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# When small interaxials just don't cut it! - Page 35

Working between rain storms today but here is the wide angle NEX5n 10mm equivalent with 20" ( 50cm ) IA paired up. I'm standing about 7 ft in front of the camera. Normally I wouldn't shoot a principal object so close to such wide IA. My intended subject will actually be at a distance around the center roof lines of the 3 houses in the background. In front of the main subject will be water from the lake.

Second image is from the TD10 in full wide.

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When you set these rigs up are the cameras parallel or do they cross paths at a set point, and if so, how do you determine the point of intersection?
You can try to converge, but that is a litte bit tricky - I use a slighty dfferent hardware as Don does - ballheads where he uses Mantrotto clamps, but both of us use Igus sliders.

With the Sirui ballheads, what have a perfect mechanical stability, convergence can be done easier, since they have a separtate adjustment of the angle at the bottom of the ballheads. But the scale is not really fine enough. So I really recommend to shoot with parallel axis, what is seen as best practice by a lot of people.

The calibratoin of the rig can happen in 2 steps:

- first, you look for a horizontal axis somewhere. Distance 50-70m maybe. Can be a building for example. You go in full zoom and adjust the height of the cameras.

- if that is done, you go to a significant base - maybe 50-70 cm. Still in full zoom, you look for a far distant point. Distance maybe 1 or 2 km. Using the overlay grid in the units, you adjust both units to the SAME point. The trick is the large distance, where you converge near to infinity. That is not infinity really, but well enough in terms of pixel disparity.

I have also tried indoor adjustment, using cross-lasers. And I have tried adjustment in full wide angle. There will be a difference between full wide angel and full zoom - hopefully that is small. But that is something that you can correct in the postproduction, using the autocorrection in the s3d plugins in tools like Vegas or Edius.

Be aware that those rigs are not fine-mechanical parts really. That means, that you cannot achieve an adjustment to 1 or 2 pixel really. For my system the limitation are the Igus sliders, but since that part can be moved that cannot be avoided really. But you can adjust them. Go to that link and have a look to the video for the "tunr to fit"s:

http://www.amazon.com/DryLin-Linear-Motion-System-Sliders/dp/B0087U4V3W/ref=sr_1_1?s=electronics&ie=UTF8&qid=1345794261&sr=1-1&keywords=igus
Quote:

When you set these rigs up are the cameras parallel or do they cross paths at a set point, and if so, how do you determine the point of intersection?

Mostly what Wolfgang said is what I do with a few differences that he and I differ on.

My goal was not to just build a SBS rig but also a design that was simple and light weight for travel, not just by commercial airlines but also to back pack on mountain hikes.
My first design was patterned after the system built by Frank the Thread starter using set screws for alignment. The system used standard Aluminum extruded stock metal and was a chore to fabricate in my limited shop. It also was difficult to calibrate. Long before Wolfgang built his, I also made a second version that used ball heads same as his. While these were faster than the setscrews, the adjustment was just too coarse, added over 2 pounds of weight to the system, required calibration with every setup and raised the center of gravity for the cameras making it less stable in moderate to strong wind I experience on my high altitude locations. Then Frank designed his adding the dove tail quick releases from Manfrotto. He used the heavier ones but I went lighter for previous mentioned reasons. Both worked and taking extra time in the shop to calibrate the base of the quick release to the igus slide table using brass shims in a permanent mount ( but could also be dismantled if needed) I was able to achieve the present design that locked the system so I never needed to align and calibrate the vertical tilt and cross section rotation in the field again. I calibrate once and then it stays. The horizontal rotation as set by the position of the little foot that mounts to the camcorder 1/4-20 hole does need to be aligned with each setup, if you remove it. It stays aligned even for a week of shooting. To avoid even this alignment task in the field, I have semi permanently mounted that foot to all my cameras so everything adapts to every support, whether the monopod, a single tripod, SBS rig. The only camcorder I don't have one for is the Panasonic 3D1.

The igus system I use is the smaller one from the referenced one that Woolfgang referenced. Mine is about half the weight and works strong enough for the weight of the TD10's

To aid in the alignment of setting the two cameras parallel, I turn on the grid lines in the LCD screen. Both the TD10 and the NEX5n have them as an option in the menu.
Then I set the rig up in my shop and aim at a set of calibration distances I have on my wall. There is a center line with distances marked off from center. If the IA is set for 20" then I use the marks 10" left and right from center. The horizontal level and position should be perfect if the construction alignment was done with the shims properly. To get the cameras adjusted the only change is to twist the camera in respect to the little foot mounted on the bottom. This only needs a little nudging normally as eyeballing the mounting of it is actually pretty accurate. In the field, I would verify the calibration by setting the system up and zoom in on a distant object that I can use for reference, such as a building roof line that has known level and plumb lines in the design. Here, I just have to verify that the field assembly has not knocked things out along the way. To date, never have I had to recalibrate as the alignment has remained. So, I now describe this as just a safety check.

I briefly experimented with trying to converge the center points of the cameras on distant objects but found there was no real advantage to this exercise that was tedious and time consuming for no better results. Plus that would need changing with each shot. Parallel works and works for every shot distance.

Here you can see a part of the brass shim sticking out between the igus slide table and the quick release base that was used to tilt the left camera up angle to match the position of the right camera( not shown). Once calibrated these shims do not need changing, ever.
Well, that is right. The major difference is that Don uses the Manfrotto clamps that I have here also. But the mechanical quality is not so great, to my opinion - even if Don and Frank have here different opinions. I also have to state that the Sirui heads are much better then all the other ballheads that I have seen. That is a piece for great fine mechanics! And the Sirui clamps are great too. If the rig is calibrated, it holds the calibration for a significant time span.

But that is the major difference that I see. Beside that we agree that we make the final adjustment in the postproduction, where Vegas is great.

My experience with all kind of indoor calibration is that you can do it much better if you have a far distance object available. But that is a question for what purpose you calibrate your rig - indoor calibrartion can be fine enough for a lot of purposes.

At least to my experience, the consumer cameras are not exactly the same build. At least with the units that I had in hands. Maybe it is better if you can acquire units from the same serial production.

So there are different opinions, but they seem to deliver similar results. Today I would think about other - high quality - clamps, at least with the possibility to adjust the convergence to parallel axis - or to be able to converge the units better. A part that allows that is this unit:

http://www.ebay.de/itm/190580482826?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

http://www.ebay.de/itm/190583288090?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

To much weight for Don, but a great adjustment possibility if requrired.

They also nice rigs that look fine:

http://www.ebay.de/itm/SUNWAYFOTO-Stereo-Dual-3D-Camera-Rig-Arca-Compatible-w-300mm-Rail-Sunway-NEW-/360423801974?pt=LH_DefaultDomain_0&hash=item53eaeec476
Some interesting hardware. Thanks for posting those. Not for my SBS rig but something to keep in my memory for future projects.

One of the concerns I have always had with the quick release systems regardless of who makes them is the ability to lock the small dove tail foot to the camera in a way that alignment can be repeated. There is too much slop in the 1/4-20 screw and any way to make this permanent, is not a desirable alternative since it would be... "Permanent." As in gluing the foot to the camcorder so it never could twist out of alignment. I considered some additional setscrews off center that would be pinned into a couple drilled out holes in the base of the camcorder so that when the foot is screwed down tight it only would fit one way which is in perfect alignment each time. The little plastic pin is way to sloppy for this purpose. I've held off on that idea because it would need some holes drilled into the bottom of the TD10. That is very risky.

Any ideas?
I think that is much too risky. I would fix the plates and leave them on the camcorders. If the plates are high quality plates, they will not change their position.

Those plates are these ones for example: http://www.amazon.de/Sirui-TY-50-Schnellwechselplatte-Sliding-Arca-Swiss/dp/B004QC4TNC/ref=sr_1_14?ie=UTF8&qid=1345840006&sr=8-14

And the position is reapeatable, even if you take them out. Compared to what the rest of the system is able to achieve at least.
That Sirui plate looks to have more sloppiness in it's mount position than the Manfrotto due to it having a slot rather than a hole for the 1/4-20 screw. I don't get the red stops either and what they do to help. Regardless those plates even if they did only mount to the camcorder in one position would require a complete redesign of my entire system.

I rarely remove the little Manfrotto feet from my equipment since all my support systems have standardized 323 quick releases. But, I still recognize the one last weak alignment in my design. Just looking for a way to improve upon that.
No, there is no sloppiness at all. The red stops help to prevent that the cameras can fall out if you open the clams.

Same with the Sirui plates - if you do not remoeve them the alignment stays stable.
Quote:
Originally Posted by Wolfgang S.

No, there is no sloppiness at all. The red stops help to prevent that the cameras can fall out if you open the clams.
Same with the Sirui plates - if you do not remoeve them the alignment stays stable.

Ok, we're not communicating again.
The issue I have is not going out of alignment when the foot (adapter plate) is mounted to the camera. It is when you mount the foot to the camera, lining it up perfectly before tiightening down the screw. I can line it up by eye but it always needs to be fine tuned. My goal is to be able to put the foot on the camera and when I tighten it down it is lined up automatically, the same as when I put the camera and foot into the quick release. If I never remove the foot, I never need to do a realignment.

Thanks for the explanation on those red stops. I thought that's what they were but wasn't sure.
I see no way how we could avoid the realignment, regardless if we use Mantrotto, Sirui or other plates. That is why I do not tough the plates anymore, if the systems are aligned. I wish to be able to switch between the sbs and the beamsplitter rig, and that can be done - as long as I do not tough the plates.

But I think it is no issue really, since I do not tough the plates - is there a need to do that?
Quote:
But I think it is no issue really, since I do not tough the plates - is there a need to do that?

tough = remove ??

I rarely remove mine either but for some things I do. Both my TD10's are highly modified anyway so I may drill two small holes in the base next to the 1/4-20 fitting and add a couple pins in the foot adapter so when I mount it, it can only position one aligned way. It is on my "to do" list. I also need to do this for my NEX5n's too but I'm more reluctant with those.
Sure, remove or change their position.
Quote:
Originally Posted by Powerplay4

This video was made with two Sony Camcorder HDR-CX130, with stereo base 20cm and 28cm. Originally recorded in 1080p60. Edited with Sony Vegas Pro 11.

Milton,
this is arguably your most powerful 3D video yet. The extra interaxial distance gives a wow factor to so many of the scenes. I recognised many of the locations in Curitiba from your previous videos but this time the scenes really came to life for me.

There is the question whether to use the Sony Vegas stereoscopic adjustment tool. My own vision can cope with vertical misalignments of several pixels. However I suspect some people would be more sensitive. I would suggest use of the tool where the vertical discrepancy is more than a few pixels.

I thought your choices of interaxial distance very appropriate and effective. I didn't experience eye strain in the video footage itself.

There is the question in any 3D video of what apparent distance to use for superimposed titles. For my own vision I found it a momentary distraction to read the text at the bottom of a scene when it faded in. The text was in the apparent foreground. For my eyes, I would have preferred the text at a greater apparent distance.

I liked the pace of the video.

Jeff
I found also the time yesterday, to view that video on my 50-inch HDTV. I think the depth bracket is fine, what can be expected from the IA. Well done.

What brings me to the point why we do not discuss the relevant stereoscopic fators here really. For me that is in more detail roundness and disparity, that must be adjusted with the base to deliver a great s3D video.
I also watched Milton's video on my 32" screen and the depth was very nicely done. I felt like I was there.

I agree with Jeff however on the lower third titles.
I think the practice of using lower third design for titles in 3D is too old fashion and hold over from 2D video. I like to see stereographers take advantage of the 3D space and place the titles in the scene as opposed to always be in the lower third area of the screen popping out in front of everything. You just have to be more careful with occlusion. Also, using more creativity in the font or type face is called for. Don't go overboard with different type faces for every scene but a good selection of 5 or 6 different styles that compliments the theme of the story is what works. A good hint here is to just copy the style of the existing signage associated with the main building. Type faces or fonts will enhance the mood of your story.
Quote:
Originally Posted by MLXXX

There is the question whether to use the Sony Vegas stereoscopic adjustment tool. My own vision can cope with vertical misalignments of several pixels. However I suspect some people would be more sensitive. I would suggest use of the tool where the vertical discrepancy is more than a few pixels.
I thought your choices of interaxial distance very appropriate and effective. I didn't experience eye strain in the video footage itself.
There is the question in any 3D video of what apparent distance to use for superimposed titles. For my own vision I found it a momentary distraction to read the text at the bottom of a scene when it faded in. The text was in the apparent foreground. For my eyes, I would have preferred the text at a greater apparent distance.
I liked the pace of the video.
Jeff

Jeff, you're right. I was not able to use the AUTO CORRECT of Sony Vegas 3D Adjust. Today I found out why. In the video track option was selected in the Compositing Mode = 3D SOURCE ALPHA, I found that should be SOURCE ALPHA only. After much research on the Internet and after reinstalling Sony Vegas 11 is what I find out. But making mistakes is that you learn. In my next video I'll use the 3D AUTO CORRECT and then ask your opinion. Regarding subtitles, I will follow your and Don recommendations.

Thank you!
Milton
Very welcome.
Hi All,
Haven't been around for a while as a few might have noticed.
I looked at Don's latest and Milton's and I don't feel I can comment as my eyesight issues make it difficult for me to watch them without discomfort.
After my macula pucker surgery I hope to be able to enjoy 3D again.
Frank, I think we have missed you and I hope that you will be fine again, after the mcula pucker surgery.
Always good to see you posting, Frank. I hope all goes well with the surgery, and with that new business (which I'm hoping is somehow 3D related ).
Quote:
Originally Posted by Frank

Hi All,
Haven't been around for a while as a few might have noticed.
I looked at Don's latest and Milton's and I don't feel I can comment as my eyesight issues make it difficult for me to watch them without discomfort.
After my macula pucker surgery I hope to be able to enjoy 3D again.

Glad to see you still with us, Frank. You keep disappearing on us. ???

I did some reading on your surgery to learn what you will be in for. Seems you'll have to go through a lengthy recovery period of restricted activity. Just keep us posted so we won't worry so much.

Getting ready to do some extreme wide angle wide stereo base projects next year. The equipment is ready on the 3D side with 10mm lenses, but now working on my sound recording as these projects will require lots of live sound including one remote mic.
I also used google to find out something about macula pucker - so I wish you the best recovery from that. And I agree with Don - please keep us informed a little bit what is going on, if possible.
All the best, Frank. Please stay in touch.
You guys are great.
I appreciate your concern very much.
The surgery has to wait for a few weeks as I'm too busy with my company startup to take the time off and make the trip to Minneapolis.
On another note,
I just bought an Acer HN274H 3D 120 hertz 3D vision monitor for my office for viewing my designs in stereoscopic 3D using e-drawings from Solidworks.
Interestingly, I am able to view my models this way without too much discomfort.
I wonder if it has something to do with the fact that I can directly control what I am seeing as opposed to passively watching 3D videos.

P.S. I am streaming live 3D from my office via VLC media player onto the internet.
If anyone would like to view it let me know and I'll let you know how.
My wife and I are able to sit at home and view the live 3D from our living room . Pretty cool.
Quote:
Originally Posted by Don Landis

Glad to see you still with us, Frank. You keep disappearing on us. ???
The reason is:
Several things happened to me recently that pretty much made up my mind to put my interest
in 3D down the list of importance.
Fatigue from seemingly fighting a losing battle with the 3D standard.
(I require windowed 3D with the ability to vary the size of the 3D window. Nothing else is
acceptable to me. The 3D standard obviously doesn't support this.
Canon dropping the line of camcorders that I depend on for what I do.
(Vixia HF21 and Vixia HF-M32)
My total disinterest in anything shot in 24P. Yes, I haven't watched a movie in a long time.
My lack of enthusiasm for 24P goes back decades and isn't likely to change now.
My poor vision, especially in my left eye.
My new business which takes most of my time.

I still read the forum as I'm interested in what you guys are up to, it's just that I don't much much to contribute to the conversations.
Quote:
I did some reading on your surgery to learn what you will be in for. Seems you'll have to go through a lengthy recovery period of restricted activity. Just keep us posted so we won't worry so much.
Getting ready to do some extreme wide angle wide stereo base projects next year. The equipment is ready on the 3D side with 10mm lenses, but now working on my sound recording as these projects will require lots of live sound including one remote mic.
I like what you're doing with the wide angle lens setup. I am following with interest.

This camera setup is transmitting live 3D @ 1920 by 1080 sbs from my office building onto the internet using VLC.
I am able to watch/record and pan/tilt/zoom remotely.
It serves as a 3D security camera at the moment.
I can record both on the cameras and remotely record the stream.
Interestingly, I took a short clip that I recorded from the stream and tried to import into Sony Vegas and it makes Vegas crash.
This is somewhat surprising as all my video players play it fine and Adobe Premiere has no problem with it.
The clip is here.
my hard drive and it imports into Vegas just fine.
Quote:
Originally Posted by Frank

Hi All,
Haven't been around for a while as a few might have noticed.
I looked at Don's latest and Milton's and I don't feel I can comment as my eyesight issues make it difficult for me to watch them without discomfort.
After my macula pucker surgery I hope to be able to enjoy 3D again.
Frank, if I may, I'll add my own very best wishes to you, to the wishes already expressed by others in this thread.
Quote:
Originally Posted by Frank

The reason is:
Several things happened to me recently that pretty much made up my mind to put my interest
in 3D down the list of importance.
Fatigue from seemingly fighting a losing battle with the 3D standard.
(I require windowed 3D with the ability to vary the size of the 3D window. Nothing else is
acceptable to me. The 3D standard obviously doesn't support this.
Yes fully windowed 3D doesn't seem to be happening. I use Arcsoft Total Media Theatre for a single sizeable 3D window, though with my particular AMD graphics card it only gives me 24p, not 60i or 60p. I assume if I used a later model card I might be able to get a sizeable 60p 3D window.
Quote:
Originally Posted by Frank

I can record both on the cameras and remotely record the stream.
Interestingly, I took a short clip that I recorded from the stream and tried to import into Sony Vegas and it makes Vegas crash.
This is somewhat surprising as all my video players play it fine and Adobe Premiere has no problem with it.
Both Vegas and Premiere can be very picky. I've often found they would reject as source material what other software would play just fine.

Strong 3D effect for the foreground with the IA used. [Just within my comfortable range.]
Edited by MLXXX - 9/9/12 at 5:47pm
Quote:
Originally Posted by MLXXX

Quote:
Originally Posted by Frank

Hi All,
Haven't been around for a while as a few might have noticed.
I looked at Don's latest and Milton's and I don't feel I can comment as my eyesight issues make it difficult for me to watch them without discomfort.
After my macula pucker surgery I hope to be able to enjoy 3D again.
Frank, if I may, I'd like to add my own very best wishes to you for the surgery, to the wishes already expressed by others in this thread.
Quote:
Originally Posted by Frank

The reason is:
Several things happened to me recently that pretty much made up my mind to put my interest
in 3D down the list of importance.
Fatigue from seemingly fighting a losing battle with the 3D standard.
(I require windowed 3D with the ability to vary the size of the 3D window. Nothing else is
acceptable to me. The 3D standard obviously doesn't support this.
Yes fully windowed 3D doesn't seem to be happening. I use Arcsoft Total Media Theatre for a single sizeable 3D window, though with my particular AMD graphics card it only gives me 24p, not 60i or 60p. I assume if I used a later model card I might be able to get a sizeable 60p 3D window.
Quote:
Originally Posted by Frank

I can record both on the cameras and remotely record the stream.
Interestingly, I took a short clip that I recorded from the stream and tried to import into Sony Vegas and it makes Vegas crash.
This is somewhat surprising as all my video players play it fine and Adobe Premiere has no problem with it.
Both Vegas and Premiere can be very picky. I've often found they would reject as source material what other software would play just fine.

Strong 3D effect for the foreground with the IA used. [Just within my comfortable range.]

Edited by MLXXX - 9/9/12 at 6:33pm
I made another video in 3D using two Sony HDR-CX130. This time inside and outside the car using a 30cm rig (28cm stereo base). I had to write most of the images with two cameras reversed because they were secured to the windshield with a "Car Window Suction Cup". Then I reversed the images while editing with Sony Vegas. The final part of the video was recorded with the cameras on the outside of the car (29:19), safe in the windshield the same way as they were in the car, but in the normal (non-inverted). This second form worsened the stability of cameras. I'm buying two more "Car Window Suction Cup" to hold the rig in three points forming a triangle (see red arrows in the photos). Thus I believe that the rig will remain firm and will not wobble. Anyway I'm recording all the pictures with SteadyShot active. Sorry for the subtitles, but still could not place them correctly in the video.

I will also put a black denim cloth on the dashboard, attached with velcro to reduce the reflection of the sun on the glass when making video inside the car.

I will use also two UV filters on both cameras to protect the lenses in case of dust and stones, when recording with the camera out of the car.

Inside:

Outside:

Reflexion of the sun on the glass:

Thank you!
Milton
Edited by Powerplay4 - 9/10/12 at 10:44am
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