iOS开发 iPhone14 Pro/Pro Max后置摄像头近距离无法对焦解决

一、解决方案

iPhone14 Pro/Pro Max的主摄焦距更长。在近距离拍摄时无法对焦。只需要判断机型然后更换焦距更短的摄像头即可。该摄像头与主摄相比，同样的距离会拍摄到更多的内容，此时可以通过调整摄像头的缩放来达到与主摄一样的效果（下面代码没有缩放）。

#import <sys/utsname.h>
#import <sys/stat.h>

- (AVCaptureDevice *)captureDeviceWithPosition:(AVCaptureDevicePosition)position {
    if ([UIDevice currentDevice].systemVersion.floatValue >= 10.0) {
        AVCaptureDeviceType deviceType = AVCaptureDeviceTypeBuiltInWideAngleCamera;
        if (position == AVCaptureDevicePositionBack) {
            struct utsname systemInfo;
            uname(&systemInfo);
            NSString *deviceModel = [NSString stringWithCString:systemInfo.machine encoding:NSUTF8StringEncoding];
            if ([deviceModel isEqualToString:@"iPhone15,2"] ||
                [deviceModel isEqualToString:@"iPhone15,3"]) {
                if ([UIDevice currentDevice].systemVersion.floatValue >= 13.0) {
                    deviceType = AVCaptureDeviceTypeBuiltInUltraWideCamera;
                }
            }
        }
        AVCaptureDeviceDiscoverySession *devicesIOS10 = [AVCaptureDeviceDiscoverySession  discoverySessionWithDeviceTypes:@[deviceType] mediaType:AVMediaTypeVideo position:position];
        NSArray *devicesIOS  = devicesIOS10.devices;
        for (AVCaptureDevice *device in devicesIOS) {
            if ([device position] == position) {
                return device;
            }
        }
        return nil;
    } else {
        NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
        //遍历这些设备返回跟position相关的设备
        for (AVCaptureDevice *device in devices) {
            if ([device position] == position) {
                return device;
            }
        }
        return nil;
    }
}

二、AVCaptureDeviceType介绍

1、AVCaptureDeviceType

2、对焦

查看当前设备可用的摄像头

AVCaptureDeviceDiscoverySession *discoverySession = [AVCaptureDeviceDiscoverySession
                                                         discoverySessionWithDeviceTypes:@[AVCaptureDeviceTypeBuiltInWideAngleCamera,AVCaptureDeviceTypeBuiltInTelephotoCamera,AVCaptureDeviceTypeBuiltInUltraWideCamera,AVCaptureDeviceTypeBuiltInDualCamera,AVCaptureDeviceTypeBuiltInDualWideCamera,AVCaptureDeviceTypeBuiltInTripleCamera,AVCaptureDeviceTypeBuiltInTrueDepthCamera]
                                                         mediaType:AVMediaTypeVideo;
                                                         position:AVCaptureDevicePositionUnspecified];
    NSArray<AVCaptureDevice *> *videoDevices = discoverySession.devices;
    for (AVCaptureDevice *device in videoDevices) {
        NSLog(@"Device name: %@", device.localizedName);
        NSLog(@"Device ID: %@", device.uniqueID);
        NSLog(@"Position: %@", device.position == AVCaptureDevicePositionBack ? @"Back" : @"Front");
        NSLog(@"-----------------------------------");
    }

iPhone13可用设备：

(
    "<AVCaptureFigVideoDevice: 0x10508d000 [Back Camera][com.apple.avfoundation.avcapturedevice.built-in_video:0]>",
    "<AVCaptureFigVideoDevice: 0x105015200 [Back Ultra Wide Camera][com.apple.avfoundation.avcapturedevice.built-in_video:5]>",
    "<AVCaptureFigVideoDevice: 0x10508d600 [Back Dual Wide Camera][com.apple.avfoundation.avcapturedevice.built-in_video:6]>"
)

iPhone14 Pro/Pro Max可用设备：

(
    "<AVCaptureFigVideoDevice: 0x11706f200 [Back Camera][com.apple.avfoundation.avcapturedevice.built-in_video:0]>",
    "<AVCaptureFigVideoDevice: 0x11706f800 [Back Telephoto Camera][com.apple.avfoundation.avcapturedevice.built-in_video:2]>",
    "<AVCaptureFigVideoDevice: 0x117075200 [Back Ultra Wide Camera][com.apple.avfoundation.avcapturedevice.built-in_video:5]>",
    "<AVCaptureFigVideoDevice: 0x117075800 [Back Dual Camera][com.apple.avfoundation.avcapturedevice.built-in_video:3]>",
    "<AVCaptureFigVideoDevice: 0x117077000 [Back Dual Wide Camera][com.apple.avfoundation.avcapturedevice.built-in_video:6]>",
    "<AVCaptureFigVideoDevice: 0x117077600 [Back Triple Camera][com.apple.avfoundation.avcapturedevice.built-in_video:7]>",
    "<AVCaptureFigVideoDevice: 0x11707d000 [Back LiDAR Depth Camera][com.apple.avfoundation.avcapturedevice.built-in_video:9]>"
)