Sony Zone


The DSC-F707/717/V1/828 cameras are very, very infrared sensitive. But only when their inner 'hot mirror' is pulled aside for NightShot mode.

What if there were a one-step, easy to implement technique that could turn your camera into a world-class infrared gathering super beast fully capable of working in the brightest sun?

There is, and it is here.

The Panacea Filter

By Peter iNova  
Layout by Peter iNova

1. INFRARED light is made up of photons that have frequencies lower than the reddest light we can see with our eyes. Technically they are longer than 700 nanometers.

Excuse me? That's so small a virus could use them for pocket change. If we could see them with our Sony cameras, we could see the world in a completely different way.

2. The world moves too fast. Everything is nice and crisp, even when it is moving. If we could make time stand still, it would look like a still photo. No change there.

But if we took a looooong time to see things, people--most of them--would simply disappear, streams would lose their waves and become satiny smooth, traffic would become streaks and nobody could hand-hold a camera.

The Panacea Filter makes this all possible. Get out your tripod.

1. The Photon, Infrared and the Panacea Filter:

The Photon.

A single photon is a weird thing. It's an electric charge in one direction with a magnetic field 90 degrees perpendicular to it. And, just to make it seem stranger, it is moving at 186,000 miles every second (300,000 kilometers per second).

Okay, you knew that. It's the Speed Of Light. Everybody knew that.

The photon doesn't wear out. The only thing that can happen to it is that it gets absorbed fully or partially by matter that has the property of "opacity." Or, it can be perceived as having a longer or shorter wavelength if astronomical distance phenomena get invoved. Red shift won't be a problem for you in your digital photos.

These little energy clumps each define one wavelength. But the size of that wavelength can be from microwave size (a fraction of an inch) up past X-ray size (a fraction of a molecule). Our eyes are interested in the 700 to 400 nanometer photons--less than a one-octave range of frequencies. Photons in the 900 to 700 nanometer range are longer, lower energy and "redder" than red. Infrared.

The span of photographable light frequencies that reach the Earth's surface from the sun is several octaves and statistically centers on the energy range we see.

Mother Nature is no dummy, so when she was passing out the eyes, she made them efficient. "No sense looking for photon frequencies that show low demographics. I'll concentrate on the more populated ones," she said in a recent interview.

For an organism to see infrared directly involves stranger and stranger light sensitive cells and optical systems than the ones we have in our heads. Mother Nature's comment; "Trust me, you do NOT want to carry around six-inch eyeballs."

For the small sub-set of animals that have color vision--primates and birds, notably--the strong mid-range we call the visible spectrum is easy to detect, and by sensing separate colors in our brains, we can find ripe food using visual cues more easily.

At the top end of the visible spectrum, we see photons as blue. In the middle, we see them as green. Each one, being a single wavelength, is a pure color. In fact, each photon is the purest color imaginable. There are no white photons. But are there purple ones?

As these infrared photons shoot out of the sun and slam down through the atmosphere, they bounce off things or get absorbed just the way the visible ones do.

Leaves need photons to interact with their chlorophyll to make starches and sugars out of oxygen, carbon and hydrogen plus a pinch of nitro. But they don't find infrared photons particularly useful, so they kick them away and don't absorb them.

A-HA! That's why infrared shots of foliage show the leaves as white!

And that's why people like to play around with infrared. For all its strange physics, it becomes a tool for seeing differently. Peoples' faces look strange, the sky looks black sometimes, and man-made colors behave unpredictably. (The sky only looks blue because it scatters blue photons--red ones don't scatter, and infrared ones really don't scatter.)

Reflections in a reddened eye:

Objects in our world reflect certain colors. Actually, they absorb certain colors that are the exact opposite of the colors we see them as. Red paint absorbs blue and green photons and bounces out the red ones. And so on.

What escapes the notice of our eyes is that pigments and dyes often reflect portions of the spectrum that are separated. Purple plants, inks and pigments bounce both the red and blue parts of the spectrum while absorbing the middle gold, yellow, green and cyan portion. And it gets more complex than that.


A bunch of purple photons? Guess again. On close inspection, red ones and blue ones are here. There are no purple photons. You are seeing a mixture.

In the case of plants, they like the visible red and blue parts of the sun's rays, but don't like the green so much. We think of them as "greenery" but what they really don't want is all that green color they kick out of the leaves. The do like the red, but only the part we see. Many green plants throw away nearly all the infrared photons that hit them.

Getting the F707/717/V1/828 to see infrared.

When you click to NightShot mode, you hear a distinct mechanical "thwack" inside the camera. That's a filter being swapped out of the optical path. It's job is normally to block infrared rays from reaching the imaging chip, because the chip is extremely infrared sensitive. A piece of glass that passes infrared light is substituted so optical focus isn't changed.

The camera assumes that you will be shooting in the dark, so it switches on its infrared LED emitters. You can see these as showing deep red if you view them in a dark environment, and they let you shoot in zero light. In Night Flash mode, they help focus the camera and find the view, but for daylight shots, they just get in the way.

There is a problem with this in that the emitters are now behind any filter you put over the lens. And this article is about the Panacea Filter which goes over the lens. Emitter light will bounce off the back of the filter and into the camera on the 707/717.

Hold that thought.

Sony has decided, as a matter of prudence, to limit the IR viewing abilities of the 707/717/V1/828 to indoor viewing and shooting. They did this because IR shows somewhat through certain clothing and people were calling this the "naked mode" in earlier video cameras that feature the zero light abilities that the 7x7/V1/828 cameras have inherited.

Not kidding. A woman wearing certain fabrics and no bra can be slightly seen to have nipples under her blouse in bright infrared light. You can imagine the middle American Puritanical outcry, "We don't want our wives and daughters to be known for having nipples!" or some such. Sony bent to American prudence and limited their cameras to NightShot mode, making it shoot only 1/60 sec or slower using auto exposure. (1/30th on the 828)

That's too bright for daytime shooting. Way too bright. When the IR filter is out of the optical path, even ISO 100 sensitivity jumps through the roof. And in NightShot mode, Auto ISO setting, the camera will produce up to ISO 2500!!

On the surface of the imaging chip, the red, green and blue filters that separate out the colors don't affect IR light very much. Long IR photons sail right through them. That's good for shooting in weak IR illumination, like the camera's emitters, but it makes daylight shooting of IR subjects problematic.

The usual IR shooting stack consists of three filters: An IR filter such as an R72, and two neutral density filters to cut back the total amount of light entering the lens. This stack of parts costs about $65 from and generally works well.

But what if you simply cut out the visible light and took advantage of NightShot's extreme sensitivity to infrared? Would that work?

Yes. And that's just what the Panacea Filter does:

No IR filter was used to capture this shot in the Rheinland. And the temperature outside was a balmy 76 degrees, so that white stuff could NOT be snow. If I had used a real IR filter, the sky would have been much darker, too.

The Filter in Question;

The Panacea Filter is a rare and extreme filter. It's called an ND-400 and it costs about the same as the IR stack mentioned above if you get it from I've seen it in 58mm as high as $135. You have to want it.

We are used to the nomenclature of ND (Neutral Density) filters, where ND-8 is a three-stop reduction of light (A.K.A "0.9" in Tiffen nomenclature) but what does an ND-400 do? It cuts the heck out of the light so completely that there isn't much left. Less than a quarter of 1% of the original light gets through.

And even though it cuts the visible spectrum way down, the infrared sensitivity of the camera in NightShot mode is way up. The IR light makes pictures, and the visible light is almost completely drained from the shot. But not absolutely completely.

Blue sky still has some faint color. Bright neon signs can show color, too. It's unpredictably selective, but since you can view things live through it, you will see a different world. And a world of new imaging possibilities.

But what about the emitters in the 707/717? They won't put out enough light to ruin noon shots in full daylight, but they will be a hassle in dim light. Use the same emitter light controlling trick outlined in the Sony eBook and you won't have a problem.

Note that a true IR filter gives a cleaner IR result. The image up there was tweaked in Photoshop to get the contrast up.

2. Time Span Increased.

Since the ND 400 lets in about 1/500th of the normal range of light, it finds another interesting uses in regular color shooting mode.

It makes moving objects speed up by 500 times. Any image you would normally shoot at 1/500 sec will now need 1 sec to expose. And if that object moves, it becomes a blur, a ghost of its former self. Longer exposures can almost entirely erase anything that moves.

See the people on the escalator? I did. Where did the steps go?

Stacking the ND 400 with other ND filters increases the time, proportionally. A common, low-cost ND8 on top of the ND 400 now makes the example above require 8 seconds. Close the f-stop down and you might need dozens, scores or hundreds of seconds to capture an image.

Shoot a stream and it becomes a pastoral blur of water. Shoot traffic and it becomes a streak of reflected highlights with no cars visible. Shoot a rush hour crowd and it becomes an image of ghosts vaporously whisking over the background.

Dozens of happy shoppers traverse the busy plaza. I saw them with my own eyes. But only one lonely reader sits under the umbrella in the shot. Wait a minute, I think I see someone else...

Stack two and the exposure factor goes up to 250,000 times normal. A 1/125th sec exposure now becomes 2,000 seconds, and that's over half an hour. Clouds become blurred, animal cages show only dozing creatures, theme parks become sunlit wastelands and shadows take on an airbrushed quality.

There is a lot to play with inside this single filter.

More will be here as the Sony Zone pages evolve.


PS: As experience grows with these cameras, so will this review and the Sony eBook. Available now on the order page.

© 2004 Peter iNova. All rights reserved. Do not replicate or link to images without permission. All photos by Peter iNova unless attributed to others. Photos are the copyright of their originators.