Letus GG alignment - well to the right. Faulty?

Stuart Campbell · June 20th, 2008, 10:14 AM

Stuart,

Your alignment issue is nothing compared to mine! My Letus is more than double offset than what your image shows!

I've been having no end of trouble with mine ever since it arrived and as such have not been able to use it.

Sadly I've had NO HELP WHATSOEVER FROM LETUS so far. Bob and Ted have been absolutely superb in helping me try to sort out the issues, and we're still not there! They are by far the most knowledgeable on this subject. Their advice is invaluable! See my thread on 'using macro to see ground glass'

I've a hugely busy small company and I purchased the unit for several specific jobs. So far the bloody thing has been a complete waste of my money and nearly 3 complete days trying to get it to work. As you can probably tell I'm just a little bit less than satisfied with Letus right now.

I've got one more thing to try (as suggested by the guys above) and if that doesn't work I'll be sticking the bloody thing in the bin or using it as a vase or something.

I'm soon to be of the conclusions that the Letus Extreme is;

a: not really suitable for the JVC gyhd200
b: not consistent in build quality with all other models
c: meant to be tinkered and fiddled about with before you can get a satisfactory image.
d: not suitable for use on paid jobs where the client expects a specific product by a specific time.

I sincerely hope I can avert these conclusions and soon sing it's praises as there are plenty of people out there who obtain superb images with it. Hopefully the Letus guys will have emailed me with a satisfactory reply by Monday and I begin to forget my sorry saga! My only other thought is that I should by a Z1 or HVX200 if I want to persist with the Letus. Or...buy P+S.

Good luck with yours!

Bill Ravens · June 20th, 2008, 11:10 AM

Just a quick note from my own experiences with the LE on my EX1. I, too, have experienced the asymmetric positioning of the image frame on the ground glass. My letter to Letus was responded to with the explanation that the GG is oversized to accomodate positioning issues?!. Their reply is somewhat of a non-sequitor to the question. I have disassembled the LE to attempt to determine if there is something I could devise to perform an alignment of the image center axis to the axis of the EX1. What is apparent is that the LE GG screen is mounted on elastomeric mounts to allow the screen to vibrate when acted upon by the eccentric weight on the motor shaft. The very fact that the screen is mounted on a moving elastomeric mount is sufficient to preclude any attempts at a precision alignment. What's even more disturbing is that it is quite possible for the GG screen to be mounted at a small angle relative to the optical axis. This can cause defocus across the image plane.

hmmm, hope my post makes sense and doesn't sound like double-speak. the bottom line is that this design is lacking in optical precision. Had I known this beforehand, I wouldn't have ordered the LE. Caveat emptor.

Stuart Boreham · June 20th, 2008, 12:18 PM

Everyone here (Phil Bloom, Mitcorp etc) seems to be satisfied that its the misalignment of the chip block on the cameras that causes the issue. Have you guys (especially Stuart) tried the letus on another camera to see if the issue persists? (sorry if your post says that you have- I can't read that and type this at the same time!). I have done a test with 2 out of my 5 cams and they both seem to show similar offset which would indicate a letus issue or it could just be a co-incidence - I cannot be certain until have been a bit more rigorous.

I will try and swap my unit with Phil Bloom's one as he has offered ane we live near and that should proove it one way or another.

Sorry you are all having such a load of trouble for something that should be such a creative joy.

s

Bill Ravens · June 20th, 2008, 01:18 PM

It occurs to me that if the build tolerances on the CCD block are that loose, the off-axis aberrations caused by a decentered optical system would be horrible. I find it very difficult to accept that even Sony would have such sloppy CCD alignment tolerances; and, optically, it's just out of acceptable practice for someone with Sony's (arguable) reputation..

Stuart Boreham · June 20th, 2008, 01:28 PM

I tend to agree. It would also mean making a lens witrh a much larger image circle than necessary in order to ensue that the chip was fully within it. However, is it possible that any chip alignment issues would be exagerated by the 'close up' nature of the GG screen?

Plus of course if it is the cameras then one would imagine that al 35mm adaptors would highlight the same issues - I do not klnow if this is the case.

S

June 20th, 2008, 10:14 AM	#16
Stuart Campbell Major Player Join Date: Nov 2006 Location: Hannover, Germany Posts: 400	Stuart, Your alignment issue is nothing compared to mine! My Letus is more than double offset than what your image shows! I've been having no end of trouble with mine ever since it arrived and as such have not been able to use it. Sadly I've had NO HELP WHATSOEVER FROM LETUS so far. Bob and Ted have been absolutely superb in helping me try to sort out the issues, and we're still not there! They are by far the most knowledgeable on this subject. Their advice is invaluable! See my thread on 'using macro to see ground glass' I've a hugely busy small company and I purchased the unit for several specific jobs. So far the bloody thing has been a complete waste of my money and nearly 3 complete days trying to get it to work. As you can probably tell I'm just a little bit less than satisfied with Letus right now. I've got one more thing to try (as suggested by the guys above) and if that doesn't work I'll be sticking the bloody thing in the bin or using it as a vase or something. I'm soon to be of the conclusions that the Letus Extreme is; a: not really suitable for the JVC gyhd200 b: not consistent in build quality with all other models c: meant to be tinkered and fiddled about with before you can get a satisfactory image. d: not suitable for use on paid jobs where the client expects a specific product by a specific time. I sincerely hope I can avert these conclusions and soon sing it's praises as there are plenty of people out there who obtain superb images with it. Hopefully the Letus guys will have emailed me with a satisfactory reply by Monday and I begin to forget my sorry saga! My only other thought is that I should by a Z1 or HVX200 if I want to persist with the Letus. Or...buy P+S. Good luck with yours!

June 20th, 2008, 11:10 AM	#17
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	Just a quick note from my own experiences with the LE on my EX1. I, too, have experienced the asymmetric positioning of the image frame on the ground glass. My letter to Letus was responded to with the explanation that the GG is oversized to accomodate positioning issues?!. Their reply is somewhat of a non-sequitor to the question. I have disassembled the LE to attempt to determine if there is something I could devise to perform an alignment of the image center axis to the axis of the EX1. What is apparent is that the LE GG screen is mounted on elastomeric mounts to allow the screen to vibrate when acted upon by the eccentric weight on the motor shaft. The very fact that the screen is mounted on a moving elastomeric mount is sufficient to preclude any attempts at a precision alignment. What's even more disturbing is that it is quite possible for the GG screen to be mounted at a small angle relative to the optical axis. This can cause defocus across the image plane. hmmm, hope my post makes sense and doesn't sound like double-speak. the bottom line is that this design is lacking in optical precision. Had I known this beforehand, I wouldn't have ordered the LE. Caveat emptor.

June 20th, 2008, 12:18 PM	#18
Stuart Boreham Regular Crew Join Date: Dec 2005 Posts: 56	Everyone here (Phil Bloom, Mitcorp etc) seems to be satisfied that its the misalignment of the chip block on the cameras that causes the issue. Have you guys (especially Stuart) tried the letus on another camera to see if the issue persists? (sorry if your post says that you have- I can't read that and type this at the same time!). I have done a test with 2 out of my 5 cams and they both seem to show similar offset which would indicate a letus issue or it could just be a co-incidence - I cannot be certain until have been a bit more rigorous. I will try and swap my unit with Phil Bloom's one as he has offered ane we live near and that should proove it one way or another. Sorry you are all having such a load of trouble for something that should be such a creative joy. s

June 20th, 2008, 01:18 PM	#19
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	It occurs to me that if the build tolerances on the CCD block are that loose, the off-axis aberrations caused by a decentered optical system would be horrible. I find it very difficult to accept that even Sony would have such sloppy CCD alignment tolerances; and, optically, it's just out of acceptable practice for someone with Sony's (arguable) reputation..

June 20th, 2008, 01:28 PM	#20
Stuart Boreham Regular Crew Join Date: Dec 2005 Posts: 56	I tend to agree. It would also mean making a lens witrh a much larger image circle than necessary in order to ensue that the chip was fully within it. However, is it possible that any chip alignment issues would be exagerated by the 'close up' nature of the GG screen? Plus of course if it is the cameras then one would imagine that al 35mm adaptors would highlight the same issues - I do not klnow if this is the case. S