# The difference between Factor and Image: How can I combine them?

I do not understand here what is the difference between Fact and Image:

## Inputs

Factor

Controls the amount of influence the node exerts on the output image.

Image

The background image. The image size and resolution sets the dimensions of the output image.

How can I combine those two: Image and Fact ?

• The easiest way is to try :) Instead of images you can set two colors in each socket and try what happens if you slide Factor or plug another black/white image into this socket. Seems to me self explanatory. The only attention is good to have on mind - top socket is for bottom image, second socket is for top image (and not like in other apps in oposite order) Commented Jun 19, 2020 at 20:05
• There's a breakdown of what Fac does here Commented Jun 19, 2020 at 21:01

You dont combine Image and Factor.
You combine two images and Factor says how to blend these two images.

Color 1 (red) is background (BG)
Color 2 (blue) is like in foreground (FG)

Factor 0 = 0% of FG (second socket)
Factor 0.5 = 50% of FG and BG (equaly mixed)
Factor 1 = 100% of FG

As factor can be used also 3D textures or black-white image.

Note:
The order of items is one of Blender speciality :) logic comes from coding (I guess) from typing commands. Like first you order:
- paint red and then
- paint blue on top of red

... so sockets looks like these two rows. Other apps ussually use visual order - items for BG are lower, items of foreground on top.

It is easier to understand if you use a black and white image to combine the elements.

This black and white image has two values: 0 means Black, and 1 means White.

The Factor input determines how two other elements in a node are combined:

Whatever is black will be the color of the Top image socket,

Whatever is white will be the image connected to the Bottom socket.

All other values between 0 and 1 (different tones of gray) in the Factor image, will result in a mix between the two values.