When using a 48-inch SID, how much OID is needed to achieve two times magnification?

To achieve two times magnification in radiography when using a source-to-image distance (SID) of 48 inches, it's important to apply the relationship between SID, object-to-image distance (OID), and magnification. The formula for magnification (M) is given by M = SID / (SID - OID). In this case, for two times magnification (M = 2), we can formulate the equation as:

2 = 48 / (48 - OID).

Rearranging this equation helps us to solve for OID. By multiplying both sides by (48 - OID), we can simplify it to:

2(48 - OID) = 48.

When you distribute the 2, it comes out as:

96 - 2OID = 48.

Next, isolating OID involves subtracting 48 from both sides:

96 - 48 = 2OID,

which simplifies to:

48 = 2OID.

Dividing both sides by 2 gives:

OID = 24 inches.

Thus, to achieve two times magnification when using a 48-inch SID, an object-to-image distance of 24 inches is required. This reasoning aligns with the principles of imaging physics and highlights how adjustments