topic Re: 470ex AI auto metering in Speedlite Flashes

470ex AI auto metering to avoid overexposure

johnrmoyer — Tue, 05 Aug 2025 13:05:22 GMT

I know little about speedlights. I seem to get things over exposed often. It seems that I do not understand how auto metering works when the speedlight is attached.

I was experimenting with using a flash with wildlife in deep shade. I was using Speedlite 470EX-AI on the camera and set for straight ahead with no bounce or automatic movement.

I used -2/3 exposure compensation for the squirrel, but it still seemed over exposed. I used "flash priority" metering because I was not wanting to lighten background shadows.

The Squirrel image was processed in DPP, saved to 16 bit TIFF, loaded into gimp, additional noise reduction and unsharp mask in gimp, saved from gimp as JPEG with quality 85 and 4:4:4 sampling. The low quality setting was to get it under 5 MB for upload here.

The eye of the squirrel has reflected the flash, but I did not try to fix that.

ExifTool	ExifToolVersion	13.30
File:Other	FileName	IMG_4319.dr4
CanonVRD:Image	AngleAdj	0.7
CanonVRD:Image	WorkColorSpace	sRGB
CanonVRD:Image	RawBrightnessAdj	-1
CanonVRD:Image	WhiteBalanceAdj	Shot Settings
CanonVRD:Image	ColorSaturationAdj	1
CanonVRD:Image	UnsharpMaskStrength	2
CanonVRD:Image	UnsharpMaskFineness	4
CanonVRD:Image	UnsharpMaskThreshold	5
CanonVRD:Image	HighlightAdj	-1
CanonVRD:Image	DLOSetting	50
CanonVRD:Image	DLOOn	Yes
CanonVRD:Image	DPRAWMicroadjustBackFront	0
CanonVRD:Image	DPRAWMicroadjustStrength	8
CanonVRD:Image	CropRotatedOriginalWidth	8258
CanonVRD:Image	CropRotatedOriginalHeight	5564
CanonVRD:Image	CropX	713
CanonVRD:Image	CropY	1341
CanonVRD:Image	CropWidth	6000
CanonVRD:Image	CropHeight	4000
CanonVRD:Image	CropRotation	0
CanonVRD:Image	CropAngle	0.7
CanonVRD:Image	CropOriginalWidth	8192
CanonVRD:Image	CropOriginalHeight	5464
ExifTool	Warning	Bad length ICC_Profile (length 3140)
File:Other	FileName	IMG_4319c.JPG
File:Image	ImageWidth	6000
File:Image	ImageHeight	4000
EXIF:Camera	Model	Canon EOS R5
EXIF:Camera	ExposureProgram	Aperture-priority AE
EXIF:Camera	Flash	On, Fired
EXIF:Camera	ExposureMode	Auto
EXIF:Camera	SceneCaptureType	Standard
EXIF:Image	Software	Digital Photo Professional
EXIF:Image	ExposureTime	1/250
EXIF:Image	FNumber	11.0
EXIF:Image	ISO	2500
EXIF:Image	LensModel	EF100-400mm f/4.5-5.6L IS II USM +2x III
MakerNotes:Camera	CanonFlashMode	External flash
MakerNotes:Camera	ContinuousDrive	Continuous, Low
MakerNotes:Camera	FocusMode	AI Servo AF
MakerNotes:Camera	RecordMode	CR3+JPEG
MakerNotes:Camera	CameraISO	Auto
MakerNotes:Camera	FlashActivity	157
MakerNotes:Camera	FlashBits	E-TTL, External
MakerNotes:Camera	CameraTemperature	39 C
MakerNotes:Camera	CanonFirmwareVersion	Firmware Version 2.2.0
MakerNotes:Camera	ShutterCount	24400
MakerNotes:Camera	CanonModelID	EOS R5
MakerNotes:Camera	ValidAFPoints	1
MakerNotes:Camera	MeasuredRGGB	630 1024 1024 495
MakerNotes:Camera	WB_RGGBLevelsAsShot	1975 1024 1024 1879
MakerNotes:Camera	ColorTempAsShot	5228
MakerNotes:Camera	RollAngle	0.7
MakerNotes:Camera	PitchAngle	2.9
MakerNotes:Camera	FocalLength	800 mm
MakerNotes:Image	MeasuredEV	9.75
MakerNotes:Image	ExposureCompensation	-2/3
MakerNotes:Image	MeasuredEV2	13
MakerNotes:Image	FocusDistanceUpper	18.82 m
MakerNotes:Image	FocusDistanceLower	15.17 m
MakerNotes:Image	ShutterMode	Electronic First Curtain

Fox Squirrel (Sciurus niger) on Parthenocissus quinquefolia vine in Norman, Oklahoma, United States on August 2, 2025

Re: 470ex AI auto metering

deebatman316 — Tue, 05 Aug 2025 00:31:50 GMT

What do you mean by Auto Flash metering. Do you mean E-TTL. I believe the camera uses more flash power when set to flash priority. If you don’t want fill flash you should avoid using full automatic or semi automatic modes. Also avoid Auto ISO and Manual mode on the camera. This puts the camera into fill flash mode also. In Full Manual mode on the camera and the flash set to E-TTL. This will treat the flash as main light and the only light source. For more information check with @Brian I’m not near my 470EX-AI for testing. Nor do I own an EOS R5 to test it out on.

Re: 470ex AI auto metering

p4pictures — Tue, 05 Aug 2025 07:42:26 GMT

Hi John,

To my eye, this shot does not look overexposed, certainly the flash element in the scene. With aperture priority added flash the camera by default will set the shutter speed from 1/60 to the sync speed 1/250 in your EOS R5 with electronic first curtain shutter. The fact that you have 1/250 suggests you have set the Slow synchro setting for a fixed shutter speed as I would expect 1/60 to be selected with default settings here. Though equally that could be a result of the ISO 2500 selected as the camera tried to balance the ambient light.

Selecting flash priority flash balance would conventionally mean that the photos look a little more "flashed" than Canon cameras normally aim for. I tried the flash balance settings in the past, but actually prefer the standard flash balance setting.

https://www.p4pictures.com/2022/05/e-ttl-balance-speedlite-settings/

With your ISO so high it is possible that f/11 from your lens + extender, and 1/250 are the maximum settings the camera can work with, and despite you selecting -2/3 EV on the ambient compensation, the image was already overexposed with ambient light and 1/250, f/11, ISO 2500. Adding flash simply adds more light.

One suggestion is to try using manual mode on the camera, setting the shutter speed to the sync speed of 1/250 you chosen aperture and then adjust ISO to give you the ambient exposure you want, even if that is underexposed. Then when the flash is used it will illuminate the detected subject, but the flash intensity will fall off the further the light travels, meaning the background will be darker.

As an example here is a photo taken with flash inside a butterfly enclosure. I set the camera to manual mode and chose 1/200 f/4 ISO 200. The flash was set for E-TTL automatic flash exposure. Without the flash the frame would be very underexposed. So the camera determines the flash exposure and illuminates the subject but the light falls off the further from the subject it goes.

Re: 470ex AI auto metering

johnrmoyer — Tue, 05 Aug 2025 13:03:09 GMT

Thanks to Brian for explaining in a manner that made sense to me.

I used Fv mode and specified shutter speed, FNumber, and ISO. The camera obtained proper metering by controlling the flash.

This year, painted buntings have not been willing to pose for me in a tree, but still come to a bird feeder when there is not much light.

ExifTool	ExifToolVersion	13.30
File:Other	FileName	IMG_4339cs.dr4
CanonVRD:Image	DR4CameraModel	EOS R5
CanonVRD:Image	Rotation	0
CanonVRD:Image	AngleAdj	0.5
CanonVRD:Image	WorkColorSpace	sRGB
CanonVRD:Image	RawBrightnessAdj	0
CanonVRD:Image	WhiteBalanceAdj	Shot Settings
CanonVRD:Image	PictureStyle	Shot Settings
CanonVRD:Image	ContrastAdj	0
CanonVRD:Image	ColorToneAdj	0
CanonVRD:Image	ColorSaturationAdj	0.3
CanonVRD:Image	UnsharpMaskStrength	2
CanonVRD:Image	UnsharpMaskFineness	4
CanonVRD:Image	UnsharpMaskThreshold	5
CanonVRD:Image	ShadowAdj	0
CanonVRD:Image	HighlightAdj	0
CanonVRD:Image	DLOSetting	70
CanonVRD:Image	DPRAWMicroadjustBackFront	1
CanonVRD:Image	DPRAWMicroadjustStrength	7
CanonVRD:Image	CropRotatedOriginalWidth	8239
CanonVRD:Image	CropRotatedOriginalHeight	5535
CanonVRD:Image	CropX	2010
CanonVRD:Image	CropY	950
CanonVRD:Image	CropWidth	4500
CanonVRD:Image	CropHeight	3000
CanonVRD:Image	CropRotation	0
CanonVRD:Image	CropAngle	0.5
CanonVRD:Image	CropOriginalWidth	8192
CanonVRD:Image	CropOriginalHeight	5464
ExifTool	ExifToolVersion	13.30
ExifTool	Warning	Bad length ICC_Profile (length 3140)
File:Other	FileName	IMG_4339cs.JPG
EXIF:Camera	Make	Canon
EXIF:Camera	Model	Canon EOS R5
EXIF:Camera	ExposureProgram	Not Defined ( exiftool does not know about Fv mode )
EXIF:Camera	Flash	On, Fired
EXIF:Camera	ExposureMode	Auto
EXIF:Camera	SceneCaptureType	Standard
EXIF:Image	Software	Digital Photo Professional
EXIF:Image	ExposureTime	1/250
EXIF:Image	FNumber	13.0
EXIF:Image	ISO	400
EXIF:Image	LensModel	EF100-400mm f/4.5-5.6L IS II USM +2x III
EXIF:Time	DateTimeOriginal	2025:08:05 07:10:13
EXIF:Time	OffsetTimeOriginal	-05:00
EXIF:Time	SubSecTimeOriginal	96
MakerNotes:Camera	CanonFlashMode	External flash
MakerNotes:Camera	MeteringMode	Evaluative
MakerNotes:Camera	CanonExposureMode	Flexible-priority AE
MakerNotes:Camera	FlashActivity	157
MakerNotes:Camera	FlashBits	E-TTL, External
MakerNotes:Camera	CameraTemperature	41 C
MakerNotes:Camera	CanonFirmwareVersion	Firmware Version 2.2.0
MakerNotes:Camera	ShutterCount	24420
MakerNotes:Camera	CanonModelID	EOS R5
MakerNotes:Camera	ValidAFPoints	1
MakerNotes:Camera	MeasuredRGGB	947 1024 1024 463
MakerNotes:Camera	WB_RGGBLevelsAsShot	2194 1024 1024 1651
MakerNotes:Camera	ColorTempAsShot	6578
MakerNotes:Camera	WB_RGGBLevelsFlash	2245 1024 1024 1628
MakerNotes:Camera	ColorTempFlash	6806
MakerNotes:Camera	PerChannelBlackLevel	2048 2048 2048 2047
MakerNotes:Camera	AFConfigTool	Case 1
MakerNotes:Camera	AFTrackingSensitivity	0
MakerNotes:Camera	AFAccelDecelTracking	0
MakerNotes:Camera	AFPointSwitching	-1
MakerNotes:Camera	AIServoFirstImage	Equal Priority
MakerNotes:Camera	AIServoSecondImage	Equal Priority
MakerNotes:Camera	AFAssistBeam	Enable
MakerNotes:Camera	AutoAFPointSelEOSiTRAF	Enable
MakerNotes:Camera	InitialAFPointInServo	Manual AF Point
MakerNotes:Camera	SubjectToDetect	Animals
MakerNotes:Camera	EyeDetection	On
MakerNotes:Camera	RollAngle	0.5
MakerNotes:Camera	PitchAngle	4.1
MakerNotes:Image	MeasuredEV	8.12
MakerNotes:Image	MeasuredEV2	3.5
MakerNotes:Image	FocusDistanceUpper	9.07 m
MakerNotes:Image	FocusDistanceLower	7.89 m
MakerNotes:Image	ShutterMode	Electronic First Curtain
MakerNotes:Image	FlashExposureLock	Off
MakerNotes:Image	AntiFlicker	Off
IPTC:Other	Keywords	bird, bunting, Painted Bunting, Passerina ciris, birdfeeder, wildlife, wildlife photography, Oklahoma
XMP:Image	Description	Painted Bunting (Passerina ciris) in Norman, Oklahoma, United States on August 5, 2025

Painted Bunting (Passerina ciris) in Norman, Oklahoma, United States on August 5, 2025