[Konvas] Base Plates, Rods, and Diameter Hell...

[H. W. Stone]

 Oh, JOY!

I'll put the answers in the message in BOLD italics--


 


 

-----Original Message-----
From: Adam Frey <thefirstrule at chainsawlinux.com>
To: Konvas Discussion List <cinema at konvas.org>
Sent: Sun, 26 Oct 2008 4:51 pm
Subject: [Konvas] Base Plates, Rods, and Diameter Hell...









I have a few quick (but rather important) questions:?
?

1) I didn't get an exact measurement just yet (I'll get it later this 
afternoon), but it looks like my Konvas 1M is approximately 4.3125" 
inches (roughly 110mm) from the center of the Optical Axis of the lens 
port to the bottom of the camera (or base of the camera). Is this the 
same with the Konvas 2M as well? Or does the 2M have a different 
measurement to its optical axis? 

Not even all 2m bodies are the same distance from the bottom to the center of the lens axis.? I had one that was about 20mm shorter than the others, and saw one that was taller than mine-- but of five bodies I checked they varied about one or two millimeters, it seems as they got newer they were taller.? I had a set of shim blocks built to fit an Arri base unit for use with the Konvas-- the shims were just aluminum sheet surfaced dressed and drilled.? One or two millimeters is not that much.
?

2) As I understand it, the "15mm rod rule" is kinda getting pushed aside 
for the newer "19mm rod rule" (at least in New York, possibly the rest 
of the East Coast, as well as most of Europe). Is this correct, or is 
this only with people running around with something modern, like an Arri 
435 Extreme? I haven't seen any 19mm rod based systems around here. 

15mm rods on 100mm center are "more or less" standard for the prime sets--? BUT 15mm STEEL rods centered 100mm is a whole ball of wax different than the 15mm aluminum "kinda something like around" 100mm centers that a lot people used.? Early Arri 2b rod sets were 15mm on 88mm centers, and then Arri went to the Mitchell 100mm centers for the 35BL series, with a 120mm unit arriving and then being discontinued.? With some of the big lenses and a desire to keep flex to a minimum I can see 19mm rods.

Aluminum rods and 60mm centering is miniDV crap.

If you check you'll find I've been saying that repeatedly over the past few years, usually upsetting people, but holding things in alignment means leverage becomes a major problem, and the aluminum and/or smaller space between rod centers gives you more flex, less support.? Plus, in spite of the label, a lot of "15mm" 60mm center gear is really 12mm or 14mm, not 15mm rods, and the fit is a sloppy as you can get and not have it fall out.? Why?? They use English drill bits and metric measures.

3) If you are using 15mm rods: Are you using the Arri 100mm rod spacing 
or the Arri 60mm rod spacing? (Off-subject, but I have a set of Cavision 
60mm rods, and they seem to allow a little bit of play, which I 
absolutely despise. Is this typical of other 60mm rod sets, or is it 
because mine are carbon fiber?) 

60mm centers are not suitable for 35mm work, 88mm was marginal, which is why Arri went to the Mitchell 100mm spacing-- which Mitchell called 4 inch centered 9/16 full measure.? If you check the early Kinor 35C rods you'll find they are a shade under a true 15mm-- instead of 0.59, they are 0.57, which is more or less 9/16 of an inch.? Later versions are 15mm-- and talk about barely being able to squeeze along-- sometimes they fit, sometimes not, and more than once I have used a sheet of abrasive to dress down a rod that super tiny amount so it would fit, or put it on a wooden dowel and dressed the hole.

No, I am not kidding.
?

4) Does the average Konvas user require 15mm rods w/100mm offset 
spacing, 15mm rods w/60mm centered spacing, 19mm rods w/104mm centered 
spacing, the Konvas Mattebox built into the rods, or the Konvas dovetail 
system (can be seen with the 50mm/75mm anamorphic sets) for use with 
their lenses? 

The Konvas T bar (and the Kinor version of it) was because of the problems with rod fit, flex, and costs.? I use the T bar with the 37-140mm with the anamorphic on it when we put it on the Konvas 2m or Im, but I use the 100mm spaced 15mm SOLID rods for it on the Kinor-- the hollow tubes are supposed to work as well, but I just like the rods.? And BTW, the rod set connects to the lens yokes with the same dovetails the T bar uses. ? I did not buy the 19mm set I was offered because even used it was as much as a good car.? 

Some of the 1500/100mm center units are dovetailed to clamp directly onto Oconnor baseplates instead of screwing on.

That lets you position it forward and backward using the tripod head as part of the slider.

Nice.

I'll avoid saying any more about what I think about 60mm units.

?

If you want to know why I'm asking, I can't explain it all *just* yet - 
hopefully within the next few days though. But I promise it's exciting!?
?


Cheers,?
?

Adam Frey?

Director/Cinematographer?

Crimson Chain Productions?

http://crimsonchain.com?
?

Crimson Chain Productions?

PO Box 35?

Libertytown, MD 21762? 



 

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