For nearly all research topics the STOE powder data increment of 0.015° 2theta is fully sufficient. But what can be done when a higher number of data points is necessary, e.g. for ultra-precise profile calculations or for the investigation of splitting reflections in the course of a phase transition?
Here is an explanation of an easy way to reduce the internal step width to 0.005°:
Create a raw-file with three ranges, the first from n.000° to m.000° the second from n.005° to m.005° 2theta and the third from n.010° to m.010° 2theta and start the data collection.
After the measurement open the raw-file with the WinX^POW Raw Data Handling tool and chose the Export function in the File menu. Select the destination folder of the ASCII xy-file and tick Merge Ranges.

The resulting ASCII xy-file from n.000° to m.010° 2theta is written into the destination folder and can be used by any popular Rietveld software or re-imported as a STOE raw-file using the Import function of the WinX^POW Raw Data Handling.
The following example is Transmission data from Si powder (NIST 640c), measured from 5.000° to 116.010° 2theta in three ranges with a 0.005° offset on a STOE STADI MP with Cu Kalpha₁-radiation and a Dectris MYTHEN2 1K (1.11° steps, 10s/step).

The effect of the lower increment of the data set can be seen in the magnified areas of the pattern showing the Si111 reflection from 28.25° to 28.55° 2theta, red the standard data point increment of 0.015° and blue the lowered increment of 0.005° 2theta.