Letus Extreme vs. Letus Ultimate for EX3

[Larry Huntington]

Hi Rob,
I appreciate your thoughts on going with a long lens vs. the Letus. This was my original thought. I wanted to go with a Canon KH-20 or an XS-17 Fujinon. I just don't feel that spending $8,500 for for the Canon 20x is worth the money based the additional zoom range. I will be shooting music videos and music performances, so I will be in situations where it is not run and gun. I figure I will use the Letus Ultimate about 10% to 15% of the trip, but those images will stand out amongst the rest and be worth the investment. I have the weekend to think this out clearly; to decide whether or not to purchase the Letus Ultimate. If I had the bucks, I would no doubt go with the P+S Pro35 adapter, but I feel I should either go with a long zoom lens or the Letus setup. If anyone can talk me into the KH-20 or XS-17, please feel free to lend your words. I'm looking for options that will give me flexibility, ease of use, and most importantly, the best image quality.

[Justin Benn]

Originally Posted by Larry Huntington

Thanks Justin for the PM. I have to scramble here to get a package soon- I leave for Africa in 3 weeks and I want a few days to spend with the adapter to get used to it. I will have two camera assistants to help me, so it might be easier to get a quick handle on the 35mm option.

I'm beginning to wonder about the quality/ reliability of the Letus based on my reads.

Where is a good link to the P+S adapter? Is the Redrock Micro a quality product?

Larry, I can get beautiful images out of my Ultimate. I just wouldn't rely on it as its physical integrity is representative of an enthusiast's product at best. That said, I would feel more comfortable about the support and QC you would get from Zacuto and their version. I have several of their products and not only are they great, their customer service is very good too. I would feel confident that they would work hard to keep me shooting no matter where I was in the world.

The P+S for the EX3 is very new. Can you afford one? At about US$18k the last time I checked, I can't right now, so it would be rental for me and the usual suspects seem to have them in stock for hire. The P+S may seem overkill for the EX3/1 but unless you've seen a decent DOF adapter (The Ultimate, on a good day) on a XDCAM EX using the HD-SDI out on a recorder like the FLASH XDR with 50mbps or 100mbps (I have all of the links in this chain), you won't understand just how special an image you can get. That's why I'm thinking of ways (some straining the definition of legal...) to get me some kind of version of the P+S for my kit. I have played briefly with a Pro35 on an F900 with some Zeiss Ultraprimes and it seemed very robust by comparison.

Jus.

[Bob Hart]

Justin.


If you go with any adaptor, vigilence with relay focus (also called backfocus in relation to detachable lens style cameras) can not be over-emphasised.

The common practice is to establish relay focus by adjusting for sharpest groundglass texture "grain" by closeing the iris of the lens in front to provoke the groundglass texture into visibility and opening up the iris of the relay lens (camcorder lens) to maximum to make the camcorder lens depth-of-field as shallow as it can be before trimming the focus.

Some regard the follwing comment as an urban myth however I observe that there is a tiny fraction more resolution to be had by adjusting the relay focus to the visible image which lies within the depth of the groundglass texture, an uneven surface of pits and peaks which is in the ballpark of three to five microns from bottom of pit to peak.

The only way to arrive at this "fine tune" is with the groundglass running so that it is in its normal operating position and the lens on front of the 35mm adaptor, already in sharp focus upon some finely patterned object. In desperate times, this could be the fabric of a threadbare curtain but it is more useful to take a focus chart with you. Siemens stars are helpful but a chart with varying pitches of straight lines in blocks is better.

Even if your viewfinder resolution is poor, the parallel lines in the resolution blocks throw off visible moire patterns when focus is sharpest. With the Siemens pattern, your eyes can play tricks with you. If you are really stuck, a simple hair comb in front of a piece of paper or sticktytaped to a window glass is better than nothing.

You will be very hard put to get this right with the camcorder viewfinder. A HD monitor or HDTV is about the only way to go. With the P+S direct relay systems for detachable lens cameras, the focus ring is locked off once you have found the setting and you need only check it periodically or if the camera goes through extremes of temperature or is dismantled. Some trust the integrity of the P+S Technik products and this is generally okay to do, but I prefer to check.

Until the vendors of the alternative products finalise their own direct relay lenses, you are stuck with using the camcorder's standard zoom lens and its focus system for trimming relay focus.

It is quite adequate but is more vulnerable to being moved off sharp relay focus and correct relay framing, even if you tape the lens focus ring and zoom rings and select the zoom rocker switches off.

Before you set off, you need to find an underscanning monitor somewhere. I don't think you can set the EX1 or EX3 LCD viewfinder to an underscanning mode like you can the Z1. Use this to establish just how far back you can come with the zoom before you pick up an edge of the optical path.

If you zoom furthur in than you need to frame out the edges of the path, you then crop your relayed image and lose some apparent resolution. These cameras create a crisp image and if the groundglass image is over-soft it will not intercut without being noticeable.

It can be helpful to make up a framing card while you have an underscanning monitor only temporarily. Whilst observing the monitor, set up a large card a fixed distance of your choosing from the taking lens on front of the adaptor.

While looking through the viewfinder, use a sharpie to trace an outline of your viewfinder frame. Then whilst looking at the underscanning monitor, trace another outline of the visible frame edge.

In the field, you can then set your card up the same distance from your lens (the same one you calibrated with), then widen the view with the zoom until you find the viewfinder frame edge, then zoom in just a mere trace.

Some operators simply frame the edge of the path to the edge of the LCD display, then pick an object within the image which rests on the left or right side safe-area guide frame, then zoom in until this object moves onto the LCD display edge. I'm fine with this as a quick fix but there remains a risk that the camera manufacturer has been too generous or too cautious.

Most cameras err on the side of caution and throw much of the usable image outside of the guide frame to assure your subject remains within the final exhibition frame of the common household television set.

The caveat emptor is that optical centricity has to be maintained. Shipping and several cycles of assembly and breakdown can send it off. You need to check, preferably after each transport, by un-taping the zoom ring, widening the view and checking the vignette of the edges of the optical path.

When people initially set up adaptors on rods (rails or whatever else you call them), there is a tendency for haste born of the understandable desire to get out there and drive the thing.

While you can wing it on your own, it is more helpful to have two people on the job setting up. The 35mm adaptor and its mounting system to the front of the camcorder lens should be aligned correctly first, then the remaining fitments adjusted so that there are no mechanical loadings on the camera to 35mm adaptor optical junction.

Many camcorders are of plastic construction and a considerable amount of flex can occur in the casework which can move the optical centre off alignment with the centre of the sensor.

The actual weight of a camera can cause a bending misalignment during assembly. This becomes locked in after all the rails and clamps are secured.

I find it more helpful to offer the camera to the 35mm adaptor's optical junction by pointing the camera and adaptor camera upwards, then joining and securing them together in that orientation. The combination is slightly more awkard to assemble but is easier to get right in that orientation. The extra pair of hands is very helpful with this task.

Adaptors make for great images but they are also higher maintenance for consistent and predictable results to be had. You need to budget for extra operating time if you are going to use one. Haste most often means a ruined shot and becomes time wasted.

Adaptors also lose light, some more than others.


My sense is that allowing yourself only one week to get used to the adaptor is too short a time. In reality it won't happen because of all the other stuff associated with overseas travel. Packing, remembering things, mishaps and somebody else's last minute demands on your time will erode this practice window and you will be learning on the job.

[Justin Benn]

Bob,

Thanks, as ever, for your super informative posts. As it happens, my issue with the back focus adjustment of my Ultimate has more to do with the perceived range of adjustment at one end of the scale, so to speak. It all feels so imprecise! But, I haven't brought this up before because, so far, I have been able to get the sharp focus I've needed - just - using a Zeiss ZF 50mm or 85mm for interview work.

As it happens, I use a TV Logic monitor when using the Letus for the reasons you highlight. It has an underscan mode.

Jus.

[Bob Hart]

Justin.


Kind comments appreciated.

Actually I think I may have become a little confused as to who is going to Africa. Doesn't matter, the wordstuff is written.

[Larry Huntington]

Hi Bob,
I'm going to Africa in 3 weeks, and due to time constraints/learning curve, I have decided to forego the 35mm lens options at this time. Your information is very valuable and I will be looking at this thread again when I decide to go with the 35mm adapter. If I purchase anything at this point and if I am allowed to take it out if the budget, I might go for a Canon KH-20 or a Fujinon XS-17.
Thanks again for everyone's input!

~Larry

[Michael Palmer]

One option is to get the Fujinon ACM-21 2/3 lens adapter and rent a nice 2/3 ENG lens that with give you the long lens you need.
I have this ACM-21 and have stolen my HPX-500 18x7.6 Fujinon 2/3 lens and it is great, nice and long.

Fujinon ACM-21 Lens Mount Adaptor for Sony PMW-EX3 :: HDV, HD Lens Adapters :: Optical Lens Adapters :: Lenses & Optical Lens Adapters :: Equipment Sales :: Abel Cine Tech

I have my eye on the Cinevate Brevis MP.1 35MM adapter as they have optimized their one of their Cine Fuse for the EX factory lens and they are working on producing a new EX3 rely lens that is said to be released in the Spring.

Good Luck with the shoot.

Michael Palmer

[Alex Raskin]

Larry, Letus Extreme is quite enough to produce beautiful images, and it only loses 1/2 stop of light.

Problem is, it has severe issues with backfocus. They say it is set at the factory, but it was not so in my case. There's no legitimate adjustment; you are expected to disassemble the adapter and arbitrarily pull fragile parts to achieve the backfocus. Not only that, but you are forced to do it repeatedly, since you can only see your result after you re-assemble the thing back.

As you can tell, I'm not a fan of LEX engineering.

Now, I seem to have kicked the beast to the point when it performs as expected; but it did cost me a lot of spoiled blood, lost time, and dangerous assembling/disassembling. Your mileage will vary.

To my knowledge, Letus Ultimate, mostly, is just a grossly overpriced Letus Extreme with backfocus issue fixed. Apparently owners are still unhappy with it though.

Supposedly Zacuto has an adapter that specifically fixes LEX's backfocus issue by replacing crappy Nikon mount block provided by Letus with the Zacuto-made part that should work OK. I do not own that part so cannot attest to it.

But I do own LEX (Letus Extreme), and by looking at B&H kit, I can tell you that one of the best lenses is missing from it.

Zeiss 100mm Makro is truly awesome - I own it, and never regret spending money on it. (If you have a chance, please research what people who are much wiser than me say about that lens. You'll be amazed.)

With it, LEX's image quality is really great.

Bottom line... from my own experience, Letus is voodoo magic (too temperamental and fragile), and I would NOT rely on it solely, if I did a commercial project.

But I would at least try to use it on some shots (preferably in studio), because when it works, it does produce great images with the right setup. (Including Zeiss 100mm lens above, plus special achromat for EX1 that I had to buy separately...)

Of course you need rails (Letus makes very good kit for LEX with the riser that fits EX1 perfectly), and a good follow focus as well...

Comments above are for LEX with EX1 since I own and have experience with it, not EX3.

[Michael Palmer]

Alex,
I purchased the M-2 adapter at NAB last year for my EX1 and what a nightmare, I can't tell you how horrible it was dealing with RRM and their so called customer support. I finally found out the guy at this years NAB from Red Rock Micro knew of the EX1 lens issue and knew it wouldn't have very good edge to edge focus but sold it to me anyway.

I have been waiting and as I just posted I am looking at the Cinevate Brevis MP.1 35mm adapter as they have an optimized Cine Fuse specifically for the EX1 LENS. The Brevis also has a variable speed for the oscillation of their Cine Fuse for fine tuning to each lens choice. Cinevate has also said they will produce a rely lens for the EX3 that should make a big difference to those of us still undecided on the right tool.

My question to you is what zoom setting (number) do you zoom out to for the best performance with your adapter. The Cinevate website has some videos that show it somewhere between 67-72 on the zoom.

I appreciate your thoughts,

Michael Palmer

[Keith Moreau]

Originally Posted by Alex Raskin

Larry, Letus Extreme is quite enough to produce beautiful images, and it only loses 1/2 stop of light.

Problem is, it has severe issues with backfocus. They say it is set at the factory, but it was not so in my case. There's no legitimate adjustment; you are expected to disassemble the adapter and arbitrarily pull fragile parts to achieve the backfocus. Not only that, but you are forced to do it repeatedly, since you can only see your result after you re-assemble the thing back.

I agree with you Alex about the Letus Extreme backfocus. It's just too fiddly to be a professional solution. The adjustment method for that is too unprofessional and trial and error. They came out with an 'Elite' backfocus add-on for the Letus Extreme for $600 which I'll probably get when I start using the LEX again more often. I used some older Nikon lenses on it and sometimes the images are amazing though. Sometimes it seems they're clearer than without it, which seems impossible but maybe with the zoom in and proper aperture maybe there's sweet spot on the EX1 that can be exploited by the LEX. I'll check out the Zeiss 100mm you mention. Kind of long maybe for me. What subjects do you find it useful for?

[Alex Raskin]

Keith, I use my 100mm Zeiss on almost everything :)

I know how it sounds :)

But if you think about it, after certain length, you can simple reframe by increasing/decreasing the distance between the cam and the object, and that's what I'm doing. Beats changing lenses; and none of my other ones, although also good, approach the image quality of Zeiss 100.

And you can even get extreme closeups with this same lens, since it is a macro!

For specific wide angle shots, of course, you will have to change the lens.

By the way, Zeiss 100mm Makro is also available here - although it says only 1 left in stock now.

[Alex Raskin]

Originally Posted by Michael Palmer

what zoom setting (number) do you zoom out to for the best performance with your adapter.

Michael, on my EX1, I go to Z68 - at which point the entire ground glass is covered.

[Phil Bloom]

The Zacuto sold Letus Elite fixes the Extreme back focus problem with the (available separately) backfocus add on. This is actually made by Letus, not by Zacuto.

The Ultimate is spinning GG not Vibrating GG like the Elite and the Extreme.

I would throughly recommend getting the Elite rather the Extreme as the back focus issue is a 'mare to fix.

The EX3 relay, I am told, will be out very soon!

[Alex Raskin]

Hey Phil, thanks for the correction - indeed the backfocus add-on ring is made by Letus and carried by Zacuto. (For some reason, B&H does not have it separately from the adapter kits at the moment.) I learned about it just before you posted :))

Elite adds almost 50% to the cost of Extreme. If you are facing a shoot, and are hell-bent on using Letus, I agree - get Elite to avoid backfocus issues.

I was considering purchasing a backfocus adapter recently, but after my pull-and-pray session my LEX backfocus still holds... So I guess I'll just wait until it gives in, and then buy the Letus add-on ring.

I have to say that, especially comparing to the cost of the entire LEX, the backfocus ring's $600 price tag appears unreasonable - especially for something that should have been part of the original LEX design to begin with.

[Phil Bloom]

Totally agree. Is it too expensive. As far as I know it is a Zacuto exclusive hence no B&H.

The extreme really should be discontinued and replaced with the elite as the back focus is absolutely essential...