jonnyapple said:
...still, good enough for a rough estimate.

My kind of engineer, haha :^)

Just check the javascript yourself, Niko. It's obviously right. ;-)

function compute_parallax()
{

var f = document.parallax_calculator;
var pixels_per_degree = f.image_width_pixels.value/f.image_fov.value;
var nodal_point_shift = f.nodal_point_offset.value * Math.sin((Math.PI/180) * f.rotate_angle.value);

//convert offset to either meters or feet
if (f.units.value.search(/meters/i) != -1)
{
nodal_point_shift = nodal_point_shift / 1000;
}
else
{
nodal_point_shift = nodal_point_shift / (25.4 * 12);
}

var theta1 = Math.atan(f.dist_to_near.value/nodal_point_shift);
var theta2 = Math.atan(f.dist_to_far.value/nodal_point_shift);
var angular_dist = (180/Math.PI) * Math.abs(theta2-theta1);
//This isn't quite accurate for rectilinear lenses where one degree
//gets spread over a varying amount of pixels depending on the
//distance from the center...still, good enough for a rough estimate.
var pixel_error = angular_dist * pixels_per_degree;

f.angular_parallax_error.value = dec5(angular_dist);
f.pixel_shift_parallax_error.value = dec1(pixel_error);
}

Well of course it's true - it's on the internet....

NikoDoby said:

So should we start calling you praynpray now? We had a forum member named FerrariDad but after his divorce we had to start calling him bmxdad :^)

You know thanks a lot for reminding me, but I sure miss that Ferrari, but I'm telling you just one oil change cost and arm and leg, more than most DSLR's,

Pete

You know how do you guys know the info on that website is correct? I don't see an AMS, LMS, or Royal Statistical Society sticker anywhere on there certifying the results. I mean I know the internet never lies, but I'm just say'n :^)

NikoDoby said:
Ha, Ha, Nerds! They make life so much easier for the rest of us right jonny? :^)

Yeah, they sure do. ;-)

(even my wife calls me a nerd if you can believe it, and I don't make useful webpages like that one)

There's that great calculator again. I have it in favs now because it is really useful at this stage to me.

Cheers chaps.

Ha, Ha, Nerds! They make life so much easier for the rest of us right jonny? :^)

I don't know about miraculous, but you can type in a 0.5mm nodal point offset in the parallax calculator at this link to see how much that kind of error will affect the images in terms of pixels (it looks like less than a pixel for most indoor shooting, which I think I remember you saying you're going to use this for):
http://www.tawbaware.com/maxlyons/calc.htm

Ah, thanks mb. Whenever I have asked a question here before, people have miraculously come up with links to places with the answers I need but not this time it seems.

Well, I make it about 43.5mm and I can't believe that +/- 0.5mm will make much difference (I hope).

I will post a pic of it when it is done, but I am waiting parts from all over the place so it will not be soon.

I would really like if Nikon is to give all exact measures and technical drawings of their cameras publicly available, unfortunately this is not the case so all do it your self projects have to start with do it your self measures.

Beats paynpay!

spraynpray said:
Well, I guess I'll be getting divorced so a few more bucks for another head won't matter!

So should we start calling you praynpray now? We had a forum member named FerrariDad but after his divorce we had to start calling him bmxdad :^)

Change cameras? Well, I guess I'll be getting divorced so a few more bucks for another head won't matter! No seriously, I will just make another base plate.

You were clear. I just didn't read your post right. Sorry, I don't know that.
What happens when you change cameras, though?

Sorry guys, maybe I wasn't clear: Of course the nodal point varies from lens to lens for front to back positioning of the camera, it is the height from the base of the camera to the centre (axis) of the lens I need which doesn't vary whatever the lens used. I have measured it as 'about' 43.5mm, but I just wondered if any of you had any kind of tech data that gave it exactly?

Niko: Less (unnecessary) adjustability equals greater consistency in my experience.

Thanks.

jonnyapple said:
The tripod screw goes right through the axis of the lens, but if you're talking about one generic distance from the imaging plane to the nodal point of the lens, it doesn't exist. It's different for every lens, so I'd make it adjustable. ;-)

edit: PS, if you end up making one, I'd be interested to see pictures if you want to post them here. Has anyone else here made a panorama rail?

I have also though about making one, but it would be no point in making one that could not be used with different camera height, lens length, horizontal or vertical position

They are sure expensive to purchase, $300 plus from Manfrotta to who know what from Really Right Stuff

I want this one: http://www.gigapansystems.com/

Pete

Why would you NOT make it adjustable? Unless we're confused about what you are asking?

The tripod screw goes right through the axis of the lens, but if you're talking about one generic distance from the imaging plane to the nodal point of the lens, it doesn't exist. It's different for every lens, so I'd make it adjustable. ;-)

edit: PS, if you end up making one, I'd be interested to see pictures if you want to post them here. Has anyone else here made a panorama rail?

Hi Guys,

Is anybody here able to help me by telling me the exact distance from the camera base to the centre of the lens on a D5000? I want to make it precise and non-adjustable.

Thanks,