Before you start work, think again about the version of this camera you want. The movements might need to build in and the amount of complication you need to incorporate in have to be taken in to account at this stage. There is also no point in giving yourself work if you do not need to, or embarking on a complicated construction method, if you think it may be beyond your capabilities. A few minutes thought now may save problems later.
While I have been talking about making simplifications to my basic Field camera, this shows a more complicated version. It was build for a client who had special requirements. He wanted a 5x4 camera that was light to carry but would take very long focus lenses. It had also to fit the lens panel from his studio camera as well as the back and ground glass arrangement so they would be interchangeable with both cameras. I gave it a long square bellows and a triple extra extension. However you can still see the family resemblance it has to my other cameras.
This shows, starting from the top, the method I use to make the focusing platform for the camera. Ply and MDF users might want to make this from the solid. The metal runners for the sliding front lens support have not been shown or the rack pieces for focusing. Anyway they are fixed from below.
Below is the comb joint method of making the back. The sides are taped in pairs and the pairs clamped together offset by one tooth width. They are kept in this position while both ends are cut. This has to be done very carefully, particularly when marking out before cutting, if you want a neat job and a good fit when all the sides are separated and joined together. Do not forget the channel sections and holes that will be needed. It is easer to do them at this stage than later.
Finally, there is the simpler butt joint method. As I said in the text the easy way to do this is to glue the sides in their right position first and then drill the holes for the peg after the glue has set. Make sure the drill is truly vertical or it will come out in the wrong place. The pegs should be a tight fit in the holes you have made. Cut a narrow grove down each length-wise, coat them with glue before tapping them in place. The grove will allow the peg to bed down and any surplus glue to escape.
The first move should be to gather your main components. By this, I mean the lens you are basing the camera around, the bellows and the type of dark slide you want to use.
We will take the bellows first, as the final dimensions of the camera hinge on these important parts. While you can make bellows yourself, unless you are an expert your finished camera is going to look and even work better with a professionally made set. For my own 5x4in Field, I use a set intended for the MPP Technical camera. The Web is full of advice on where to go for this type of thing. In fact, it is possible to have a special size handmade if you have any special requirements. I always, as I have said before, try to use standard bought in components. It is less expensive and replacement is easier.
I feel much the same about dark slides and for the same reasons. However it is the sizes of these two parts of the project that dictate everything else, which is why you need to decide on them first.
Think about the camera you want. Are you going to stick to my design or do you want to simplify it? The most obvious simplification is to abandon the feature where the back slides up and down the baseboard. I build this into my cameras because it makes them more user friendly when using short focus lenses. By moving the front standard and the back towards each other so that the camera's centre of gravity is over the tripod, makes everything so much more stable when it is in use.
If this feature is not required, simply hinging the back from the end of the baseboard simplifies the whole job and cuts out a lot of work. The camera still can fold but you will not have to bother about the long slotted sidepieces to the baseboard. Remember what I said about not building in features you do not need.
The other simplification is to make the design non-folding. This means the baseboard will have to be shorter to prevent the whole camera being too bulky to carry about easily. However, a shorted baseboard means a shorter focussing extension. This is why I mentioned earlier that the lens you intend to use must come into your calculations. If lack of extension is a problem, then you will need to build in a second extension slide on top of the first one. A focussing knob does not have to control this; simply move it by hand. It will however, need a lock of some sort to keep everything rigid once in position.
Back to the task in hand, open the plan of my 5x4in model supplied here at the bottom of this section as a PDF file. You can then see the dimensions of everything when it is full size on your screen. If you start with the back, make this 180mm square. The wood used should be 180mm x 50mm by 8mm thick. In order to keep your wood neat and true you may find a sheet of glass paper laid on a hard flat surface, a thick piece of plate glass is ideal, will help. Slide the edges of the wood you want to rub down over the glass paper rather than the other way round. Keep the wood vertical by rubbing it against a larger block of square wood resting on the glass paper. This helps to produce a true right-angled edge as well as ensuring the longer dimensions are straight. It may take a while to do but the results are worthwhile.
To assemble this back, I use a comb joint. Cut these with care to make a neat job. I tape the sides together in two pairs then clamp the pairs together off setting one pair by the thickness of one tooth of the comb. After making the cuts, remove the wood between alternately. If you have done it right, when all the sides are undone, they should fit together perfectly. The illustration opposite will show you what I mean.
If you do not want to use this jointing method, you may find the following simpler. Butt join the sides together in the final shape using just glue making sure the resulting frame is perfectly square. You will have to shorten two of the sides by 16mm to allow for the over lapping thickness gained by this method. When the glue is set, you can drill down into each joint and peg it through with a piece of suitable dowel. The result may not be as pretty as a comb joint but it does the job. Before you glue everything together, using either method, you should cut 8mm channel round the inside 8mm from the back edge to insert a frame for attaching the bellows. You will also need a smaller channel cut through the inside of the bottom section of the back. This need not be more than 3mm deep and about 1.5mm wide. You can use a saw for this if the cut is the same width as the back hinge rod. The channel should run the whole length of the side and be 5mm from the edge. The purpose of this is to make a path for this hinge rod when attaching the finished back to the baseboard via the brass trunnions that I shall describe later on.
It is of course, possible to insert the inner frame later if screwed through from the outside to secure it firmly. If you use this method, you need not bother about the channel. This frame, when in place, forms a ledge to rest the camera's reversing back on as well as an attachment point for the bellows on its other side. Finally you will need a hole for a 2BA screw to provide the locking point for the back support strut set about 15mm from the front edge and halfway up the side and in the corner below it a smaller hole for the hinge rod. This should be 5 mm from both the side and bottom. This will line up with the channel you cut in the bottom side of the back. I also screw a strip of brass to the bottom corner of my camera back and make the hole through this as well, as it adds strength to a part of the body which is going to have both strain and wear.
Now you have a camera body that is big enough with space to spare to accommodate the MPP bellows, which measures approx 155mmx150mm around the back frame. I think it worth pointing out at this stage to those who do not already know, if you are thinking of using MDF for making your camera, the dust produced by cutting or sanding is an irritant, so a face mask and eye protection is advisable when working with it. During the construction of this camera, you will need to make several frames of different sizes. If you are using hard wood then they should be constructed by mitring like picture frames, but if you are using Ply or MDF there is no reason why they cannot be cut from sheet material of the right thickness in one piece. In the long run, it might be easier if you feel that the picture frame method is too daunting.
Next the base unit: you can make this as described earlier so let us imagine you have passed this stage. On my cameras I build, the focussing platform as a frame. I sink the brass rack into channels along its longer sides from underneath. This frame is made of the 12mm thick wood. I make the sides 180mm by 10mm and the ends 10mm x 150mm. I use tongue joints but you can of course use glue and peg system as already described. In addition to the brass rack, I let into the bottom, two brass strips made from 1.5mm brass 180mm x 10mm, that will provide the runners for the camera front. The reason theses runners at located at the bottom of the frame rather than the top is to allow the front standard more room to be fold into when the camera is shut. This frame will also now need a channel 1.5mm wide down its longest sides on the outside. Screw two more brass strips of the same size to the baseboard. The frame you have just made must now slide into the recess in your baseboard to using these strips as runners to provide the focussing movement. I make the way for the focussing rod that crosses the baseboard oversize to allow room for adjustment when meshing the pinions with the teeth of the rack. When you have added these and it all works smoothly, you can breathe a sigh of relief as the hardest part of the project is finished.
