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Old February 15th, 2009, 10:25 PM   #31
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That would suck! What size is the opening of an Ultimate mounted on an EX1/EX3 lens? In other words, when you zoom in the least amount possible. Is it pretty close to 1:1? My 17x35mm seems pretty darn wide on the Ultimate/EX3.

Sorry for all the questions but this is a very helpful conversation......well at least for me. I would assume there are other people reading this as wel.
pretty much...yes losing part of the wide end of lens isn't great...
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Old February 15th, 2009, 10:28 PM   #32
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Well you need to use some of that huge amount of influence you have (now that you're a household name) and get Letus to make 2 versions. hehehehehe

See you at NAB.
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Old February 16th, 2009, 10:25 AM   #33
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Yes, to reiterate Mitchell's question: without the relay and the Extreme on an EX-1/3 set to about Z70-74, are we closer to the Academy or Full Frame size? I guess I could put a lens on a 35mm camera to check, but my DSLR is not Full Frame, either.

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Old February 16th, 2009, 12:13 PM   #34
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had to take down video. sorry!
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Last edited by Phil Bloom; February 16th, 2009 at 03:15 PM.
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Old February 16th, 2009, 09:36 PM   #35
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To muddy the water further....when I frame up the Letus Ultimate my zoom is around 40 (maybe 42-45.....I know it's 40 something). The Extreme is 70 something. That's a big difference. Maybe the opening of the Ultimate is different than the Extreme?
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Old February 16th, 2009, 10:25 PM   #36
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The spinning disk on the Ultimate is quite small and has to be for some very practical reasons. So also was the disk in the older P+S Technik Mini35-300.

The motion picture image frame size was adopted by P+S it seems to keep the faith with DPs intuitively accustomed to their cine lens choices.

The Ultimate is likewise intended as a professional tool for such operators.

Those of us who play with the alternative adaptors or home-build are less inhibited and experiment. If something goes wrong and we pick up an edge or an artifact we don't go out and slash our wrists because there is less at stake.

As a tool intended for professionals, the Ultimate has to be both reliable, predictable and conform to an accepted standard. Re-shoots for technical failure are not an option longterm.

A person with an infectious contagion only takes one bite at your chocolate bar and its all gone for you. Likewise for the professional level appliances. One stuff-up and consequent bad press and its all over.

The Le brothers are being exceptionally conservative and careful with this one, a courageous development in these financially straitened times.

As for hacking the relays to the SGBlade, there are a few things at play for a reasonable chance of a successful consummation.

1. The optical distance from groundglass to front of relay lens has to be about the same or within the adjustable focal range of the lens.

2. The condenser element between the groundglass and the relay lens may have to be of similar power and diameter, otherwise bads like edge softness, hot spot or even hot corners around a dark ring may occur.

3. Wayne ( and he needs to slap me over the ears here if I am wrong ) I recollect has traditionally gone for a larger groundglass area and more solid bokeh using a coarser groundglass diffusion and restoring apparent sharpness by using the larger image area.

Therefore his groundglass may not resolve as sharply as the Letus Ultimate for the same smaller motion picture frame area the direct relay is confined to. He has a new optional groundglass offering which may permit this.

Wayne's flip adaptor seems to be a bit shorter, more like the Brevis. To get the correct distance from groundglass to front of relay lens may require a longer bridgepiece between the front of the relay lens and the rear of Waynes flip adaptor.

As for the comment of improved apparent resolution through a flip adaptor, I have also observed this. It is related to the longer optical (folded back on itself) distance between the groundglass image and the camera which allows the use of a less powerful dioptre in the relay path for a given size of appliance. The angles of incidence are less severe. The problems of edge softness are reduced. If the optics and prisms/mirrors are of good quality, it is a win all the way.


Benjamin.

If you are framing Z70 on the Extreme, you are probably in academy frame size on the groundglass. Are you having to zoom so far in to avoid picking up a side edge? If you are, chances are your Extreme received a damn solid clout during its journey and the prism has been shocked slightly to left and forwards against the rubber wedge retainer which retains the compound prism against a centre support spine and the rear face of the enclosure.

There is a quick hack based on my adjustable centricity mod that I can give you to restore centricity to within manufacturer's limits if this has happened but it requires you to have good dextoral skills, a clean working environment and the necessary tools. Parts required, scizzors, tweezers, maybe a throwing dart, (or splinter pick, scriber or saftety pin) and a sheet of quality thick printer paper or plastic lens shim of similar thickness. You assume all risks of damage-failure of the appliance.

Also, what are the measurements on your mounting setup to the rails system. I can give you the correct dimensions for the EX1 on the original Letus rails kit, not the new one or the Zacuto.

Last edited by Bob Hart; February 16th, 2009 at 10:59 PM. Reason: error
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Old February 16th, 2009, 10:59 PM   #37
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relay hack ...

Good to hear there may be a way to hack the letus EX3 relay for SGBlade! I been wonder about this since it came out. I'm willing to give it a try anyway!
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Old February 16th, 2009, 11:07 PM   #38
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As for the comment of improved apparent resolution through a flip adaptor, I have also observed this. It is related to the longer optical (folded back on itself) distance between the groundglass image and the camera which allows the use of a less powerful dioptre in the relay path for a given size of appliance. The angles of incidence are less severe. The problems of edge softness are reduced. If the optics and prisms/mirrors are of good quality, it is a win all the way.
This has been my experience too, with just buying the separate Letus flip adapter. I have an old Letus35a, which had condenser and achromat. I bought a flip adapter, and was able to eliminate both from the 35a when I added the flip adapter.
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Old February 16th, 2009, 11:21 PM   #39
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Dean.


If you want to eliminate some of the guesswork and have any 35mm Nikon prime lenses and your SGBlade is already mountable along with your EX3 on a rails/rods system, there is a bit of a test you might do. I am assuming your SGBlade is a flip appliance. If it is not, then what spills onto the page below is useless comment to be ignored.

Try taking the EX3 lens off after you have got everything aligned and centred on the rails, get a 35mm Nikon prime if you have one and offer it up by hand into the space between the camera and back of SGPro. YOu will need to have the camera hooked up to a good monitor to see what you are doing.

Set the focus of the 35mm prime in midrange, say about 8ft.

To avoid shorting out any hotpins in the EX3 lens system, tape over the conductors inside the EX3 mount orifice before you go shoving a wild lens in there. It WILL be hell expensive to repair. Take extreme care not to let any part of the rear of the Nikon lens clash with the transparency in back of the EX3 mount orifice. It WILL be hell expensive to repair.

As a starting point, there may need to be about 8mm between flange face of the Nikon lens and flange face of the EX3 mount, maybe closer, maybe furthur. If you know the flange to focal plane "in-air" spec for the EX3 lens then you can calculate this distance. The Nikon lens system is 46.5mm for the F-Mount.

If the difference is additive, not subtractive, then you can't use the Nikon for the test and get a valid result.

My guess is you will need about 18mm - 24mm of space between the rear of the SGBlade and the front of the 35mm Nikon.

This is all rough guesswork on my part, no science inolved at all.

If you can get an acceptable image to the EX3 through this mess, you may be in with a chance with the Letus EX3 relay.

You would have to have a bridgepiece machined for the rear to go into the front of the relay lens, which appears to be the same Letus simple shoulder and clamp screw arrangement. The front would have to be machined to fit the rear mount system of the SGBlade. I do not know what that is.


Please do not ascribe any authority to my suggestions. All risks are your own. No use in sueing me as I am near to bare-ass broke and my debts will be of no use to you.
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Old February 16th, 2009, 11:36 PM   #40
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Bob ...

When I receive my Blade I will give this a try. Not to worry ... I'm a grown up. I wouldn't dream of bringing suit against you for things you suggest !!
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Old February 17th, 2009, 12:21 AM   #41
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Grown up.

That's just the problem. (Just kidding) Children drop down on the floor and throw a tantrum or just throw stones when things go wrong.

Adults have refined this reflex into a high science, point their lawyers, light the wick and see what happens, especially in the big country and regrettably to an increasing extent in mine.

Last edited by Bob Hart; February 17th, 2009 at 12:22 AM. Reason: error correction in interests of diplomacy
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Old February 17th, 2009, 12:52 AM   #42
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Yeah ...

Being grown up is a serious drawback ... isn't it !
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Old February 17th, 2009, 01:19 AM   #43
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To muddy the water further....when I frame up the Letus Ultimate my zoom is around 40 (maybe 42-45.....I know it's 40 something). The Extreme is 70 something. That's a big difference. Maybe the opening of the Ultimate is different than the Extreme?
mitchell

On the Ex3? that's impossible! mine is around 70, 40 is nowhere near enough...are you sure? I would seriously double check...least i have managed is z69 on ex1/3

phil
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Old February 17th, 2009, 06:43 AM   #44
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"Being grown up is a serious drawback ... isn't it !"

Sure beats the alternative. Wouldn't have it any other way.
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Old February 17th, 2009, 11:20 AM   #45
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mitchell

On the Ex3? that's impossible! mine is around 70, 40 is nowhere near enough...are you sure? I would seriously double check...least i have managed is z69 on ex1/3

phil
I'll double check. I don't have the adaptor installed on the camera right now. (I've probably got it wrong....I'm looking at the numbers on the zoom ring, not in the viewfinder)
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