using System;

using System.Threading;

public class Program

{

    public static void Main()

    {

        DateTime startDateTime = DateTime.Now;

        DateTime endDateTime = startDateTime.AddSeconds(5);

        Thread workerThread = new Thread(DoRecord) { IsBackground = true };

        workerThread.Start();

        while (DateTime.Now < endDateTime)

        {

            // Spin

        }

        _manualResetEvent.Set();

        workerThread.Join();

        Console.WriteLine("Finished at " + DateTime.Now.ToString("HH:mm:ss.fff tt"));

    }

    private static void DoRecord()

    {

        long ticksBetweenFrames = TimeSpan.FromSeconds(0.04).Ticks;

        int screenShotsTaken = 0;

        DateTime startDateTime = DateTime.Now;

        while (!_manualResetEvent.WaitOne(0))

        {

            Console.WriteLine($"Took screenshot at " + DateTime.Now.ToString("HH:mm:ss.fff tt"));

            ++screenShotsTaken;

            while (DateTime.Now.Ticks < (startDateTime.AddTicks(ticksBetweenFrames * screenShotsTaken).Ticks))

            {

                // Spin

            }

        }

    }

    private static ManualResetEvent _manualResetEvent = new ManualResetEvent(false);

}