March 20, 2012

Sunwayfoto DLC-42 Duo Lever/Knob Quick Release Clamp Review

Sunwayfoto DLC-42 Duo Lever/Knob QR Clamp in transport foam
Soon after my Sunwayfoto DB-36TRLR Traveler Ball Head Review, where I expressed a little disappointment with the operation of the ball head's DDC-42 Lever release clamp, I was contacted by Mr. John Simmonds of OEC Camera Accessories, a Sunwayfoto US dealer, who offered me to try the recently released and improved DLC-42 duo Lever/knob clamp at a special discount price.

This attitude shows exactly that a manufacturer or dealer in this case, cares about client satisfaction and the reputation of their business.
As I was curious to test the new clamp, I accepted the offer and in a few days a small package arrived at my door.

Packaging & Contents
DLC-42 Duo Lever/knob Quick Release clamp was designed to address the major issue of all lever release clamps. Compatibility with small size differences found between Arca Swiss® compatible dovetail rails and plates from various manufactures.

Sunwayfoto DLC-42 Duo QR Clamp box shrink wrap
There was no golden rimmed box this time. The clamp arrived in a nice shrink wrapped display box which ensures that the product has not been opened after it left the factory.
Sunwayfoto DLC-42 Duo QR Clamp box top window
The clamp is visible through a transparent plastic window on the top side...
Sunwayfoto DLC-42 Duo QR Clamp box bottom window
While on the bottom side a card with product specification, a short description and a bar-code, is visible through another transparent window.
Sunwayfoto DLC-42 Duo QR Clamp out of box
The DLC-42 Duo Lever/knob Quick Release clamp together with an M5 screw and the appropriate Allen hex key are nested in a precut foam piece that keeps them safely in place for transportation. The feeling when opening the box is once again of high quality fitting and finishing. The quick release clamp is hard coat anodized in a satin black color.

The Clamp

Manufacturer Specification:
Model:DLC-42 Duo
Width:87 mm
Jaw Length:42 mm
Height:15 mm
Mounting thread:1/4"-20 UNC
Clamp Type:Duo Lever & Screw Knob Release
Weight:88 gr

Sunwayfoto DLC-42 Duo QR Clamp top
The DLC-42 clamp apart from its dual function innovation, follows the design of all Sunwayfoto 42 mm Quick release clamps, which fit the Sunwayfoto DB-36 series of ball heads, since it is secured by an M5 screw, instead of the more common M6. The center hole is also threaded 1/4"-20 in order to match other manufacturer's heads.  Its jaws length is 42 mm, total width is 87 mm and it is 15 mm thick.
There are 2 cm long decimal scales on both jaws, the first cm closer to the center is marked in 1 mm increments and then in 2,5 mm increments, with numbers every 1 cm from 0 to 1 counting outwards. There are two safety stop screw relief grooves 4 mm deep, one at each side, permitting a motion of 9 mm either side into the clamp, for better camera/lens plate alignment.
The innovation of DLC-42 clamp is that the jaw opening may be very easily regulated via a short knob at the opposite side of the lever release, in order to accommodate different size dovetail Rails or Base plates.
Sunwayfoto DLC-42 Duo QR Clamp side-top
The knob takes 3.5 rotations from closed to fully open, which means that it can fine tune the jaw opening really well. However, since the regulating action is accomplished by opening the jaw on the other side, and as we can see in the above photo the opening on the knob side is equal to the opening on the lever side, then someone can use the knob to open or close the clamp instead of simply regulating the lever, giving to the clamp a true dual function. Using Lever or knob is your choice.
The clamp's top surface is carved 1,8 mm deep, wherever possible, in order to remove excess weight and compensate for the addition of the extra knob. Total weight is 88 gr which is not bad at all.
Nested in one of the stop screw relief grooves lies a small dark green one-axis spirit level. I don't know how useful this spirit level can be due to its one-axis nature and low visibility on the black background. Somehow, considering the clamp's design there is no other place or enough space to put a larger bulls eye bubble level as the ones used on other Sunwayfoto clamps. Is an one-axis spirit level better than no spirit level at all?
Well, personally even if a bubble level did not exist, I wouldn't care much, since I seldom use the on clamp spirit levels. I prefer better an on camera 3-axis spirit level or in crucial circumstances I use a very accurate digital protractor.
Sunwayfoto DLC-42 Duo QR Clamp bottom
The clamp's bottom side is also carved 1,8 mm deep in order to remove excess material and lower the weight as much as possible. The center hole is threaded 1/4"-20 and has the usual anti-twist grooves on the sides for ball head alignment.
Next to the center hole, there is a small rectangular opening that reveals the lever retaining screw head.
Sunwayfoto DLC-42 Duo Lever release positions
The release Lever is equipped with a locking mechanism protecting against accidental unlocking of the clamp. It utilizes a spring loaded dowel pin which blocks the lever from opening and can be manipulated by a small sliding plate on the side of the Lever (read more about the locking mechanism in the DLC-42 vs DDC-42LR comparison below).
The release Lever stays in three positions. One is closed and locked (as in the lower left photo), two is half open and locked (as in the upper photo) in order to permit sliding a rail or plate for fine adjustment and three fully open and unlocked (as in the lower right photo) in order to slide in/out or install/remove a rail/plate from top.
However, unlike to its predecessor DDC-42LR clamp, the release lever cannot be simply rotated on its axis, in order to change the orientation for right or left handed operation. It can be done though, by unscrewing the retaining screw a little from the small opening located at the bottom side of the clamp but this would require a special tool. This is not a problem for the majority of right handed users but I suppose that a left handed user can do it once or maybe order the clamp with the lever reversely mounted.

DLC-42 vs DDC-42LR Comparison
Since I had both clamps in my hands it was very tempting to lay them down side by side and conduct a little game of spotting the differences.

Sunwayfoto DLC-42 vs DDC-42LR comparison
Starting from the photo on the top, we can see that in place of DDC-42LR's detachable bull's eye bubble level  there is a small knob and a moving jaw responsible for the clamp width regulation, but also capable to operate the clamp by itself. (A little slower method though, compared to the lever release, since it takes 3.5 rotations to open the clamp fully but still it is an option). The knob function on the DLC-42 clamp eliminates the need of the little controversial thumb wheel of the DDC-42LR.
Other apparent differences, better seen in the bottom photos, are the more detailed and numbered scales engraved on the DLC-42, as well as the carvings on its top and bottom surfaces in order to keep the weight low.
Looking at the bottom right photo, we can see that the anti-twist/alignment grooves on the sides of the center hole are elongated probably for better compatibility with other manufacturers' ball heads.
There is also a small color difference between the totally black DLC-42 and the partially dark gray DDC-42LR (which matches the DB-36TR body shell color) but it is of no functional importance.
Considering the addition of the extra knob, screw, springs etc in order to operate both opening jaws, and just omitting the detachable bubble level on DLC-42 clamp, I think that Sunwayfoto's designers did a great job with only 2 gr increase of weight over the DDC-42LR clamp.
Sunwayfoto DLC-42 vs DDC-42LR Lever lock comparison
Another small and not so obvious difference between the two clamps is in the Lever release lock. The size of the  lock sliding plate lip has been increased by a mere 1,5mm. It is now 3mm instead of the previews 1,5mm and this small increase  affects dramatically the Lever operation. It is so easy now to grip and unlock the lever that the clamp opens in less than a second. Well done gentlemen!
In my opinion, besides the innovation of the clamp's dual function, this is the major improvement over the previous model.
Sunwayfoto DLC-42 vs DDC-42LR Lever lock pin comparison
But this is not the only improvement on the Lever release mechanism. If you look closer  by enlarging the photo, you will notice in the yellow circles, also a small increase in the dowel pin resting groove size. Small changes that make a big difference in the Lever operating smoothness.
Another improvement lies in the re positioning of the jaw springs, as seen in the green circle, hidden further inside, thus avoiding the accumulation of dirt and possible misoperation of the jaws.

Using with DB-36TR Ball head

Sunwayfoto DLC-42 on DB-36TR ball head front
The clamp fits perfectly on the DB-36TR ball head. Although the addition of the regulating knob has increased also the clamp's width by a few millimeters, this is no obstacle for the fine fitting of the ball head between the reverse folding legs of a traveler tripod.
Should I mention here, that the DB-36TR ball head with the DLC-42 quick release clamp combination can be purchased as model DB-36TRDL.
Sunwayfoto DLC-42 on DB-36TR ball head side
With the DLC-42 clamp, the ball head can accept any kind of Arca Swiis® compatible rail or plate easily. No need for trial and error thumb wheel regulation by inserting and removing a rail/plate a few times. All it has to be done now, when a different rail/plate will be used, is just to open the clamp by the knob once, insert the rail/plate, close the clamp by tightening the knob well and then operate the clamp with the Quick Lever Release.

Arca-Swiss® Compatibility
Sunwayfoto has a complete range of universal or dedicated camera and lens plates as well as a series of multi purpose rails which cover almost any need. Of course DLC-42 Duo Lever/Knob quick release clamp is fully compatible with Sunwayfoto's own gear.

One the other hand, in order to check its compatibility with other manufacturers plates and rails, DLC-42 was tested with various camera plates, lens plates and multipurpose long rails of various thicknesses and widths. Plates / Rails tested were from Benro, Kiwi Fotos, Fotoporo, Marumi and Hejnar PHOTO, with very good results in general.
For the readers that like numbers, I hereunder quote detailed measurements of the clamp Jaw dimensions, so as they can decide whether this clamp is compatible with the dimensions of their plates or rails.

Clamp Jaw dimensions        mm
Jaw Length41.97
Knob Jaw Height04.45
Lever Jaw Height04.50
Min Jaw Lip Opening32.95
Max Jaw Lip Opening39.90
Min Base Opening38.60
Max Base Opening46.30

All dimensions fall within the average limits, consisting this clamp compatible with almost any Arca-Swiss® type plate and rail.

Innovative dual function lever/knob design.
Excellent machining, finishing, fitting and build quality.
Gradual jaw control with the knob, that permits fine tuning for any type of Arca compatible rail or plate.
Drastically improved Lever release operation over previous models.
Very smooth operation in all aspects.
Excellent value for money ratio.

Small and dark one-axis spirit level.
Not easily reversible right-left handed operation of Lever release as in previous models.

Great innovation, implementation and versatility. The evolution of the DLC-42 clamp, shows to me that Sunwayfoto listens and improves.
Just a minor reservation for the spirit level for those that need one.
Fully recommended as a separate unit and/or in combination with the DB-36TR ball head.

I hope you found this review useful, thank you for viewing.
All Photos: © 2011-2012 S.C.Vlachos

DLC-42 QR Clamp is available from or from eBay

Referenced Articles:

Sunwayfoto DB-36TRLR Traveler Ball Head Review

Relevant Articles:

New Improved DDC Series QR Clamps from Sunwayfoto

Sunwayfoto DLC-60L Duo Lever / Knob Quick Release Clamp Review


  1. I just received my DDC-42LR.
    I always liked my Sunwayphoto stuff 100%, with this clamp it's a little different. I own 8 devices from Sunwayfoto: FB28-DDHi, T1A10, DDC-26, DMP140R, PFL-XE1, DPG-39, DP-39.
    With this clamp I know: Sunwayfoto's tolerances are far too big!
    I'm German, so maybe I'm too accustomed to German Engineering, but this is a fact:
    You tested "Arca Swiss compatibility" by measureing. I didn't measure, I simply tried all my different Sunwayfoto "plates" DMP-140R, PFL-XE1, DPG-39, DP-39 in the DDC-42LR clamp.
    Result: ALL need a different preset of the adjustment screw.
    DP-39 and DPG-39 are squares, so bidirectional. They at least work with the same setting for both dierctions, but the setting for DP-39 is too tight for DPG-39.
    PFL-XE1 needs a different setting again, but here it's worse: The setting that is OK for horizontal ist too tight for vertical. With fine tuning you can get it to one setting that is "just enough clamping to feel save" horizontlly and "upper limit for tightness" vertically. For DMP-140R I have to open the adjustment screw a lot. The setting that works for DMP-140R leaves all the other plates completely loose.
    This makes the advantages of a QR lever clamp obsolete!
    Replacing the clamp won't help: It's the different width of the different Sunwayfoto plates that cause the problem.

    Conclusion: Sunwayfoto is fine, but the use of the lever clamp DDC-42LR is very limited. I'll keep the DDC-42LR, as shipment back to England is too moch effort. Maybe I'll file / mill down my plates one day to the same size...
    I don't know the elder DLC-42, but as it's easier adjustable it might make more sense. But if you have to adjust the setting to ANY different plate, why not use a screw knob clamp from scratch?
    IMHO an adjustable lever clamp should work with one settiing at least for plates / rails / brackets of the same manufacturer.

    Idea: Why not build a lever clamp that clamps with a heavy spring load and thus can take higher tolerances or another way of "auto adjustment"?

    1. Thanks a lot for your feedback on compatibility between DDC-42LR and different Sunwayfoto QR plates and rails.
      For certain, all Sunwayfoto rails and/or plates marked with an R at the end of the model name and all rails or plates released in 2016 (even lacking the R) have slightly different dovetail design with more rounded dovetail edges, thus compatible with RRS lever release QR clamps.
      Previous models have slightly thinner edges matching all early Sunwayfoto QR clamps which have sharper jaw edges.
      Having said that, differences on the dovetail dimensions between the base and vertical plates of the same L bracket as the PFL-XE1 are unjustifiable and inexcusable.

      Chinese manufacturers like Sunwayfoto have taken a giant leap into product quality in only a few years by just listening to user comments and suggestions, but there is still a way to go in accepting the mentality of strict obedience to norms and standards, in order to reach German standards. Yet let's hope they can achieve that without an increase of the prices to the German standards as well! ;-)

      Nevertheless, your comments and suggestions will be forwarded to Sunwayfoto management for evaluation.

      However, please note, that your idea is already implemented and patented in the US by RRS on their lever release QR clamps, therefore not to be easily adopted by other manufacturers unless totally differentiated.