When small interaxials just don't cut it! - Page 21

Unfortunately, the alignment that you do does not work out for my camcorder pair. It took me some time to figure out why that happens. The result is, that if you zoom in and go back to wide-angle, the center position of the optic of one of my camcorder does not stay at the same position. So, if I adjust the camcorder in full zoom, this position will not be the optimum for full wide-angel.

To overcome that, I have developed another workflow for adjusting the two camcorders in wide-angel. I do following steps:

1. the tripod is in a horizontal position.
2. using a longer rapid change plate, I pre-align the two ball-heads.
3. then I put on the two TD10 units, and put them in full wide-angel
4. I have the crossline-laser on a second tripode, the crossline laser adjustes itself always in a horizontal position and is projected to a white wall, with a distance of about 2m.
5. I move the tripod with the camcorders, and bring one of the crossairs of the left camcorder in allignment with the crossline of the laser. A fine allignment is done by adjusting the camcorder with the ballhead to both the horizontal and vertical line of the laser. That is done in full wide angle.
6. I move the right camcorder in a defined IO, for example 50 cm what is the maximum for my middle sbs-rig.
7. On the wall, I mark a position that has the distance of 50 cm too.
8. I move the cross-line of the laser to that position.
9. Now I adjust the second camcorder to that cross-line, by adjusting the ball-head. The second camcorder is in full wide angle too.

Then the rig is ready.

Doing some shoots in Vegas, the autocorrection showed follwing figures:

- vertical offset -0,0043
- zoom 0,0019
- keystome 0,0013
- rotation 0,370

Roation was a little bit high here.

With the other method, where I adjust the rig in the full zoom and run it the in full wide angel, I had following figures in two independent tests:

- vertical offset -0,02/-0,0074
- zoom 0,0001/-0,0021
- keystome 0,0002/-0,0015
- rotation 0,147/0,262

So, my impression is that the figures are not soo different - but the vertical offset is much better in make the adjustment with the laser method. Still thinking about that.

I am not sure if I understand what you mean by "dove tail quick clamps" and "shims". Do you have a link for the parts you use?

Your procedure sure sounds complicated for use in the field.

The quick release is on Amazon: http://www.amazon.com/Manfrotto-323-...6853612&sr=8-1

I bought a minimum of three. One for the tripod fluid head, and one for each TD10. This way the TD10 could be mounted singly on the tripod. I then bought a 4th so I had one on my monopod too.

Aha, you mean the Manfrotto 323 rapid connect adapter - yes, I know that you use that. I use that too for the connection between rig and monopod.

The reason why I was reluctand to use that for the camcorders was that i do not see the correction possibility for the vertical offset. Unfortunately, especially with my camcorder pair I need that or I accept a higher vertical offset correction in Vegas - but for sure, the rotation figure could be better with that parts, what is high in my actual setting and the major disadvantage.

There is another good method to adjust the ballheads. One can use a longer platte and adjust both ballheads at the same time:
http://www.amazon.de/gp/product/B005...ls_o02_s00_i00

That's what the shims are for! It's more work in the shop but once you have the shims in place they are permanent and part of the assembly that remains assembled. I stated before, that I tried set screws but then these need adjusting every time I switched I.O. distance and I didn't want that. When I change vertical offset the vertical disparity remains identical per Sony auto correction number. If you remove the little dovetail from the bottom of the TD10, this action will require a final adjustment of the camera angle but the Vertical offset remains the same as before. The shims are responsible for this accuracy.

I first tried to use a shim between the TD10 bottom and the little dove tail fitting but this required too much repeat effort every time I removed the fitting. So, putting a shim where I have indicated allows it to be permanent and one calibration during initial construction.

I credit Frank here the Thread starter for convincing me to use these quick release Dovetails. Today, I have them for all my cameras, even the NEX5n and the 3D1 which allows me to switch off cameras fast and accurately. I'm considering building a second Twin Camera for stereo using the NEX5n which shoots in 1080 60p and has the ability to use wider angle lenses including a fisheye that does 180*° view angle. ( Disadvantage is no sync capability ) I'm still researching this decision.

This isn't a new or sophisticated idea but I was pleased at how easy it was to obtain a 3D effect from existing footage...

Old 2D video footage of a static scene, with the camera moving sideways, may lend itself to a convincing 3D version. The attached half-width side by side stereo pair was extracted from 50i video taken in 2010 with a Canon HV20 camcorder, resting on the ship's port rail and pointing north. The cruise ship was heading east (leaving the Port Canaveral channel for the Bahamas).

A satellite view of the scene can be found with Google Earth by "flying to": 28°24'41.09" N 80°35'46.85" W

The time between the two frames was 760mS. If the ship was moving through the channel at 6 knots, that would mean a distance travelled, and effective inter-axial distance of about 2.345 metres. [1 knot = 1.852 km/h]

No adjustment was made when combining the two extracted video frames other than changing them to half-width.

(I also found it possible to create a reasonable looking 3D video in Vegas Pro, using the 2D footage as two time-offset sources for Left and Right.)

Well, I have here now the same experience with the ballheads. If they are adjusted, you can change IO and it does not matter. The SIRUI ballheads are pieces of very fine mechanics, it is also possible to remove the camcorders and put them in again, and the alignment is still fine. So from that side the systems seems to be compareable - even if the ballheads are with 0.4 kg heavier, for sure.

One additional reason that I have for the ballheads is the question of convergenc adjustment. My first tests with an IO of up to 50 cm and parallel axis were fine so far - but I reach the limit of the 3D-Vegas-plugin if I wish to adjust convergence to the positive divergence. With the ballheads I have the possibility to adjust the convergence angel - not very accurate since the scale is in 5-degree steps only. But it is possible to adjust convergence. Especially for hyperstereo that will be important, to avoid to loose not too much of the video footage.

But in addition I will order the Manfrotto 323 rapid connect adapter too. To collect experience with both methods.

The Pulfrich effect is very effective. I've been using it for years with recordings on various van tours around Hawaii. I've been thinking about converting that video to Bluray 3D so I won't need Pulfrich glasses any more.

MLXXX- Looked great! I may try that on our HT cruise in November. Thanks for the idea.

BTW- the NEX5n shoots 3D the same way but you swing the camera in a horizontal arc while the camera bangs off a bunch of pictures. Then it processes them where every other picture is stitched together to give a series of them left right left right left right etc. When done you get a wide panorama in 3D. I shot a bunch of these in Valley of Fire and Bryce Canyon. I have a novel way I will be presenting them in the video.

Very nice, Frank! I've missed your nature videos over the Winter.

Hey- I have a suggestion for you in the Lanc Shepherd. This should work especially well with the Merlin. Instead of mounting the Lanc Shepherd on the camera backs, make a forearm strap and mount it on the forearm you hold the Merlin. Then with your free hand you can operate the Lanc shepherd controls like the zoom, and not affect the camera balance, i.e. continue shooting steady as you zoom in. I've been playing around with this idea myself.

That is a nice video and a nice idea. What is the IO of the two Canons on the steadycam? And I liked the bear too.

Well, both 76 mm and 89 mm are fine. I have no experience now the a Merlin, even if I have to say that I think about to use that too.

In terms of IO, the two TD10s that I use have a minimum IO of 100 mm. What is a little bit large, but on the other hand I have both the TD10 itself with the 31 mm and the Z10K with 41 mm.

Well, then your wife is near to me - ok, if you think that Vienna-Frankfurt is at least less compared to Frankfurt and the states. My wife is from Hamburg too - so the world has become small.

What is a long time? I have tested the synchronisation with the ste-fra LANC

http://www.digi-dat.de/produkte/index.html#stefraLANC

and have seen that my two TD10s runs 30 minutes without any issue synchron, even longer if I accept more variance (up to one hour).

The Canons are great for sure, but I am a fan of 1080 50p for recording, since I am able to produce any format from that. That is one reason why I use the TD10 with 1080 50p recording - the PAL versions do not have 1080 24p what I would like to have for 3D Blu-ray, but the PAL versions have 1080 25p or 1080 50p only.

Right, that is why see from time to time pairing actions for camcorder. My two TD10 show another issue: from time to time - not every time - the length of the events are not the same. I see that after the import in Vegas. Up to now it is not clear to me what happens here.

And there is an other issue with my two TD10: the optical system is not very precise - if I adjust the camcorders in zoom I have another adjustment compared whe I adjust them in wide angel. Should not be - but is so.

Well, we are taking about consumer units....

Frank- When I first got the Lanc Shepherd from you, I had a few problems getting the two TD10s to sync up. But after some practice, I found some menu settings that resolved the problems. I had to switch the on -off of the LCD screen open so it did not switch the TD10. Then I needed to make sure the camcorders were both in the full wide angle setting before connecting the LANC cables. Now turn both off and then connect the cables. Now turn the system on with the Lanc Shepherd button.
I had hoped that the LacShepherd would sync the exposure setting if I manually set it in the Master side and then have the slave side track it but it does not do that. So, I end up setting my manual exposure on each camera individually. Also, I only shoot the TD10's in 1080 24p 2D mode using only the left side cameras. I recall you were experimenting running the twin cams in 3D mode and then selecting a mismatched pair like master on the right using left cam and slave on the left using right cam to get a closer I.O. I never do this, ever. That could be the source of your run away sync, just guessing.
I also slate my clips with audio announcement to both cameras at the beginning and at the end. My pairs are always a match, even for 45 minutes which is about the longest roll I have done.
According to the hyper stereographers I have talked to the process of alignment in Vegas requires that the two eye files need to be matched to frame sync using quantize to frames only. Be sure the alignment is done that way even if the audio seems to be a few milliseconds off. Consequently, exact frame sync to the microsecond is not important as is both pairs have the same frame alignment. This is why you can shoot stereo without a sync device but it limits your work creatively. Because we can pair this way in Vegas, getting the two camcorders to be exact same startup on record is not as important as having the frame size the same and cameras parallel.

While you were hybernating with your bears , I was out shooting this rig and have gained considerable experience with what works consistently and what is irrelevant.
Much of what didn't work in the field can be corrected in post. Like differences in color balance and contrast. Vegas is a powerful tool for pairing stereography.

I had this nice stereo base calculator for my laptop I had been using but this year have decided to retire the PC in favor of my ipad. But I missed my calculator. As I was waiting for a render to finish up, I decided to research this highly specialized tool in the ipad app store. I found one that looks nice and is easy to use. Anyone doing hyper stereo base shooting will appreciate this:

This looks like it will work on the iphone too.

Here is another tool I like that helps me determine the distances for my large stage sizes to zero in on more accurate stereobase settings. It also is useful for setting up cameras to shoot super wide I.O on individual tripods and it has a level indicator too. You can get less expensive ones but in stereography shooting extreme large scenes like I do, the cheap ones have limited range, maximum up to 100 yards. This model will not spot a deer at 2000 yards but it will spot and measure a house at that distance.

http://www.amazon.com/Bushnell-Legen...I2VQCLWFC63RL8

I was also thinking about a laser distance measurement - it is afforable. At the moment I suffer from the optical limitations in my systems. Don, you see for your TD10s that you can zoom through the optical system and both camcorders behave in the same way? So no breakout from the optical achse?

In terms of a separate 3D comapct camcorder, my TD10s are fine - but I can decide to shoot either in wide angle or in zoom, but cannot adjust both at the same time.

Thank you for the video - that is nice. Compared with your video, I would estimate that the deviation in the height with my system is 4 to 5 times higher, compared with your system. I see your camcorders has such an error too, but it seems to be less significant.

Frank- It is normal to have to do auto correction for any paired file set. I never pair a file set without also adding the auto correction at least once. You can do the correction manually, but it's just much harder.
If I never zoom during a recording, I only do the auto correction once. If I zoom, then I do a keyframe in the beginning, KF #2 at the beginning of the zoom, KF#3 at the end of the zoom and this holds until the next zoom. Some times I'll even slide to a new IA a is also requires a keyframe at the beginning and at the end of the IA slide. There is another time when keyframe auto correction is mandatory, this is when your primary subject moves in Z space. Again set the keyframe at the beginning of the move a ain at the end of the move. These are the times they taught us in the Vegas class on 3D editing.

Wolfgang- Are you telling me your sync device does not hold a match between the two TD10's while zooming? The device you have is supposed to handle that not just a simple zoom but also variable speed zoom. That was the primary reason I was considering upgrading to it. I would contact the source and see if you are not doing something right. As long as my two TD10's are full wide when powered up with the Lanc Shepherd, I can zoom in and out with the Lanc Shepherd zoom control and the two track perfectly. However, if I touch either camcorder's zoom while recording only one will respond and this throws the recording out of sync. Rule #1, with the Lanc shepherd, don't touch anything on the camera except the manual adjustment knob for exposure. Control everything through the device.

If you use the 3D-stereoscopic plugin of Vegas for the track but not for the event, if you enable the keyframes for all the corrections you can position the cursor at the beginning of each event - start the auto correction and generat a keyframe for the specific event. You have to enable hold for the events, but that can be helpfull if the correction changes due to different wide angle/zoom settings.



No, only because I zoom the camcorders do not become asynchrone. And yes, I control also zoom from the controller device, and the device has different zoom speeds - what is a great feature. So it is not a question of sync - it is a question of the optical system that I see here.

Maybe the answer to my problem could be, that the optical axis of the camcorders are at a different heigth. And that is something that I cannot correct with my ballheads really, I can only do an adjustment for either wide angel or zoom. But if this is true it should be possible to increase the heigth of one camcorder a little bit, by laying something between the igus and the ballheads.