Problems with my Letus Extreme...help

MatthewC

MatthewC

Well-known member
Hi,

I bought a Letus Extreme from another user on this board a while ago. Finally had some time to set it up on a tripod today and use it after I ordered a thread mount replacement. This was originally used on a Sony EX1, dont know if that could be the cause of some issues. A few problems have arisen.

1. First, the image is not directly centered in my viewfinder. I have to overzoom in to get a full frame, but I'm obviously losing image when I do that.

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I have everything tightened and the adapter appears to be on there evenly (although quick movement I notice a bit of wiggle on the adapter, however I didnt tighten the bottom bolt where the adapter meets the camera, I was on a time constraint) but that doesnt appear to be related to why the image isn't going through the adapter straight. I checked for cracks everywhere. I have properly tightened it before and had the same issue, but I assumed it was because of a messed up thread on the mount, I bought a new one and this was the test to see if it works. See problem below...


2. When I have the Letus on my HPX 170, I can't get the Zacuto (full Zacuto rails/support) to line up directly with my Letus screw hole for the support. If I rotate the Letus so the screw fits from the support to my Letus, then the image is not level. I'm not sure exactly how this works, is there a way to rotate the image inside my Letus? This could also be related to problem #1.

3. I know that it's best to have the iris on my camera anywhere between f4 and f5.6 for maximum image clarity. Should I be worried about that, or should I have my attached lenses iris set to that and then use my cameras iris to control the light?

4. I noticed a pattern when I was filming, I did notice some fingerprints directly on the glass closest to where it mounts to the camera, I'm assuming that's the problem, or because I'm focusing past that on the GG it shouldn't actually show up and is potentially something inside? I will clean it all next time I can test the adapter and see if its the problem.

Any help would be appreciated in this matter before I tear my hair out. I'm really regretting not being patient and just getting a Brevis...
 
1) Every camera will "see" the GG differently depending on how the sensor is aligned. That's why the image isn't centered on the adapter, it's different for each individual camera. Nothing you can do about that, just zoom in more.
2) You need to use an allen wrench to remove the three hex screws on the front end of the Letus (the smaller tube) and then rotate it so that the screw hole is aligned, then retighten.
3) Doesn't really matter, difference is miniscule.
4) If there is a pattern, either it's a dust issue or you're stopping past f4 on the SLR lens or you're going past 1/120 shutter speed. Don't do it.
 
Huy Vu said:
1) Every camera will "see" the GG differently depending on how the sensor is aligned. That's why the image isn't centered on the adapter, it's different for each individual camera. Nothing you can do about that, just zoom in more.
2) You need to use an allen wrench to remove the three hex screws on the front end of the Letus (the smaller tube) and then rotate it so that the screw hole is aligned, then retighten.
3) Doesn't really matter, difference is miniscule.
4) If there is a pattern, either it's a dust issue or you're stopping past f4 on the SLR lens or you're going past 1/120 shutter speed. Don't do it.
Click to expand...

1. I think I can adjust the back of the rails system to change the angle a bit, looking at this video here:
http://vimeo.com/groups/9897/videos/2772552 Might help align it up a bit.

2. Your talking the hex screws at the very front here: http://www.letusdirect.com/cart/images/D/letus-extreme-big.jpg the ones that are embedded right before the lens cap? That will let me rotate that small tube? I tried the four closer to the back of the small tube but I see they have screw holes on the inside and those arent meant to be loosened.

4. So dont go under f4 on the SLR lense? Good to know, thanks. I will also wipe those fingerprints off and blow everything with some air next time I use it, but it's definitely a pattern and not a speck or too. I figure its those fingerprints I noticed at the end.
 
The 4 protruding screws right below the Letus Extreme engraving. Loosening them will let you rotate the entire tube.
 
Huy Vu said:
The 4 protruding screws right below the Letus Extreme engraving. Loosening them will let you rotate the entire tube.
Click to expand...
I couldve swore that they are going into threaded holes on the large piece of the adapter. You sure about
that?
 
Last edited:
Yeah, those bolts are stuck in those holes, thats not meant to be rotated. This is all a bit confusing.
Is it possible something inside is not level or straight and that's why its crooked?
 
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