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Silicon Imaging SI-2K
2/3" 1080p IT-integrated 10-bit digital cinema w/direct-to-disk recording.


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Old July 24th, 2010, 06:06 AM   #1
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Anamorphic on si2k

Here is a link to an article which might be of interest.

http://www.johnbrawley.com/wp-conten...ial_Review.pdf


The site also has a trailer of the short film shot in the format.

John Brawley - Cinematographer | VIDEO


I am not too sure how much advantage there would be, versus cropping the frame to 2.35 as it brings with it all the same hassles of the 16:9 adaptor on 4:3 MiniDV cams. In theory there should be a similar proportional vertical resolution gain versus cropping, offset by lesser horizontal resolution.

I would imagine there would be a furthur resolution loss due to the 16:9 anamorphic lens being cost-effectively engineered for adequate results at SD resolution not HD.

For curiosity sake, I fastened a Century 16:9 anamorphic for Sony PD50 on front of the CP Ultra T* lenses on the SI2K to see what would happen. This Century anamorphic has the bayonet fitting for the PD150 lens hood as its means of fixture but I had built a 52mm screw-in adaptor for using it on an AGUS35 groundglass adaptor with Nikon lenses, so it screwed right on.

The front element of the PD150 is 52mm inside a 58mm filter mount so I thought it might be a fair match for the Ultras with their smaller front element.

I was surprised to find it was sharper than I thought it would be. There is a slight side vignette with the 12.5mm so that is about as wide as it will go.

This anamorphic was also modified by me for slightly wider view on the Sony at full wide angle because it otherwise vignetted the left frame edge due to the significantly offset optical centre of the Sony relative to the centre of sensor, so a non-modifed one may vignette more.

The Panasonic 16:9 adaptor mentioned in the article was made for the DVX-100 with its larger front element diameter and 72mm filter thread fitting thus less likely to vignette.

I observed the sharpness and clarity falls away badly due to flare over the last 1.5 f-stops before wide-open.
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Old July 25th, 2010, 10:41 AM   #2
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Furthur to above I set up a resolution chart and shot it with and without the Century Optics 16:9 anamorphic adaptor on a CP Ultra T* 25mm lit for the sweet zone of about f5.6.

Versus cropping the sensor image there is no resolution advantage. The optical losses in the anamorphic adaptor are too great and there is distortion. This anamorphic lens was engineered for satisfactory results for MiniDV.

On HD it falls down to my eye at least.

There may be some sharpness lost in the squeeze processing to frame it comparatively with the cropped image, so it may not be a fair test.

The Panasonic 16:9 anamorphic may fare better.

Except for creating an effect like elliptical flares from reflections or the sun, I don't see any advantage in going this route, certainly not with the Century lens for the Sony PD150. The anamorphic lens does enable a closer position to frame the subject for the same lens. An anamorphic lens of HD quality might be a different proposition.


Images below from L to R.

L = cropped sensor image. R = squeezed and matched anamorphic image with mask to emulate cropped frame.
Attached Thumbnails
Anamorphic on si2k-frame-cropped.jpg   Anamorphic on si2k-anamorphic-cropped.jpg  


Last edited by Bob Hart; July 25th, 2010 at 10:56 AM. Reason: added text
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Old July 25th, 2010, 07:07 PM   #3
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LOL, this is what Arnold would say about this anamorphic lens ;)
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Old July 25th, 2010, 10:48 PM   #4
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Big Arnie "shoore 'as a woonderfool wair wi wurrds". Four words to summarise several paragraphs, economic, truthful and to the point.
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