5.3mm Ultra-thin 7-speed adjustable BENRO SD NDX-HD Review





    ND filters don’t need too much introduction I believes that many users are experienced photographers more or less have a in his hand.




    During the P & E2013 BENRO released a series of filters, including the CPL, UV, and this NDX. Indeed, the highlight of which several filters are sufficient, but also allow us to see the hope of domestic optical industry. SD NDX - HD adopted ULCA ultra-low color coating technology, different from the traditional filter of coating technology, in light show faint brown.




SD NDX-HD in the light shows faint brown color





Compared with traditional filter

    ULCA Design by Germany coating experts provides high spectral transmittance and low reflectivity, Can reduce the glare. A balanced reflection spectrum can reduce more impact on image than the traditional coating, Perfect to restore the color of the image.



    5.3mm super slim design the same as normal CPL

    SD NDX - HD is not too much fancy design, one black packing box, and one Plastic case with a lens, clean and tidy. Before I have seen many manufacturers struggle in the packing box, even use iron material similar to the high-grade cigarette case, although these look good, but is not conducive to carry out.


BENRO SD NDX-HD Packing and Filter

BENRO SD NDX-HD Plastic Case


    SD NDX-HD single polarizer thickness of 1.6mm, with the thickness of the lens is 5.3 mm, the thickness is almost the same as ordinary CPL. The thinner filter, the more dark corners to avoid, and we will be tested in detail later.


SD NDX - HD left, the upper right of the ordinary CL, Ordinary ND lower right


    BENRO SD NDX-HD composed by the two polarizers, using aluminum alloy frame, sturdy and durable, Lenses also have waterproof, anti-oil and anti-scratch function.




    Left and right rotation, 7-speed tuning


    BENRO SD NDX-HD is different to the traditional adjustable ND, using a cut-off Left and right rotation design, set the Min and Max each side two tranches, in the middle labeled with 5-speed adjustment, a total of 7-speed adjustment.

Product Identification

7-speed adjustment

Aluminum alloy material frame



    Because the filter design is too thin, so a little inconvenience during installation. I get the evaluation of products for the 77mm diameter, above the mounting diagram using the Canon EOS 5D Mark III with 24-105mm combination.



    Resolution of standard board, decreased after 5 speed

    Tradition Variable ND all use glued lens, complex gluing process, the lens and glue have different characteristics. The glue solidified in all directions a huge impact stress on the lens surface accuracy, resulting in deformation of the lens. Glued the lens is also easy to cause the lens distortion, the imaging quality declined dramatically.

    BENRO SD NDX-HD uses a high-definition optical manufacturing process, we adopted the following resolution standard board test its actual image quality. We use the Canon 5D Mark II with 17-40mm camera, the lens image stabilization is turned off, the body of all auxiliary functions are turned off. We capture the center of the target boards and edge position, figure from top to bottom respectively without ND filter resolution, 7 Min and Max fine-tuning.


Standard board two positions of interception


    BENRO SD NDX - HD from 4speed began to affect the resolution, After 5-speed resolution became obvious decrease remarkably, can click on the above, see big size screen.



    Partial color test, each speed has no obvious color


    Previously mentioned BENRO SD NDX - HD adopted ULCA ultra-low coating, is designed by BENRO with Germany optical coating expert, coating under the light is light brown color. BENRO Ultra Low Chromatic Aberration compared with other traditional coating system (green coating, blue coating), Straight uniform reflectance curve, curve has no obvious bulge, no obvious reflection band is too high, few partial color, also has very low reflectance.

BENRO Ultra Low Chromatic Aberration coating compared with traditional blue/green coating reflection curve

反射率曲线  Reflectivity curve


纳米  nmnanometer


百诺ULCA超低色差膜   BENRO Ultra Low Chromatic Aberration coating

传统蓝膜Traditional blue coating

传统绿膜Traditional green coating


Brown curve BENRO Ultra Low Chromatic Aberration coating


Design by Germany coating experts, Rmax-Rmin<0.45Rmax


Around 680nm, coating color close to colorless

蓝色曲线:传统蓝膜  Blue Curve: Traditional blue coating

Rmax-Rmin>0.9 Rmax420nm附近,膜色显蓝色。Around 420nm, coating shows blue color


    绿色曲线:传统绿膜 Green Curve: Traditional green coating

Rmax-Rmin>0.6 Rmax540nm附近,膜色显绿色。Around 540nm, coating shows green color.


Spectral color: Purple Blue Cyan Green Yellow Orange Red


    Here we are at 2500 k, 5000 k, 8000 k under the three color temperature measure BENRO NDX - HD partial color, in the samples we capture a picture in highlights and shadows.


Three color temperature partial color test


    BENRO SD NDX - HD under three color temperature did not produce significant partial color, but when the density reached 7 speed produced obvious colour cast.


    Dark corners test, the advantages of ultrathin design

    Filter the thicker, the more easily lead to Dark corners, Benro SD NDX-HD exposed lens section thickness of only 5.3mm, compared with the traditional ND filter, can better restrain dark corners


SD NDX-HD left, normal CL upper right, lower right of ordinary ND


BENRO SD NDX-HD dark corners test


    Dark corners test using the focal length is 17 mm, we choose the F4, F5.6 and F8 three aperture, Respectively under the 7 density of filter shooting the white wall. In order to let you see more clearly, we choose a few pictures to further comparison.

Maximum speed comparison dimmer

ND滤镜 without ND Filter

最大减光档Maximum dimming

    Compared with Benro SD NDX-HD and did not see significant changes in dark corners. Through careful observation though slight dark corners increases, but the magnitude is much smaller than traditional adjustable ND filter. SD NDX-HD formed by the two polarizers, single thickness of 1.6mm, so the exposed portion of the lens thickness of only 5.3mm. Meanwhile, Max ends Benro SD NDX-HD appeared reticle.


    Reticle test appeared in the Max end.


    Adjustable ND in the density reaches 450 or more, the reticle will appear, and before reaching the 450 density, because the polarization overlay reasons, the picture has caused uneven illumination effects, the use of adjustable ND actual shooting of reach ND400 effect, or the screen brightness unevenness appears.

Reticle motioned

Focal length: 17Mm, Aperture: f/4.0, ISO sensitivity: 100

Exposure time: 1/2, exposure compensation: 1EV, white balance: automatic



Focal length: 17Mm, Aperture: f/5.6, ISO sensitivity: 100

Exposure time: 1/1, exposure compensation: 1EV, white balance: automatic

Focal length: 17Mm, Aperture: f/8.0, ISO sensitivity: 100

Exposure time: 1/0, exposure compensation: 1EV, white balance: automatic


    The above picture shows the three apertures uses maximum density filter

    BENRO SD NDX - HD adopted the rotation design, at the end of the Max shows reticle.



    NDX filter used in the making video


    Now more and more netizens to DSLR take video, adjustable ND actually is one of the necessary professional camera function, also is an important factor to distinguish the equipment is good or bad. For now, don't have a camera with a built-in ND function, so is equipped with an adjustable ND filter is especially important to make video.



    Previous two videos, is moving from indoors to outdoors. Therefore, the move comes to the operation of the dimming time. But the camera's aperture and shutter speed are main through the dial to adjust, when it will appear not smooth image. Test 1 for regulating the shutter, test 2 is used for reducing the light.



    Use the BENRO SD NDX - HD for reduced light



    Using the shutter and aperture to reduce the light, the picture does not have produced a smooth feel, while using BENRO SD NDX-HD filter for dimming the screen over very gentle.





    In general, the camera video frames for the highest 60, according to the conversion formula, had better use the shutter speed of 1/120 of the ideal. But under the environment of strong large aperture, shutter speed must be up to, and sometimes even to 1/1000. 1/1000 corresponds to 500 frames, and then 440 frame of information has to be discarded. As the record is continuous, discard 88% information is bound to cause the picture incoherent, and that's why video NDX filters is necessary accessories.



    BENRO SD NDX - HD shooting samples

    Here we compare several groups to learn about Benro SD NDX-HD



The official picture 1


The official picture 2


Focal length: 45Mm, Aperture: f/22.0, ISO sensitivity: 100

Exposure time: 1/0, exposure compensation: 0EV, white balance: automatic


Focal length: 45Mm, Aperture: f/22.0, ISO sensitivity: 100

Exposure time: 1/0, exposure compensation: 0EV, white balance: automatic

Without ND filter

Focal length: 58Mm, Aperture: f/22.0, ISO sensitivity: 100

Exposure time: 1/1, exposure compensation: 0EV, white balance: automatic



Focal length: 58Mm, Aperture: f/22.0, ISO sensitivity: 100

Exposure time: 1/1, exposure compensation: 0EV, white balance: automatic

Without ND filter


Focal length: 55Mm, Aperture: f/22.0, ISO sensitivity: 100

Exposure time: 1/0, exposure compensation: 0EV, white balance: automatic


Focal length: 55Mm, Aperture: f/22.0, ISO sensitivity: 100

Exposure time: 1/0, exposure compensation: 0EV, white balance: automatic

Without ND filter


    ND filter plays an important role in daylight shooting, from the picture we can see it’s difficult to shoot slowly during the day. Aperture has been reduced to the F22, the exposure time 1s will appear overexposed situation, but with BENRO SD NDX-HD will have a lot better after the effect.


    Review summary: Domestic optical power


    This SD NDX-HD filter is The high-quality goods, A lot of performance and technology over the international big brands. During the P & E shows, BENRO issued a large number of accessories products; with the German coating experts to develop ULCA, in the actual tests have very good results.


BENRO ND filter family



无镀膜: without coating

    In SD NDX - HD marked place we can see the words of WMC WMC is the short of Waterproof Muti-Coating, stand for the lens with a waterproof / anti-oil / anti-scratch function, The author more willing to call Benro three anti NDX filter.


Benro SD NDX-HD evaluation

    The Advantage of BENRO SD NDX-HD


1.Use HD lenses

2.Using ultra-thin lenses and frames, exposing part of the lens is only 5.3mm
Use the limit function, effectively prevent the occurrence of the reticle

5.Low reflectivity, reduced glare
Uniform transmittance
Waterproof / anti-oil / anti-scratch
Aluminum alloy material, strong and durable



    Use the filter to reduce the shutter speed
    Do not use the filter high shutter speed

    The main function of the ND filter is to reduce light; in a well-lit environment using a long exposure can avoid the image. Today, we are evaluating products for BENRO SD NDX-HD, is a seven-speed adjustable ND filter. Optical materials, surface accuracy, the light transmittance and reflectance, etc., are the determining factors of the ND filter is good or bad, this evaluation we have from the several aspects of the performance of this NDX filter detailed evaluation.

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