Oh I am going to start a huge fight here!
In the arena of Film vs. Digital, one of the hardest aspects to understand or explain for that matter is that the Mp Count really isn’t as important as image AREA! A 4x5 will hold much more information than a 35mm as is the obvious reason. But the real issue is the full area exposed in relation to the area viewed in real life. I came up with a term one time and got hammered on it.
I call it Aspect Ratio Distortion.
Though it is NOT an actual photographic term used, it is however valid when you consider the following:
Here is where it gets extremely difficult, so go slow!
The image area (35mm, MF, LF, etc) determines the full detail allowed in a given viewed area (image as seen in the view finder). The larger the format, the less distortion occurs.
What distortion you say?
Now bear with me here.
When the area of an image is larger overall, (one format larger than the other) there is a certain amount of distortion on the smaller end vs. the larger end. This distortion is a result of two things: The size of the image area, and the glass needed to achieve the specific distortion needed to get the desired image to that particular size. (Think focal point here).
The problem is that with smaller formats, there is less actual data; yes: BUT if you were to take that 35mm negative and proportionally stretch it back up to actual size, you will see that the objects in the image DO NOT FALL exactly back into place. In fact, the smaller the image, the more distortion. This distortion is why 35mm images REGARDLESS OF THE Mp count will NEVER be as good as a MF or LF image.
The 4:5ths Aspect ratio actually allows for less distortion, and is why it’s better for portrait and landscape.
So, to cut to the chase, if you want superior images, go LARGER format, rather than Mp. Count.
A simple test is to set up a series of shots with small, med. and large format with a 1 foot ruler.
Regardless of the actual length of the ruler, (but I use a 1 foot ruler for demo), take a picture of that ruler at exactly 3 feet away from the Image Plane area. (From the actual surface of the sensor or film.)
And yes, you actually can measure that if your camera has a surface position indicator on it. It looks like a letter “o” with a line through it. It looks like this but sideways: Ф
That indicates the actual point where the image area is at inside the camera. Then measure the distance from that point to the ruler. Set up your camera using a 50mm lens on a 35mm camera, or equivalent for larger formats. Then take the picture.
Blow the image up where the edge of the ruler and the Number “1” in the image matches that against the ruler. When you blow each image up back to original size, you will see a lot of distortion take place. Start at the edge of the ruler in the image and place the actual ruler against the image. Compare the tick marks in sequence against the image and you will see in the larger formats, the closer to actual size you get or, less distortion. The smaller, the tick marks wont line up exactly.
This is not to say that the image is going to be way off, but even at 50mm or equivalent, the image is still distorted a bit.
This distortion cannot be gotten rid of, because you cannot accurately project an image in a 3 dimensional world onto a 2 dimensional plain accurately.
Try flattening out an orange peel.
Because Aspect Ratio is the term used for the size of the image area compared to itself (one side’s length vs. the other side) the ratio such as 1.61 or 2.14 for Hollywood type film (see super 35), that makes another difference in the overall quality of the final image. The lens needed must be able to “squeeze” the light onto the given image area.
The larger the format, and the wider the ratio, the less “squeezing” takes place.
Because the image area of a larger format comes closer to actual real life size, the more image area is exposed and thus more detail, along with less distortion.
Anyone who has ever played with large format from 4x5 to 8x10 can tell you that the larger the area, the less actual distortion of perspective occurs.
Sorry if I confused you here.
