When small interaxials just don't cut it! - Page 23

Somehow I have overseen that posting. Do not know why, only Franks comment made me look up and then I have seen it.



Well, at least it gives me some objective information how this first couple behaves - and I will be able to compare it to the second couple. Yes, it could be done easier maybe, but it is also part of a learn process.



I see here a clear advantage. Since the mechanical precision is better, I think that you able to get more reproduceable results. MAYBE. You know, from a technical perspective you have a system with a lot of bottlenecks and constrains. When you clear a bottleneck, you will run into the next one. So the ballheads generate the better mechanical precision - but I do not know yet if that is important really, since maybe the next bottleneck will prevent us to utilize that benefit. Or it helps us. Whatever the next bottleneck is - maybe the precision of the optics, maybe of the Igus parts - I do not know yet. But my idea was to get a higher precision. If it turns out that it is worth nothing - well, then I have here the Manfrotto parts too.


Well, that is not impossible. Maybe I can shoot some photos.


But with regard to the results: my interpretation of the figures - and the most impressive result was the test with the simple cross in - is that with that cameras it is not able to end up with the optical pairment of the two cameras. At least not in zoom.



Sorry to hear that.


Yes, I assume that you are right here. There will always be some standard deviation, especially at the edge of the system. And with full zoom we are at such an edge. Like you I expect that a pair of cameras must have a standard deviation in full zoom. The question will be how large that the variance is for the new pair - since I am not able to purchase TD10s in an endless way.

But my error was that I purchased the two cameras with a distance of one year - and there my be changes in the production or they use other settings.... and then the TD10 is still fine if you use it as intended, but not to use this unit in a camera pair

I have ordered another TD10, and I will see what are the deviations with another new camera. I have ordered it from the same dealer, who has still 3 pieces left (and since the turnover with the old TD10 is still limited yet, there is a good chance that this second camera is from the same production charge as the other one - but I will see that after some testing). But it will take the dealer 3-4 days, since the camera is not in Vienna yet.

Since I have now some experience how to measure and compare two cameras, the next comparision should work fast. At least to know it the new pair behaves better in terms of synchronisation and optical geometrics as the old pair.

And if the new pair works fine, well then I should be able to compare also the effect of the Manfrotto 323 and the ballheads.

You could shoot the twin TD10 rig you made with your Z10k and then just post a frame grab. I just wanted to see what the rig looks like with your ball heads in use.

I think the ball heads do offer one advantage over my semi-permanent shims. IF your setup is out of alignment, you can quickly adjust the ball heads and get working quickly. On my system, and Frank's, the alignment is not so easily adjusted in the field. But then after nearly 9 months of use, it has been locked down accurate on every setup. And every setup takes less than 2 minutes including final angle calibration.

Frank- When I zoom with the two TD10's in sync using the Lanc Shepherd, starting from full wide or from full telephoto, and stop anywhere along the way, the edges of the frames of both the TD10's are really close to being identical. I have no trouble getting excellent alignment with the two cameras.

I will shoot the rig - but today I had another exercise. I had ordered a set with longer 1/4 inch screws, suitable for our video and photo equipment. Not easy to receive, here in Europe where the measures are metric. The idea was to be able to increase the heigth of one of the cameras. A first estimation has shown something about 4 to 5 mm - and my impression was that this is much.

Ok, I did the increase with some metall plates and longer screws from the set, adding them between the Igus sledge and the bottom of the ballheads. The amount to bring the two optical axis to the same level was not 4-5 mm - it was 7.8 mm (!!). No idea why it is soo much. But fact is: now I can focus in full zoom the centered test cross on the wall, and zoom out and in - and the test cross does not break out any more. Means, both optical axis are now centered really, at the same heigth.

Off course, there is a divergence in the margin of the frame, if I am in full wide angel - something about 1.9% or 20 pixel. I think that is acceptable.

So that results looks fine so far.

That has to be something in the ball head. With that much difference in height, you should have seen the two ball heads were not the same height. I can't imagine The Sony optical block construction being that sloppy. In fact, I have seen the internals of the TD10 and there is just no way they could have that much slop internally. There is hardly a mm of room under the hood.
In my construction I used a single brass shim .002" on one corner to adjust for a slight rotation from level. That's about .05 mm.

There are different ways how one can check that - for example switch the cameras and you see the effect is sitched too. Or measure the ball heads height direct. No, the ball heads are high precise and have the same height. And it is also not the image stabilisator too (that is disabled). It are really the optical systems of the two camcorders.

I have purchased the two TD10s with a time-distance of one year, and yes I see here such significant changes. I agree that this is unbelieveable, but unfortunately it is so. For me there are two possiblities: either I sell the old TD10 via ebay, and purchase a new one since that is ordered. Or I cancel the order and stay with the now working solution, where I can now use the full wide angel-zoom range, but have to trimm the edges of the video for sure (but that happens anyway). Hmm still think about if I stop the running order.

No I do not think that it is removed - it is disabled, that is all. My point was only that it was disabled.

I am still thinking about different kind of errors, that are here acting - in a combination maybe. An error in the height. Maybe an error that the optical axis are not parallel really.... and maybe other things.

I assume that there is an overlay of different errors - otherwise I would not still see the 2% variance in wide angle. Think about how to correct that too.

I think Frank may be on to something.

The OIS will move the image considerably. I have seen it on screen when the camera is moved quickly and stopped. The movement is as much as the ~8mm you measured, Wolfgang. But you claim the OIS is shut down. What if when you shut down OIS in both cameras and the OIS locks the lens in a different position than the other camera? This would indicate one of the cameras may be malfunctioning and locking the lens position, not centered, but where ever it happens to be. This could be very bad for any sort of consistent alignment.
OIS on the Sony is done in two ways, what makes it superior to other brand camcorders. It does the usual electronic image stabilization based on pixel match and also does a mechanical kind of shock absorber strut stabilizer ( kind of a micro steadicam mechanism, originally developed by Canon Broadcast)
On my TD10, if I have it on the tripod and OIS is active, and I bump the tripod, the image on the screen will move to try to compensate and then slowly move back to where it was before. The reason why you don't want OIS active when using a tripod is when you pan the scene the OIS will cause the pan to lag the movement and can over reach the pan, then backlash.
If you have a third TD10 on the way, it would be a good idea to find which one is not working properly, whether or not it is the OIS lens lock for off position.

That is an interesting idea. But would that not mean that the stabi blocks everything?

Well, I did one test: the aligment was done yesterday night with disabled stabi. This morning I wanted to see if there is a difference with enabled stabi. And there is another background - if you activate the automode, the TD10 will enable the stabi anyway again. So I enabled the stabi to see if there is a difference with regard to the cross test. But I saw no difference.

Would the step, to enable the stabi, not mean that a reset of a locked position should have taken place? Means, that the 8 mm should have been wrong again. But that I have not seen.

Maybe there is another issue. One error seems to be that the axis are not at the same heigth. The second one could be that they are not parallel - so they cross each other if you look from the side. My (theoretical) assumption: a full adjustment is achieved, if the axis are parallel and build a plane. And that plane must have an right angel with respect to the projection plane - so here the wall.

So with the actual adjustment, I should have a similar heigth - but I wonder if the axis are parallel really. So I think I will adjust next in the wide-angel the full picture - and then I will have a look how well the zoom is still adjusted.

Yes I agree with you: if somebody uses this older TD10 as it is designed to be used, the unit works fine for him. But in a paired cam system you have troubles with this unit.

I have to assess if I stop the second new camcorder that is orderd. I will try to adjust the 2% better. I could live with the 7-8 mm, but I think about if I am willing to live with the 2% vaiance in the wide angel.

So I will try to adjust the 2%, and then I will have a look to the 7-8 height adjustment. Is it possible to find a combination where the older TD10 works both for the full zoom but also full wide angel? So, that the 2% variance go away and the heigth position is fine too?

So that will be the interesting exercise in the evening.

Well, it has not worked out yesterday evening - even if I did not have a lot of time for testing.

I will receive today another TD10, and I will see how that comes out. Hopefully better!

Well, I would be happy if it has a better match - I am not looking for the perfect world with consumer cameras.

But thanks a lot, the story becomes boring.

Bingo! The two new TD10s fit really nice together, in terms of optical geometrie. The full zoom can be adjusted well, and then the full wide angel fits nice together too. That is something that I have not seen with the old TD10, and is that what Don describes all the time.

The adjustment with the ballheads is fine too, they have been adjusted in some minutes. My impression: that seems to be stable - maybe it holds even if I take off even the Igus slides. But that is something that I will check.

So at the moment it looks really nice. I have not checked now the drift in synchronisation, that is something that I still have to do.

Glad you decided to not cancel the order. There was just too much to gain by testing the third camera. Interesting that the one TD10 is so far out of alignment.

Now you can do some meaningful simplifying of your system for speed and convenience in the field.

Yes, I am glad too. I think about what to do with the older TD10 - it works well, maybe something for ebay. Or I keep it.

Simplification of the system: the first decision is, what convinience you want to have - in terms of adjustment. For me that are 3 points.

1) What I see here even with the new TD10s is that it is necessary to adjust the inclination and bending a little bit. Not sure if that are the right words, but I think you know what I mean.

2) To shoot with parallel axis or convergence - hmm, also a decision if somebody wants to have an easy adjustment here.

3) To have the same alignment of the cameras again, even after taking off the Igus slide.

For me, this 3 points are the quality level that I can think about. The other questions are for sure speed and weight.

Well, both Frank and I have come to the same conclusion. The Manfrotto quick releases are sufficiently accurate in repeat setup without adjustments. While I believe I do much more travel with my system than he does, weight and quick assembly play a very important role for my operation.
I would like to have the final field calibration lock in too but haven't figured out a way yet. That is the alignment of the foot of the Manfrotto quick release to the bottom of the TD10. Fortunately, as long as I don't remove it, the alignment stays where I last calibrated it. It is also that alignment that will set the convergence point at your target or behind the target ( parallel) but I generally work with parallel. I have found only one stereographer who recommends convergence at the target and that is you.
Besides, out that far away to my targets on wide stereo base, it is very difficult to claim where it converges.

I don't like converging the cameras on a distant object when there is significant background behind the object which is mostly the case in my shooting. This behind the primary target subject matter will result in double imaging as the camera images cross over at the converged target. Convergence of the cameras could have an advantage when shooting excessive I.O. for close up objects that would cause double imaging in the foreground due to an I.O. that is too great. This is why I like to have that calculator handy. If I feel I may be shooting targets in a foreground that the I.O is excessive for, I consult the calculator and if those objects are indicated too close, then I can either slide my cameras closer or converge them. Since I don't have a precise way to align convergence quickly such as your servo or the $$$$$ rig I got some hands on time with from Technica3D I choose to decrease my I.O. and achieve the same thing without creating double images. I'm happy to announce that none of my shooting at Valley of Fire or Bryce Canyon has double imaging due to targets located too close or background scenery. When I experimented with convergence, it became quite a difficult thing to get right since I didn't have a high resolution 3D monitor and my system really wasn't designed to deal with convergence.

Well, make it better three. The third is Cameron who has shoot Avatar with converging cameras.

I like to shoot with parallel cameras too - for one reason: the disparity you end up can be low at the end of the day. However, you pay a price for that - the horizontal adjustment tends to be the IO at the minimum, as long a you wish to move everything behind the zero window.

I think it depends. I agree with you - for a huge IO this adjustment would be too large, for hyperstereo we must converge camcorders to avoid a disparity that would be too large. If I shoot in a room with the TD10 or the Z10K, you may have good results with converging to the nearpoint, but then you must maintain the minimum distance to avoid that the disparity become too huge in the farpoint. But here parallel axis are fine too, but need more adjustment. A good compromiss could be farpoint convergence, since it tends to middle between horizontal adjustment in the postpro and limits disparity too.

In terms of weight: I purchased today a travel tripod that I wish to take with me to vacation - must be able to carry that - 800 g carbon stative from Sirui

http://www.amazon.com/Section-Carbon...7894573&sr=8-1

what should be able to burry 10 kg - well, I do not believe that, with my two TD10s and the Igus it tends to be at the end. I combinde that with a Manfrotto 701 HDV with other 830 g.

The weight of the Manfrotto 323 is 168g, of the ballheads 494g. So to exchange the ballheads against the 323 clams brings you 652g, something that we should not underestimate. My total system with the two TD10 cameras, with two strong accus, the controller and the 60 cm Igus system is 5.5 kg - so we talk about 12%.

Don and Frank, what is the weight of your systems? Don, from your pictures I saw that you use the 701 too - and the Manfrotto seems to be a carbon stative too but I was not able to recognize which one it is. You use the small accus I think.

My basic carbon fiber/mag tripod is a bit heavier than stock, because I added the 556B Ball leveler option. The 4 stage tripod is a Manfrotto 190MF ( earlier model to the 190CXPro4 which I recall only difference is a new design center column.)

and the head is the 701HDV
Total Weight: 5.15 pounds

The igus 26" rail with 2 igus slide tables and 3 Manfrotto 323 quick releases brings it to 9.4 pounds. I also have the 32" igus rail and a 39" rail but these do not fit in the tripod case. If I need additional length, I have a tripod case that I switch to for the longer rails.

What I carry in the tripod case is normally two rails, a 10" and a 26" three igus slide tables with manfrotto 323 quick releases. and an aluminum monopod with a ball head and 323 quick release. The total weight of the package including the case is 12.05 pounds that I sling for the hike. I have another camera bag for the two TD10's and my NEX5n with lenses, filters and 6 batteries, microphones, Hoodman 450's, a small LED camera light, laser sight, and a couple tools. It weighs in at 9 pounds.



What is "accus"?

Oh sorry, that means power-packs.

I think such a ball leveling option is great, especially for 3D. When I upgrade my larger system I will take that too. But at the moment I was looking for a light travel system. But 5.15 is a good figure for a larger tripod.

I have ordered a nice bag
http://www.amazon.de/gp/product/B002...ls_o00_s00_i01

what I will use to transport the small tripod, the two cameras and powerpacks... Have not measured the exakt weight yet.

I was also thinking about the Manfrotto 190CXPRO4 that Franks use, the price is simliar to what I use now. The Sirui is a little bit lighter, but I think they are similar. The 701 seems to be still the standard, I see not that the new Manfrotto heads with the Bridging Technology are available for that low-weight class yet. But 4.45 kg is a great number.

I think there is room for improvement in my system. I could use the 45 cm Igus system and the Manfrotto 323 parts. Would save maybe 850g (estimation), a little bit more then Frank has (but I think the Canons are leigther then the TD10s?).

The main difference in the use of the two tripod designs is the time it takes to set up and tare down the legs. The twist lock systems take longer than the lever locks. This is especially true for setup. I had the twist system ( Gitzo) before and prefer the levers much more. I also went with a lever lock for my monopod. Of course there is the full extended height and I think the Sirui is a little short for my liking. Actually I wish mine was even taller but I like that I can slide out the center column and shorten my total collapsed length to what fits inside my roller bag for airline travel.

In terms of heigth the Sirui has 140 cm - in addition there is a small part that adds 9.5 cm (but I have not used that upto now really). Yes the major difference are twist and levers - in terms of speed for sure, but also in terms of weight (I am not sure but that I think that is the reason why the Manfrotto is a little bit heavier). In terms of fit in the bag - the sirui has also 40 cm only, very similar to the Manfrotto. I am keen to collect some experience in the field with that part.

Frank, I for my part shoot in 1080 24p with the Z10K - and that is fine for me, since the firmware adds a blur that looks not bad. For the paired TD10 I shoot with 1080 50p, since here 24p is not available but only 25p. So the disadvantage is that - for 3D Blu-ray - I have to convert to 720 50p or to 1080 24p. But coversion to 1080 48p would be possible too - so I am on the level of the Hobbit!

In terms of drift in synchronisation I am not so happy, I see here 0.2 ms/Min. After 5-10 minutes the system reaches 1-2 ms, and I think we should not go beyond 4 ms for 3D. What is the synchronisation drift that you have? Have you measured that?