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Re: Pinnacle VR, first observations

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  • Mark D. Fink
    Hi Daniel, Thanks for the detailed comments! I have no problem with these going on the list as those who might be interested will find your point helpful. I ll
    Message 1 of 1 , Jan 24, 2007
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      Hi Daniel,



      Thanks for the detailed comments! I have no problem with these going on
      the list as those who might be interested will find your point helpful.
      I'll answer inline.



      > Hi Mark,

      >

      > It took me longer than expected to have the time to calibrate the

      > head. I was putting it off partially because I felt it required a fair


      > amount of time.

      >

      > Here are my first observations (I am not sure if you would like me to

      > send them to the list):

      >

      > I'll start referring to the parts as follows, from the bottom to the

      > top:

      >

      > Base of the head (attached to the tripod).

      > Rotating base

      > Long Side Arm

      > Tilting Arm

      > Camera plate

      >

      >

      >

      > First some "problems"

      >

      > * The head comes with a 1/4 thread at the bottom of the base of the

      > head. I also got the adapter to turn it into a 3/8' (I think I got

      > the numbers right). When I insert the 3/8 it is not totally flush

      > (it protrudes slightly).



      You got the numbers right, just backwards. The base comes with a 3/8-16
      thread and a reducing ring that brings it down to a 1/4-20 so that it
      can be mounted on a tripod head rather than directly on the post of the
      tripod itself. This is helpful if you want to use a ball head to level
      the unit rather than something like the Bogen leveling base. I didn't
      notice that it protrudes slightly. Thanks for catching that. I'll see
      what needs to be done to fix that.



      >

      > * The holes of the tilting arm are slightly small. That means that the

      > screw literally makes a thread in the hole when it goes in. This

      > makes it difficult to get the screws in the first place; and once

      > the screw is completely in it makes it difficult to keep rotating

      > it.

      >



      Yes, they are tight, and on purpose. I wanted to make sure that
      everything was as snug and unmoving as possible. Otherwise, the
      precision is affected. The first couple of times that you insert the
      screws, it takes a bit of elbow grease, but then the holes work well
      after that. Part of it is also manufacturing tolerances. It's possible
      that some of the holes are "slightly" smaller than others and require
      more work to use. We're talking very small fractions of an inch, but the
      effect is noticeable. Still, with a choice between slightly loose and
      slightly tight, I chose slightly tight.



      > * I wished the holes in the tilting arm were labeled, and there

      > was a distance scale that would tell me some type of distance

      > (ideally located on the surface where the camera plate sits).



      I had tried to do that in a meaningful way. One of the versions of the
      design had a silk screened distance scale, but the more I thought about
      it, the more I realized how relative that scale was. Should I create the
      scale so it gives you the distance from the rotation point to the front
      of the camera plate, to the back of it, to the forward portion of the
      lip that holds the camera in place (basically, the very backmost part of
      the camera at its base)? I was leaning towards the latter when I came up
      with the idea of creating the table of values that is in the PDF file.
      (I hope you found that at the end of the PDF - it helps tremendously
      knowing which set of holes put you where.)



      >

      > * In the few times I have used it, the pin used to hold the tilting

      > arm in place sometimes gets screwed past the bottom surface of the

      > long side arm. This means that the tilting arm is no longer flush to

      > the long side arm. I am now checking, every time I tilt the head,

      > that this is not happening.



      I know it's possible to screw it too far in, but I've found that
      screwing it into the flat part of the pitch plate where a hole isn't
      drilled allowed me to get it snug without pushing the two apart. After
      that, I haven't noticed the pin being an issue. I'll keep a close look
      on it while I use mine and see if it is an issue that I haven't noticed.
      (This is why I really appreciate your comments. Something that might
      seem obvious or a non-issue to me isn't necessarily the case for
      others.)



      >

      > * The head is built for left-eye dominant people :) I can't mount the

      > camera such that the long side arm is in the right hand side (with a

      > short lens the tilting plate protrudes too far behind the camera,

      > making it difficult to use my right eye).



      Actually, the head is built for right-hand dominant people. 8^) I think
      most of the heads out there are. You're right, there isn't a way to
      switch it around. Personally, I'd rather use my left eye on the
      viewfinder than my left hand to work the controls.



      >

      > * The screw that holds the tilting arm against the long side arm:

      > sometimes it is difficult to screw/unscrew. (I discovered it is

      > easier to rotate the tilting arm to loose it). A longer screw head

      > will definitely help.



      Oh, I see what you're saying. If the knob on the nut were larger, it
      would be easier to loosen and tighten. I think you'll find it easier if
      you just tighten it slightly, still allowing the two plates to slide
      past each other while still maintaining contact. Then, you don't need to
      touch the bolt or nut.



      >

      > * The screw that holds the camera is too difficult to reach in the

      > field. In fact, replace all 3 screws with screws that can be

      > manually attached (see the manfrotto screws of its camera plates for

      > an example). The camera screw is soo far in, that I can't even use a

      > coin. This means I need a screwdriver in the field. At the price

      > range you are, you could provide a architectural quick-release plate

      > (see the Manfrotto again). I am going to buy one to permanently
      leave

      > in the head.



      Yuval had the same feeling about attaching the camera. I pack a
      screwdriver in my camera case which doesn't take up much space. Yes, the
      screws aren't easily reached, but adding a quick release system to the
      head would have added extra expense. As it is, I'm breaking even on the
      costs with my current pricing.



      >

      > With respect to the rotating base:

      >

      > * Put a mark in the rotating base so it is easy to know the yaw. It

      > would be nice if the rotating base and the base of the head had the

      > same diameter.



      Not a bad idea, and easy to implement, even after the fact. As far as
      the diameter of the base vs. the yaw plate, I made the rotating base
      that diameter so that when mounted on the Bogen leveling base, you could
      still see the bubble head for leveling while everything was mounted.



      >

      > * Mark the center of the screw that holds the rotating base and the

      > base of the head. It will make calibration of the camera easier. (I

      > usually point downwards the lens, take a photo and discover how far

      > off center the camera is).



      I had thought of doing something like that, but my approach to finding
      the yaw point is by direct measurement. I measure from the base of the
      camera to the inside lower lip of the lens mount opening. Then I measure
      the size of the inside of the lens mount opening, divide that in half
      and add it to the first measurement. I find the corresponding
      measurement in the PDF file for the yaw base and know precisely which
      sets of holes to use without the need for trial and error.



      >

      > Now some suggestions:

      >

      > * Sell a smaller version, with a smaller tilting arm, and long side

      > arm. It will make it more manageable, light and easier to use (I am

      > right-eye dominant but I have to use my left eye to see through the

      > camera when I mount the fish-eye lens. Or sell them as optional

      > accessories.



      Right now, I'd be happy to just sell what I currently have in stock. 8^)
      The next version, if there is one, depends on the sale of these. (This
      is a very tiny side job that I do. I created the designs, but don't do
      any of the manufacturing.) The decision for the size of the current one
      was a long process. I wanted to balance the ability to pack the thing in
      a camera case, which it does since it is about the same length as my
      80-200 zoom, but still have lots of flexibility regarding what camera
      bodies and lenses you can use.



      For someone who shoots exclusively with a fisheye lens, this isn't the
      head for you. If you shoot with two or three different lenses, and
      occasionally go out as far as a 135mm lens, then this is the one for
      you. I had to keep the upright arm long enough to allow the camera to
      point straight up with the longest lens it was designed for.



      >

      >

      > Now the rant:

      >

      > * It is time consuming to calibrate a lens.



      Agreed! But I think that is the nature of calibrating a lens. Yes, it is
      tedious moving the camera forward and backward in 1mm increments until
      you get it right, but at least it is a one time ordeal. Plus, once a
      user base is established, we can share our settings and save some people
      from going through the process.



      >

      > * The head is heavy, and with its long arm swings very easy at the

      > least touch of the camera or tripod.



      I guess heavy is a subjective measure. Interestingly, added weight helps
      keep things from bouncing around too much, while too light would have
      the opposite effect. I have found that the head is most prone to
      vibration when you are using negative pitch for nadir shots. Other than
      adding another piece of metal in an arc to in effect create a hypotenuse
      from the pitch plate to the upright arm, I don't think there is a way to
      avoid this.



      >

      >

      > and finally the good

      >

      > * If feels like a precision instrument. I am very curious to know how

      > repeatable the yaw/pitch/roll is.



      Hurrah! I'm sure many others would be interested to know your findings
      on repeatability. This is a claim that I don't make, since I can't
      guarantee it. (If one of your templates doesn't work in PTGui, do I
      refund you your money?) However, my experience has been positive. But
      then, I'm a somewhat biased source.



      >

      >

      > That is all for now. I haven't tried any panorama yet.



      Keep us posted!



      Roger, I'd appreciate your reactions to Daniel's points. Are you coming
      to the same conclusions?



      Thanks!



      Mark

      www.pinnacle-vr.com <http://www.pinnacle-vr.com/>

      www.northernlight.net <http://www.northernlight.net/>





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