iShoot Improved Universal 150mm Macro Focusing Rail Slider Close-up Shooting Head All Metal Camera Support Bracket Holder, Built-in Arca-Swiss Type Clamp and Quick Release Plate for Tripod Ballhead

Does exactly what it's intended for. My copy is well built to tight tolerances and has very little play in the movements; none that affects usefulness.

The iShoot macro focusing rail is very well made and an excellent value for the money. It is made from high quality materials that are precision machined. There is very little play in the mechanism - which is really important in macro photography. The rail uses a worm drive design that allows precise adjustment of the distance of the lens from the subject. Even with a heavy lens on the camera (Canon MP-E 65 on an 80D body), I could not detect any slippage down hill when the lens is angled down - presumably due to the friction between the threaded rod, bearings and the threaded clamp that is mounted in the slider. All of the mechanism is exposed so cleaning and lubrication are possible if needed. I'd recommend storing the rail protected from dust to avoid the need to clean it. One issue with this design is that it is possible to touch lubricated parts of the rail so care must be taken to avoid spreading lubricants to your other photographic equipment.The rail can be mounted directly on an ARCA clamp on your tripod or you can use the threaded hole on the bottom of the rail to attach any quick release plate. The camera or lens is mounted on the rail by means of an ARCA quick release plate (not supplied). The clamp on the top of the rail holds the quick release plate securely with no detectable play. It is also possible to attach a second iShoot focus rail perpendicularly on top of the first rail using the same clamp if you want to provide controlled side-to side movement (I have not tried this).To adjust lens distance from the subject (and thus adjust the area in focus). you twist the knob at either end of the rail. The slider moves smoothly and hold its position well. The knobs are well made from high grade aluminum and are machined to provide a very sure grip. It is a treat to watch the area in focus move along the subject as you watch through the viewfinder. For large movements, you can press the quick release lever at the side of the slider. This disengages the threaded clamp form the drive rod so that you can rapidly move the camera/lens in and out. The quick release lever can lock to avoid accidents. There is also a knob on the far side of the slider that can fix the slider in position.I found the iShoot macro focus rail to be easy to use, precise and very well made. Obviously it is not as sophisticated as the $500 programmable electric focus rails but it is an unbeatable value for the price. Strongly recommended for those photographers looking for a simple manual focus rail.

First and foremost, the threaded rod should be left hand threads not standard right hand threads. This makes operation counterintuitive. Clockwise rotation should make something move away from you, but this is backwards. Think putting in a screw. Clockwise rotation makes the screen move away from you. Also every machine tool properly built on the planet operates like this.The half nut is loose enough that operation in one direction (moving away from large knob) gets so stiff it's hard to move without disturbing the setup.In attempting to fix it somewhat, I removed the knob, polished and deburred the bushings, added graphite and reassembled with a little less tension on the spring washer.It's in a usable state now but that lose half nut on the carriage still causes it to get tight. I'll probably disassemble further and add some shims in order to keep it in place.For the price, I expected to have to tweak a little but not this much.

works fine, nice details, sturdy construction, tested yesterday, recommend it!

I was surprised at the heft and build quality of this item. Very sturdy, which is pretty essential in close focus work.The movement is precise, with little slop. Be nice if it were easier to move the camera to another position on the rail more quickly, but I'll take slow and precise vs fast and loose any day in this situation. EDIT: I didn't notice it at first, and maybe missing from instructions, but if you push in the clutch on the side it releases it, and you can just slide the clamp back and forth without turning the knob. Doh.The dovetail seems to hold well in my clamp, and I've even used this for non macro work, where I want to re-orient the camara and get it more balanced on top of the tripod for say pano work.The only suggestion I'd make is to have a marking on the knobs so that without needing to look at the scale you could approximate how many turns you've made. I just marked mine.

Been hunting for a "precise" macro focusing rail and this was the second product I tried. It looked great and reviews at the time of my purchase were very positive so figured I would give it a try. Unfortunately, after the first 10 minutes of testing I found it completely useless for precise movement. There is some variance in the worm screw or slide which causes the camera mount to shift while turning the adjustment knob, which has far too much tension by the way. When trying to do a focus stack series of images at 5:1 that variance changes the composition a ridiculous amount, 1/4 or so of the entire frame. This is with the rail rigidly mounted to a thick heavy desk, not a tripod which can move. Returned it for a refund

This is a good focus rail at its price. I had a cheaper one, and that was a mistake. I like everything about it, except that the slider adjustment knob is very stiff and tedious to adjust for ten's of positions in a focus stack shoot.

Disclosure: I am no macro expert.I bought this to help with fine focus while scanning negatives with my a7Rii and a Nikkor 55mm AI micro with extension tube. For my purposes it works well. It has a solid build and I like the clutch for making a large movement.The one downside that I will mention is that the plate has a good amount of twisting play when you you have it unlocked to make fine focus adjustments. If you need extreme percussion this could be a deal breaker for you.Otherwise, I’m very happy with the product.