My Letus Extreme:( GG haze with shutter off??

GRENCH

GRENCH

Well-known member
UPDATED:
Finally some answers. Thank you guys for getting me on to the right tracks with some of your advice and suggestions. After speaking with an Letus sales rep, lol I did realize that, Yes I was dealing with a classic issue of slo mo, shutter & stops. Thank you Disjecta and a few others for your input. Everything started to make since after reading some of your comments.

But, what was confusing the hell out of me was the fact that I could not achieve a sharp focus with my 35mm, & 50mm Ziess lenses. It bugged the Sh*t out of me until reading a few more threads, and then presenting what I have found to the Letus corp. I believe this is what made me most confused and worried because it made no sense to me at the time, but now that I know about the achromat upgrade for HVX200 users I can see a bit more clearly. Well not actually, because I haven't received it yet but the idea that this part will allow for a me to achieve a sharper image makes me extremely happy.

Now comes the task of trying to get Letus to see my point of getting this upgrade for free minus shipping and handling. I mean they were aware back in Sept. of 07 that I was planning to use my unit for a HVX200. Am I wrong for thinking this way? With current conditions I am not too crazy about spending 1 cent for something that should have been address before this unit went to market. I know, I know Letus is a great company, and thats why I brought the unit but at the same time this sounds more like a recall issue, and not something that I should be paying $250.00 for.

Any advice?

Thanks
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Hey Everyone,

Having 1 hell of a time with my LETUS Extreme. Here is the message I sent to Hein.

"Attached is the footage showing the ground glass issue. You notice a winding grain that reminds you of noise in some ways, but the with a haze to it. You notice it most in the lighter section of the footage like the sky, and white sheer drapery. It's a lot easer to see in my hi res footage. This filmed at 1/60. I'm also seeing this with my shutter off. :(This was filmed at a dress rehearsal before the actual shoot. As far as the focus issue it normally only happens with wider lenses like 35mm and wider. I have to get right up on a subject to achieve a sharp focus. With other adapters I've tested my lenses on this didn't happen, so I'm figuring something is out of wack, but I don't know what at this point."

I am planning to upgrade to an Ultimate pretty soon. If I can resolve the issue I plan to sell my extreme which beside this obvious problem is 1 hell of an adapter. If your not concerned with hi shutter speeds.

Any feedback is valued.
 
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Could you explain what you mean by your shutter being off? There are issues with the Extreme at high shutter speeds, but from my tests they start becoming obvious around 1/250. You should definitely be safe shooting at 1/60, unless there is a defect in your adapter.

Could you post some footage? I'd like to see the haze you're referencing. I have a LEX, and there's a bit of discoloration on the GG of mine, but it doesn't affect the footage.

Thanks,
Paul
 
Hey lovetrumpsfear,

I agree, my unit use to perform in that manor. As of a few months ago I began seeing hazy grain in my footage at lower shutter speeds. When this happened in the beginning I thought maybe my backfocus was off, but once I stopped the adapter the grain on the glass was very sharp through my monitor. I was using my 85mm Zeiss lens and noticed my actual subject was totally in focus also. So I'm like, whats going on? Rather then post my problems right away, I chose to take the time to figure out what could cause this. I have read up on other user's threads in reference to the GG issue and could not find out why my adapter was doing this. Also I have problems with my 35mm Zeiss nikon mounted lens achieving sharp focus. My 85mm, & 50mm work fine. I spoke with Kholi a good while back, and I believe he spoke of it being a backfocus issue, but even at the increments he recommended I still can't achieve a truely sharp image. I'll be honest from time to time I have, but it's the luck of the draw and its driving me crazy. I was wondering could my ground glass be offset, or could it have come out of it's shoe sort of speak. If someone speaks with Hein could you ask if he would chime in at his earliest. I did get in contact with him around 2 weeks ago, but after sending the footage I haven't heard from him. I know they are pretty busy over there, but I need some answers big time. I'll be emailing him again today.

http://exposureroom.com/members/SLEEPINGIANT.aspx/assets/4edd9c86e4fc4eb0873a727ec06e1593/
 
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If you are able to get a sharp image every once in a while, it sounds like it is something on your end. Even if the backfocus is off, you should still be able to get a sharp image, and improper backfocus is not as noticeable when using prime lenses.

If it is only one lens, in this case your 35mm, that is always out of focus then I would try a different 35mm lens. The two causes of seeing moving grain from the ground glass are:
1) the 35mm lens is stopped down too much (don't go past f/5.6 - I don't go past f/4 to be safe)
2) your shutter speed is set too high. The shot you showed us was overcranked - are you sure your SHUTTER SPEED was 1/60th of a second? Or were you shooting at 60 FRAMES PER SECOND?There is a huge difference.

The grain pattern in that footage looked like one of the two above problems.
 
Thanks trudd,

I stopped the footage down on purpose to exaggerate what I was seeing. Like I said, and based on what you are telling me it just doesn't add up. I have been shooting at 24fps-60fps,and the same thing. I was amongst the 1st Extreme buyers, and from the 1st day I have had no problems other then the 1/250 shutter issue. As of a couple months ago this problem came about. I'm very familiar with the typical shutter and stop issues. It's not that I'm counting them out, but I believe there is something else adding to this situation. Now the frame rate thing I didn't know about. The clip was shot at 60fps. But that doesn't make much since to me because I have shot many times at 24fps without stopping down pass f4 and still the same issue has arose. Now granted you have to take into account the stoppage of the lens it's self, and due to the speed of my lenses I have been known to stop them down 2.5 to 3 stops alone.

Hmmmmmmm?
 
Hm. I've always heard the max safe shutter speed was 1/120. I'm not saying there isn't something wrong with your LEX (I've had to send mine back before - I am an early adopter as well) - but the tinkerer in me naturally wants to eliminate the variables and figure out what the cause is.

Shoot something at 1/250, 1/120, and 1/48 shutter speed (at 24fps) and see if that changes anything. If it doesn't, heckle Hien some more :)
 
I've tried that actually and there is some change, but still the haze remains. My DP also tried to resolve this issue by change to shutter speeds to no avail. Getting tired and need a reponse from Heins. I'm thinking I'm going to end up holding off buying the Ultimate and save up for a RED. This wait is costing me money big time. I can't sell it because I don't know what the exact problem is, and I wouldn't consider buying another adapter from the same company as the 1 I can't get an answer from. I just want to ship them the thing so that they can tell me whats wrong with it. I'm not a technician and don't claim to be. I just need answers.

Thanks for the input guys.

Any other ideas are welcome.

Grench
 
Is this "haze" you speak of, kind of like a 'wobbly image'?

As for contacting letus, submitting a support ticket is the best way to get a response.
 
I would check if the vibrating is causing it. I think that you said that when you don't have it vibrating the grain is sharp.

If this is the case then you have to secure the unit tightly so only the GG is vibrating.

I had that problem when I flipped the snorkel up to center the image. The Letus doesn't have a firm way to secure it to the rails as the other adaptor from other manufactures do.
 
I don't see any "haze" per se, but what I'm seeing is something I also encountered in a shoot when using an HVX200. The problem occurred when we were shooting slowmo at 60fps. The shutter increase is the culprit. Basically, the speed of the shutter has caught up with the speed of the vibrating ground glass and is making the grain visible. It's not practical to shoot slowmo while using a LEX because of this shutter speed issue. We had to painstakingly remove these artifacts in post production.
 
Douglas Villalba said:
I would check if the vibrating is causing it. I think that you said that when you don't have it vibrating the grain is sharp.

If this is the case then you have to secure the unit tightly so only the GG is vibrating.

I had that problem when I flipped the snorkel up to center the image. The Letus doesn't have a firm way to secure it to the rails as the other adaptor from other manufactures do.
Click to expand...

My unit is very secure by use of a support to my rails. I believe that somehow my gg has become unseated in someway. This would explain a great deal IMHO.

All I want is for someone to get in contact with me so that I can ship them the unit and then they could tell me. Like I said earlier I'm not a tech so I don't want to go inside and start tinkering around and make things worst.
 
disjecta said:
I don't see any "haze" per se, but what I'm seeing is something I also encountered in a shoot when using an HVX200. The problem occurred when we were shooting slowmo at 60fps. The shutter increase is the culprit. Basically, the speed of the shutter has caught up with the speed of the vibrating ground glass and is making the grain visible. It's not practical to shoot slowmo while using a LEX because of this shutter speed issue. We had to painstakingly remove these artifacts in post production.
Click to expand...

I see your point, and will be performing some more test this weekend. I hope one of these solutions will work, but I'm convinces that there is something out of the ordinary going on here. Like I said I along with my DP who is a pretty savvy cat went through many of the suggestion that were offered, and still the grain. It was as if one day I woke up and what the F!!, lol. I'll post some more footage after the weekend.

Thanks guys,

I'm hoping its error on my end, but I'm very doubtful.

Grench
 
nothing strange is going on here, quite common of the LEX. i have the same issues at certain shutter speeds, plus you have the extra fps going on with high shutter.
 
Finally some answers. Thank you guys for getting me on to the right tracks with some of your advice and suggestions. After speaking with an Letus sales rep, lol I did realize that, Yes I was dealing with a classic issue of slo mo, shutter & stops. Thank you Disjecta and a few others for your input. Everything started to make since after reading some of your comments.

But, what was confusing the hell out of me was the fact that I could not achieve a sharp focus with my 35mm, & 50mm Ziess lenses. It bugged the Sh*t out of me until reading a few more threads, and then presenting what I have found to the Letus corp. I believe this is what made me most confused and worried because it made no sense to me at the time, but now that I know about the achromat upgrade for HVX200 users I can see a bit more clearly. Well not actually, because I haven't received it yet but the idea that this part will allow for a me to achieve a sharper image makes me extremely happy.

Now comes the task of trying to get Letus to see my point of getting this upgrade for free minus shipping and handling. I mean they were aware back in Sept. of 07 that I was planning to use my unit for a HVX200. Am I wrong for thinking this way? With current conditions I am not too crazy about spending 1 cent for something that should have been address before this unit went to market. I know, I know Letus is a great company, and thats why I brought the unit but at the same time this sounds more like a recall issue, and not something that I should be paying $250.00 for.

Any advice?

Thanks
 
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