Richard's macro rig

If you do not have money to burn but do want to start photographic macro work then this may be of interest. Because a bellows section alone cost £400 from Novoflex I wondered if I could build a rig (photo here) myself. The project is based on the 'Multipurpose Vice and 3rd Hand System' available from RS Components Ltd.. Parts cost around £70. You will need access to a lathe (and preferably a mill and a bender) for very simple machining work.

You can get a drawing showing the dimensions of the major components.

Mounting rail

Some means must be devised for supporting the camera, the light source and the object at the correct distance in relation to each other. The Vice System uses 1/2inch steel tube - which is perhaps rigid enough.

Base

RS Components sell bench mounting bases for the Vice System but these use ball and socket joints designed for light loads such as circuit boards.

For greater rigidity use a couple of pieces of angle bracket screwed at least 11cm apart to a table leg. In the upper one drill (& preferably ream) a 1/2inch hole. In the lower one fix a piece of 1/2inch rod with a 1/2 degree taper machined at the upper end to take the diameter down to 0.393 inches. After removing any burrs present at the ends of the tube it may be dropped down through the hole in the upper bracket and push fitted on the taper. Works a treat.

Object stage

My design gives you two choices for holding the item being photographed. The quickest method is by sliding a sheet of 'grey card' into the clips below the lighting stage and simply resting the item on that. This has the advantage of providing a background that is exposure meter friendly. A disadvantage is that larger items (such as the one with the red knob in the photo will either not fit at all, or the light may merely graze across the top.

The second method is to use some combination of the '3rd hand' accessories from RS. This makes it easy to adjust the position of the item in any axis. You can still use the grey card if required.

Lighting Stage

I rejected the use of flash early on. It's difficult enough getting everything set up right without adding uncertainty about exposure. Even if your camera can control a flash using TTL metering you are still left not knowing how even the illumination is going to be.

A circular fluorescent lamp gives a very even flood. Its disadvantage is a noticeable yellow/green cast. This is easy to remove using Photoshop but I intend finding a correcting lens filter some day (suggestions anyone?). You need to add a balast choke and starter (wiring diagram here). I couldn't find a connector for the pins but they solder easily. Put sleeving over the joints.

The basis of the design is a sliding collar made from 1inch square Duralumin bar about 35mm long with a 1/2inch hole drilled down the middle. This can be locked to the main rail with an M5 screw with some form of hand wheel on the end (I found the foot off a large piece of old equipment). One face of this block has four holes tapped in it to fix it to a beam made from 1/4inch thick Duralumin 32cm by 1.5inches.

Held on the same side of the beam as the collar are the ballast choke and the starter. On the opposite side is a U-shaped frame bent up from 3mm aluminium sheet. The lamp is held in this by four smaller U-shaped clips which have neoprene rubber linings to protect the glass. I made the frame the same width as the beam to which it is fixed but 2inches would be better.

Finaly, make up a perspex cover for the light stage. This performs three functions: it protects the user from contact with the electrics, it protects the lamp from damage from the camera and you can glue a sheet of aluminium foil on the underside to reflect light (that would otherwise go upwards) back down onto the object. Spray mount glue is ideal for sticking the foil. I bent the edge of the cover down over the ballast choke by heating strongly with a hot air gun.

Camera Stage

This uses a collar similar to the one on the lighting stage except that the lower end is milled flat and the fixing holes are tapped in there. Alternatively, you could make it on a lathe from 1.5inch diameter bar.

The camera sits on a 1/4inch thick base plate with a cover of thin rubber to prevent sliding or damage to its base (cardboard would do). The standard camera fixing thread is 1/4" UNF. I found a 1/2inch long bolt in my 'scrap box' and made a 2.5inch diameter wheel to turn it by filing a slot in the centre and eight spokes around a 1/4inch dural plate - a joy to use after years of bruising my fingers tightening the fiddly little ones that you get on tripods.

The base plate and the collar are linked by a platform made from (guess what) 1/4inch dural plate. The exact width will depend on what camera you use and (in my case) whether it has a motor wind attachment. The end of the platform is best milled square where it abuts the base plate.

Extension Tubes

OK, the best way to adapt an ordinary lens for macro work is to use bellows. I shudder to think how much a set of new Nikon or Olympus bellows would cost, let alone the rails that they require. If you can find any second hand then can you be certain that they will stay light tight? Still, swapping around extension tubes to adjust the magnification ratio is a big pain.

Final thoughts

In its present form the rig is safe for its builder to use. It wouldn't meet any approvals board specifications though, and I wouldn't let your kids play with it. Make certain the lighting stage is properly earthed.

Was it worth the effort? Well it undoubtedly does the biz. The light is not as strong as you could wish; on occasions exposure time will go over a second at f22 but for most jobs it will be adequate. Whether you will want to replicate this rig depends upon how important the saving of several hundred quid is compared to how much you dislike the metal bashing involved.

Parts List

Item Supplier Stock code
Mounting rail RS 546-360
Rod mounting clamps RS 546-366
Extension rod RS 547-026
Bar mounting kit RS 546-398
PCB Clamps RS 546-427
Jaw fingers RS 546-405
22W fluorescent lamp RS 570-464
Balast choke (240V 50Hz) RS 562-047
Starter RS 809-223
Starter holder RS 562-019
Neoprene strip RS 556-525
Insulation sleeving RS 399-912
Cable clips RS 819-387
Power switch RS 119-0592
Grey card Techno 035562
Extension Tubes Firstcall -
Spray glue Firstcall 26250
Parts list for Richard's macro rig


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E-mail:R.Clarke@surrey.ac.uk
Last modified: 2000 February 27th.