Velbon Super Magnesium Slider, Macro Rail

I recently bought a new macro lens (paid for with an excellent month of photo sales in July - see BackyardSilver.com for details), and my research identified the real need for a macro focusing rail if I was going to do this properly. The Velbon Super Mag slider was the result. I bought the Canon 100mm f2.8 for two reasons - it seems to be the lens of choice for some great images on DP Challenge, and its review on The Digital Picture was very good as well. There is no way I can do a better review of a lens than they can! Incidentally, I bought my lens from a "used" seller on Amazon - about $100 less than the new price and a filter thrown in as well. The lens was in perfect condition - but that is another story!Why do you need a macro focusing rail? Well, the main problem with macro photography is the extremely small depth of field. You can try to stop down the aperture to get more of the subject in focus, but that then requires more light (or a higher ISO), and after you pass F16 or F22, the quality tends to diminish a little as the diffraction of light around the aperture increases. As a result, many studio shots with a great depth of focus are as a result of focus stacking, where you take several images of the subject with a each one having clear focus on a part of the object. You then combine these in Photoshop, which blends the sharpest parts of each image into one composite photograph. You can do this by changing the focus ring on the lens to get the different parts of the image in focus, but I understand that this changes the perspective, and so the best way of getting focus stacking to work smoothly is to move the whole lens/camera towards the subject and change the areas of focus that way. Hence a macro focusing rail, which lets you move the camera in very small controllable ways to get focus exactly where you want it. Of course, the same approach lets you focus on a small part of the subject for single macro shots without having to move the tripod and risk disturbing the insect, say.I looked around for various reviews of macro focusing rails. I wanted one that was sturdy, not too heavy, not too expensive, and had movements in both directions - towards the subject and from side to side to get the right position for the shot. After reading the reviews, I ended up with the Velbon Super Mag slider.The unit has two main sections - a three rail unit with a long screw mechanism that moves the camera backwards and forwards about 2.25 inches (6 cm). It has a detachable sideways mechanism with three rails again that can move the camera 1.25 inches (3 cm). In the field, you would normally have both fastened together to allow the full range of movement, but for studio shots I preferred just having the actual focusing rail on the tripod. Why? It removed one potential piece of instability, and I just didn't ever use it!How stable is it - the main focusing rail is very solid. You move it forward with a knurled knob, and once in position, it stays there very securely. I found the horizontal slider to be slightly less secure. At each end of its travel, it is locked in place, but in the center, with the focus rail and a heavy camera on top, there is a little wobble. Of course, if you are using flash, this doesn't really matter, and with a remote release outdoors, it would not cause problems, but this was the other reason I removed it for normal use. It is quick and easy to remove with an allen key (provided.)I use Arca-swiss tripod mounting plates on my camera/tripod and always have one screwed into the bottom of the camera, and so I decided to buy an Arca-swiss mounting plate and connector combination. This makes it very easy to put the focusing rails on the tripod and add the camera with just a few twists of a knob. Not really essential, but it makes for a smoother workflow and makes it less likely that you would damage the camera by carrying the whole tripod/rail/camera combination around in one package.I've used this a lot over the past couple of weeks, and I've got nothing but praise for its capabilities. I've really enjoyed my first steps in Macro, and the focusing rails have made this a lot more successful that it otherwise would have been.One bonus - the rail can also be used to put the camera/lens on a tripod with the rotation point being under the nodal point of the lens. This means that the perspective of near and far objects does not change as you take the various shots for the panorama. Of course it needs to be in your camera bag, but if you plan to go out to take some panoramas, this will increase your chance of success!

Let me start by saying that this is not comparable to a higher end rails like those from Really Right Stuff or the  Novoflex CROSS-MC  (or DIY rails based on Newport optics bench positioners), but it is a very solid product for the money and a very good investment if you are just starting to explore macro photography and don't want to commit to a much larger investment.The Good:For magnification up to 1:1 the rails have relatively little backlash, and I have not yet experienced any creep. There are no locking knobs on the rails, so I expect at steep angles creep might become an issue if your camera+lens are sufficiently heavy. I'm using it with a Canon EOS 7D and 5D mk II with the 100mm f2.8L Macro. I do not know how well it would fare holding heavier macro lenses like the 180 f3.5.The rails are very lightweight without feeling cheep or flimsy. All the load bearing parts appear to be cast magnesium alloy with aluminum rails. Plastic is only present for the gear covers and the plug that keeps the tripod screw knob captive (more on this later).The lateral position adjustment is sufficient for reframing a slightly out of position subject, and the longitudinal adjustment is fine enough that you can set your lenst to 1:1 and just use the rail to focus. If your working distance is too short (which may be the case on some 50mm macro lenses) it seems sturdy enough that you could mount the camera backwards on the mounting plate.As other reviewers have mentioned, you can separate the lateral and longitudinal rails so you can mount the lateral adjustment with its knob on the opposite side. I did this myself when I discovered that in some positions my clumsy fingers would start to adjust the wrong direction of movement.The Bad:This set of rails is not all shining and light. The lateral adjustment on my example seem to have increased resistance for about 30 degrees of every revolution. Also, the way the rails stack on each other increases the height of your camera over the tripod head pretty significantly. In turn, this has meant that I have taken to adding more weight under my tripod to minimize vibrations while positioning and focusing.The Serendipitous:All my camera gear has Arca-Swiss style plates on it. I was concerned that this rail was going to cause me to have to circumvent that to use the 1/4-20 screws in its camera base. I was happily surprised to discover that if you peel off the cork from the camera mounting plate that it is just large enough to fully support a Wimberley C-12 clamp. The edge of the C-12 clamp rests along the straight lip left in the platform when you remove the cork. Removing the cork also releases the plastic plug that Velbon/Hakuba is using to keep the mounting screw in place.The other nice surprise was to learn that there are two tripod mounting holes in the lower rail, parallel to the lateral movement. Both are tapped for 3/8" tripod heads but have 1/4-20 reducers threaded into them. One is centered under the slide and the other is ~2cm to the side. They appear to be spaced so that you can use a plate similar to the Really Right Stuff MPR-73 to mount to your Arca-Swiss compatible ballhead.Finally, there is a similar 3/8" tripod thread and reducer bushing in the longitudinal slide if you want to use it without the lateral slide.

The quality of build on this Macro slider is good. It holds a Canon rebel T2i with battery pack, MT-24EX flash and an MP-E 65mm macro lens. Most of the camera shake can be attributed to the tripod head and tripod. An added bonus is the ability to split the forward / back movement from the side to side movement portion of the macro slider. What I don't like is the closeness of the two slide adjusting knobs making it slightly uncomfortable for adjusting. Also there are no markings on the knobs or rails to gauge any advancements in movement.