Letus extreme - rails?

L

Lenilenapi

Carbonite Member
Does the letus extreme come with a rails system?

I notice that with this adapter the 35mm lens ends up a bit lower than the original video cameras lens.
I'm wondering if this makes it incompatible with other rails systems or is it adaptable, especially say with the shims that come with tyhe redrock or SGPro ?

I'm particularely thinking of it with an HVX.
 
It doesn't include rails, no. I've got it mounted on my HVX with the Vocas rails underneath to support it and it fits nearly perfectly. But it's so long, I should really get longer rails because now I can't fit the mattebox anymore!
 
Thanks Barry,

Don't you have to raise the HVX on its mount or quick release so that the lens will then fit the rails correctly?
The only photo I've seen is:

http://www.dvxuser.com/V6/showthread.php?t=110794

In that photo the Letus unit mounts in front and below the camera which is right over the tripod. This looks like it could be very difficult to balance with a heavy lens.

I've got a few rails systems ( Redrock and SGPro) that probably could be adapted since they have shims that can raise the camera. How far would I have to raise my HVX to make it work?

Also by the way 2 other Letus questions while i'm at it.

1. Some posts here have noticed that some Letus extreme footage posted here has soft edges. Have you been happy with corner to corner sharpness on yours? - sounds that way.

2. Have you tried high speed lenses on yours. On some of the adapters I have found oddly that they didn't respond to changes in exposure below f2.5 or so on my high speed lenses, thus i couldn't get the advantage of an f1.4.
How is the Letus extreme on this score?

Lenny Levy
 
Fastest lens I have right now is an f/1.8, so no, I can't test with faster. Should be able to a couple of weeks from now.

As for how the Vocas rails fit:
1190838474.jpg

1190838504.jpg

1190838542.jpg


It's like they were made to go together almost. Centered almost perfectly, just the right height, everything. But the rails aren't long enough to allow a mattebox too, so I gotta look into getting a set of those.
 
Thanks again,

What an odd but convenient fit.

Unfortunately lying on top of the rails like that won't do well for fatter lenses and won't work for a matte box or follow focus at all. You will need not only lobnger rails, but also will need to raise the HVX to get lens itself higher.

Even with a 1.8 lens you could tell me if you really do see a change of one stop or so when you open up from 2.8?

I was surprised to see some adapters not responding to this - something to do with the diffusing element and the angle of view I assume.

Also if I could ask you again about the corner top corner sharpness question.

- Lenny
 
Haven't tested for sharpness. As for brightness, there's discernable brightness change at every iris tick from 1.8 on down. The more I open it up, the brighter it gets. But the difference between leaving the still-camera lens open and dropping the in-camera iris by a stop is much more than the difference of leaving the in-camera iris alone and stopping down on the still-camera lens from f/2 to f/2.8.
 
Does it look like a full stop though from the 35mm lens iris.

I don't think the HVX f stops are as linear as you might expect.

On the adapter I was testing, on the 35mm lens there was barely any change from 1.4 to 2.8. Then from 2.8 to 4 it looked about a stop , yet from 4 5.6 it was even greater, I think even more between 5.6 and 8
 
Looking at thos photos from Barry, it looks like a real problem getting a folow focus and Matte Box on the rails and aligned.

The whole of the HVX will need to be raised a hell of a lot with shims.
 
email from Quyen says:
"Any rail system would work OK. It's about 1.7 inch or 44mm drop on the lens line."

That's a big distance to raise the camera - don't know if the spacers I have left over from other rigs would do it. Haven't looked yet.
Maybe you'ld need to manufacture something yourself. Actually I think they ought to consider making some kind of a spacer , but maybe that would have to be specific for the rails systems involved.

It is something to consider seriously before buying though.
 
indiRAILS with 18" of carbon fiber rods will work. You can adjust the rod mount up/down to adjust for the Letus. Also, there is a DOF adaptor that mounts to the rods and affixes the Letus firmly to the rails so that it doesn't deflect from the torsion force when pulling focus, prefereably pulling focus with an indiFOCUS ;)
 
Our carbon fibre rails system is already designed to allow the correct offset (for our own flip), and a completely balanced rig. Most folks are using the 45cm systems.
 
I have the cavision rails and matte box- currently my Letus is connected how Barry has his connected- while it does provide support, it will not allow a follow focus or a matte box. I am able to raise the camera up high enough for the follow focus to work- and it works well for that. However, the rails as they are currenlt configured will not work with the matte box. To take full advantage of the matte box and grad filters, I need to raise the camer another 1 - 2", and have longer rails.

I have some parts on order from Cavision, and they should arrive next week- I'll post back when I have it set up and let you know how it all works out. I think it will work fine- at least it does on paper- real world can be another matter ....
 
the fact that the 35mm lens is so low and what appears to be off center is the only thing that's keeping me from buying one. It doesn't seem the adapter was created with use of a rail system, follow focus and mattebox in mind. When I actually see the setup with all these things, I'm buying one!

The only thing is, like I said, it doesn't seem it was designed to work with a rail system. So pretty much anything that works is going to look like somewhat of a "hack", unfortunately.
 
Life in a Box Films said:
the fact that the 35mm lens is so low and what appears to be off center is the only thing that's keeping me from buying one. It doesn't seem the adapter was created with use of a rail system, follow focus and mattebox in mind. When I actually see the setup with all these things, I'm buying one!
Click to expand...

I beg to differ. I have a letus, matte box, rails, FF, you name it. All on cavision equipment. I've posted this pic before, but it seems like I need to post it once a week so people get it.
 

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Where does the riser block come from?

Couldn't this all be made easy if Letus would manufacture a simple riser say like a Jimmy Box designed to put the lens back at normal height?
Then you could use it with any rails system.

Its an idea anyway.
 
Lenilenapi said:
Where does the riser block come from?
Click to expand...
P&S supplies it for their mini35.

Couldn't this all be made easy if Letus would manufacture a simple riser say like a Jimmy Box designed to put the lens back at normal height?
Then you could use it with any rails system.
Click to expand...
Well, sure. And they may already have something underway for all I know.
 
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