Schneider Optics Truecut on SI2K

[Bob Hart]

I took the camera out whilst a test was being done on a campervan owned by Western Australian DOP and ecowarrior, Gavan O"Sullivan. He converted his camper to run on filtered canola cooking oil from fish and chip fryers.

The filter was used in association with an ND6 filter. If there is a difference in the image, it is subtle but subjectively to me, greens seem a little more faithful.

However, I am also apparently red-green colour-blind.

Although I don't think so, the aviation doc had other ideas and told me I would be restricted to daylight VFR and only ever hold a restricted licence, = happy flier but no passengers (shortsighted as well), so that fixed my aviation aspiration back in the days of my callow youth.

Anyway, off that subject, here's some happy snaps.

There seems to be a very subtle difference in the colour return from the laterite rock used in the stonewall which was shot with sun behind camera. Laterite typically seems to reproduce yellower than it actually is with the SI2K and the EX1. The blacks on the roo-bar of Gavan's camper seem neutral with or without the Truecut.

The images of the valley were into sun. In these, the Truecut seems to have brought the green in the distant trees to a slightly more faithful colour.

1. 2.
3. 4.
5. 6.

1. ND6 + TRUECUT.
2. ND6 + TRUECUT.
3. ND6.
4. ND6.
5. ND6 + TRUECUT.
6. ND6.

Lens. Angenieux. 17mm - 75mm zoom at approx. T10.5. Whitebalance - Daylight preset.

The location is Mt.Dale lookout. The view is north-west, back towards the Fremantle coast through the gap in the Darling Range where the Canning River runs out. My patch is to the right of where the trench in the forest on the top of the hill is. Now I know why CALM rang my father when he burned off some leaves about 15 years ago. No problem ensued. He had a permit.

[Mark Deeble]

It is pretty subtle, but the greens do look a little more saturated. I don't see such a marked difference between the greens in 1 and 4 though, although there appears to be a slight exposure difference.

Bob, if you fly, have you ever tried putting the si2K mini on a strut mount? I've done it with an Arri SR2 and a Sony 700 on a Cessna 206 - using a cable-operated bug deflector and cabling video and power down the back of the strut to the cabin, but would have thought the mini a much better size - less weight and less windage, esp if used with a small prime like a Kern 10mm.

[Bob Grant]

Based on my experience with the Truecut on the EX1 it is very close to neutral. It is reflective so nothing should be in front of it. I have had it create a green reflection back onto the subject. In this case the light source and subject was a candle so that's probably not a usual concern.

[Alex Raskin]

Certain cameras (Sony EX1...) have really bad infrared contamination problem.

Luckily, SI-2K is not one of those cams, so I wouldn't mess with extra filters unnecessarily. Even if one had spare $300-$500 lying around. Such money is best spent on hookers and coke ...so I heard.

[Bob Hart]

Can't do long replies presently. Home computer is kaput due to trojan - work computer will only hold dvinfo for a few seconds - possibly an embargo on unapproved webesites.

[Bob Hart]

Furthur to above, I am on somebody else's system so can talk freely.


Alex.

As I am also using the EX!, the filter is mainly for that but also to deal with what may be a IR focus related issue when using a groundglass 35mm adaptor on the SI2K, also with anti-aliasing filter removed for the 35mm adaptor tests for increased apparent sharpness as it is thought that the groundglass itself will function as an anti-aliasing filter somewhat.


Bob

I had the Truecut behind the ND6 so that might account for the slightly increased green on the into-sun shots. Thanks for that tip. It might have otherwise brought me undone in the future.


Mark.

I have flown the SI2K but only inside a Mauile M5 with the Mini head on a stick within the cabin.
A mini head on each strut/wing junction, both harmonised for 3D shooting 3D would be about the correct separation for air-to-grounds and would be a cool look. It would only be good for straight aheads and behinds but would be cool regardless.

Over here, the authorities are a bit more unsympathetic to people haing things off airframes without an engineer having signed off on it.

The mini is about the same frontage as a cigarette packet.

[Bob Hart]

Here are a few grabs from Cinevate varifocal relay - Brevis + Truecut + ND9 filter tests.


All frames have been graded to Chroma Dumonde Chart in same location and lighting conditions which were 4.00pm-4.30pm early summer outdoors facing east, sun behind.

1.2.
3.4.

1. Chart about one stop underexposed, levelled up to "RGB Parade" display.
2. Graded with same corrections applied to restore Dumonde correctly in "RGB Parade" display. Point of focus - Azalea tips near mid upper centre.
3. Graded with same corrections applied to restore Dumonde correctly in "RGB Parade" display. Point of focus - Azalea tips near mid upper centre.
4. Graded with same corrections applied to restore Dumonde correctly in "RGB Parade" display. Point of focus - Rose leaves near right upper quarter.


Lighting conditions for the charts without ND were too bright for apertures to be within acceptable limits for groundglass relay and selective focus.

Camera settings :-

2048 x 1152 @25P.
Gain -3db.
Whitebalance. Daylight Preset.

On "RGB Parade" blue channel was down on the Lemac Chart. Lighting conditions were bright with broken light cloud, outskirts of city smog plume which might explain lower blue level.