Topics

Preston Fiz3 not matching marks


Saul Oliveira
 

Hello: 
Preston HU3 with MDR-2, G4 converted.
After mapping a lens the premarked ring does not match the marks on the lens anymore. Did a Soft Reset and  the Focus knob Calibration and nothing improved. It’s always the same amount of offset and to the same direction, less in the D ring more towards the A ring. At 2 meters it sets the focus at around 2,10 more or less. 
Any ideas?
Best regards
Saul Oliveira
AC
Spain


Ben Tubb
 

Hey Saul, forgetting what happens to the lens itself, does the premarked ring match the electronic display?

Thanks,
Benjamin Tubb
A-Cam 1st AC - The Haunting of Bly Manor
604-908-5219
Vancouver, BC


Steven Bailey
 

Hey Saul,

The pre-marked rings for the Preston FIZ HU3 are mathematically created, whereas the majority cinematic lenses are hand made and even the focus markings on 2 identical Cookes s4 50mm will differ, especially at the Close Focus end. The Preston Handunit is mathematically calculating the distance between set points to then predetermine where the focus points should be (mathematically) but this isn’t always the case.
Other factors - The gears on the motors - Are they the correct gearing? Are they clean? Yes, These do need to be cleaned & yes it makes a difference
When doing a standard calibration, and turning off the focus ring so you can use blank rings, do you get a difference each time you calibrate?


Regards

STEVEN BAILEY
FIRST ASSISTANT CAMERA
TWISTED VISIONS PTY LTD
P.O. BOX 49, MALVERN VIC 3144
M : +61 409 553 655    E : twisted.visions@...
Linkedin.com/in/stevenbailey1stac

On 4 Dec 2019, at 12:16 am, Ben Tubb <benjamin.tubb@...> wrote:

Hey Saul, forgetting what happens to the lens itself, does the premarked ring match the electronic display?

Thanks,
Benjamin Tubb
A-Cam 1st AC - The Haunting of Bly Manor
604-908-5219
Vancouver, BC


Andy Hoehn
 

Any chance lens mapping is turned off?

Is the amount the lens is off consistent?  You could always slide the motor up or down a bit on it's mount while engaged to the lens to compensate.


Andy Hoehn
First Assistant
Atlanta, GA USA


Jessie Turner
 

Do you have the corresponding ring selected in the options on your handset?


Jessie Turner
613 668 2426


On Tue, Dec 3, 2019 at 8:59 AM Steven Bailey via Cml.News <twisted.visions=icloud.com@...> wrote:
Hey Saul,

The pre-marked rings for the Preston FIZ HU3 are mathematically created, whereas the majority cinematic lenses are hand made and even the focus markings on 2 identical Cookes s4 50mm will differ, especially at the Close Focus end. The Preston Handunit is mathematically calculating the distance between set points to then predetermine where the focus points should be (mathematically) but this isn’t always the case.
Other factors - The gears on the motors - Are they the correct gearing? Are they clean? Yes, These do need to be cleaned & yes it makes a difference
When doing a standard calibration, and turning off the focus ring so you can use blank rings, do you get a difference each time you calibrate?


Regards

STEVEN BAILEY
FIRST ASSISTANT CAMERA
TWISTED VISIONS PTY LTD
P.O. BOX 49, MALVERN VIC 3144
M : +61 409 553 655    E : twisted.visions@...
Linkedin.com/in/stevenbailey1stac

On 4 Dec 2019, at 12:16 am, Ben Tubb <benjamin.tubb@...> wrote:

Hey Saul, forgetting what happens to the lens itself, does the premarked ring match the electronic display?

Thanks,
Benjamin Tubb
A-Cam 1st AC - The Haunting of Bly Manor
604-908-5219
Vancouver, BC