Anyone bought the reald Stereo Calculator App?

[Nick Hiltgen]

So I get this email yesterday offering a discount on the stereo 3d course talked about in an earlier thread, frame forge 3d, and a new application for iphone, ipad and ipod touch from reald.

The catch is the application is 230 bucks. As much as I'd want to buy it so I could legitimately(ish) write off the purchase of an ipad I just can't help but wonder if 230 bucks is anywhere close to a reasonable price to pay for what appears to be such a simple piece of software. Anyone bought this yet?

RealD Professional Stereo3D Calculator for iPhone, iPod touch, and iPad on the iTunes App Store

This link opens up both a web page and the itunes info page.

[Mathew Orman]

If you wait a week I will sell you one for US$ 29.00
For the moment I have one for PC but working on iPhone one and should have it ready by next week.
With the package you would also get stereoscopic camera simulator in OpenGL
supporting: toe-in, parallel and off-axis camera geometries.

Mathew Orman

[Nick Hiltgen]

if it has the same functionality i think you'll have a great ap at that price.

[Steve Shovlar]

There's already one out there for $30.
http://itunes.apple.com/us/app/3d-mo...377269776?mt=8

[Mathew Orman]

Originally Posted by Nick Hiltgen

if it has the same functionality i think you'll have a great ap at that price.

Yes, it has the gimmick stereo mode like all of them but the unique feature is
the real undistorted stereoscopic geometry mode for creating stereoscopic content that is distortion free and matches the target screen size.
Also, there are support for toe-in, parallel and off-axis stereoscopic camera geometries.

Mathew Orman

[Alister Chapman]

There is also the very good Speedwedge app.

[Tim Dashwood]

I concur on Speedwedge IOD Calc. It has the most "bang for the buck" at $50 and is easy to use and understand.

[Leonard Levy]

I just got the 3D StereoTool app for my iphone and it seemed very cool but something has me confused and I'm wondering if I misunderstand something or if the app has a problem.

Also I tried going on the web and looking for other stereo calculaters and they all seemed to want you to set a near and far point and then the app would calculate the correct inter-ocular. However that seems backwards to me. I would prefer to start with a set inter-ocular -like 65mm and then see what the acceptable near and far points are for any given shot.

Ok specifically the 3D Stereotool lets you set lens in mm, inter-ocular distance and convergence point ( for toed in) . Now I would expect with those 3 parameters it would then show you the acceptable near and far points for a stereo window. However it also allows you to set a " far " distance on the stereo window and then calculates the near. So you can change the far point from infinity to anything while the convergence point remans set. That doesn't make sense to me. Shouldn't the convergence point determine both the enar and far?

How about the Speedwedge IOD. Will it let you set up a shot with a given inter-ocular and then show you the near and far points based on a given convergence distance?


Lenny Levy

[Adam Stanislav]

Why not just use a hand-held calculator and calculate it yourself? Why do we need a dedicated application for everything these days?

Just use the Bercovitz and Di Marzio Formulae that all these applications use anyway.

And if you absolutely must use a computer, why pay for something you can get for free, such as the BaseCalc application for Windows (including Pocket PC)?

[Pavel Houda]

Great link, thank you Adam. Given that I know my camcorders, I can probably pre-calculate for few situatios and remember the values. This doesn't need to be a rocket surgery.

[Adam Stanislav]

Indeed it does not. Plus, doing it yourself allows you to test the formulae for your own work and not rely on some hardcoded math that someone else decided should work for you.

Some additional links for those who want to get into the guts of the math are these two PDF links:

The Di Marzio Equation

The Di Marzio Equation for Stereography

The first one being an overview (10 pages), the second one quite technical (75 pages).

[Pavel Houda]

Thanks again Adam. I like to understand the basic theory and rules for these types of things, and how to be in a ballpark, but improvise as I go. I don't do theater movies. For me it was more useful to build the steresocopic/dual monoscopic previewing system for the cameras, that can let me see camera alignments, luma and chroma states, as well as if I am still in stereoscopic range, and other easily visible issues, than running a computer for the shots. Even though the resolution is poor, there is still a wealth of information one can receive.

I can see how that is useful for bigger production though, specially since one cannot preview on IMAX screen very easily.

I do enjoy to understand the theory behind it, so I can make sensible guesses. I mostly used the 30/60x rule so far, that I originally received from Tim Dashwood. Thank you for the links. It is fascinating to learn from it.

[Leonard Levy]

I'm sorry guys, I used to be quite competent in math when I was younger, but it is not practical to expect the average working DP or stereographer to have to deal with calculations or even articles like these. If it works for you great but if I can get a nice calculater on my iphone that I only have to plug values into, its a far better solution for me and I would guess the vast majority of other professionals.

I would be quite pleased if anyone would respond to my question about the StereoTool. Should I not be able to see the near and far points of a stereo window by inputting my preferred interaxial distance, convergence point and lens?

It doesn't seem to work on the 3D StereoTool and I don't get why not.

Can you do this with the RealD calculator?

Am I missing something?

Lenny Levy

[Adam Stanislav]

Originally Posted by Leonard Levy

Am I missing something?

Actually, yes. In the very first link I posted it shows clearly that the near distance changes if any other parameter changes. That includes the far distance.

It also suggests you limit your far distance to twice the near distance. But from what you are describing your fancy app does not seem to let you specify that. Hence the suggestion to calculate it yourself. It is not that hard. We were taking pictures long before the portable computer (or even the personal computer) and we got it right doing the calculations with a pencil and paper, though mostly straight in the head. Doing it with a handheld calculator is much simpler and you do not have the limitations your app is imposing on you.

The most complex of those formulae require addition, subtraction, multiplication and division. No trigonometry, no calculus, just things any 10 year old can do.

Anyway, if your app is asking you to give it the far distance, give it a far distance. Play with it. Try different far distances and see what it comes up with. Maybe give it infinity first and then keep it bringing closer until you get what you need. At first you'll be guessing. Very soon you will see a pattern of how it works and will take the guessing out of it.

[Bruce Schultz]

Lenny, you tried to help me some time back with an EX1 color rendering problem I was having so perhaps I can try and reciprocate here.

Why would you want a "preferred inter-axial" ?

The basic measurements needed to avoid background (and foreground) parallax or divergence is the distance between your foreground object(s) and the background. These measurements can usually be obtained with the help of a tape measure (foreground) and general guesswork about the background if it is very deep. Once you have these two numbers, then the calculators will let you know the minimum and maximum lens inter-axial distance to set to minimize or eliminate divergence. I can't think of a reason why you would want to do this backwards with a mirror rig because you would just be guessing at the proper inter-axial for every shot since the FG and BG distances would almost always be different distances from shot to shot.

65mm adult human inter-occular is fixed, but lens inter-axial can be adjusted in a mirror rig down to 1mm and out to as much as 200 - 300mm for deep distance shots - even further apart with side-by-side rail rigs. The key is understanding the relationship between the FG and BG distances as I've outlined above and then setting your correct inter-axial to maximize roundness and minimize divergence.

Now with the new Panasonic 3D camera, all of this changes and you actually do have a fixed 62mm inter-axial distance. Having shot it in tests recently I can say that it is going to change the measuring metrics used for mirror rigs and the IOD calculators will have to start making the kinds of "backwards" calculations you have requested. We'll have to see how the calculation designers handle that. The Panasonic 3D camera will be very limited in it's depth availability - Panasonic says 10 feet to 100 feet, but my calculations using it indicate a much more compact depth of 10 feet to about 50 feet. It's going to be a real challenge to use this camera as effectively as a mirror rig.