video duration and multiple sublots in a single video

I have the following modified demo code for creating video:

Z = peaks;
surf(Z); 

set(gca,'nextplot','replacechildren'); 
v = VideoWriter('peaks.avi');
open(v);
for k = 1:50
     
    subplot(1,2,1);
   surf(sin(2*pi*k/20)*Z,Z)
   axis tight manual
   subplot(1,2,2);
   surf(sin(2*pi*k/20)*Z,Z)
  axis tight manual
   frame = getframe(gcf);
   writeVideo(v,frame);
end

close(v);

I have the following questions:

1. Why doesn't work "axis tight manual" well?
2. How can I change the duration of the video?

[Stijn Haenen]

You can change the frame rate with

v.FrameRate=60 %for 60Hz

I think you should place axis tight manual outside the for loop.

[Gaetano Pavone]

Thanks, it works!