I often see comments that one should just crop instead of using a 2x extender.
As an experiment, I stacked 2 extenders. It was cloudy, so there is high ISO noise.
Today, I was able to get macPorts to successfully build gmic-gimp, so I used gimp to further reduce noise after editing in Canon DPP software. While I usually run gimp on my Debian Linux machine, I wanted to test my build from source on my iMac. I share files between my iMac and my Debian Linux machine using SMB file sharing.
I tried using 2 stacked 2x extenders on my EOS R5, but image stabilization does not work with this combination and this firmware version. In some previous firmware versions this combination worked but others did not. My best guess is that IBIS does not get the correct focal length. I used EOS R5 plus EF100-400mm f/4.5-5.6L IS II USM +1.4x III plus Kenko TELEPLUS HD C-AF 2X DGX for a total focal length of 1120 mm. I made this photo hand held standing on my front porch to demonstrate the image stabilization. The Kenko extender reports the increased focal length, but does not get its name put into the metadata.
The disadvantages to using a 2x extender include:
- increased F Number possibly results in increased small aperture diffraction blur
- increased resolution comes with decreased contrast at edges of small features
I have used exiftool to make a table of camera settings and edits done in DPP.
Northern Cardinal (Cardinalis cardinalis) in Norman, Oklahoma, United States on February 26, 2025
From DPP with no additional noise reduction
additional noise reduction using the GMIC Gimp plugin
| ExifToolVersion | 13.09 |
| FileName | IMG_2841c.JPG |
| Model | Canon EOS R5 |
| Software | Digital Photo Professional |
| ModifyDate | 2025:02:26 11:14:06 |
| Artist | John Moyer |
| Software | Digital Photo Professional |
| ModifyDate | 2025:02:26 11:14:06 |
| Artist | John Moyer |
| DateTimeOriginal | 2025:02:26 11:14:06 |
| OffsetTimeOriginal | -06:00 |
| ContinuousDrive | Continuous, Low |
| FocusMode | AI Servo AF |
| CameraISO | Auto |
| MeteringMode | Evaluative |
| ImageStabilization | On (2) |
| MeasuredEV | 11.50 |
| MeasuredEV2 | 9 |
| TargetAperture | 16 |
| TargetExposureTime | 1/512 |
| ExposureCompensation | 0 |
| WhiteBalance | Auto |
| MeasuredEV2 | 9 |
| CanonImageType | Canon EOS R5 |
| CanonFirmwareVersion | Firmware Version 2.1.0 |
| AFAreaMode | Face + Tracking |
| NumAFPoints | 1 |
| ValidAFPoints | 1 |
| FocusDistanceUpper | 18.79 m |
| FocusDistanceLower | 15.15 m |
| ShutterMode | Electronic First Curtain |
| PeripheralLightingSetting | Off |
| ChromaticAberrationSetting | On |
| DistortionCorrectionSetting | Off |
| DigitalLensOptimizerSetting | On |
| PeripheralIlluminationCorr | On |
| AutoLightingOptimizer | Off |
| HighlightTonePriority | Off |
| LongExposureNoiseReduction | Off |
| HighISONoiseReduction | Off |
| DigitalLensOptimizer | Standard |
| DualPixelRaw | On |
| AmbienceSelection | Standard |
| WB_RGGBLevelsAsShot | 1771 1024 1024 2330 |
| ColorTempAsShot | 4167 |
| AFConfigTool | Case 1 |
| AFTrackingSensitivity | 0 |
| AFAccelDecelTracking | 0 |
| AFPointSwitching | -1 |
| AIServoFirstImage | Equal Priority |
| AIServoSecondImage | Equal Priority |
| InitialAFPointInServo | Initial AF Point Selected |
| SubjectToDetect | Animals |
| EyeDetection | On |
| RollAngle | 0.6 |
| PitchAngle | 6.4 |
| FocalLength | 1120 mm |
| SceneCaptureType | Standard |
| LensModel | EF100-400mm f/4.5-5.6L IS II USM +1.4x III |
| Keywords | cardinal, bird, Northern Cardinal, Cardinalis cardinalis, wildlife, wildlife photography, Oklahoma, TELEPLUS HD C-AF 2X DGX |
| ExifToolVersion | 13.09 |
| FileName | IMG_2841.dr4 |
| AngleAdj | 0.6 |
| WhiteBalanceAdj | Daylight |
| WBAdjColorTemp | 5200 |
| PictureStyle | Shot Settings |
| UnsharpMaskStrength | 2 |
| UnsharpMaskFineness | 3 |
| UnsharpMaskThreshold | 5 |
| LuminanceNoiseReduction | 3 |
| ChrominanceNoiseReduction | 3 |
| DLOSetting | 40 |
| GammaContrast | 0 |
| GammaColorTone | 0 |
| GammaSaturation | 0.7 |
| GammaUnsharpMaskStrength | 2 |
| GammaUnsharpMaskFineness | 3 |
| GammaUnsharpMaskThreshold | 5 |
| GammaSharpnessStrength | 4 |
| GammaShadow | 0 |
| GammaHighlight | 0 |
| GammaBlackPoint | +0.000 |
| GammaWhitePoint | +2.000 |
| GammaMidPoint | +0.000 |
| GammaCurveOutputRange | 0 16383 |
| DPRAWMicroadjustBackFront | 1 |
| DPRAWMicroadjustStrength | 7 |
| CropRotatedOriginalWidth | 8249 |
| CropRotatedOriginalHeight | 5549 |
| CropX | 772 |
| CropY | 1168 |
| CropWidth | 6000 |
| CropHeight | 4000 |
| CropRotation | 0 |
| CropAngle | 0.6 |
Some of the command lines I used on macOS or on Debian Linux:
exiftool -cameratemperature -description -keywords -focallength -datetimeoriginal -ISO -rollangle /Volumes/EOS_DIGITAL/DCIM/100CANON/IMG_2841.CR3 Camera Temperature description=Northern Cardinal (Cardinalis cardinalis) in Norman, Oklahoma, United States on February 26, 2025" IMG_2841c*.[JHT][PI][FG] exiftool -sep ", " -"keywords=cardinal, bird, Northern Cardinal, Cardinalis cardinalis, wildlife, wildlife photography, Oklahoma, TELEPLUS HD C-AF 2X DGX" IMG_2841c*.[JHT][PI][FG] exiftool -tagsfromfile /Volumes/EOS_DIGITAL/DCIM/100CANON/IMG_2841.JPG -makernotes IMG_2841c*.[JHT][PI][FG] gm convert -verbose IMG_2841c.TIF -depth 16 IMG_2841cs3.png /home/jrm/src/libjxl/build2/tools/cjpegli -v -q 84 IMG_2841cs3.png IMG_2841cxlis.JPG exiftool -tagsfromfile IMG_2841c.JPG IMG_2841cxli.JPG
Source code for cjpegli is at https://github.com/google/jpegli and eventually I expect I will publish some version of this photo at https://www.rsok.com/~jrm/photos/index.html
EOS R5 #DPP #Extender_EF_1.4x_III #Kenko_TELEPLUS_HD_C-AF_2X_DGX
EOS R5
Canon
EOS R5
