Major issue with HVX and ND

If you can get the indoors to look fine and the windows are your only problem, I'd suggest just color correcting for them in post. It really shouldn't be that difficult to key or mask the rest of the image out and then fix the windows and would save you a lot of head aches.
 
David - thanks for the suggestion - we did consider that - but the light coming in takes on the hue - so if a person is lit on one side by window light and a fixture on the other i think the CC will be more difficult - certainly not impossible though - I will keep this in mind if it is a critical shot that we cannot change.
 
David there is not always time or money for a detailed/masked post. As I have said earlier. This might be a problem with the camera (if the cast is also on a different monitor than LCD of the camera). The inside filter is usually a very good filter designed to the chip in the camera (this was mentioned earlier). The problem with the gels is a standard. Any gel will add magenta (not green as with fluorescents - unfortunatley finding those realy flickery greenish fluos is really hard these days sigh... they give very nice effects) after 2.4 ND This is a problem with manufacture. It is a gel foil. You can't produce sth that has hundreds of meters on a roll and every part of it always the same thickness and physical capabilities. This is the same problem as with filmstock. As was mentioned. The filter will never reduce every wavelenght the same amount. Now a task. Why it adds magenta? (think about the wavelenghts)

A problem with the glass filters can have the same source. It is not a coloured piece of glass but sometimes a gel filter between a thin layer of glass.

This thing you encounter is probably a thing that HVX is... too good. It can have the color temp setting very tight with not much tolerance. Filmstock has a bigger tolerance for tints but remember, all Fuji stocks have a magenta sensitive layer added.
 
Hey smelni,

Don't know if this is the cause of your problem, but any light passing through standard glass home windows will be given a slight green cast - unlike optically clear glass (that they should be using) in filters. Ever see the edge of glass how it has that greenish color? The thicker the glass, the more pronouced this greenish cast will be. It's slight, and it's definitely easier to see with less light, and perhaps that is what you are seeing.

Hope this helps.
Garrett
 
thanks for the idea - its not the glass though cause it occurs with the ND but not without. And its a very VERY significant color cast - not a slight one
 
Check With Panchro Filters . They are silvered filters and are your best shot at being truly "nd". They cost more but are worth it.
 
Let me see if I get this right, you white balance against the light coming in the window but it's abount 4 stops over. So you add gel to the window and now it has a green tint?

If so I can see the problem, you cannot set WB if the camera is saturated. Don't know how well I can explain this but I'll try. In this state the R,G,B channels are all at full scale, even if the light source isn't pure white. So when you hit WB the camera determines what offset is needed and the answer is none. Fact is you haven't WBed the camera to that source. You need what you're setting WB with to be below 100 IRE for the WB to work.

Possibly I've misunderstood what you're doin in which case I'm way off the mark.
 
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This might sound stupid, but how about a faster shutter speed, If you don't want the ND's in camera?
 
Rob might have your answer, or part of it.
I "paint" my camera daily. I've gotten pretty good at looking at my main object and seeing the blue from outside, green from floressents and orange from our tools.
I then have my Cam assist move and roll the white card up, down, left and right until I see the right combination of I want to eliminate FROM the scene.

Then I white balance.
I will sometimes eliminate a key or fill which paints my scene/subject warmer when turned on AFTER the white balance. Sometimes I'll need to re-paint the camera if I'm not happy with my balance, but not too often any more.

We don't always have time to control the "set" and being able to paint your camera is critical.
I'm just now getting comfortable enough with my HVX to know how to make it perform for a client, and I've had mine over a month.

Keep us posted.
 
Most ND filters are neutral as seen by our eyes, so in the visible spectrum. CCD/CMOS cams however often see more than the visible spectrum, specifically NIR is a critical point. Of course, all cams have a build-in IR cut- filter. The filter properties can vary in cut-off steepness, and wavelenght. There is a trade off between good magenta reproduction (needs deep red wavelengths combined with some blue) and on the other side avoiding IR light to offset color and luma in scenes with a significant IR content. If an ND filter starts to get more transparant
at the NIR wavelenghts and the internal (design dependent) IRC filter doesn't fully cut these wavelenghts, then the red and green sensors in a 3CCD system get activated, resulting in redish images when there is IR content in the scene light. Same leakage story can (less frequently) happen with blue and/or red and blue combinations (resulting in magenta)
Spectral measurement can of course reveal the above, but I would suggest to take a standard IR remote control and veryfy if your cam with e.g. the 1/64 ND on or off, results in a 6stops (1/64) difference for that blinking IR light from the activated remote control.
 
I'm curious to know what the tungsten and daylight presets look like as a baseline?

Have you tried to first force and lock a balance using a source known to be reliable (e.g., 3200 or 5600k fixture direct on card)?

We recently saw a little pink in our HVX footage (with a linear polarizer) compared to an unpolarized DVX that was shooting simultaneous but finally attributed it to us pulling WB off two disparate surfaces on-set.

I'm curious to see how this situation is resolved. Not NDing windows in digital filmmaking is simply not an option.

It cannot all be done in camera - period. This needs to be sorted.

e
 
I would love to offer any solution I have got - but so far there is none - I can repeat the problem and the closest thing I have to an explanation is that the ND filters are not "calibrated" to the sensitivity of the camera and therefore in high amounts have a tint.

We have tried every type of white balancing and cannot get it to work - this effect both ND gels and filters -

Please if someone else is successfully using high amounts of ND successfully to cut sunlight down with the HVX please let me know
 
There was a realted thread on the CML list about shooting long exposure time lapse with digital cameras and lots of ND in front of the lens resulting in pink images. Ira tiffen of tiffen fame chimed in and said that ND may not be neutral for electronic based imagers at high densities. ND was designed primarily for film.... and the way film saw light. ND light the type that Panchro makes which are silvered glass really are neutral...
That said it won't help you with your windows---- Why not try some degree of ND + 85, change the daylight to something like tungsten, use your tungsten lights indoors without CTB and maybe you'll be happier than you are now.
 
i know this is an old thread, just wanted to share an exprience I had with some old ND gel. we threw this old ND.9 on a kitchen window and to my astonishment, everything in the window looked pink. sound familiar? fortunatley, I had picked up a fresh roll of LEE ND.9 at mole-richardson that morning. we put that up in its place and the pinkish tint was gone. not all ND gel is created equal. that, or the first ND was so old it had begun to change color.
 
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