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Film Snorkels on HD Cameras

Published : 2nd February 2007

Hello HD Profs.,

Read all about this Innovision Probe System thing, but please allow me one question, if we use a snorkel, like a T-Rex Superscope System, or a Innovision Probe, designed for film use (35mill), with a HD Cam, isn’t there a Problem, because the Snorkel is calculated for a Film Plane?

What I mean is, some Snorkel Systems, like the T-Rex do have an adaptor in the kit, to use this lovely Film device, for Sony Cameras with B4 Sony Mount - also Varicam or what ever, almost every 2/3`Chip Camera, right?

But the adaptor is just a mechanical thing, just to get the lens/snorkel on/in the cam within the right "depth". Nothing is adapted concerning "filmplane" and prism. In terms of film, colours are after each other in the emulsion, right?

In terms of Video colours are getting split, like in a prism (beamsplitter), like in every Video Cam, right?

Just to leave this very simple, I know what I’m talking about, but maybe I can not write so understandable about what I mean in English because I’m German, sorry for that!

I think you know what I’m talking about...For one Shoot I used a T-Rex wide open (T7) with a HD Cam for a interior set, in front of a curtain (window front), sun came in the window through the curtain - high, very high contrast ratio, within the frame.

The footage, shot with the T-Rex on HDCAM Camera (F900), was almost not useable, we got that high chromatic abs, like blue rims around white things (pillows), it was even not to fix in a high class post process. So, OK, I heard about the Optex "Excellence" System, they do provide a HD adaptor. Is this a complete solution? I shot so many commercials (as AC) with the T-Rex in 35mill., we never had problems with chrome. aberrations at T7 and high contr. circumstances.

I heard about many people shooting with the T-Rex in HD, never heard about problems, did this people had an "HD adopter" for the T-Rex - this adaptor is for sure not provided by P+S Technik, the company manufacturing the T.Rex - I talked to them.
You guys stopping down (lighting high) to T 16?

Just a maybe stupid question,

Emanuel
1st AC - Munich - Germany


class="style15">> What I mean is, some Snorkel Systems, like the T-Rex do have an >adaptor in the kit, to use this lovely Film device, for Sony Cameras with >B4 Sony Mount - also Varicam or what ever, almost every 2/3`Chip >Camera, right?

I can't wait to hear the answer to this one! Snorkels in prism cameras? Anyone have any ideas? Mr. E. M. Schwermer is asking the right question. And he is asking the right kind of question for this list.

Dave Stump ASC
DP/VFX Supervisor
LA, Calif.


class="style15"> > And he is asking the right kind of question for this list.

Absolutely!

I'm also very interested in this.

I'd hazard a guess that the Optex Excellence is the only probe that has
a lens system optimised for a 3 chip system.

--

Cheers

Geoff Boyle FBKS
Director of Photography
EU Based
www.cinematography.net


class="style15">> The footage, shot with the T-Rex on HDCAM Camera (F900), was >almost not useable, we got that high chromatic ab´s, like blue rims >around white things (pillows), it was even not to fix in a high class post >process.

The system must be corrected for the spherical and chromatic aberrations induced by the prism optics system, including the colour landing spec for HD. (stopping down probably helps you here) As well as the increased rear ("in air" not physical)l focal distance, and the optics ideally should be telecentric or you'll get edge fringing from the dichroic filters with wide lenses.

(There's a reason DigiPrimes cost $ 20,000 apiece.......)

-Sam Wells
film/etc/nj/usa


Geoff Boyle wrote :

class="style15">> I'd hazard a guess that the Optex Excellence is the only probe that has >a lens system optimised for a 3 chip system.

What about Innovision HD Probe ? Is it just a mount change, or optics truly optimised for HD ?

Mark Doering-Powell
LA based DP


Yes but I've seen chromatic error and fringing even @ f11 on wide angle lenses when relays etc are not done right.

-Sam Wells
film/ex snorkler./usa


Guys,

These systems you are talking about are designed for a single plane back focus (e.g. film or one chip cameras) and are not designed for 'ENG Prism' like most video cameras has. That's a fact, But not necessary an issue. In fact we all used systems like Innovision or even regular film telephoto lenses on video cameras without special adapters, except of-course a B4 mount, and never gave it another thought for the results are perfect.

How come?

The key is that long focal length lenses enjoy a bigger depth of back focus.

Yes, the same DOF we know and cherish only backwards. This means that longer lenses have more tolerance in back focus (as we all know). Innovision probes are built so that the back focus have a big depth of back focus - similar to a telephoto lens - so the differences in the sizes of the circles of confusion of each colour are immaterial, so you don't have a problem using apochromatic lenses on a video camera. Does this make any sense to you?

I never used a T-Rex on a video camera so I can't comment on that.

In a nut shell...

Oren Arad
Tel Aviv, Israel.


Mark Doering-Powell wrote :

class="style15">>What about Innovision HD Probe ? Is it just a mount change, or optics >truly optimised for HD ?

Or collimated (or nearly collimated) light entering the prism?

Dave Stump ASC
DP/VFX Supervisor
LA,Calif.


Geoff Boyle wrote :

class="style15">>I'd hazard a guess that the Optex Excellence is the only probe that has >a lens system optimised for a 3 chip system.

I'm currently looking into HD Probes as well. I need to be able to get the lens on the deck via 90 degree, spin the image, and not have to light to f16.

Does the Excellence allow you to rotate the image on-axis, via microforce, like the Revolution ? If so, is it smooth like Revo ?

I'm actually wondering if the Excellence even has an internal roof prism to spin, since perhaps its one of those relays that keeps the image upside-down to flip back in post ? How the heck else is it so fast, and such high quality telecentric optics ? What changed in the last 10-15 years to allow such fast/sharp probes ? CAD lens design ?

Anyways, rotating image in-probe. Can the Excellence do it ?
Innovision HD Probe ?

Mark Doering-Powell
LA based DP


Mark Doering-Powell wrote :

class="style15">>Anyways, rotating image in-probe... Innovision HD Probe ?

Just spoke to Mark Centkowski of Innovision. Probe cannot rotate/spin image on-axis (Dutch angle). Well, you build a probe that can do everything and suddenly its fatter than an optimo and max ap at t11, right?

He did say that its not their film probe merely mounted to B4. Its a whole new optical design optimized for HD.

And he said Innovision's all setup in Santa Monica (they just moved) with a Z-Jib, probes and lights so you can actually try out some shots beforehand.

I thought this was very helpful.

Mark Doering-Powell
Director of Photography


I've had confirmation from Mark at Innovision that the Innovision HD probe is indeed optimised for 2/3 3 chip cameras.

Optex have also confirmed that the optical system for the Excellence is totally different for HD and is also optimised for 2/3 3 chip cameras.

No, the Excellence does not turn in any way it's a straight probe/periscope.

Some footage of the Excellence in use here :

http://www.zgc.com/zgc.nsf/c7a682995edb4e7585256b4d001ebd57/

7e03fae05199b0e385256c76000b38e4?OpenDocument

Although I've used the Innovision a lot I haven't got any equivalent footage.

Cheers

Geoff Boyle FBKS
Director of Photography
EU Based
www.cinematography.net


The Innovision HD Probe lens system has been optically designed for the 3 chip prism block on the 2/3" HD cameras. It comes with direct, 45 degree and 90 degree attachments along with 5 prime lenses. It is waterproof up to the focus ring.

Mark
Mark Centkowski
Creative Ways of Imaging
www.innovision-optics.com


Some of us shot with the P+S Pro 35 adaptor to use 35mill. lenses on HD or SD 2/3 chip cams, right?.

OK, nice device to get the same DoF like in 35mill. format with video cams.

Same thing - we are using 35mill. lenses on 2/3 chip cameras. I never heard about problems with the P+S Pro35 adaptor, in terms of extreme chromatic aberrations - you will have little chrom. aber., of course, because of... other topic.

What I know is (by my own experience), that the system (P+SPro35) is much more sensitive for flares (compared to DigiPrimes for example, sure)... no wonder, you are filming a spinning ground glass what has a structure... but that’s again the other topic.

Backward.

If I would use a T-Rex on a HDACM, Varicam, F900... what ever, would it be the solution (in theory) to involve a Pro35 from P+S or an Angenieux adaptor, with a T-Rex or a Innovision Snorkel system? What happens in these systems (P+S / Angenieux)?

What has to be "changed" exactly? What has to be "adopted" concerning the film plane and the prism?

This is just a theoretic question, I know, if I have a T-Rex System (T7) plus a P+S Pro35 adaptor (-1.5 stops), even more glass... not a good idea at all, right?
Or is there anybody out there who shot with a T-Rex or In.Probe and P+S adaptor?
Please let us not going just only in optical physics, its all about how we can work with our gear practical.

In this case, film gear is joining HD gear, isn’t this (also) the target for this forum at all?

Sorry for having problems writing this complex things in the English language, its not my mother language.

I heard about an adaptor manufactured by ABAKUS, Abakus 100 something, this device, some people told me, should make every Film-Lens-System a HD-Lens-System - just decreasing light by one stop.

I heard also about a adaptor which should make every 2/3 Lens a "FilmPlane" (16mill) Lens.

I thought about this adaptor one time, because I searched for a very long zoom lens, for 16mill format, for a Formular 1 shoot, and in the HD/Video world (ENG/EFP) you can find amazing long zooms - with optical stabilization - you wont find in the film world.

Anyone with experience out there?

We are still @ Film Snorkels on HD Cams.
Aren’t we?
Am I still at snorkels?

Emanuel M. Schwermer, bvk
1st AC
Munich-Germany


class="style15">>Please let us not going just only in optical physics, it’s all about how we >can work with our gear practical.

Excuse me but you know what they say about optical physics, like gravity "it's the law".

You'd be surprised how many people coming from a film-only-single-imaging surface get tripped up here.

It sounds like you're getting good answers. Plus, I'd hope Optex should know a thing or too about film / "video" optics and compatibilities !

Sam Wells
fillm/etc/usa


Hi colleagues,

just to let you know, I know now, there are excellent Snorkels out there - now - for HD use, and for sure, I believe these systems are corrected/designed for a 3 2/3 Chip Prism System (Video SD, HD , XXLHD).

Thanks a lot for your post to my private Email address Mr. Mark Centkowski from Innovision, I appreciate that very much!

BUT:

In Germany - at the moment - I don’t know about just one HD Snorkel @ any rental house, whether it would be ARRI, Ludwig... all the big houses.

So, if I would get a call to shot something in the med. high Budget area (mid for Germany is low for US/UK), I’m facing the prob. to get the adequate tool! At the moment, I have to live with the snorkels calculated for 35mill, not for 3 2/3" Prism Cameras.

Mr. Mark Centkowski, Dedo Weigert Film in Munich is your distributor for Germany, right? As imp just interested in getting a HD Snorkel for rental, not for purchasing it, can you say me, wether there is one of your systems for rent in Germany or not? OK, I could call Dedo also by myself. But maybe you know it.

Hey HD Guys,
some of you are interested in this topic I mentioned, where are you guys experienced my Problem?

Thank you so much in advance all cml.net members, for giving me the opportunity to read your great discussions and for getting so much valuable advice from you all.

This forum is something else.

It was just my wish to say this today, after joining this forum for such a long time.

Greetings from Munich-Germany


Emanuel Maximilian Schwermer, BVK
1st AC / DIT


I used the Excellence on a shoot recently, albeit on Digi rather than HD. Picture quality was absolutely stunning and cut perfectly with the cannon zoom's. OK I know it was on SD but we were all gobsmacked. Brian Rose at Optex told me a director had a problem on a film shoot when the pictures from the periscope were sharper than the pictures from the primes - but he designed it so he might be biased.

I can't really comment on the bits about focal planes etc but as I understand there are different blocks for film and video which gets round the back-focus, collimation issues, but don't quote me.

Anyway the unit works brilliantly although there's a few mill between the bottom of the 90 degree block and the lens which means you can't get right on the deck but it worked for us. Light wise we had no problems with exposure, I was running pretty wide open with ND in to get the DOF I wanted. Anyhow, there's a little bit of it at http://www.glowstars.demon.co.uk/ - follow the link into movies and look at the National Hi-Tec Crime Unit promo.

Michael Sanders
Director of Photography/Lighting Cameraman
London UK.



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