While getting the lens data and scale from the master primes, the digital scale matched the scale on the lens (as it should), but when adding a premarked ring for the digital scale, all of the premarked rings where off while the digital scale and the one on the lens still matched each other perfectly.
The distance it was off was different on all the lenses.
1. There is a difference between LDA and LDS. LDS can not be saved on the hand unit, but comes from the lens directly. We do not recalculate LDS data itself, but we map it in realtime to a pre-marked ring.
2. LDA is basically a .tap file stored on the ARRI camera. You can save it on your cPRO hand unit and also edit it. We usually re-interpolate that data when we convert it to .cml data
Pre-marked rings use an interpolation between the lens scale and the ring scale in general. You can improve the accuracy by selecting the closest matching ring with your close focus distance on the lens.
Anyways, we do our best to reduce minor miss matches that are different from lens to lens to a minimum.
So to make it work I just taped a new index marking on my hand unit every time I switched lens.
Could you please let me know what you did exactly to make it work?
One thing that I noticed was that when racking focus slowly between infinity and the hyper focal mark, there was a weird jump in the digital scale. This might be the problem.
We have double-checked the jump at the end of the focus scale towards infinity. Other than in a previous bug the jump shows on the focus scale GUI only, but the lens moves continuously towards infinity.
We will fix that GUI display issue with a future SW release.
ALSO, when adding digital markers (love them!) all of the markers ended up at the infinity mark no matter where I tried to add them.
Thank you very much for the report. That is a bug and
will be fixed with a future SW release.
So I’ll let Clemens chime in and give you the official answer but just know that you’re not alone in these observations :) From my understanding, LDA data from the Master primes is “Read Only” per se - it’s a readout of the position the lens is at. Because of this, if cmotion (or Arri or Preston for that matter) were to interpret the distances and map them onto a PreMarked ring, there would be a lag and it probably wouldn’t be good enough for what we do. This is because it would have to read and re-map the values in as-close-to real time as possible, which is limited by the speed of processing in the hand unit. Don’t quote me - I think cmotion is experimenting with this as it was something that was brought up in beta testing and I have some ideas for work arounds, but I’m not really all too hopeful as I understand the technical limitations of what that would involve and it’s not simple at all...
As for the infinity bug, this has been something that’s been brought up in the beta testing and it likes to come up every now and again with different firmware releases... It was solved with the last iteration of SW3.0 and somehow it’s back again with SW4.0... They are aware but thank you for bringing it up! Always helps to have more voices to improve the system - if not just because I hate being the squeaky wheel :)
EDIT: And just to clarify, it’s not just Master Primes - it’s any lens that sends data to a camera... S4is, Zeiss XD lenses, etc
And thanks for the reply!
To clarify i get the whole digital scale from the master primes. Not only the current readout. And it is spot on from close focus to infinity.
The problem is only the translation between the digital scale and the premarked one. Where the premarked ring for some reason don’ match
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|Asked: 6/21/20, 5:50 PM|
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|Last updated: 6/23/20, 12:24 PM|