AVCaptureDevice的exposureDuration和iso属性不被AVCapturePhotoOutput所遵循，因为AVCapturePhotoOutput是用于拍摄静态照片的，而不是处理实时视频流的。但我们可以使用AVCaptureVideoDataOutput来获取实时视频流，并使用AVCaptureDevice的exposureDuration和iso属性来设置摄像头的曝光时间和ISO值。

以下是一个示例代码，演示了如何使用AVCaptureVideoDataOutput来获取实时视频流，并设置摄像头的曝光时间和ISO值：

import AVFoundation

class ViewController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate {
    private var captureSession: AVCaptureSession!
    private var videoPreviewLayer: AVCaptureVideoPreviewLayer!
    private var captureDevice: AVCaptureDevice!

    override func viewDidLoad() {
        super.viewDidLoad()

        // 创建AVCaptureSession
        captureSession = AVCaptureSession()

        // 配置摄像头
        captureDevice = AVCaptureDevice.default(for: .video)
        configureCamera()

        // 配置视频输出
        let videoOutput = AVCaptureVideoDataOutput()
        videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue.global(qos: .userInteractive))
        captureSession.addOutput(videoOutput)

        // 配置视频预览层
        videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        videoPreviewLayer.videoGravity = .resizeAspectFill
        videoPreviewLayer.frame = view.bounds
        view.layer.addSublayer(videoPreviewLayer)

        // 启动捕捉会话
        captureSession.startRunning()
    }

    private func configureCamera() {
        do {
            // 锁定摄像头，以便进行设置
            try captureDevice.lockForConfiguration()
            
            // 设置曝光时间
            let exposureDuration = CMTimeMake(value: 1, timescale: 1000) // 设置曝光时间为1/1000秒
            if captureDevice.isExposureModeSupported(.custom) {
                captureDevice.setExposureModeCustom(duration: exposureDuration, iso: AVCaptureDevice.currentISO, completionHandler: nil)
            }

            // 设置ISO值
            if captureDevice.isISOControlModeSupported(.manual) {
                captureDevice.setExposureModeCustom(duration: AVCaptureDevice.currentExposureDuration, iso: 100, completionHandler: nil)
            }
            
            // 解锁摄像头
            captureDevice.unlockForConfiguration()
        } catch {
            print("配置摄像头失败: \(error.localizedDescription)")
        }
    }

    // AVCaptureVideoDataOutputSampleBufferDelegate方法，处理实时视频流
    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
        // 实时视频流处理逻辑
    }
}

此示例代码设置了摄像头的曝光时间为1/1000秒，并将ISO值设置为100。你可以根据需要调整这些值。