Review of the Canon J16ax8B4 lens paired with the Custom B4 adapter.
Lens Characteristics
| Canon J16ax8B4 | |
|---|---|
| Focal length | 8-128mm → 30-480mm (FF eq.) |
| Aperture | f1.8 |
| Weight | 1.33 Kg |
| Doubler | Yes |
| Min focusing distance | 0.6m (50mm w/ Macro) |
| Front filter diameter | Ø 82mm |
Complete datasheet: .PDF ↓
Test setup
Gear used
- Fujifilm X-M5 camera (APSC sensor)
- Custom B4 adapter
- Canon J16ax8B4 IRS-C SX12 lens
- ISO12233 Resolution Chart (A3 size)
Image quality
Tips:
In each viewer below you can zoomclickand panclick + drag.
The buttons under the viewer switch between apertures.
Images may take a bit of time to load at first.
8mm - 2x extender - Macro switch - APSC
15mm - 2x extender - APSC
30mm - 2x extender - APSC
60mm - 2x extender - APSC
128mm - 2x extender - APSC
Clear / Doubler Comparison
Test shot with and without the x2 extender engaged. The clear image was cropped in in post to match the x2 framing.
Without the doubler
60mm
Observations
We can see that the doubler emphasizes chromatic aberration, adds some vignetting and softens the extreme edges.
Conclusion
If your camera offers a Super 16 mode or allows you to crop in the sensor, it’s best not to use the doubler (better image quality and +2 stops of light).
If not, the doubler delivers totally acceptable results.
Zoom Showcase
Handheld crash zoom - 2x extender
Slowest motorized zoom - 2x extender
Fastest motorized zoom - 2x extender
Final Thought
Filming a chart is interesting for understanding a lens’s strengths and weaknesses, but real-world shooting is what truly matters.
Personally, I use this lens with the doubler engaged, and let me tell you, I love shooting with it and I’m very happy with the images it can create.
Yes, this isn’t a perfect setup and it doesn’t deliver the most sharp and flawless images, but it remains an excellent creative tool :)
To go Further
James and Camera creates excellent content on b4 lenses (lots of lens reviews and adapting recommendations).
You can find the playlist of all his lens tests here.
The Canon J16ax8 is reviewed there.
Note that he uses the same Blackmagic corrective optic for his tests.