Inon
UWL-H100 28LD and 28M67 test pictures
As sensor sizes have increased and camera manufacturers have
sought market advantage by increasing the available zoom range, the
change in the physical length of the lens body as the focal length is
adjusted has increased. This can result in the lens entrance pupil
being a long way behind the port at the maximum wide setting. Thus it
is not always possible to produce a 28AD port adapter and lens
combination that will avoid vignetting at f = 28. In an attempt to
solve this problem, Inon introduced the LD bayonet system, which has a
larger mount diameter and lens exit aperture. 28LD converters
will, in some cases, work without vignetting with 24 mm lenses.
The Inon UWL-H100 lens is tested below
with the Canon S100 camera (minimum f = 24mm). For the 28LD
version, a Recsea housing (for which Recsea makes both 28AD and 28LD
port adapters) is used. Test were also carried out on the 28M67
version, using an ikelite housing. In both cases, the distance from the
port to the lens is
dictated by the requirement that the lens must not crash into the port
at the telephoto end of its zoom range. Hence, the results from both
housings were essentially identical, and so only the 28LD images are
shown. For results obtained from a camera
and housing without a wide converter, see
Canon S100
test pictures
.
|
Inon
UWL-H100 28LD
Also available as M67 type 1 and II (choice of back element to port
distances)
Magnification: ×0.6
afocal
Configuration: 4 elements, 4 groups,
glass, AR coated.
Max FOV:
100.8° UW, 179°
in air.
Dimensions /mm: 90.4 Ø,
45.4 L. Weight: 530g in air, 326g
UW.
Depth
rating: 60m |
Camera lens: 24mm f/5.6
Radial correction
Radial correction coefficients |
|
Collected correction coefficients - UWL-H100 28LD lens
with S100 camera
(equiv f = 24mm)
Lens system |
magnif
-ication |
FOV |
Geometry |
Aberration |
a |
b |
c |
a+b+c |
Δdred |
Δdblue |
Camera + flat port |
|
60.0° |
0 |
0.04 |
0 |
0.04 |
-0.0014 |
0.0056 |
Camera |
1 |
84.1° |
0 |
-0.015 |
0 |
-0.015 |
0.0012 |
0.0012 |
Port
(f = 24mm) |
|
|
0 |
0.055 |
0 |
0.055 |
-0.0026 |
0.0044 |
UWL-H100
28LD |
0.6 |
|
0.02 |
-0.092 |
0 |
-0.072 |
-0.001 |
0.004 |
The UWL-H100 28LD shows no sign of vignetting at f = 24 mm
with the S100
camera. The adapter offers a small improvement over the bare port; but
leaves noticeable blue-yellow fringing, which is due to the fairly
large distance between the adapter rear element and the camera lens
entrance pupil. Cameras with less extreme zoom lenses will give better
results because the port can be placed closer to the lens at the
wide-angle setting.
The UWL-H100 adapter is also discussed in the
Radial Correction article.
© David W Knight 2012. Updated Feb. 2018.
Pictures by Steve Knight.