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Old May 4th, 2008, 09:12 PM   #1
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LETUS XL - more silly questions, much appreciation

Hello everyone -

I just purchased a Letus XL for $650 and I have some questions.

1. Did I pay too much? (seemed like a good deal at the time)

2. Was this XL unit the starting point for the Letus Line to evolve from?

3. Were these XL units built very well?

4. What typical problems did these XL units suffer from?

5. Are any options or resources available to upgrade the XL unit?

6. How does the XL unit stand up against the Letus Extreme, Brevis or Redrock?

7. Can the XL mount be retrofitted to fit other cameras or is the XL line my only option?

Anything you guys think I should know would really be appreciated.

I love this forum and appreciate the creators and moderators that make it available to us!

R. L. Appling
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Old May 4th, 2008, 10:32 PM   #2
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1. 650.00 is a good deal - it's not made any more.
2. Not sure - Ask Hien Li.
3. The one I had was a tank.
4. Back focus difficult. Must light if using indoors - looses 1 1/2 stop. My annoyance was associated with battery pack placement - it comes off easy.
5. No upgrade options - only front lens options.
6. This is the only product, other than P&S, that attaches to XL1,2,H1.
7. If you felt creative, you could hack off the relay but I wouldn't recommend it. I thought this also worked with the HD100 but I could be wrong.

Overall, I miss the ease of this unit. We shot a feature using it and really was a joy to use and connected in seconds. I upgraded to the LEX for the light difference and to connect to my HVX-200.

Hope this helps.
-C
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Old May 4th, 2008, 11:12 PM   #3
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Some responses for your questions in meantime.


1. Did I pay too much? (seemed like a good deal at the time)

Can't say. I do not know original price and current used prices.


2. Was this XL unit the starting point for the Letus Line to evolve from?

I understand the XL model was an early generation development.


3. Were these XL units built very well?

There were some problems related to adhesive joints which required screws to be added or toluene based contact adhesive to permanently refix.

The precision of parts fit up was good.

Across all early models, the combination of reversable Nikon/Canon SLR camera lens mount and single thumbscrew retaining method was problematic for stability and backfocus.


4. What typical problems did these XL units suffer from?


Dust and swarf on internal optical surfaces.

Unstable reversable Nikon/Canon mount.

Separation of adhesive joints.

Vibrator motor failure to start.

Exposed power leads vulnerable to damage.

Failure of Canon lens latchpin to engage in slot when mounting Letus35.


ALSO

Excessive curiosity of owners.

Attempts at home repairs and modifications.


5. Are any options or resources available to upgrade the XL unit?


You would need to contact Quyen Le, Hien Le or Aaron Pin.

Replacement of the existing groundglass panel with the "Extreme" grade groundglass panel should yield a resolution improvement.

The remaing limiting factors are the small area of the groiundglass seen by the direct relay arrangement, the existing reversed single element optic used as a condenser and the Minolta Lens/unmounted achromat combination used as a relay.

The motor, wiring, groundglass panel and its carrier exist as a permanent subassembly with soldered joints and adhesives and cannot be separated except by destructive means.

The panel can be removed with care from the carrier by trimming away the adhesive and carefully parting the remaining ahesive under tension by flexing the carrier whilst supporting the groundglass. A risk of breakage remains.

Attempts at product improvement or modification should not be attempted by persons without very good fine dextoral skills and mechanical abilities.


6. How does the XL unit stand up against the Letus Extreme, Brevis or Redrock?

The XL unit and HD100 units use a fixed smaller area of image off the groundglass compared to models for lens-in-camera style cameras.

Therefore there is theoretically a lesser available resolution compared to other models for "lens-in-camera" style camcorders, where a larger area of groundglass image can be aquired using the camcorder zoom.

I have not tested the Letus35 XL against the Extreme, Brevis or Redrock M2 so I cannot answer for you.

There is also no valid comparative test to be made for the XL until the direct relay models of the "Extreme" become available, unless one goes another relay route via the XL camera's own standard lens plus an achromatic dioptre.

Subjectively, from previously posted anecdotal info here, my impression is that a ranking derived from "out-of-box turnkey utility" might appear thus :-

Letus Extreme-Brevis-SGPro
Letus35 XL
Redrock M2

A ranking derived from image quality might appear thus :-

Letus Extreme-Brevis-SGPro
Redrock M2
Letus35 XL


My assessment should be regarded as a very poor yardstick.


Past published anecdotal info here suggested that :-

the Letus Extreme, Brevis and SGPro have been used for work which has achieved television broadcast.

the Redrock M2 properly set up, has been used on a theatrically released feature, "Sarah Landon And The Paranormal Hour".

the Letus35 has been used to create commercial television advertising.


7. Can the XL mount be retrofitted to fit other cameras or is the XL line my only option?

Your Letus was custom made for the Canon XL but shares most subassemblies with the other original Letus35 models.

You could modify it to work with possibly superior results with "lens-in-camera" type camcorders by dismounting the Minolta relay lens and adding a quality achromatic dioptre. Above average skills and machine workshop equipment would be required for a good result.


Anything you guys think I should know would really be appreciated.

I hope the sticky thread above is of some help to you. It represents the limit of my knowledge of the Letus35.


My comments above can be selectively read as a castigation of the Letus35 product. This is far from the intention and should be weighed against the evolutions and improvements the Le brothers have brought about since, which culminate in the Letus "Ultimate", whilst retaining their enthusiast roots.

Quyen Le also did not simply turn his device loose but provided after-sales repair services for his Letus35 from the outset, which attracted favourable comments from users at the time.

As did the evolvement of affordable high-quality consumer prosumer video cameras "democratise" the moviemaking process for the relatively unmoneyed, Quyen Le's Letus35 with its flip function was the first "off-the-shelf" device to become available at a pricepoint which enabled the same people to more affordably emulate the visual aesthetic of 35mm film originated product.

It is likely that there are a more than a few people out there right now, making their way forward with 35mm lensing skills they learned and practiced on the original affordable Letus35.

Last edited by Bob Hart; May 5th, 2008 at 08:58 AM. Reason: errors
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Old May 5th, 2008, 01:47 AM   #4
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WOW. Thats a lot more of a response than I expected and EXACTLY what I needed to know. Thanks to you both for the effort you put in responding. I feel better about my purchase and look forward to receiving it next week.
Best Regaards - R. L. Appling
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Old May 5th, 2008, 03:53 PM   #5
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$650 is a reasonable price for the Letus XL.

One main difference between the LXL and the LEX is that the LXL has a significant crop factor when used on the Canon XL. The LEX has zero or very little crop factor..
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Old September 13th, 2008, 04:44 PM   #6
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Quote:
Originally Posted by Bob Hart View Post
The XL unit and HD100 units use a fixed smaller area of image off the groundglass compared to models for lens-in-camera style cameras.

Therefore there is theoretically a lesser available resolution compared to other models for "lens-in-camera" style camcorders, where a larger area of groundglass image can be aquired using the camcorder zoom.
How much smaller was the area...was it significant? Like a 1/3, 2/3 of the 1 to 1 image?

Quote:
Originally Posted by Bob Hart View Post
You could modify it to work with possibly superior results with "lens-in-camera" type camcorders by dismounting the Minolta relay lens and adding a quality achromatic dioptre. Above average skills and machine workshop equipment would be required for a good result.
was the relay "just" a minolta lens attached to the camera body of the HD100? Was it a 50mm, 35mm, 28mm? Anyone knows if it had been altered in anyway?

thanks
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Old September 13th, 2008, 06:52 PM   #7
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Charles.


The image recovered to the camcorder was approximately equal or just under the size of the 35mm acadamy motion picture frame of 24mm x 18mm. This is faithful to the original motion picture frame fields-of-view for given film camera focal lengths.

There is a piper to be paid for faithfulness to the original movie frame and that is a lesser sharpness for a given coarseness of the groundglass finish compared to a larger image area aquired off the groundglass.

Most users of the Letus who used lens-in-camera style camcorders pulled back on the zoom to get as wide an area as possible that the size of the screen or the still-camera lenses on front would allow.

The relay was a Minolta still-camera lens of 50mm focal length. It was apparently the best optical performer of still-camera lenses in this unusual application. The mount was removed and a custom replacement made and fitted. There was also an unmounted achromat added to the front of the lens with a firm but flexable adhesive.

It should be noted that the Minolta still-camera lens was never designed to carry the mechanical loading of the Letus device on front of it. Whilst it was satisfactory, the focus mechanism adtered camcorder to front of appliance length during focus movements. The focus could become tight or baulky uness the device was supported. This was often done by adding baseplate and rods, typically a purposed Cavision kit and a little slingstrap across the rods for the Letus body to rest upon and slide on.

Last edited by Bob Hart; September 13th, 2008 at 06:56 PM. Reason: error
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Old September 13th, 2008, 08:03 PM   #8
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Quote:
Originally Posted by Bob Hart View Post
Charles.


The image recovered to the camcorder was approximately equal or just under the size of the 35mm acadamy motion picture frame of 24mm x 18mm. This is faithful to the original motion picture frame fields-of-view for given film camera focal lengths.

There is a piper to be paid for faithfulness to the original movie frame and that is a lesser sharpness for a given coarseness of the groundglass finish compared to a larger image area aquired off the groundglass.

Most users of the Letus who used lens-in-camera style camcorders pulled back on the zoom to get as wide an area as possible that the size of the screen or the still-camera lenses on front would allow.

The relay was a Minolta still-camera lens of 50mm focal length. It was apparently the best optical performer of still-camera lenses in this unusual application. The mount was removed and a custom replacement made and fitted. There was also an unmounted achromat added to the front of the lens with a firm but flexable adhesive.

It should be noted that the Minolta still-camera lens was never designed to carry the mechanical loading of the Letus device on front of it. Whilst it was satisfactory, the focus mechanism adtered camcorder to front of appliance length during focus movements. The focus could become tight or baulky uness the device was supported. This was often done by adding baseplate and rods, typically a purposed Cavision kit and a little slingstrap across the rods for the Letus body to rest upon and slide on.
You just solved my problem. I went ahead and switched my relay from a Nikon 24mm f2.8 to a Nikon 50mm F1.8 and now I can attain much better (sharp) focus!

What had me puzzled was the fact that I was way zoomed in than when using my Letus Ultimate with my DVX...but it seems that that was the norm with the real Letus HD100.
If it were not that I know that I am zoomed in, you would never notice the difference between using the Letus with a DVX than zoomed in with my HD100...actually If I tried to zoom in that much with the DVX, it would go blurry!

So what are the advantages of having more GG real estate to work with rather than the 35mm Academy size?

Thanks for the valuable info....oh and by the way...why would anyone wait for Letus to come out with a relay if it is possible today to use you Letus by just using a MTF nikon to JVC adapter and one step up ring...I've been doing it for the last 6 months with no problems...

http://vivalavhs.com/JVC2.jpg
http://vivalavhs.com/JVC3.jpg
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Old September 14th, 2008, 12:28 AM   #9
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QUOTE:
So what are the advantages of having more GG real estate to work with rather than the 35mm Academy size?


The math is something like this :-

24mm divided by 5 microns = ( )

32mm approx divided by 5 microns = ( )

You do the math as I failed mental math from age 8 onwards and my calculator battery is flat.

You will oberve from the number stuff, that 5 microns divides into 32mm a few more times than into 24mm. Therefore the scale size of individual "grains" in the groundglass is proportionately smaller on a 32mm image area width than with a 24mm width. The "apparent" resolution is superior.

So if you zoom-in more for the image relay the camera sees each "grain" as a larger entity. Now the groundglass actually moves so each grain is essentially invisible to the camera however the resolving ability of the groundglass is determined by the size of individiual grains.

A detail in the projected image smaller than 5 microns will likely be seen by the camcorder as a five micron to 25 micron sized object, depending on how many "grains are implicated. This multiplier effect of diminished resolution amplifies soft lens images, so the recovered image from a poorly performing lens will look heaps worse on a groundglass adaptor.

The older Letus groundglass was of coarser texture than in the current Extreme. To misquote Hien Le rather badly, the original objective of the Letus groundglass was to "own" the bokeh, a word which defines the visual aesthetic quality of the out-of-focus areas of the image.

This requires a groundglass to have a relatively coarse groundglass texture. A finer texture will reproduce more finer detail but at 3 microns, some aerial image also comes through which creates the "oily" look or "ghosting" effect in bokeh presentation, which is something akin to the halation effect around highlights seen in some older filmstocks.

QUOTE:
"Thanks for the valuable info....oh and by the way...why would anyone wait for Letus to come out with a relay if it is possible today to use you Letus by just using a MTF nikon to JVC adapter and one step up ring...I've been doing it for the last 6 months with no problems..."


The JVC is a three x CCD camera with a splitter prism system. Lenses which feed such systems have to be purposely designed to compensate for the varying light wavelengths of the separated colours to minimise fringing artifacts. A still camera lens is designed to project its image directly onto a film emulsion or single sensor.

Therefore a relay lens, purposed for casting an image through a splitter prism onto three sensors will likely perform better in terms of colour fidelity and contrast and the image will be seen to have better "apparent" sharpness. It may also be actually sharper. That is the brothers' objective and it is not an easy thing to pull together.

As to the differences between the Panasonic and JVC, one of the factors is the physical space occupied by camera structures between the portions of the lens which shape image and the groundglass. It may be that the Panasonic needs to be furthur away from the groundglass for sharpness to be maintained.

There are lots of variables at play here so no one cause can always be readily nailed down

Last edited by Bob Hart; September 14th, 2008 at 12:30 AM. Reason: error
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