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Auteur Sujet: 7 astuces pour prendre de bonnes photos ou vidéos d'Ovnis / VO  (Lu 1629 fois)

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dificultnspa

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Citer
Seven Tips to Better UFO Photos and Videos


by Malcolm J. Brenner, B.A.

Posted: 00:30 January 27, 2010


Recently, another writer on this site was complaining about the poor quality of recent UFO photos.

To begin with, qualifications:

My first camera, a Ansco Cadet, was made so long ago that you can only get the film from Croatia. I won’t say what year that was, but my age and the ASA (now ISO) of Kodachrome were both the same –10.


Ansco Cadet

During six years running a photo lab in Seattle, Wash., I saw every kind of problem and made every mistake you can make processing film. Our specialty was optically enlarging 35mm and smaller negatives into 2x3-foot posters with modified off-the-shelf darkroom and graphics arts equipment.

One of my retail customers was the late (and eccentric) cryptozoologist Jon Beckjord. During that time, only one man brought me UFO photos to analyze – but more about that later.

I didn’t come here to boast, however, but to bemoan the sorry state of UFO photography. Although I am seeing more UFO photos and videos than ever, thanks to cell phones and the Internet, neither their quality nor their information content is what it used to be.

Daily, it seems, we are treated to new views of a glowing blob or blobs (blobettes? Blobules?) that dance(s) against a black velvet background while the autofocus camera, unprogrammed for such an obscure subject, helplessly focuses in and out, in and out.

Partly this decline is due to the very technology that has made cameras small enough to fit in a shirt pocket or a cellular phone, the digital imaging chip. Although they are convenient, the low resolution of many of these chips makes reliable image interpretation a challenge, if not an arcane (and occasionally arbitrary) “black art.”


Is this a UFO or is it lens flare?

However, equally often, as the devious HAL 9000 supercomputer complained, “This sort of thing has cropped up before… and it has always been due to human error.”

Let me therefore enumerate seven simple, but not always cheap, ways you, the photographer, can improve your odds of getting that one-in-a-million shot where, as Arthur C. Clarke sarcastically remarked, “…(Y)ou can read the Martian license plates.”

1) GET A TRIPOD! Yes, I know they’re a drag to lug around, but at least keep one in the trunk of your car! I’ve seen so many swaying, wobbling videos of something – something – tantalizing out there that I’m on a permanent Dramamine drip. Is the object moving, or is it the camera operator? Or both?

Even the near-ubiquitous employment of image stabilization systems can’t keep up with the enormous magnification of modern ultra-zoom lenses, but keep yours switched on anyway!

Lacking a tripod, learn to think like a sniper. Try to rest the camera on something solid – a wall, a windowsill, a balcony railing. Or brace yourself against a doorway, elbows on the trunk of a car, leaning up against a tree. This can be very effective, even with a long, heavy telephoto lens!

2) Focus manually, or at least learn how to shut off the autofocus system. Many recent videos and photos show fuzzy, glowing objects at night. Sometimes the camera operator zooms back to reveal details of the landscape with varying degrees of success.

The autofocus modules in most cameras were designed to focus on typical subjects under normal daylight or indoor lighting conditions, not on points of light at night at a distance. Therefore, they hunt and seek.

Most cameras have some way to defeat autofocus, the problem is interpreting it from the supposedly “universal” symbols used by camera makers! Often there’s an auto-manual focus switch. Manual focus might be indicated by a hand icon. A couple of jagged peaks, like mountains, indicates far focus. . The numeral 8 on its side, always indicates infinity focus on a lens. And that's far as in "To the moon, Alice, to the moon!"

3) Shoot 35 mm film in old, manual-everything cameras.

Think about it – modern digital cameras, and even modern film cameras, rely on printed circuit boards and electric micromotors. What is one well-known characteristic of a close encounter of the second kind? Two words: electrical interference! Whatever the UFO phenomenon is, it reliably appears to garble radio signals and stop spark-ignition engines in their tracks. Even DC devices like flashlights may be affected.
We may take a lesson from the fact that diesel engines, which rely for ignition on compression, not a spark, have reportedly kept on running.

Old, all-metal, manually-focused, hand-wound, mechanical-shutter film cameras are not only durable; equipped with the right optics – which can frequently be had for pennies on the original dollar – they are powerful image-gathering tools.

With a decent lens, a frame of fine grain 200 speed 35mm color film, when properly scanned, can record the equivalent of a 15 or 20 megapixel imaging chip! And it holds better detail in highlights and shadows. Getting that performance in a digital camera would set you back several grand – and you wouldn’t want your abductors getting their slimy tentacles on our advanced Earth technology, would you?

4) Take the filter off the lens! If you don’t keep a filter over the lens, why don’t you? It prevents dirt, dust, fingerprints and all kinds of other crud from soiling the front element of your lens, which has been polished to gem-like perfection and coated with multiple layers of rare, anti-reflective coatings.

If you’re shooting into any kind of light source, whether it’s the sun coming up at midnight or a suspected runaway paper lantern, a filter will produce a secondary or “ghost” image of the highlights. The apparent brightness of this secondary image depends on how good the filter is, which is usually a direct function of price. Even expensive filters do it a little; cheap filters do it a lot.

This happened to the above-mentioned UFO enthusiast. He brought me an amateur’s negative with mysterious “lights in the night sky” for enlargement and analysis. I noticed that the pattern and location of car headlights in the foreground inversely corresponded to the UFO’s above, which meant they were a reflection. I demonstrated it to the client on the print with a straightedge and grease pencil. When he still didn’t believe me, I told him to ask the photographer one question: was there a filter on the lens at the time the photo was taken? The photographer said “Yes,” and we didn’t hear much from the client after that.

5) Freeze time. By that, I mean choose a fast shutter speed to stop the subject’s movement and your own. On many point-and-shoot camera, both digital and film, this can be done by setting the mode dial or menu panel to the little “running man” figure, also known as “sports” or “action” mode. This tells the camera to select the fastest possible shutter speed for the lighting at the expense of more overall sharpness and less noise.

If you’re hand-holding a manual camera, choose a shutter speed at least the same fraction of a second as the focal length of the lens you’re using, i.e. 1/250 sec. is the slowest speed with a 200mm (or equivalent) lens, etc.

The advantage is you’ll get a clearer, more detailed image.

6) If you’re shooting digital, get a better camera. Convenience and image quality are often a tradeoff. In general, physically larger imaging chips produce higher quality image files than small ones, but large chips also require larger optics, bigger batteries and bodies. The best camera in the world is useless if you leave it at home.

7) Shoot the invisible. You can capture images in the invisible spectrum – infra-red and ultraviolet – with the proper equipment. Regular high-speed color or B&W film is also sensitive to ultraviolet, which often appears in photos taken at high altitudes as a prevalent bluish haze. A UV cutoff filter for visible light is required, which blacks out an SLR viewfinder, so an external viewfinder is a good idea.

Infrared film is available in B&W and so-called “false color” slide film, which is used for reconnaissance, scientific and agricultural imaging. Since it’s also sensitive to blue light, it must be used with an orange, deep red or IR cutoff filter. Regular light meters don’t measure these frequencies of light, so exposure tests are in order.

If all that sounds like too much trouble, try a digital forensic camera, like the Fuji IS-1 or a modified Finepix S3 Pro, which will shoot both infrared and UV photos in autofocus and autoexposure!

However, no amount of technical savvy or technology can replace an inquiring, skeptical attitude. UFOlogy is riddled with attitudes and opinions that transcend belief and verge on becoming religion. I see profound disappointment and anger in some writers because “disclosure” (whatever that means) is not forthcoming from the new administration. It seems obvious to me that whatever contact is taking place or will take place is happening on the terms of what Whitley Streiber calls “the Visitors,” not on our terms. To wait indefinitely is difficult; to invent fanciful scenarios and point to every speck of dust or blurred bird as evidence of extraterrestrial visitation is worse than unproductive, it is counter-productive. Only discrimination, rationality and the thorough application of science will bring us any closer to a solution to the UFO mystery. We have no assurance, however, that our beliefs lead us anywhere at all.




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dificultnspa

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Re : 7 astuces pour prendre de bonnes photos ou vidéos d'Ovnis / VO
« Réponse #1 le: 21 mai 2010 à 19:23:25 »


Citer
How to Capture a UFO Image on Camera


Contributed by Eyes For You (Editor)
19/05/2010 20:12:51


from wikiHow - The How to Manual That You Can Edit
If you should happen to observe an object in the sky that you cannot readily identify as a fixed wing aircraft, helicopter, blimp, satellite, meteorological anomaly, meteor, comet, or other phenomenon, the following tips will help you record the event.


Steps

1- Check whether the angular size of the object is sufficient for you to spot distinct geometric detail. For example:
     *Is it unmistakably spherical, discoidal,[1] shaped like a cigar or torpedo, or triangular?
     *Does it have a distinct color or color scheme, such as a cupola on top, port holes, or landing gear?

     *"Angular size", refers to the angle that the physical extent of the object subtends at your eye: this can be expressed in degrees or minutes of arc, in mils,[2] or most conveniently and particularly in the heat of the moment, in terms of the size of your thumb or fist any number of your fingers held together and held at arm's length.


2- Be very certain about your observation. In the vast majority of sightings, if the object described is no more than a mere pinpoint of white light in the sky, day or night, and there is nothing really unusual about its movement, assuming it even has any, then the chances are superbly large that it is a misidentified rather than an unidentified object and is really not worth recording nor reporting. The annals of investigative groups are saturated with such "sightings" and they do nothing but waste investigative time and expenditure or resources.

3- Remember four keywords: date, time, range, and azimuth.



4- *Date and time. A good UFO sighting/recording is one that contains accurate date and time for future investigation and correlation. Try to condition it into a reflex that when you're busy grinding away camcorder footage of a particularly interesting or strange form in the sky, you hit the date/time button on your cam without even thinking about it.
     *Azimuth. Use azimuth.[3] Azimuth refers to the angular bearing with respect to either true or magnetic North; it is almost universally given in degrees but still often enough quoted in points of the compass as "East Northeast" (ENE) or perhaps at times but very rarely "Southeast by South", etc. This information is as important as the range: while you are recording footage with a camcorder of an unidentified or "unconventional" aircraft in the skies, with the date/time group on the screen, you could be periodically calling out the azimuth to the object so that it gets recorded on the tape, disc or flash card, or whatever recording media, as you shoot in real time. This would be of tremendous value during subsequent investigation and evaluation. It goes without saying that two observers, suitably separated in distance from each other and calling off azimuths, can pinpoint fairly accurately where the object was, and its trajectory across the landscape.
     *Range. The range (or slant height) to an object in the sky is extremely difficult even for trained observers to ascertain.



5- Learn about different aircraft and their sizes. If you know the wing span or the length of the fuselage of a certain aircraft design, you can, through training, develop a very good idea of its distance from you. But what about an aerial artifact you have never seen before? You really don't have much of anything to go on. That metallic looking disc you saw in the sky one afternoon over the desert could be thirty feet in diameter and 500 yards away, or it could be a monstrous 300 feet in diameter and 5000 yards, or almost three miles distant. Did it cast a shadow on the ground? At what position was the sun in the sky that day? That knowledge alone might be of immense help in fixing the more or less exact position of the disc, or whatever it is in the sky when you observed it.

6- Invest in the right equipment. If you happen to reside in a region where such sightings of UFOs seem to be the norm,[4] purchase something like a Rangematic 1000 or similar, or stereoscopic rangefinder that will measure distances up to about 2000 yards, within a reasonable accuracy range. This is not only a good investment but it is really a necessity if you are to be a good UFO observer or investigator. If you already have a laser type range finder, then so much the better, but these are costly and their very impressive accuracy is arguably not warranted in most UFO observations. Nonetheless, if you do have one, definitely make use of it.

7- Learn how to judge size. You should also familiarize yourself with the mil relation, touched upon previously. It goes like this: if you know the size of a distant object, and you also know its angular size in mils, as read from the mil scale in many pairs of binoculars now or by using your thumb, fingers, palm of your hand, dime, quarter or whatever held at arm's length, then range to object = 1000 X (size)/ mils, and the result will always be in the same units as the size. Thus, if you know the size in feet, the result will be in feet, yards size will be in yards distance, etc. Your thumb held out at arm's length is probably very close to 40 (forty) mils, so this would mean that if, say, you spotted a disc in the sky that was 200 feet in diameter and your thumb at arm's length just barely covered it, then its distance from you would be 1000 X 200/40 = 5000 feet.
  * Conversely, if you can determine the distance with your rangefinder, radar data, laser, etc., and have the mil reading from the scale on your binoculars, then by simple algebra, the size = MILS X range/1000. Most binoculars on the market today have a field of view of about 350 feet at a range of 1000 yards--this is about one eighth of a radian or 125 mils, which allows you to estimate the angular size of what you are viewing if your binoculars don't have a mil scale baked into the eyepiece.

8- Familiarize yourself with angular measurements and estimating the same and particularly with the mil scale. Understanding how to estimate this is an extremely useful skill.




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admn : vidéo indisponible


« Modifié: 26 octobre 2015 à 23:33:34 par katchina »
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