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Old September 12th, 2012, 01:00 AM   #1
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Letus DOF

Hey guys so I'm deciding whether or not if I should buy the Letus extreme for my HMC150 to help with DOF shootings like closeups. The ultimate seems to be what everyone is suggesting on getting so I wanted to know what your guys opinion on the ultimate. Any pro/cons? and what lenses is best when using this adapter?
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Old September 12th, 2012, 09:33 AM   #2
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Re: Letus DOF

There are three variations of the final evolution of the Letus adaptors, actually four if you consider the mini for smaller camcorders. By the time the HD video-capable DSLR cameras pulled the rug from under 35mm adaptors, the most commonly available 35mm adaptors had matured to produce good results.

Correctly managed and with good stills lenses, the Letus adaptors can yield apparent sharpness to the practical ability of your camera.

The Letus Extreme was the basic model, the Elite was an Extreme with an adjustable backfocus for the lenses which fit on the front. These adaptors used an orbital movement driving the groundglass.

The Ultimate shares the erecting prism system and internal optics of all the adaptors and the backfocus adjustment of the Elite. If differs from the Extreme and Elite in that the groundglass is a disk with a variable speed motor drive. Disk devices tolerate higher shutter speeds and higher iris numbers.

The alignment of the disk groundglass relative to the focal plane of the stills lenses is more stable than with the orbital models which can be disturbed if dismantled for cleaning.

If you can buy the full kit including rods (rails), bridgeplate etc., this will be better than trying to hang an adaptor off the front of the camera alone and improvising your own support system.

If you look up Philip Bloom - DP, Director, Filmmaker, you may still find his older blogs on 35mm adaptors. He did a shootout with several of the popular alternative adaptors and thought highly of the Letus Ultimate on the Sony PMW-EX3 at the time.

As an example of how good 35mm groundglass imaging can be can be found in the feature movie "Monsters" which was shot with a Letus Ultimate/Sony PMW-EX3 with Nikon still lenses.

If you are buying a used Ultimate, ask the seller to pack the device in padding or styro beads in a box and then that box inside another also padded with beads. The compound prism is a heavy mass of optical glass which is easily damaged by the violence of careless parcel handlers. If it comes as a complete production bundle in a case, ask for that case itself to be packed in a box with styro bead padding.

You may pay more for the shipping but trust me it is worth the investment.

Lenses - Whatever brand, go for fast prime lenses preferably f1.4, or a good zoom which should be in the ballpark of f2.8 at its widest aperture setting. Most 35mm adaptors begin to degrade the image froim f5.6 and higher aperure (iris) numbers.

Unfortunately, with the breeding up of the RED family of digital cinema cameras, video-capable DSLR cameras and the new iterations of prosumer cams from Sony etc., with 35mm sensors, previously affordable good used 35mm stills lenses are becoming more costly.

Your basic set will be something like, 28mm, 35mm, 50mm, 85mm which can be had as f2, which gives you a four-stop range to f5.6.

A ballpark basic setting for your rig will be :-

Outdoors clear sky to 3/8ths cloud.

Stills lens iris f3.5.
Camcorder lens iris f5.6
Camcorder internal ND1
Camcorder video gain 0db.
Whitebalance daylight.
Shutter 1/50th sec or shutter off.
Frame rate 25P or 24P.

There are some tricks for setting relay focus and front lens backfocus. There is not much point me going into it until you have the device assembled and ready. If you mine deep enough in this subforum you will find some handling notes on the Letus which will get you in the ballpark. The Letus .pdf manuals may still be downloadable from either Home or Letus Corporation - Manufacturer's Website.

When you are ready to go forward, post against on this forum and there should be people here will guide you furthur.

Last edited by Bob Hart; September 12th, 2012 at 09:38 AM. Reason: error
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Old September 12th, 2012, 01:16 PM   #3
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Re: Letus DOF

Nice post Bob. A lot of work put into it. Problem is that this old technology is supplanted by the modern DSLR, and other large imager video choices, starting at prices less than one of these adapters, and rails. OP ought to really consider those other options, given the fact that you have some issues to fight with an adapter, and generally will get better results with a simple DSLR like the Canon T4i or the Panny Gh2.

I was part of the original adapter revolution, and turned to DSLR with the 5DII arrival, and see no real value in it continuing with adapters given what is available as an alternative out there now.
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Old September 12th, 2012, 02:35 PM   #4
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Re: Letus DOF

A valid suggestion Chris. He could be as well served by having a second camera like a used 5D or 7D rather than the hassle of wrangling a groundglass adaptor. It depends on what he is asked to pay for the Letus adaptor he has in mind.

It would be interesting to see if anyone does the groundglass thing with an EPIC/SCARLETT and a huge platecamera sized groundglass like the Coatwolf/SI2K rig but yes, 35mm adaptors have had their run.
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Old September 13th, 2012, 02:28 AM   #5
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Re: Letus DOF

Is $400 for the letus a good deal? I was contemplating the idea of picking up a dslr but it depends on how much i would have to spend compared to buying a letus
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Old September 13th, 2012, 03:11 AM   #6
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Re: Letus DOF

At best buy.com. you can get a Canon T3i body for $549. $699.00 for one with kit lens. You will spend that much in the end on the Letus and likely not have near the results.
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Old September 14th, 2012, 03:29 PM   #7
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Re: Letus DOF

The only slr worth getting in my opinion is the 5D, but that ranges around 1K to 2. With the hmc, I only gotta buy the adaptor/mount and lenses. I might pickup a 35mm or 50mm Zeiss just cause my mentor told me its the only way to go hahaha. This whole process have been a very hard decision with so many options available. (The feeling u get as a kid in a candy store). If anyone has anymore input I appreciate it
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Old September 15th, 2012, 12:56 PM   #8
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Re: Letus DOF

I will be the first to admit that I didn't have the best adapter equipment around. But, I still believe that even out of the lowly T3i, you will get better results than you will ever get out of your HMC 150/Letus plan. I am not so sure you are getting good advice from you mentor, but then, perhap the mentor knows more about your needs.

But when you mount the adapter on the camera, and assuming you are buying the flip unit, you then have an unwieldy long piece of equipment. Yes, it may look cool and techy, but when you start trying to adjust shutter speeds, focus on two levels, and exposure in camera and via the lens, you start having so many variables that get in the way of a great shooting experience.
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Old September 15th, 2012, 05:36 PM   #9
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Re: Letus DOF

is the t3i a full sensor camera? After reading your comment, I've come to a decision to not buy the letus. As good as the price was ($350), I figure in the end I was going to be spending around 2k if i bought all the necessary equipment needed for my cam.
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Old September 15th, 2012, 08:36 PM   #10
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Re: Letus DOF

T3i is an APC sensor, about the size of super 35mm film. Remember, full frame cameras have shallower depth of field than what cinema film makers had, because the frame is larger. Film runs vertically in a cinema camera, while in a 35mm still camera it runs horizontally. Thus the APC sensor is closer to 35 mm frame size than the full frame camera.

The T3i will get you going. You will be learning about lens choices, frame rates, and things like Magic Lantern to make the camera work more like a film camera and help you get your look right. Its a long term process and it doesn't happen overnight.
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Old November 2nd, 2012, 06:24 AM   #11
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Re: Letus DOF

For what it is worth, here is a Letus Extreme/Sony PMW-EX1 frame grab. The combination is to be used for a music video this weekend by choice of the producer. It is illustrative of how the operator has to be a little more vigilent than when using a simple 35mm format video camera. This Letus has been modified and the frame area in this instance was a little too wide for the lens used.
Attached Thumbnails
Letus DOF-overcast-test.jpg  
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Old November 2nd, 2012, 07:43 AM   #12
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Re: Letus DOF

Bob is the king of 35mm adapters and his advice helped me a lot when I started using my letus. The worst thing about the adapters is the amount of work to change lenses compared to a dslr. I was a one man crew and the first time I had to change a lens it took me more than 10 minutes. I had to pull off the matte box, change the lens, adjust the ground glass etc. I got it down to under 5 minutes per change by the end of the shoot but it was painful and I longed for a dslr.

One thing to note is that you'll need to spend the money on lenses no matter whether you go dslr or adapter. For $350 i'd take a punt and start playing with it. You can re-use your lenses when you finally get a dlsr.

Here's a couple of shots from one of mine: EX1 with 24mm Nikon lens on a letus extreme and a 50mm f1.2.
Attached Thumbnails
Letus DOF-proposal-grade.png   Letus DOF-handfull.jpg  


Last edited by Damian Heffernan; November 2nd, 2012 at 07:48 AM. Reason: added pic
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Old November 3rd, 2012, 10:28 AM   #13
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Re: Letus DOF

Here'sa bit of behind-the-scenes which shows at the very end, the 4/3rds Panasonic camera used. It does make sweet images. They were also using Nikons.

I had a bit of downtime so picked off some quick shots. A tool for spontaneous cinemaverite, the EX1/Letus probably is not. Like an idiot I forgot to turn the motor on and I did not have my close-up glasses positioned right to read the focus marks so took a wild guess. Les was Sigma-for-Nikon 20mm f1.8 at f2.8.



It has been uploaded as 1920 x 1080.

Last edited by Bob Hart; November 3rd, 2012 at 10:45 AM. Reason: added text
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Old December 30th, 2012, 07:18 PM   #14
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Re: Letus DOF

I've shot a film already with a XH-A1
Should I save money for a Sony FS100 or EA50 and forget about my old XH-A1 or should I push it a few more years by adding a letus extreme 35?
Maybe I should call it an old cam and forget about it, uh?
Of course I'm a cheap skate.
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Old December 30th, 2012, 10:33 PM   #15
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Re: Letus DOF

I guess the old adage applies when it comes to risky business. - Only spend the money you can afford to lose.

If you can buy the Letus for a good price, give it a try. If it comes from eBay, try to insist on very good packaging, initial softpack around the Letus, then box, then more softpack around that box inside another box.

There are several tiers of flight in air transport, one of actually going aloft in the aircraft, the others consisting of the flights from the baggage handler's paws across to the conveyor, the bounceback to nearside floor or tumbling spillover onto the opposite floor when the package misses the sweet spot on the conveyor nearside edge, the drop off from one conveyer to the next.

The final coup-de-gras may come with the delivery, an airbourne journey from the entry gate of your home, to the front porch or stoop as you may call it where you are.

Most adaptors have a massive compound prism in the optical path. It is made of brittle optical grade glass which can chip or crack.

I vaguely recall there was an issue with most, if not all adaptors with one of the small Canon cams, also the Sony PMW-EX1/EX3, relating to the achromatic lens in the rear of the adaptors.

A special achromat was made for the Sony EX1/EX3. What happened relating to the Canon cam, I do not know.

Last edited by Bob Hart; December 30th, 2012 at 10:36 PM. Reason: error
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