[frith]

I'll have to spread this one over a few days - I can't seem to find the time to do a full write up all at once!

Phase 1: Early design and Requirements.

So I have been trying to take some panoramic shots lately - inspired in no small part by the panorama contest held recently, and some of the fantastic photos that were the result.

I found that one small modification to my $15 velbon CX449 tripod would allow me to take decent single row panoramas - it has a 'flip' type portrait mode, and by turning the mount around, so the camera mounts on the 'outside' of the stand the point of rotation was actually pretty close to the nodal point of the $20 28mm lens I was using.

But the building I was shooting really needed a two or three row panorama to get all the trees and such-like in. Also the aspect ratio was so extreme that in order to get a print a decent height, it would be as long as the wall in our flat!

So I thought about it for a long time, played around with bluetak and such like, and finally decided to check out a 'real' panorama head. A bit of googling, and I found that many people had build their own DIY pano heads - there is even a flickr group of DIY pano heads.

The problem here is that the idea of me getting all those angles right, and getting everything square and adjustable just didn't suit my style of construction (which tends from 'amateur' to 'gonzo'). So the quest was on - how to minimise the number of adjustable factors to the bare minimum (from three in the typical 'nodal ninja' type head to preferably one or two).

I got it down to one adjustable joint, and a single hinge - more detail to come... (feel free to comment on how you might do it!)

[edward jenner]

Hello Frith.
For a multirow panorama that revolves around the nodal point (or entrance pupil if you prefer) you need at least two axis to turn. That will work with one particular camera with one particular lens.

Easiest if you put the camera in portrait mode.
The basis of any Panorama head is an L. You could even buy on L shaped bracket in a local hardware store; get a nice sturdy one.
The bottom of the L attaches to the tripod and to the top of the L you attach another bracket or thick metal strip to allow the camera to turn vertically round its nodal point.

The first Panorama head I built along those lines.
Later I built a fancier one, and now I intend to adapt that for my pentax M28 lens I have been wanting to use for panoramas. I will post a few pictures of my heads soon.

Good luck.
Edward

[frith]

Hi edward,

You make an excellent point - most panoramic heads are based around an 'L' type bracket. And its true that it would be possible (in theory) to make a fairly simple 'fixed' arrangement that allows only a single camera/lens combination. However, there are a few problems in my particular case with that option:

1. There is virtually zero chance of me being precise enough in the build to create a fixed system that finally results in the nodal point being in the right place.

2. I would like to be able to use a few different lenses with it.

Both of these requirements lead to the design needing a means of adjustment. And since the usual 'three L bracket' method requires three adjustable parts, my mission was to see if some of them could be merged together.

The first usable idea was to have a 'ring' around the lens, and as long as the ring is at the nodal point, it would be fairly trivial to get any lens to rotate around this point. That would reduce the number of adjustable parts to zero! (see first picture)

But this proved impractical in my case - the problem is that my lenses are manual focus, and this would not allow me to focus the lens. My quick analysis of the nodal point of my 28mm lens put it just under the focusing ring. As a side note, this 'gyro' mounting (I thought it had a resemblance to a gyroscope) would allow the camera to easily be mounted in both portrait or landscape mode with nothing more than rotating the camera.

But I was back to trying to mount onto the 'tripod' mount of the camera...

[frith]

The inspiration for the final design struck me while I was playing with my first tripod modification. When trying to get the next level, I was adding bluetak to the back and the front of the mount - at the back to push the camera forward, and at the front to increase the elevation of the front of the camera. It got me to thinking that this problem could easily be solved with a 'ski jump' mount - one with a slight curve so that the nodal point would automatically stay in the correct position when moving the camera forward or back...

I had also seen the rather groovy looking circular flash mounts made by 'really right stuff'. So my mind was now set - I was going to use a circular 'ring' mount...

The key benefit of the curved track mount is that once the nodal point is at the center of curvature of the track, no movement of the mount will move it from that point in space. And with some careful thinking, all that is necessary to get the nodal point to the center of the circle is a single adjustable track, and a hinge for the track to rotate on.

So I had reduced the design to a single hinge point and an adjustable rail. Also, the joint of the rail to the track could be a right angle - good for stability.

So its onto the build!

Attached Images

 

[frith]

So here is the part you have probably been waiting for. After all that consideration of the design, this turned out to be fairly straightforward. I don't have many photos of the build, but that would be pretty boring anyway I think.

A lot of it is old bike parts, principally because that is what I found lying around in the shed...

Parts:

1 old bike wheel (diameter ~440mm) [larger would also work, but smaller might be pushing it]

1 old bicycle seat post clamp (the bit that attaches the seat to the post)

1 length of brass tubing (~5mm diameter, ~400mm long)

150mm of M10 threaded rod (found in hard waste, a bolt would probably be fine)

2 short M10 bolts

1 smallish bolt - this will be hand-tightened, and I was lucky enough to find (what I think to be) part of a clamp - its threaded on one end, and has a large flat section that allows for easy hand tightening on the other end.

1 'slide' - I used a mounting bracket that comes from some strange thing. Its drawn in the attached figure

2 large washers - small enough to fit inside the rim of the wheel, but larger than the overhanging 'lip' of the inside of the rim. They should stay captive but sliding inside the wheel rim.

4 M10 nuts

1 short length of pipe, ID ~10mm (the M10 threads need to slide freely in this, but not too loosely)

1 length of wooden dowel - fits snugly into tripod center post, and the other end will fit into the slide.

--- camera platform ---
1 length of acrylic (plywood would likely work just as well)
1 1/4" wingnut
1 1/4" headless thread (this should mate with your camera's mount thread)
---

Tools:

Drill (I used a press, but its not necessary)
Vice (you might be able to work around this with clamps instead)
M10 Thread tap (for threading the holes in the slide to accept the bolts)
Angle grinder with cutting disk
Sandpaper
Tenon saw / Hacksaw (something fine enough to cut the acrylic)

Process:

First to bend the tubing into a sliding rail - I used a garden tap fitting as a template for the size, just clamped it into the vise and bent the tubing around it into a 'U' shape. The key detail here is to get the spacing of the legs of the 'U' to be about the same as the distance between the 'clamps' of the seat post clamp.

Drill a hole in the seat bracket on the 'front' side - this will be threaded for a small bolt to tighten the seat post against the rail.

Remove all the spokes and central gear from the wheel until you just have a circular rim. Then cut this in half with the angle grinder (using a cutting wheel), and cut one of the halves in half again.

Drill a 10mm hole close to one of the ends of the 'quarter' sections - this will be the primary mount, the others are for when you encounter situations where you need more range of movement.

Put the M10 thread through the hole, secure on both sides with a nut, then add another nut, and the piece of pipe, and secure the pipe with a final nut. This should give you a fairly securely attached threaded rod, with a piece of pipe on the end that you can now mount the seat bracket to.

Put the U shaped rail into the seat bracket, then put the bracket onto the pipe on the threaded rod. Secure everything with a spanner.

Finally, put the slide together by putting a washer on top, and then screwing an M10 in a short distance - it should not stick out the bottom.

You are now essentially done. If you happen to have a camera mounting plate that fits between the rails (as I did) then you can just slide that in, and away you go! However, if you want to make your own camera platform, it will give you a little more adjustment range.

If you are making the camera platform:

Cut two squares from the acrylic ~ 100mm side, and two strips ~100mm long and as wide as the internal diameter of the 'U' shape you have bent.

Drill a hole about 30mm from one end - this will take a small screw/bolt and nut that will keep it together.

Drill another hole about 30mm from the other end - this will take the 1/4" thread to mount the camera onto.

Put it all together - large squares at top and bottom, strips in the middle, and slide onto the U rail.

See the picture for the finished product. I think that will answer a lot of questions where my description is lacking!


Finally, I calibrated it by drawing the outline of a nearby fence on a window, using a chinagraph (grease?) pencil (I loosened the bracket bolts slightly to allow me up/down movements). This gave me the ability to easily calibrate it in two dimensions, although calibration was quite a mission...

[edward jenner]

Hello again Frith.

What an intriguing design. I must admit I find the bicycle parts esthetics most appealing.
How do you go about setting up this head for a specifics camera-lens combination? I mean, do you need to calibrate the setup every time set up the camera or is there some preset.
How do you take pictures? I mean, do you turn this head around on the tripod (which then needs to be level) or do you slide the camera along the bicycle wheel track?

Edward

[frith]

Hi edward,

I'm glad you like the aesthetics - I personally find it has a very 'mad scientist' feel to it.

In order to set it up for a specific camera lens combo, one must find both the correct 'rotation' of the hinge and the length of the track - this took a bit of trial and error. But once I had it set up for one lens, its a fairly simple matter of moving back and forth on the track to set up additional lenses. So its pretty flexible in that regard - although changing bodies requires a full set up again.

As for taking photos, it is as you say both times - the 'wheel-rail' rotates on the (level) tripod, and the next row is taken by moving the 'wheel-rail' up (or down) to get the correct elevation. Then the panning is done at the tripod-bracket join.

The camera 'hinge' point remains fixed - the points of rotation are all at the 'slide/bracket' point - that funny looking thing at the bottom.

Hope that helps!

Frith