Same lens, same settings, different cameras?

Ok, i did an experiment. I have a nikon D90 (cropped) and D700 (full frame). I set the cameras on exactly the sam settings, and took a pic of the same thing. I've used a 105mm macro, and a 50mm 1.8. Now, the D90 seems to be alot more zoomed in with both lenses. Now I assume its because of the cropped and full frame format. But why does this happen? How does it work? Will the crooped frame make it worse quality?

The D90 has a 1.5x crop factor compared to full frame. Full frame cameras have the ability to resolve more detail than cropped sensored cameras, and the results are much better when high ISO's are used.

You are exactly right. The crop factor for thf D90 is 1.5X, so the 50mm will act like a 75mm lens. The 105 will be 150-something.

Google "crop factor" and you will find hundreds of articles with illustrations that explain it better than we can here.

That'll be because of the crop factor.

How will a cropped frame be worse? All it means is that the circle of light created by the lens is cropped more. The difference between these types of cameras is in the sensor size. Full frame sensors, because they are bigger, are less susceptible to noise at higher ISOs. That is the main difference and the only real and noticeable benefit of a full frame camera.

The quality of images taken on full frame versus APC-C sensor cameras are virtually indistinguishable with modern cameras. Even an expert in digital imaging would be hard pressed to tell the difference without knowing which was which.

The sensor in both cameras is the same distance away from the lens. When light is projected into the camera by the lens the image is the same size. However on the D90, more of the image misses the area of the sensor (and so is not recorded).So the sensor on the D90 only records the central part of the image, not the wider part of the image that has "over-shot" the sensor. The effect of only recording the central area and not the wide parts is that the image recorded appears zoomed.

Contrary to what people keep posting in here this does not affect the Depth Of Field (DOF), but it does change the Field Of View (FOV).

It's not the crop itself that tends to mean that full frame sensored cameras are better quality, but that the pixel size (in X-Y dimensions of individual pixels) in full frame cameras tend to be larger. All but a very few cameras are built to a budget, but the buyers of cheaper cameras are more worried about overall costs then those who are looking for ultimate quality. So the larger sensors in full frame cameras can also be manufactured to higher specifications all round while remaining at an acceptable price point for their purchasers.

You're looking outside your room through a window.

A full frame camera has a larger window.

A cropped sensor has a smaller window.

What you see, when enlarged to the same size, from a smaller window will appear "more zoomed in".