Gigapixel Pan head for DSLR

[Kryten]

Hi
Im trying to make a gigapixel pan head for my Nikon D80.

Im looking to using a PIC18Fx and two stepper motors (one for alt and one for azimuth). I have been looking at Nigels exampel for controlling Steppers..


The big question is if its possible to make the unit programmable, so that i can set the parameters (no. of steps in alt and azimuth at home or via laptop) so that i dont touch the rig when im taking the pictures?

Or would it be simpler to use a LCD and (four) buttons to set the parameters in the field?

I have looked at HexWax's USB - 232 (or I2C) for doing so.

Can any one advise on what to do?

 

[mramos1]

I have a serial port on my PC and would go RS232. But the LCD and buttons would be a little more work, but totally portable, no PC or laptop to drag.

Since you went the 18F direction, swordfish basic is a good free compiler.

 

[Kryten]

Yes i think i will go for a set up where i define the width an height of each frame and for the entire picture.

Using arrow keys to set and enter (or something) to set. Im currently working on a schematics for the unit (2-3 boards I think).
Dunno what LCD to use yet ( I havent got any)

 

[mramos1]

A lot of the compilers have LCD support too. So might want to check that out too. Google should have a number of projects with LCD and buttons.

Atmel had an AVR Butterfly that you might want to look at too. Was $20 when I bought one years ago.

 

[futz]

Atmel had an AVR Butterfly that you might want to look at too. Was $20 when I bought one years ago.

They're still the same price.

 

[Kryten]

Ok!
Here's the "progress" so far.
I have made the decision to use a 18F4550 with a LCD and two steppers, external controlbox with 5 buttons (direction and ok).

Will it work with two steppers on the same port (stepper 1 on portD 0-3 and stepper 2 on portD 4-7)?

Is it much code needed to make the unit calculate the number of shots needed when i set the outer limits and shot size?

Would it be simplest to have pots to determine the limitations rather then counting the number of steps used?

 

[Kryten]

Will this LCD **broken link removed** be hard to interface (with just text)

 

[bryan]

Sparkfun.com sells a nice button set that would work nicely for your project.

SparkFun Electronics - Mini Button Pad Set - Red

 

[Kryten]

Ive got the buttons in a remote already but thanks.

 

[astronomerroyal]

I recently built a gigapan head, using an LCD and keypad so it was programmable in the field. The head is actually a precision head for motion timelapses, but I added the gigapan function for fun. 18F4620.

The bearings from a 'lazy susan' make a nice smooth platform for the pan.

I switch both steppers on one port. Assuming a unipolar 2 phase motor; calculate each motor's phase/signal (a nibble), shift one left by 4 bits, then OR them together. -> one byte containing both stepper signals, one in upper nibble the other in the lower nibble. these can then just go to ULNxxxx darlington arrays to switch the current.

use optocouplers for firing the pretrigger and shutter


A very good book (I use his keypad method - brilliant)
Designing Embedded Systems With Pic Microcontrollers: Principles And Applications
by
Tim Wilmshurst

LCD tutorial - hands down the best one i've seen - google 'Intelligent LCDs by Julyan Ilett'.

It's all quite easy, and once you have the basic routines, you'll consider using a keypad/lcd for every project.


When you're triumphant please post some photos.

p.s forget the computer, this is simple for a microcontroller. Long live Red Dwarf.

 

[Mike - K8LH]

astronomerroyal,

Bravo! Just wondering if you have posted photos of your completed project anywhere? I'd love to see it.

Regards, Mike

 

[Kryten]

Astronomerroayl

I would also like to see how your pan head looks so I can get ideas as for what im thinking is far off or not

Im planning on using a uC and LCD and keypad (arrows and OK/enter)

I have just not had enough time yet to start building.

As far as i can read you use a 8bit port for your steppers and used upper 4 for one and lower 4 for one.

Does your unit calculate the number of frames needed ?

Im planning on making it so that you set top left and bottom right, then the width and hight of each frame and the let the unit calculate how many stops needed.
Less work for me

 

[astronomerroyal]

I've taken a few photos with it, but not of it.

I was going to take some snaps of it later today and I'll put them up here. in the meantime here's a small testrun I did, I believe it's a small tiling of 2 frames by 10 frames. 200 million uninteresting pixels. Canon 40D. Effective 160mm lens.

Just don't tell the apartment manager that I have a drill press in my apartment...

 

[astronomerroyal]

As far as i can read you use a 8bit port for your steppers and used upper 4 for one and lower 4 for one.

Does your unit calculate the number of frames needed ?

Im planning on making it so that you set top left and bottom right, then the width and hight of each frame and the let the unit calculate how many stops needed.
Less work for me

Yes, 4 bits each. Had I some spare ports maybe I would've been lazy and given them a port each.

In my controller I have a ludicrously large menu system (because the machine was designed for a rather larger job than gigapans). In the gigpan menu I enter the focal length of the lens and how many frames horiz and vertical, the uC calculates the field of view and pointing positions. It factors in a 20% frame overlap to be safe. Actually the device has a 'dry run' mode which allows you to move directly to the end position. In this way I can check that the gigapan will have the correct coverage. Your method is, of course, the more sensible.

If you want the microcontroller to calculate the fov for a given lens focal length, the equation is,

Angle of view - Wikipedia, the free encyclopedia

This was the first time I used he Tan function in a uC and was appalled by how much memory it required. In fact it required that I move from the 18F4520 to the 18F4620.

 

[Kryten]

Well that sounds like a big job. I was planning on "just" making it so that you actually set the fov by using the arrow keys, and of course you must allow for at least 10% overlap (depending on the stitching software, im using autopano pro)

 

[astronomerroyal]

well, the functions were already there, so I thought I might as well use them fully.

If I were just making a gigpan machine I'd probably take your approach. Isn't that what the original machine does?

I tried using Photoshop's panorama thing but it failed miserably. Perhaps I had too little depth of field for it to work with.

Here's a picture of the contraption (mounted on an experimental motorized rail, but normally sits atop a tripod). the black box is just the motor driver. One light for each stepper pole. controller is still on a breadboard.

 

[Mike - K8LH]

That really looks very nice...

 

[astronomerroyal]

It's rather more than is needed for a gigapan, but fairly modest in terms of what is needed for good motion timelapse filming.

Nominally it has 0.03 degree precision, which means I shall definitely buy a 50,000mm (50 metre) lens and make a 100 Terapixel image of my apartment.

So far it's cost about 100 dollars per axis, several weekends, and many hours of gurning.

 

[Kryten]

Looks good and I am also thinking about making mine in a double fork configuration. I was hoping for some what less expensive but will see what happens.

And Im thinking about making mine with a self release so I dont have to shoot and "move" the camera

Edit
Have you tried Autopano Pro? here its really easy and gives a really good result

 

[astronomerroyal]

Of course, forget the worm gears (damn hard to find anyway). Use two (instead of my 3) steppers (but I strongly recommend NEMA 23 size for directly moving a dSLR). I used pricey precision bushing/shafts from servocity, but not necessary for the gigapan. The wood i found... Yes, a basic direct-drive rebuild of this would be ~100. I wish you lots of luck and don't forget the lazy susan.

I'm going to give that autopan a try, thanks.