Letus Extreme Nikon Mount

PaPa

PaPa

Major Contributor
Since getting my indifocus in the mail, i have been playing around with every which setup to find the smoothest and best gears for which lens and so on.

What i am noticing is that when my camera is static, and i'm using a telephoto lens ( 105mm 135mm ) there is enough play in the nikon mount to bump my image as i'm rack focusing. There seems to be a good .5mm of play which results in bumpy focus, but only when i switch between focusing near infinity and going in the opposite direction towards the macro end of the lens. i.e. going one direction and switching to the other...

The question is, does this happen due to the nature of the Nikon mount? If so then ill live with it, OR, is this just a faulty nikon mount that i was given and possible isn't as tight or as firm as it should be?

Please let me know if i am not clear. Thanks!
 
Last edited:
glad you asked this papa because i was about to chew out a sales rep because i experienced that with 50mm and was thinking that my lens was the issue only to find that my nicon mount has the same play which isn't that big of a deal if your not racking to hard against the infinity mark.but anyways if someone can clear this up tha would be wonderful.oh,now that i think about it i think i experienced this with my red rock and nikon mount.
 
IIRC we experienced similar looseness with the LEX Nikon mount in the recent NYC "shootout" Tim Naylor and the rest of us did at Kwan's studio. Tim could elaborate on it much better than I can.
 
im just wondering if this is inherent in all nikon F mounts and ai/ais lenses. or if this is simply a defective mount.
 
Actually those slr lens mounts used on Letus, Brevis and SGpro are from $10 macro tubes beacause this approach provides significant costs savings for production. The locking pin on those cheap mounts can be modified with one turn of tape around its shaft so it won`t wobble.
The original Nikon BR3 ($35) macro reverse mounts in the other hand are stiff and made from stainless steel not from potentially chipping aluminum but no one seems to use those except the Cinemek`s legendary ones and our not so well known Cinedof ones that were made on special order.
Times change, now I´m thinking if I should replace the mount on my Letus Mini with the BR3 as I have several at hand.

BTW the Zeiss will potentially wear out the aluminum mount faster as it`s snugger fit but no one seems to complain so maybe it`s just pointless fear of mine.

Cheers,
T
 
toenis, im trying ti pucture where to put the tape, but therea re two areas that are both wobbly, but interconnected.

there is the release/ lock pin that is visible, and then there is a little pin on the inside. Which one requires tape, how much, and where exactly does oen put it? I would love to solve this issue.
 
PaPa said:
toenis, im trying ti pucture where to put the tape, but therea re two areas that are both wobbly, but interconnected.

there is the release/ lock pin that is visible, and then there is a little pin on the inside. Which one requires tape, how much, and where exactly does oen put it? I would love to solve this issue.
Click to expand...

Around the little pin on the inside but it might require to unscrew the whole shiny part of the mount and putting the tape around the inside pin so that the taped part wouldn`t be visible - just so much that it doesn`t wobble inside.
If you dismantle the shiny part of the mount by 4 screws you`ll see that there are different manufacturing defects or more like side effects that differ on all mounts of that breed, possibly introducing backfocus issues or edge to edge sharpness differentiations.
Actually those cheap mounts would sometimes disalign optical axis when used with unsupported telephotos as the spring type tensioners inside the mount are too weak for heavier lenses, that might vary of course.

It`s interesting that the use of cheap mounts possibly introduced the backfocus issues to be corrected with additional collimation mechanisms that in the other hand makes the initial production savings pointless, but then again some lenses really are that crap that they require all the adjustments.

Cheers,
T
 
man, wish someone could post a picture of this, i understand generally what your speaking up, but instructions would provide much less stress while im taking this thing apart.

Hienle? Anything? hehe would love your input here!
 
I wish I could post a picture of this but honestly if it does work now don`t do anything with it, this shouldn`t be a serious problem.

T
 
right, but it can become a potential problem, especially if my shot is on sticks, where the camera is completely static, and all there is a rack focus in one direction, and then another, betwen those two opposing directions, it jolts and nudges the mount enough to move the image in an up/down motion, very quick but quite noticeable when u get into the 105mm + lenses.
 
Papa, are you using rails? I remember using the G35 with no rails and going over this issue. It was actually flexing at the threads of the camera, rather than the nikon mount.

edit. whoops, just saw that you're using an indifocus, so you have to be using rails.
 
Last edited:
so i am to remove the four little screws and do what exactly? what tape should i use and how much.lol i wish i was more of a techie.
 
I have the LEX w/ Nikon locking mount running Nikon Ai-s & Zeiss ZF glass and all my gear locks nice and snug no play. Guess I'm one of the luckier few?
 
maybe, but i would still like to know who else is suffereing from this, and did they bother opening it up and fixing it, or just got a new piece?
 
Toenis said:
Actually those slr lens mounts used on Letus, Brevis and SGpro are from $10 macro tubes beacause this approach provides significant costs savings for production.
Click to expand...

Do you know that to be a fact?
Or is that just an educated guess?

I'm thinking if I should replace the mount on my Letus Mini with the BR3 as I have several at hand.
Click to expand...

How difficult would that be? Could you give us some idea of what would be involved?
If that is an easy mod then perhaps swapping out mounts would be easier than trying to fix it with tape (which seems a bit more like a bandaid than a solution).
 
exactly.

unfortunately i can't reach hienle. I guess they are very busy with orders, being the holidays and all. However i really need thi solution soon!

i may have to give him a call.
 
I think they're pretty busy getting things together to release their rail system.
In another post he said they were releasing it 'this week'
Of course, that would mean today...or tomorrow.

But my post was more directed at Toenis who seemed have a decent understanding of this.
I'm wondering if this isn't a mod you could do yourself, PaPa.
(not that you should have to, of course)
 
You must log in or register to reply here.
Back
Top