[Python] Detect circles in openCV

I have a problem with choosing right parameters for HoughCircles function. I try to detect circles from video. This circles are made by me, and has almost the same dimension. Problem is that camera is in move.

When I change maxRadius it still detect bigger circles somehow (see the right picture). I also tried to change param1, param2 but still no success.

gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
blurred = cv2.medianBlur(gray, 25)#cv2.bilateralFilter(gray,10,50,50)


minDist = 100
param1 = 500
param2 = 200#smaller value-> more false circles
minRadius = 5
maxRadius = 10
circles = cv2.HoughCircles(blurred, cv2.HOUGH_GRADIENT, 1, minDist, param1, param2, minRadius, maxRadius)

if circles is not None:
circles = np.uint16(np.around(circles))
for i in circles[0,:]:
cv2.circle(blurred,(i[0], i[1]), i[2], (0, 255, 0), 2)


Maybe Im using wrong function?

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