I have designed a GUI using QtDesigner which is a MainWindow with central widget that only has a graphics view.

In the following Python code, I used openCV to get a camera connection and tried to show camera feed inside the graphics view:

from Ui.uiLoader import load_ui
from PySide6.QtWidgets import QWidget, QGraphicsScene, QGraphicsPixmapItem
from PySide6.QtCore import QTimer, Qt
from PySide6.QtGui import QImage, QPixmap, QPen
import cv2

class MainWindowTest:
    def __init__(self):
        # Load main window
        self.ui = load_ui("graphicsviewTest.ui")
        
        self.graphicsview = self.ui.graphicsView
        self.scene = QGraphicsScene()
        self.pixmap_item = QGraphicsPixmapItem()
        self.scene.addItem(self.pixmap_item)
        self.graphicsview.setScene(self.scene)
        
        # Persistent camera object
        self.cap = cv2.VideoCapture(0)

        # Timer drives the video stream
        self.timer = QTimer()
        self.timer.timeout.connect(self.update_frame)
        self.timer.start(30)  # ~33 FPS

    def update_frame(self):
        ret, frame = self.cap.read()
        if not ret:
            return
        qt_image = self.convert_cv_qt(frame)
        pixmap = QPixmap.fromImage(qt_image)

        self.pixmap_item.setPixmap(pixmap)
        self.scene.setSceneRect(pixmap.rect())

        self.graphicsview.fitInView(self.scene.sceneRect(),Qt.KeepAspectRatio)


    def convert_cv_qt(self, frame):
        rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
        h, w, ch = rgb.shape
        bytes_per_line = ch * w
        image = QImage(
            rgb.data,
            w,
            h,
            bytes_per_line,
            QImage.Format_RGB888
        )
        return image.copy()

This code is running BUT what is shown inside the graphicsview is a cropped camera stream (Not the whole scene that the camera is already seeing).
How can I got this problem (cropped camera scene) solved?