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questions about filters on cameras


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#1 Jim Feldspar

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Posted 31 December 2006 - 07:35 PM

From the Tiffen site:

"Haze 2A - Absorbs all UV light; reduces haze; maintains color and image clarity. Best for high
altitude and marine scenes."


If all UV light is absorbed, wouldn't that take the daylight or "blue" light out of the outdoor
light?
I'm pretty sure that's not what's maent but they do say all UV light and isn't UV light what makes
daylight (relatively) blue?

"Ultra Contrast - Recognized by an Academy Award® for Technical Achievement, this filter
series
redistributes ambient light to capture details that would be lost in shadows. Lowers contrast
evenly
throughout image with no flare or halation. Available in several grades."

I'm confused. The "Ultra" contrast filter means lower contrast? Doesn't ultra mean more?

"Low Contrast - Spreads light from highlights to darker areas; leaves bright areas bright;
lowers
contrast, mutes colors. Makes videos look more like film! Available in several grades."


I need to understand contrast more. I know that video has much less contrast latitude than film.
I know that when
watching old westerns (especially b/w) on t.v., scenes that I would consider high contrast
such as the sheriff in the middle of the street under the noon sun with a bad guy inside the
shade of the livery stable often look ugly in a way that I doubt would be the case in a theater.

Would the above low contrast filter be desirable for shooting short narrative Mini-DV projects
because it lowers the contrast and that's good because a. low contrast has some inherently
pleasing effect or b. because spreading light to darker areas allows images to be captured
as they would with the wider range of film but would be lost in a shadow in video? Therefore,
is the low contrast filter primarily working to help the person shooting video to simply
go further than otherwise possible with the limitations of video?

I've read definitions and I've played with the contrast and brightness controls on monitors and
I still don't think that I get what people mean when discussing contrast. Is it the way it's said?

For example, I've heard people say that they want a "low-key" approach to lighting but they're
using low-key in its common useage of meaning laid back, nothing too crazy and thus often
they really want soft undistracting or good old high-key lighting.

As I shoot more I'd like to avail myself of filters that would help me but I don't have much access
to them to do testing. Right now I'm shooting as many shorts as i can, mostly in Mini-DV and as
filmically as possible. I hear people talk about desiring to heighten or lower contrast when
shooting. I guess that some of those approaches must be dictated by circumstance, e.g. if
you have Danny Glover next to Mel Gibson do you bring up the light on one's face or down on the
other? Otherwise though, what makes you want to alter contrast and what filters do you use?

"Magenta CC05M, 20M, 30M, 40M, 50M & Red CC30R - Balance excessive green cast and
produce
creative effects. Great for early morning tint. These filters can be combined to achieve more
density. Use the CC30R to produce warmer or more accurate colors when shooting underwater
photography or heavily green tinted glass. "

Sounds great. I love the early morning look but why would you use this as opposed to an
early sunrise grad ?

Thanks!
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#2 David Mullen ASC

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Posted 31 December 2006 - 08:39 PM

I'm pretty sure that's not what's maent but they do say all UV light and isn't UV light what makes daylight (relatively) blue?


You're confusing the blue end of the visible light spectrum with the next area beyond visible light, the ultraviolet area. Too much UV light tends to fog/haze the image, exaggerating atmospheric haze, so you'd use a UV filter to cut that down, especially when shooting landscapes at high altitudes. We don't see UV light but a film or video camera is a little more sensitive to it.

I'm confused. The "Ultra" contrast filter means lower contrast? Doesn't ultra mean more?


Not in this case. Really means "ultra low contrast filter".

Would the above low contrast filter be desirable for shooting short narrative Mini-DV projects because it lowers the contrast and that's good because a. low contrast has some inherently pleasing effect or b. because spreading light to darker areas allows images to be captured as they would with the wider range of film but would be lost in a shadow in video? Therefore, is the low contrast filter primarily working to help the person shooting video to simply go further than otherwise possible with the limitations of video?


Low-con filters are not really substitutes for using a camera or format that delivers more exposure information, but they can help slightly by lifting up some low-end detail in the shadows that might be buried. Trouble is that video cameras normally have more problems with overexposure detail, not shadow detail, but the theory is that with a low or ultra-con filter, you can underexpose to hold more of the bright highlights and then use the filter to keep the shadow detail from dropping off. But the end result may be more noise in the image -- there's no free lunch. However, since low / ultra-con filters tend to milk up the blacks, they also give the illusion of less contrast / more exposure range. They may also help reduce that "harsh" feeling that lower-end video cameras create.

For example, I've heard people say that they want a "low-key" approach to lighting but they're using low-key in its common useage of meaning laid back, nothing too crazy and thus often they really want soft undistracting or good old high-key lighting.


"Low key" usually means a predominence of shadows, dark areas, but one could also mean that a "low-key approach" means a simple, low-profile approach to a production.

I hear people talk about desiring to heighten or lower contrast when shooting. I guess that some of those approaches must be dictated by circumstance, e.g. if you have Danny Glover next to Mel Gibson do you bring up the light on one's face or down on the other? Otherwise though, what makes you want to alter contrast and what filters do you use?


You alter contrast either for creative reasons or to solve a contrast problem. Since filters only slightly help solve a contrast problem, they shouldn't be considered a substitute for lighting for the contrast you want. But since you can't always fix it with lighting, filters may be better than doing nothing.

I love the early morning look but why would you use this as opposed to an early sunrise grad?


Magenta filters add an overall magenta (red + blue, sort of a pink) color to the image. They aren't grads... unless you get a Magenta Grad filter. If you want to add more magenta to the image, you may want to do it with a filter or maybe you'll just do it in post. Most common use of a magenta filter is to cancel some green. A sunset or sunrise grad filter is probably some other shade, or a mix of colors, probably with more reds and yellows. People also use Coral or Tobacco grads for sunsets, just depends on the color you want to add.
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#3 Jim Feldspar

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Posted 31 December 2006 - 11:08 PM

You're confusing the blue end of the visible light spectrum with the next area beyond visible light, the ultraviolet area. Too much UV light tends to fog/haze the image, exaggerating atmospheric haze, so you'd use a UV filter to cut that down, especially when shooting landscapes at high altitudes. We don't see UV light but a film or video camera is a little more sensitive to it.
Not in this case. Really means "ultra low contrast filter".
Low-con filters are not really substitutes for using a camera or format that delivers more exposure information, but they can help slightly by lifting up some low-end detail in the shadows that might be buried. Trouble is that video cameras normally have more problems with overexposure detail, not shadow detail, but the theory is that with a low or ultra-con filter, you can underexpose to hold more of the bright highlights and then use the filter to keep the shadow detail from dropping off. But the end result may be more noise in the image -- there's no free lunch. However, since low / ultra-con filters tend to milk up the blacks, they also give the illusion of less contrast / more exposure range. They may also help reduce that "harsh" feeling that lower-end video cameras create.
"Low key" usually means a predominence of shadows, dark areas, but one could also mean that a "low-key approach" means a simple, low-profile approach to a production.
You alter contrast either for creative reasons or to solve a contrast problem. Since filters only slightly help solve a contrast problem, they shouldn't be considered a substitute for lighting for the contrast you want. But since you can't always fix it with lighting, filters may be better than doing nothing.
Magenta filters add an overall magenta (red + blue, sort of a pink) color to the image. They aren't grads... unless you get a Magenta Grad filter. If you want to add more magenta to the image, you may want to do it with a filter or maybe you'll just do it in post. Most common use of a magenta filter is to cancel some green. A sunset or sunrise grad filter is probably some other shade, or a mix of colors, probably with more reds and yellows. People also use Coral or Tobacco grads for sunsets, just depends on the color you want to add.


Thanks as always for taking the time, David. I've learned a lot this year from this forum and
probably the most from you, in both your thoughtful, clear answers to my questions and in
your other postings.

I made a list of the filters that I'd like to get and it ran into hundreds of dollars! Series
Nine or 4"x4" would probably give me the most versatility for the cameras I'm likely to use but
I'm not going to be able to do that right away.

I spent a couple of hours today and tonight reading about filters and the Tiffen website was
helpful because it has the same image with a portion showing how it's affected by a given
filter so you can compare filtered/unfiltered and filter to filter.

I have been able to use some filters: polarizers, NDs, Skylight 1A (guess I spaced on the UV
question, should have known that!) and some Harrison and Harrison Series Nine diffusion
filters, as well as some homemade nets and stuff but I sure would like to check out some of
the low-contrast and Pro-Mist filters.

I'm looking forward to watching "Big Love" this year. I came onto the forum kind of well after
everybody had talked to you about "Akeelah and the Bee" but I thought that it was great. It
looked terrific and it was fun to read your postings about it and then see them on the screen.

Happy New Year to you and thanks for all your help!

While I'm at it, Happy New Year to everybody out here!
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Media Blackout - Custom Cables and AKS

Metropolis Post

Rig Wheels Passport

Opal

The Slider

Aerial Filmworks