Tool units such as Photoshop Rectangular marquee change method: pixel change to cm

This article explains why Photoshop has a number of 1 pixels to 300000 pixels between the value of the error prompts, mainly the rectangular marquee and other tools, such as the unit from pixel to centimeter units.

Open PS every day, step-by-step use of a variety of command tools to make manuscripts, sometimes seemingly very skilled operation PS, today is really a small small problem to be stuck.

Originally wanted to use the rectangular marquee tool to draw a rectangular selection of 30 centimeters by 30 centimeters, the result is that Photoshop has the hint that a value between 1 and 300000 pixels is required, and the nearest value is inserted.

Why not? By default, the unit of Photoshop is Pixel (PX), and if we want to be in centimeters, we can do this:

1. Select the rectangular marquee tool-fixed size, then in the rear width and height of the input box, click the right mouse button, select "cm".

2. Then enter 30. By doing this, you can change the rectangular marquee unit from pixel to centimeter. Similarly, selecting a different tool in the toolbox also changes the unit.