how is interpolation between numbers being determined?

Answer 1

In the mathematical subfield of numerical analysis, interpolation is a method of constructing new data points from a discrete set of known data points.

One of the simplest methods is linear interpolation (sometimes known as lerp). Consider the example of determining f(2.5). Since 2.5 is midway between 2 and 3, it is reasonable to take f(2.5) midway between f(2) = 0.9093 and f(3) = 0.1411, which yields 0.5252.

Generally, linear interpolation takes two data points, say (xa,ya) and (xb,yb), and the interpolant is given by(at the point (x,y)):

y = ya + ((x - xa)(yb - ya))/(xb - xa)

Answer 2

What ISO denotes is how sensitive the image sensor is to the amount of light present. The higher the ISO, the more sensitive the image sensor and therefore the possibility to take pictures in low-light situations. Most cameras will allow you to change the ISO to fit your needs. ISO is not defined as shutter speed. It influences what shutter speeds and apertures will be used based on the lighting and ISO setting. SLR means single lens reflex and refers to cameras that use a series of mirrors that allow you to see exactly what the lens sees. The light passes through the lens and is relflected into the viewfinder. The best way to expand your knowledge is to do a search on the basics of digital photography or just basics of photography. Some cameras with lower pixel ratings are more expensive due to other elements built into the camera, i.e. ruggedness(high end Nikons and Canons), lens, features, variety of accessories available, etc. You can have a 10 megapixel camera that is low on options and lens quality and have a 6.1 megapixel camera with superior quality and the 6.1 will take much better pictures. Texture is something you control with your lighting of the subject or at what angle you shoot your subject under certain light sources. It is most noticeable with black and white photography. Special effects can be done with filters on camera or later in post processing using a photoshop type program.