function [Zval, Variance] = focusstack_3(s,vid,z)
    t1 = toc;currzpos=z;
    %       fINECRUDE AF. 
    Z_travel_for_crude = 1000;  crude_step_count = 50;
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    crude_pulse_count = Z_travel_for_crude / crude_step_count;
    crude_max_var=0;   
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    %        go to starting Z loc (we've hit limit switch via arduino already so its z=0)
    crude_start_loc = z - (Z_travel_for_crude/2);
    gotoZ(s,crude_start_loc,currzpos); currzpos=crude_start_loc;
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    % now keep going up and taking var
    crude_curr_loc = crude_start_loc;

    for i=1: crude_pulse_count     
        % variance
        crude_img = double(getsnapshot(vid));     crude_curr_var=var(crude_img(:));

        if (crude_curr_var > crude_max_var) 
            crude_max_var = crude_curr_var;
            crude_loc_max_var = crude_curr_loc;
        end 
        % update loc 
        crude_curr_loc = crude_curr_loc + crude_step_count      ;
        gotoZ(s,crude_curr_loc,currzpos); currzpos=crude_curr_loc;
    end
    gotoZ(s,crude_loc_max_var,currzpos);currzpos=crude_loc_max_var;
    
    % The fine AF begins here
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    Ztotaltravel = 100;     final_go_backpulses = 0 ;
    currZ = crude_loc_max_var;

    % first go above
    start_above_loc = currZ - (Ztotaltravel/2);
    gotoZ(s,start_above_loc,currzpos);currzpos=start_above_loc;
    % now build the var array
    localAF_loc_array = zeros(1,Ztotaltravel);   localAF_var_array = zeros(1,Ztotaltravel);
    localAF_curr_loc = start_above_loc;
    for q=1:(Ztotaltravel/5)
        % location
        localAF_loc_array(q) = localAF_curr_loc;
        % variance
        localAF_img = double(getsnapshot(vid)); localAF_var_array(q)=var(localAF_img(:));

        % move and update loc    
        localAF_curr_loc = localAF_curr_loc + 5;    gotoZ(s,localAF_curr_loc,currzpos); 
        currzpos=localAF_curr_loc;
    end  

    % Finally go to the max var location
    index_of_max_var =  localAF_var_array == max(localAF_var_array);
    loc_of_max_var = localAF_loc_array(index_of_max_var) - final_go_backpulses  ;    
    gotoZ(s,loc_of_max_var,currzpos);currzpos=loc_of_max_var;
    Zval = loc_of_max_var;
    Variance = max(localAF_var_array);
    t2 = toc;
    disp(t2-t1)
end