action shots etc) that would be fantastic

ive pieced together as much as i can from other threads but a set in stone definition for these things would help me as im about to lay out a fair bit of money on something i have nooo idea about

No worries mate

Shutter speed - The time in which the sensor is exposed to ambient light. Shutter speeds are measured in fractions of a second, or in seconds if it's long. IE 1/2000th of a second is a fast shutter speed, whereas 1/10th of a second is a slow shutter speed. 5/1 is 5 seconds, and that's obviously rediculously long.

Aperture - The hole in which light passes through the lens onto the sensor/film. Measured in f/stops. IE f/1.8 is a large aperture (larger hole = smaller number) whereas f/22 is a small aperture (Tiny hole, large number). Aperture does 2 main things.

1) Controls all light falling on the sensor
2) Controls depth of feild

The larger the aperture, the more light that will be let in. However, the larger the aperture, the shallower the plain of focus. (Amount of picture that is in focus). The smaller the aperture, the more that will be in focus.

ISO - Sensitivity to light. A higher ISO mean's a higher sensitivity, and thus a faster shutter speed is needed to gain a correct exposure. General rule of thumb, higher ISO for darker areas, lower ISO for lighter areas.

With a higher ISO comes grain/noise. So you want to try and shoot at the lowest ISO possible whilst still getting a faster enough shutter speed to counter camera shake. Or if you're shooting sports, subject sharpness. (The faster your subject is moving, the faster shutter speed you'll need to make them appear frozen and sharp) Another way of doing this, and most popular amoungst biking photographers, is flash. As flash fires at a very quick speed, it will freeze a certain amount of the subject. This is how you do those blurry/sharp panning shots you see a lot of.

ISO has no bearing on depth of feild.

Exposure - The balance of light in the frame. Measured by what's called a Histogram. A correct exposure is retaining the detail in the shadows, without blowing out the highlights. Loose the detail in the shadows and there will simply be a large black area that cannot be recovered. Blow out the highlights and there will be a white area with no detail, which can also not be recovered.

Obviously the aim of the game is to balance your shutter speed, aperture and ISO to gain a correct exposure. You can do this by having a low ISO, slow shutter and a large aperture.. Or maybe a fast shutter, low ISO and a smaller aperture.. that's for you to decide. Also remember, that rules are there to be broken. Not every photo has to be sharp, perfectly exposed and contain no noise

that's exactly the kind of post i've been looking for for ages!

[quote author=Roo link=topic=83910.msg784690#msg784690 date=1149021089

After using both 350D/300D and D70/D50 my general opinion is the canons can produce slightly better quality pictures, but the Nikon can take more knocks and abuse.
[/quote]

yeh the Nikon's have a really nice to finish to it, where as the cannon has a plastic to it, and lets face it, if you are taking the camera riding with you i would rather have the Nikon, especially as you probably wont see the difference between quality.

I have a D50, and bought magazines to choose between the same as you have, one of my mates had a 300D and it was always playing up, also the sensor size on the D50 is bigger than the 350D and with less pixels should give a better picture.

the outcome in the magazines was always 350D best but the D50 always getting the runner up. I just got my D50 at such a good price and i already had SD cards so had to go for it!

And the battery life is amazing better than any other camera/ device i have ever used. 2Gb of pics off 1 battery!

D70s:

- Faster than the Cannon.
- Better than the D50.

Got mine for