---
title: "supportsExposureModeCustom(lensAperture:duration:iso:)"
framework: AVFoundation
role: symbol
role_heading: Instance Method
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, tvOS 27.0+]
path: "avfoundation/avcapturedevice/format/supportsexposuremodecustom(lensaperture:duration:iso:)"
---

# supportsExposureModeCustom(lensAperture:duration:iso:)

Reports if the given set of exposure parameters are supported by this format.

## Declaration

```swift
func supportsExposureModeCustom(lensAperture: Float, duration: CMTime, iso ISO: Float) -> Bool
```

## Discussion

Discussion The intended use of this method is to query which combinations of “Auto” parameters (AVFCapture/AVCaptureLensApertureAuto, AVFCapture/AVCaptureExposureDurationAuto, AVFCapture/AVCaptureISOAuto) are supported by this format. If you pass a numeric constant it will be range checked against the parameter’s supported min and max. However you can also pass the “Current” constants (AVFCapture/AVCaptureLensApertureCurrent, AVFCapture/AVCaptureExposureDurationCurrent, AVFCapture/AVCaptureISOCurrent) to generically query locked vs. auto parameter support without picking arbitrary lock values. note: To query support for “shutter priority” where the exposure duration is locked but auto-exposure continues to manage aperture and ISO: format.supportsExposureModeCustom(lensAperture: AVCaptureDevice.autoLensAperture, duration: AVCaptureDevice.currentExposureDuration, iso: AVCaptureDevice.autoISO) Devices that have fixed aperture will have equivalent support for AVFCapture/AVCaptureLensApertureAuto and AVFCapture/AVCaptureLensApertureCurrent.