diff --git a/modules/calib3d/src/calibration.cpp b/modules/calib3d/src/calibration.cpp
index fee02f5b9d..f5f9771287 100644
--- a/modules/calib3d/src/calibration.cpp
+++ b/modules/calib3d/src/calibration.cpp
@@ -52,7 +52,6 @@
     that is (in a large extent) based on the paper:
     Z. Zhang. "A flexible new technique for camera calibration".
     IEEE Transactions on Pattern Analysis and Machine Intelligence, 22(11):1330-1334, 2000.
-
     The 1st initial port was done by Valery Mosyagin.
 */
 
@@ -896,9 +895,9 @@ CV_IMPL void cvProjectPoints2( const CvMat* objectPoints,
                     double dicdist2_dt = -icdist2*icdist2*(k[5]*dr2dt + 2*k[6]*r2*dr2dt + 3*k[7]*r4*dr2dt);
                     double da1dt = 2*(x*dydt[j] + y*dxdt[j]);
                     double dmxdt = (dxdt[j]*cdist*icdist2 + x*dcdist_dt*icdist2 + x*cdist*dicdist2_dt +
-                                       k[2]*da1dt + k[3]*(dr2dt + 2*x*dxdt[j]) + k[8]*dr2dt + 2*r2*k[9]*dr2dt);
+                                       k[2]*da1dt + k[3]*(dr2dt + 4*x*dxdt[j]) + k[8]*dr2dt + 2*r2*k[9]*dr2dt);
                     double dmydt = (dydt[j]*cdist*icdist2 + y*dcdist_dt*icdist2 + y*cdist*dicdist2_dt +
-                                       k[2]*(dr2dt + 2*y*dydt[j]) + k[3]*da1dt + k[10]*dr2dt + 2*r2*k[11]*dr2dt);
+                                       k[2]*(dr2dt + 4*y*dydt[j]) + k[3]*da1dt + k[10]*dr2dt + 2*r2*k[11]*dr2dt);
                     dXdYd = dMatTilt*Vec2d(dmxdt, dmydt);
                     dpdt_p[j] = fx*dXdYd(0);
                     dpdt_p[dpdt_step+j] = fy*dXdYd(1);
@@ -935,9 +934,9 @@ CV_IMPL void cvProjectPoints2( const CvMat* objectPoints,
                     double dicdist2_dr = -icdist2*icdist2*(k[5] + 2*k[6]*r2 + 3*k[7]*r4)*dr2dr;
                     double da1dr = 2*(x*dydr + y*dxdr);
                     double dmxdr = (dxdr*cdist*icdist2 + x*dcdist_dr*icdist2 + x*cdist*dicdist2_dr +
-                                       k[2]*da1dr + k[3]*(dr2dr + 2*x*dxdr) + (k[8] + 2*r2*k[9])*dr2dr);
+                                       k[2]*da1dr + k[3]*(dr2dr + 4*x*dxdr) + (k[8] + 2*r2*k[9])*dr2dr);
                     double dmydr = (dydr*cdist*icdist2 + y*dcdist_dr*icdist2 + y*cdist*dicdist2_dr +
-                                       k[2]*(dr2dr + 2*y*dydr) + k[3]*da1dr + (k[10] + 2*r2*k[11])*dr2dr);
+                                       k[2]*(dr2dr + 4*y*dydr) + k[3]*da1dr + (k[10] + 2*r2*k[11])*dr2dr);
                     dXdYd = dMatTilt*Vec2d(dmxdr, dmydr);
                     dpdr_p[j] = fx*dXdYd(0);
                     dpdr_p[dpdr_step+j] = fy*dXdYd(1);
@@ -1945,14 +1944,12 @@ double cvStereoCalibrate( const CvMat* _objectPoints, const CvMat* _imagePoints1
 
     /*
        Compute initial estimate of pose
-
        For each image, compute:
           R(om) is the rotation matrix of om
           om(R) is the rotation vector of R
           R_ref = R(om_right) * R(om_left)'
           T_ref_list = [T_ref_list; T_right - R_ref * T_left]
           om_ref_list = {om_ref_list; om(R_ref)]
-
        om = median(om_ref_list)
        T = median(T_ref_list)
     */