# How to use waitkey with VideoCapture()
**URL:** https://forum.opencv.org/t/how-to-use-waitkey-with-videocapture/10718
**Category:** Python
**Created:** [October 28, 2022, 4:14am UTC](https://forum.opencv.org/t/how-to-use-waitkey-with-videocapture/10718 "2022-10-28T04:14:13Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Maia1003](https://forum.opencv.org/u/Maia1003)
#### Post date: [October 28, 2022, 4:14am UTC](https://forum.opencv.org/t/how-to-use-waitkey-with-videocapture/10718/1 "2022-10-28T04:14:13Z")
Hi,
I am struggling about this example. I’d like to update the frame window wrt key press, e.g. display grayscale image when I press ‘c’ on the keyboard, but this does not work:
My codes:
```auto
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
if not cap.isOpened():
print("Cannot open camera")
exit()
while True:
# Capture frame-by-frame
ret, frame = cap.read()
# if frame is read correctly ret is True
if not ret:
print("Can't receive frame (stream end?). Exiting ...")
break
# Our operations on the frame come here
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
# Display the resulting frame
cv2.imshow('frame', frame)
key = 0xFF & cv2.waitKey(1)
if key == ord('q'):
break
elif key == ord('c'):
print('pressed c')
cv2.imshow('frame', gray)
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
```
---
### Author:  [@sturkmen](https://forum.opencv.org/u/sturkmen)
#### Post date: [October 28, 2022, 12:29pm UTC](https://forum.opencv.org/t/how-to-use-waitkey-with-videocapture/10718/2 "2022-10-28T12:29:19Z")
Your question related to general programming skill
Try the following code.
```auto
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
if not cap.isOpened():
print("Cannot open camera")
exit()
convert_to_gray = False
while True:
# Capture frame-by-frame
ret, frame = cap.read()
# if frame is read correctly ret is True
if not ret:
print("Can't receive frame (stream end?). Exiting ...")
break
# Our operations on the frame come here
if convert_to_gray:
frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
# Display the resulting frame
cv2.imshow('frame', frame)
key = 0xFF & cv2.waitKey(1)
if key == ord('q'):
break
elif key == ord('c'):
convert_to_gray = not convert_to_gray # Toggle convert_to_gray value
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
```
---
### Author:  [@Maia1003](https://forum.opencv.org/u/Maia1003)
#### Post date: [October 28, 2022, 1:02pm UTC](https://forum.opencv.org/t/how-to-use-waitkey-with-videocapture/10718/3 "2022-10-28T13:02:53Z")
Thank you.
I found that I had issues while using several waitkeys for the same window.
Best