iOS : AVFoundation Image Capture Dark -

i'm developping app captures photos ipad front camera. photos coming dark. have idea how fix issue, please ?

here code , explainations :

1) initialize capture session

-(void)viewdidappear:(bool)animated{      capturesession = [[avcapturesession alloc] init];     nsarray *devices = [avcapturedevice devices];     avcapturedevice *frontcamera;     (avcapturedevice *device in devices){         if ([device position] == avcapturedevicepositionfront) {             frontcamera = device;         }     }      if ([frontcamera isexposuremodesupported:avcaptureexposuremodecontinuousautoexposure]){         nserror *error=nil;         if ([frontcamera lockforconfiguration:&error]){             frontcamera.exposuremode = avcaptureexposuremodecontinuousautoexposure;             frontcamera.focusmode=avcapturefocusmodeautofocus;             [frontcamera unlockforconfiguration];         }     }      nserror *error = nil;     avcapturedeviceinput *frontfacingcameradeviceinput = [avcapturedeviceinput deviceinputwithdevice:frontcamera error:&error];     [capturesession addinput:frontfacingcameradeviceinput];     [capturesession setsessionpreset:avcapturesessionpresethigh];     capturevideooutput = [[avcapturevideodataoutput alloc] init];     captureimageoutput =[[avcapturestillimageoutput alloc] init];     [capturesession addoutput:capturevideooutput];     [capturesession addoutput:captureimageoutput];  } 

2) when user presses button record, starts timer , preview content of camera preview layer

- (ibaction)but_record:(uibutton *)sender {      mainint = 4;     timer = [nstimer scheduledtimerwithtimeinterval:1.0 target:self selector:@selector(countup) userinfo:nil repeats:yes];     previewlayer = [[avcapturevideopreviewlayer alloc]initwithsession:capturesession];     previewlayer.connection.videoorientation = avcapturevideoorientationportrait;     cgrect rect = cgrectmake(0, 0, self.aview.bounds.size.width, self.aview.bounds.size.height);     previewlayer.frame = rect;     [self.aview.layer addsublayer:previewlayer];     [capturesession startrunning];  } 

3) @ end of timer, photo taken , saved

- (void)countup {     mainint -=1;     if (mainint == 0)  {               [timer invalidate];         timer = nil;          [capturesession stoprunning];         avcaptureconnection *videoconnection = nil;         (avcaptureconnection *connection in captureimageoutput.connections)         {             (avcaptureinputport *port in [connection inputports])             {                 if ([[port mediatype] isequal:avmediatypevideo] )                 {                     videoconnection = connection;                     break;                 }             }             if (videoconnection) { break; }         }          [captureimageoutput capturestillimageasynchronouslyfromconnection:videoconnection completionhandler: ^(cmsamplebufferref imagesamplebuffer, nserror *error)         {             cfdictionaryref exifattachments = cmgetattachment( imagesamplebuffer, kcgimagepropertyexifdictionary, null);             nsdata *imagedata = [avcapturestillimageoutput jpegstillimagensdatarepresentation:imagesamplebuffer];             stillimage = [[uiimage alloc] initwithdata:imagedata];         }];          [capturesession startrunning];         [capturesession stoprunning];     }   } 

4) finally, when user press save button, image recorded in specific album

- (ibaction)but_save:(uibutton *)sender {     uiimage *img = stillimage;     [self.library saveimage:img toalbum:@"myspecificalbum" withcompletionblock:^(nserror *error)];   } 

in fact, code works resulting images dark...

this happening me , turned out trying capture , camera didn't have enough time stabilize. had add 0.5 seconds of delay before pictures normal brightness.

hth