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-   -   Glass for SI-2K (https://www.dvinfo.net/forum/silicon-imaging-si-2k/126840-glass-si-2k.html)

John DeLuca July 28th, 2008 12:15 PM

Glass for SI-2K
 
What kind of glass are you guys using with your SI-2K? We are currently looking at a used S16 Canon 7-63mm T2.6 and a set of super speeds to go with our Nikkor glass.

-John

Rohan Dadswell July 28th, 2008 03:26 PM

Hi John,

I got myself a set of Optar Illumina Super 16 lenses (8-50mm) and some Nikkors for telephoto work. And a Kinoptic 5.7mm for those super wide shots.
The Optars open up to T1.3 and match with the Nikkors quite well, I have no issue intercutting between the two.

How are you finding the Canon zoom ?

cheers
Rohan

John DeLuca July 28th, 2008 04:56 PM

Rohan-

It’s good to hear the Optars cut well with the Nikkors. I found the Canon through a big local production house (going out of business). Hopefully I can get it in the $11-14k range.

They also have a used Century 5.7mm T1.8 (C-mount) in the $700 dollar range. Im not sure how sharp it is, but a 5.7mm would be nice to have in the collection.

-John

Bhaskar Dhungana July 28th, 2008 09:40 PM

We are using a set of Optar Illumina Prime lens, also have Canon 8-64 zoom in one. The result from both lens are really good.

Bob Hart July 29th, 2008 12:46 AM

The Century 5.7mm f1.8 might be a Kinoptik lens rebarreled with more accessable iris controls. Century rebarreled the Kinoptik 9.8mm f1.8 for 35mm film cameras. You do get a wild field-of-view but by todays standards you may find the Kinoptiks a bit soft and flary.

Rohan Dadswell July 29th, 2008 01:47 AM

I actually have a Century 5.7mm T1.8 C-mount lens that I got off ebay before I got my Si-2K - it's not a rehoused Kinoptik.
I'll happily sell it to you for $700 ;-)
This lens isn't really up to 2K production (it could be just my lens but I also have a Century 3.5mm C-Mount fisheye that is also a bit soft)
The Kinoptik 5.7 is good at T4 or even 4/2.8 split but wide open it does go a tad soft but it's handy to have in the kit.

Jason Rodriguez July 29th, 2008 10:21 AM

BTW, just in case anyone is interested, watch out with using B4-mount lenses for covering the entire 2K image. They work well for 1080-resolution images, but the sensor we're using is spec'd at 5um, which creates an image width that perfectly fits the EBU standard for 2/3" 16:9 chips at 1080P resolutions. As a result, the 2K image is slightly larger, and this can lead to vignetting when using a B4-mount lens on a 2Kx1152 image.

Super-16mm lenses are strongly suggested for optimum 2K shooting.

Thanks,

Jason

Lior Molcho July 31st, 2008 04:39 AM

We did quite a research with the lenses, bought a used set of Zeiss super 16 at "Alan Gordons" for about 5K
9.5 mm
16 mm
25mm

they're fast lenses(very helpfull in maintaining low light levels)
later on we did a few days of comparing them to about 10 different lens sets in different rental houses. (optar, super 16, 35 primes)
i must admit i was a little scraed we'd find out we bought a "turkey", but they really stand up in chart tests againt 35 ultra primes!
so dont be afraid to go for older used lenses, (theyre at least 15 years old!)
they might be better then new cheaper ones

Lior
2Flags

Alex Alexandrov February 18th, 2009 11:21 PM

i have
nikon
1.4 35mm
1.2 50mm
1.4 85mm

i'm wondering what usage can i get out of these on si-2k? what will be downsides?

thank u.

Bob Hart February 22nd, 2009 08:26 AM

We have used loaner Zeiss for ARRI (distagon) 9.5mm, 12mm, 16mm, 25mm and more recently some Cinema Products Ultra T* 12.5mm and 25mm.

Ken Whitehouse (Whitehouse AV) apparently gets a few in every now and again and services, rebuilds them. They were apparently made by Kowa in Japan for Cinema Products. The Zeiss lenses apparent trend towards a bluish cast. The Cinema Products lenses are warmer.

The Ultra T* series existed in 9mm, 12.5mm, 16mm and 25mm, T1.3. The 9mm has to be modified for Super16mm coverage.

Sergio Sanchez March 28th, 2009 01:26 PM

I´ve heard about Hawk v-lite s16 anamorphic lenses. I´m wondering how will they perform on the SI2K? What kind of problems/benefits could you expect, compared to doing the anamorphic in post? Anyone nows of someone who had tested the SI2K with this lenses?

Jean Louis Seguin April 7th, 2009 09:26 PM

Cinema products 9mm lens
 
Do you have any information on the modification required to eliminate vignetting on the Ultra T 9mm? I have this lens and it does vignette on S16. I would have assumed that nothing could be done.

Jean-Louis

Bob Hart April 7th, 2009 10:03 PM

Jean-Louis.


Ken Hale at Whitehouse Audiovisual in California is doing the two for me. (www.whitehouseav.com). Apparently Visual Products in Ohio also does them. We are getting stuff together for a 3D rig, which is why the greed of adapting two lenses.

Apparently, within the lens, a celled optic or group is retained by some sort of collar which comes into the optical path. Clearances for the corners of the frame are dressed out of this part.

If you are contemplating doing it yourself I would counsel against it as it is really a lens-smith's operation. Apparently it can be very easy to get wrong and the lens may then be irretrievably ruined. Ultra Ts seem to be pretty scarce and parts may be even scarcer.

You may find at 2048 x 1152, that you may still pick up a stray corner but it is likely that you can compose that out into an opposite dark corner of the shot by rotating the PL-Mount 180 degrees or that it will go away if you are cropping to cinemascope.

You may have to file out an opposite pin slot in the lugs of the PL-Mount if it has only one pin slot. The older PL-Mounts have a pin slot in each lug. We have used this to re-position a Zeiss-ARRI 9.5mm which has a tiny chip which appears white.

The Kinoptik 5.7mm I have here does not vignette but is a bit flary wide-open and not the sharpest kid on the block. I would only use it at the largest screen size like 2048 x 1152 as it will be distinctly softer in the smaller sizes.


FOOTNOTE:

It seems you can use the Angenieux 12-120mm from a CP16 (not CP16R) with its own optical split side viewfinder on the SI2K. The SI2K c-mount face might have to to be skimmed back a fraction as the lens does not achieve infinity focus. The cupped mount attaches to the CP16 via a c-Mount hollow collar which is unfastened by a special blade tool. It appears that a coin will do the job and that this may have been a design intention for in-field repairs.

I have not examined this lens for a collimation adjustment which would likely achieve the same result as I want it to remain operable on the CP. It does not seem to vignette the corners at 2048 x 1552.

Jean Louis Seguin April 8th, 2009 05:45 AM

Thank you Bob for this very useful information.
I'll definitely be looking into this.

Jean-Louis

Bob Hart April 8th, 2009 08:35 PM

In regard the Angenieux 12-120mm, I have read elsewhere that it may vignette the corners part way through the zoom movement at about 25mm. I did not observe this but it was a very quick test in a gloomy environment.

The 10-150mm will vignette at wide-open and again in the zone about 25mm through to about 35mm. It is also less sharp than the 12-120mm.


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