13 Febbraio 1997 | Riparazione del Telescopio Spaziale
Il 13 Febbraio del 1997 lo shuttle Discovery decolla da Cape Canaveral per riparare e tarare alcuni strumenti del telescopio spaziale Hubble. E’ la seconda delle 5 missioni di servizio che si sono susseguite dal 1993 al 2009.
Il telescopio spaziale Hubble Fonte Nasa Il Telescopio Spaziale Hubble
Lanciato nel 1990, il telescopio Spaziale Hubble svolazza da trent’anni nell’orbita bassa terrestre, ficcando il naso nei più remoti anfratti dell’universo come nessun altro strumento posizionato a terra potrebbe fare.
Il contributo di Hubble alla nostra comprensione dell’universo non ha eguali, eppure il suo specchio di 2,5 metri di diametro è nato con un difetto che ne ha compromesso le potenzialità nei primi tre anni di servizio, prima di essere corretto con una complessa missione che impegnò ben 7 astronauti per 10 giorni.
Gli astronauti Musgrave e Hoffman installano le ottiche correttive durante la prim missione di servizio. Fonte: Nasa
Il nucleo della galassia a spirale M100, fotografata con l’Hubble prima e dopo l’installazione delle ottiche correttive. Fonte: Nasa Il Telescopio di Tutti
Nonostante Hubble sia stato costruito dalla NASA con il supporto dell’ESA, ed i fondi per le analisi siano stanziati solo da istituzioni statunitensi, chiunque può sfruttarlo per le proprie ricerche, senza restrizioni di nazionalità o istituzione accademica di appartenenza. Addirittura tra il 1990 ed il 1997 è stato a disposizione anche degli astronomi amatoriali, purché le osservazioni proposte fossero di interesse per la comunità scientifica e non si sovrapponessero a quelle già presentate dai professionisti.
I Pilastri della Creazione
Una delle foto più iconiche scattate con il telescopio spaziale Hubble è “
The Pillars of Creation” (i Pilastri della Creazione). Ritrae tre colonne di gas e polvere nella nebulosa Aquila, a 5700 anni luce dal nostro pianeta (la luce proveniente da quella nebulosa impiega 5700 anni ad arrivare fino a noi). Queste torri sono alte alcuni anni luce e la materia contenuta al loro interno sta dando vita a nuove stelle. Foto Spaziali in Bianco e Nero
Hubble non è il solo occhio che la nostra civiltà ha puntato verso lo spazio, ci sono tutti gli altri
, le varie sonde che abbiamo lanciato nel sistema solare e i telescopi terrestri che, seppur limitati dall’atmosfera, ogni giorno catturano spettacolari immagini dallo spazio profondo. Grandi Osservatori della NASA
Le fotografie scattate da Hubble e dagli altri strumenti in volo e a terra sono realizzate per lo più in bianco e nero e solo successivamente vengono colorate dai tecnici. I motivi sono essenzialmente tre:
Per gli strumenti in orbita o le sonde in volo interplanetario la questione è legata al fatto che una foto in bianco e nero contiene meno dati di una a colori, quindi può essere inviata più facilmente a terra. Dettaglio non irrilevante se stiamo usando una macchina fotografica spaziale che viaggia ad un centinaio di milioni di chilometri dal nostro pianeta. Alcuni strumenti, come Hubble, sono progettati principalmente per misurare la brillantezza della luce prodotta o riflessa dagli oggetti nello spazio, quindi l’uso del bianco e nero è la soluzione più funzionale. Molti dei soggetti di queste foto brillano di una luce che i nostri occhi non possono vedere, ma le nostre macchine fotografiche spaziali sì. Accade ad esempio che molte galassie emettano pochissima luce visibile, ma siano particolarmente luminose agli infrarossi, quindi per vedere esattamente come sono fatte occorre catturare lunghezze d’onda per le quali i nostri occhi sono ciechi.
One square degree image of the Tarantula Nebula and its surroundings. The spidery nebula is seen in the upper-centre of the image. Slightly to the lower-right, a web of filaments harbours the famous supernova SN 1987A. Many other reddish nebulae are visible in the image, as well as a cluster of young stars on the left, known as NGC 2100. Technical information: the image is based on observations carried out by Joao Alves (Calar Alto, Spain), Benoit Vandame and Yuri Beletsky (ESO) with the Wide Field Imager (WFI) at the 2.2-m telescope on La Silla. These data consist of a 2×2 WFI mosaic in the B- and V-bands, and in the H-alpha and [OIII] narrow bands. The data were first processed with the ESO/MVM pipeline by the Advanced Data Products (ADP) group at ESO. This image is available as a mounted image in the ESOshop. #L This colour image of the region known as NGC 2264 — an area of sky that includes the sparkling blue baubles of the Christmas Tree star cluster and the Cone Nebula — was created from data taken through four different filters (B, V, R and H-alpha) with the Wide Field Imager at ESO’s La Silla Observatory, 2400 m high in the Atacama Desert of Chile in the foothills of the Andes. The image shows a region of space about 30 light-years across. This image is available as a mounted image in the ESOshop. #L Measuring 70 000 light-years across and laying 13 million light-years away, the nearly edge-on spiral galaxy NGC 253 is revealed here in an image from the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at the La Silla Observatory. The image is based on data obtained through four different filters (R, V, H-alpha and OIII). North is up and East to the left. The field of view is 30 arcminutes. Colour composite image of Centaurus A, revealing the lobes and jets emanating from the active galaxy’s central black hole. This is a composite of images obtained with three instruments, operating at very different wavelengths. The 870-micron submillimetre data, from LABOCA on APEX, are shown in orange. X-ray data from the Chandra X-ray Observatory are shown in blue. Visible light data from the Wide Field Imager (WFI) on the MPG/ESO 2.2 m telescope located at La Silla, Chile, show the stars and the galaxy’s characteristic dust lane in close to “true colour”. #L This colour-composite image of the Helix Nebula (NGC 7293) was created from images obtained using the Wide Field Imager (WFI), an astronomical camera attached to the 2.2-metre Max-Planck Society/ESO telescope at the La Silla observatory in Chile. The blue-green glow in the centre of the Helix comes from oxygen atoms shining under effects of the intense ultraviolet radiation of the 120 000 degree Celsius central star and the hot gas. Further out from the star and beyond the ring of knots, the red colour from hydrogen and nitrogen is more prominent. A careful look at the central part of this object reveals not only the knots, but also many remote galaxies seen right through the thinly spread glowing gas.This image was created from images through blue, green and red filters and the total exposure times were 12 minutes, 9 minutes and 7 minutes respectively. This image is available as a mounted image in the ESOshop. #L Three-colour composite image of the Omega Nebula (Messier 17, or NGC 6618), based on images obtained with the EMMI instrument on the ESO 3.58-metre New Technology Telescope at the La Silla Observatory. North is down and East is to the right in the image. It spans an angle equal to about one third the diameter of the Full Moon, corresponding to about 15 light-years at the distance of the Omega Nebula. The three filters used are B (blue), V (“visual”, or green) and R (red). #L This magnificent 360-degree panoramic image, covering the entire southern and northern celestial sphere, reveals the cosmic landscape that surrounds our tiny blue planet. This gorgeous starscape serves as the first of three extremely high-resolution images featured in the GigaGalaxy Zoom project, launched by ESO within the framework of the International Year of Astronomy 2009 (IYA2009). The plane of our Milky Way Galaxy, which we see edge-on from our perspective on Earth, cuts a luminous swath across the image. The projection used in GigaGalaxy Zoom place the viewer in front of our Galaxy with the Galactic Plane running horizontally through the image — almost as if we were looking at the Milky Way from the outside. From this vantage point, the general components of our spiral galaxy come clearly into view, including its disc, marbled with both dark and glowing nebulae, which harbours bright, young stars, as well as the Galaxy’s central bulge and its satellite galaxies. As filming extended over several months, objects from the Solar System came and went through the star fields, with bright planets such as Venus and Jupiter. For copyright reasons, we cannot provide here the full 800-million-pixel original image, which can be requested from Serge Brunier. The high resolution image provided here contains 18 million pixels. The second of three images of ESO’s GigaGalaxy Zoom project is a new and wonderful 340-million-pixel vista of the central parts of our galactic home, a 34 by 20-degree wide image that provides us with a view as experienced by amateur astronomers around the world. Taken by Stéphane Guisard, an ESO engineer and world-renowned astrophotographer, from Cerro Paranal, home of ESO’s Very Large Telescope, this second image directly benefits from the quality of Paranal’s sky, one of the best on the planet. The image shows the region spanning the sky from the constellation of Sagittarius (the Archer) to Scorpius (the Scorpion). The very colourful Rho Ophiuchi and Antares region features prominently to the right, as well as much darker areas, such as the Pipe and Snake Nebulae. The dusty lane of our Milky Way runs obliquely through the image, dotted with remarkable bright, reddish nebulae, such as the Lagoon and the Trifid Nebulae, as well as NGC 6357 and NGC 6334. This dark lane also hosts the very centre of our Galaxy, where a supermassive black hole is lurking. The image was obtained by observing with a 10-cm Takahashi FSQ106Ed f/3.6 telescope and a SBIG STL CCD camera, using a NJP160 mount. Images were collected through three different filters (B, V and R) and then stitched together. This mosaic was assembled from 52 different sky fields made from about 1200 individual images totalling 200 hours exposure time, with the final image having a size of 24 403 x 13 973 pixels. Note that the final, full resolution image is only available through Stéphane Guisard. #L The third image of ESO’s GigaGalaxy Zoom project is an amazing vista of the Lagoon Nebula taken with the 67-million-pixel Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. The image covers more than one and a half square degree — an area eight times larger than that of the Full Moon — with a total of about 370 million pixels. It is based on images acquired using three different broadband filters (B, V, R) and one narrow-band filter (H-alpha). #L This image, the first to be released publicly from VISTA, the world’s largest survey telescope, shows the spectacular star-forming region known as the Flame Nebula, or NGC 2024, in the constellation of Orion (the Hunter) and its surroundings. In views of this evocative object in visible light the core of the nebula is completely hidden behind obscuring dust, but in this VISTA view, taken in infrared light, the cluster of very young stars at the object’s heart is revealed. The wide-field VISTA view also includes the glow of the reflection nebula NGC 2023, just below centre, and the ghostly outline of the Horsehead Nebula (Barnard 33) towards the lower right. The bright bluish star towards the right is one of the three bright stars forming the Belt of Orion. The image was created from VISTA images taken through J, H and Ks filters in the near-infrared part of the spectrum. The image shows about half the area of the full VISTA field and is about 40 x 50 arcminutes in extent. The total exposure time was 14 minutes. This image is available as a mounted image in the ESOshop. #L This new image of the reflection nebula Messier 78 was captured using the Wide Field Imager camera on the MPG/ESO 2.2-metre telescope at the La Silla Observatory, Chile. This colour picture was created from many monochrome exposures taken through blue, yellow/green and red filters, supplemented by exposures through a filter that isolates light from glowing hydrogen gas. The total exposure times were 9, 9, 17.5 and 15.5 minutes per filter, respectively. #L This very detailed enhanced-colour image from ESO’s Very Large Telescope shows the dramatic effects of very young stars on the dust and gas from which they were born in the star-forming region NGC 6729. The baby stars are invisible in this picture, being hidden behind dust clouds at the upper left of the picture, but material they are ejecting is crashing into the surroundings at speeds of that can be as high as one million kilometres per hour. This picture was taken by the FORS1 instrument and records the scene in the light of glowing hydrogen and sulphur. The Antennae Galaxies (also known as NGC 4038 and 4039) are a pair of distorted colliding spiral galaxies about 70 million light-years away, in the constellation of Corvus (The Crow). This view combines ALMA observations, made in two different wavelength ranges during the observatory’s early testing phase, with visible-light observations from the NASA/ESA Hubble Space Telescope. The Hubble image is the sharpest view of this object ever taken and serves as the ultimate benchmark in terms of resolution. ALMA observes at much longer wavelengths which makes it much harder to obtain comparably sharp images. However, when the full ALMA array is completed its vision will be up to ten times sharper than Hubble. Most of the ALMA test observations used to create this image were made using only twelve antennas working together — far fewer than will be used for the first science observations — and much closer together as well. Both of these factors make the new image just a taster of what is to come. As the observatory grows, the sharpness, speed, and quality of its observations will increase dramatically as more antennas become available and the array grows in size. This is nevertheless the best submillimetre-wavelength image ever taken of the Antennae Galaxies and opens a new window on the submillimetre Universe. While visible light — shown here mainly in blue — reveals the newborn stars in the galaxies, ALMA’s view shows us something that cannot be seen at those wavelengths: the clouds of dense cold gas from which new stars form. The ALMA observations — shown here in red, pink and yellow — were made at specific wavelengths of millimetre and submillimetre light (ALMA bands 3 and 7), tuned to detect carbon monoxide molecules in the otherwise invisible hydrogen clouds, where new stars are forming. Massive concentrations of gas are found not only in the hearts of the two galaxies but also in the chaotic region where they are colliding. This broad image of the Carina Nebula, a region of massive star formation in the southern skies, was taken in infrared light using the HAWK-I camera on ESO’s Very Large Telescope. Many previously hidden features, scattered across a spectacular celestial landscape of gas, dust and young stars, have emerged. #L The oddly shaped Pencil Nebula (NGC 2736) is pictured in this image from ESO’s La Silla Observatory in Chile. This nebula is a small part of a huge remnant left over after a supernova explosion that took place about 11 000 years ago. The image was produced by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. This image is available as a Mounted Image in the ESOshop. #L This VLT image of the Thor’s Helmet Nebula was taken on the occasion of ESO’s 50th Anniversary, 5 October 2012, with the help of Brigitte Bailleul — winner of the Tweet Your Way to the VLT! competition. The observations were broadcast live over the internet from the Paranal Observatory in Chile. This object, also known as NGC 2359, lies in the constellation of Canis Major (The Great Dog). The helmet-shaped nebula is around 15 000 light-years away from Earth and is over 30 light-years across. The helmet is a cosmic bubble, blown as the wind from the bright, massive star near the bubble’s centre sweeps through the surrounding molecular cloud. The spectacular star-forming Carina Nebula has been captured in great detail by the VLT Survey Telescope at ESO’s Paranal Observatory. This picture was taken with the help of Sebastián Piñera, President of Chile, during his visit to the observatory on 5 June 2012 and released on the occasion of the new telescope’s inauguration in Naples on 6 December 2012. The Danish 1.54-metre telescope located at ESO’s La Silla Observatory in Chile has captured a striking image of NGC 6559, an object that showcases the anarchy that reigns when stars form inside an interstellar cloud. This region of sky includes glowing red clouds of mostly hydrogen gas, blue regions where starlight is being reflected from tiny particles of dust and also dark regions where the dust is thick and opaque. Astronomers using ESO’s Very Large Telescope in Chile have captured this eye-catching image of planetary nebula Abell 33. Created when an aging star blew off its outer layers, this beautiful blue bubble is, by chance, aligned with a foreground star, and bears an uncanny resemblance to a diamond engagement ring. This cosmic gem is unusually symmetric, appearing to be almost perfectly circular on the sky. This richly detailed new view from the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile shows the star formation region Gum 15. This little-known object is located in the constellation of Vela (The Sails), some 3000 light-years from Earth. The glowing cloud is a stunning example of an HII region. It also has a similarity to a more famous HII region, the Trifid Nebula (Messier 20). The VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile has captured this beautifully detailed image of the galaxy Messier 33, often called the Triangulum Galaxy. This nearby spiral, the second closest large galaxy to our own galaxy, the Milky Way, is packed with bright star clusters, and clouds of gas and dust. This picture is amongst the most detailed wide-field views of this object ever taken and shows the many glowing red gas clouds in the spiral arms with particular clarity. Like the gaping mouth of a gigantic celestial creature, the cometary globule CG4 glows menacingly in this image from ESO’s Very Large Telescope. Although it looks huge and bright in this image it is actually a faint nebula and not easy to observe. The exact nature of CG4 remains a mystery. ESO’s Very Large Telescope in Chile has captured the most detailed image ever taken of the Medusa Nebula (also known Abell 21 and Sharpless 2-274). As the star at the heart of this nebula made its final transition into retirement, it shed its outer layers into space, forming this colourful cloud. The image foreshadows the final fate of the Sun, which will eventually also become an object of this kind. This extraordinary bubble, glowing like the ghost of a star in the haunting darkness of space, may appear supernatural and mysterious, but it is a familiar astronomical object: a planetary nebula, the remnants of a dying star. This is the best view of the little-known object ESO 378-1 yet obtained and was captured by ESO’s Very Large Telescope in northern Chile. This spectacular image of the Orion Nebula star-formation region was obtained from multiple exposures using the HAWK-I infrared camera on ESO’s Very Large Telescope in Chile. This is the deepest view ever of this region and reveals more very faint planetary-mass objects than expected. Two of the sky’s more famous residents share the stage with a lesser-known neighbour in this enormous three gigapixel image from ESO’s VLT Survey Telescope (VST). On the right lies the faint, glowing cloud of gas called Sharpless 2-54, the iconic Eagle Nebula (Messier 16) is in the centre, and the Omega Nebula (Messier 17) to the left. This cosmic trio makes up just a portion of a vast complex of gas and dust within which new stars are springing to life and illuminating their surroundings. OmegaCAM — the wide-field optical camera on ESO’s VLT Survey Telescope (VST) — has captured the spectacular Orion Nebula and its associated cluster of young stars in great detail, producing this beautiful new image. This famous object, the birthplace of many massive stars, is one of the closest stellar nurseries, at a distance of about 1350 light-years. The OmegaCAM imager on ESO’s VLT Survey Telescope has captured this glittering view of the stellar nursery called Sharpless 29. Many astronomical phenomena can be seen in this giant image, including cosmic dust and gas clouds that reflect, absorb, and re-emit the light of hot young stars within the nebula. This spectacular image of the large spiral galaxy NGC 1232 was obtained on September 21, 1998, during a period of good observing conditions. It is based on three exposures in ultra-violet, blue and red light, respectively. The colours of the different regions are well visible : the central areas contain older stars of reddish colour, while the spiral arms are populated by young, blue stars and many star-forming regions. Note the distorted companion galaxy on the left side, shaped like the greek letter “theta”. NGC 1232 is located 20º south of the celestial equator, in the constellation Eridanus (The River). The distance is about 100 million light-years, but the excellent optical quality of the VLT and FORS allows us to see an incredible wealth of details. At the indicated distance, the edge of the field shown corresponds to about 200,000 light-years, or about twice the size of the Milky Way galaxy. The image is a composite of three images taken behind three different filters: U (360 nm; 10 min), B (420 nm; 6 min) and R (600 nm; 2:30 min) during a period of 0.7 arcsec seeing. The field shown measures 6.8 x 6.8 arcmin. North is up; East is to the left. #L Nuzzled in the chest of the constellation Virgo (the Virgin) lies a beautiful cosmic gem — the galaxy Messier 61. This glittering spiral galaxy is aligned face-on towards Earth, thus presenting us with a breathtaking view of its structure. The gas and dust of the intricate spiral arms are studded with billions of stars. This galaxy is a bustling hub of activity with a rapid rate of star formation, and both a massive nuclear star cluster and a supermassive black hole buried at its heart. Messier 61 is one of the largest members of the Virgo Cluster, which is made up of more than a thousand galaxies, and is itself at the centre of the Virgo Supercluster — to which our Milky Way also belongs. This dazzling beauty was first discovered in 1779, and it has been capturing astronomers’ interest ever since. Set against a dark sky littered with galaxies, this image shows the awe-inspiring M61 in its full glory — even at its distance of over 50 million light-years. This image was taken as part of ESO’s Cosmic Gems Programme, an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. In case the data collected could be useful for future scientific purposes, these observations are saved and made available to astronomers through ESO’s Science Archive. A reproduction of a composite colour image of the Horsehead Nebula and its immediate surroundings. It is based on three exposures in the visual part of the spectrum with the FORS2 multi-mode instrument at the 8.2-m KUEYEN telescope at Paranal. It was produced from three images, obtained on February 1, 2000, with the FORS2 multi-mode instrument at the 8.2-m KUEYEN Unit Telescope and extracted from the VLT Science Archive Facility . The frames were obtained in the B-band (600 sec exposure; wavelength 429 nm; FWHM 88 nm; here rendered as blue), V-band (300 sec; 554 nm; 112 nm; green) and R-band (120 sec; 655 nm; 165 nm; red). The original pixel size is 0.2 arcsec. The photo shows the full field recorded in all three colours, approximately 6.5 x 6.7 arcmin 2 . The seeing was about 0.75 arcsec. This image is available as a mounted image in the ESOshop. #L
ESO Quindi le Foto dello Spazio Hanno Colori Inventati?
La risposta è tendenzialmente no. Ma dipende dalla specifica tipologia di immagine e dallo scopo per cui è stata prodotta.
Le foto scattate da strumenti come Hubble, che sono progettati per registrare solo immagini in bianco e nero, hanno colori assolutamente veritieri, quando puntano i loro obiettivi su oggetti che emettono luce visibile.
In questi casi si usa un processo simile a quello con cui il nostro occhio riproduce i colori partendo dai tre primari (rosso, verde e blu). Si scattano tre foto in bianco e nero, usando ogni volta un filtro che lascia passare solo uno dei primari. In questo modo otteniamo tre immagini grige, ma se le sovrapponiamo abbiamo tutte le informazioni che ci servono per ricostruire i colori della scena reale.
Immagine in bianco e nero della Nebulosa Aquila
Immagine a mosaico composito tricolore della Nebulosa Aquila realizzata sovrapponendo 3 filtri R, G e B. Fonte ESO La Luce che Non Vediamo
La luce visibile è una radiazione elettromagnetica. Ogni colore che i nostri occhi possono catturare corrisponde ad una specifica
lunghezza d’onda e tutta la gamma dei colori visibili è collocata su una roba chiamata spettro ottico, una piccola porzione dello spettro elettromagnetico che comprende tutte le radiazioni dell’universo: dalle onde radio delle frequenze di Radio Maria, ai raggi gamma delle esplosioni nucleari, passando per il lilla del cioccolato Milka.
La luce visibile è un intervallo piccolissimo compreso tra l’infrarosso e l’ultravioletto e per questo non è difficile immaginare che l’universo sia un continuo baluginare di colori che non siamo capaci di vedere.
Video del nostro sole realizzato dal Solar Dynamic Observatory della Nasa che monitora la nostra stella 24 ore su 24, catturando immagini su 10 diverse lunghezze d’onda Le Foto Impossibili
Per catturare lunghezze d’onda, come l’infrarosso e l’ultravioletto, che i nostri occhi non possono vedere, si usano strumenti (filtri e sensori) che sono in grado di enfatizzarle e riprodurle. Ma anche in questo caso quello che otteniamo è una fotografia in bianco e nero. Per colorare queste immagini si assegnano alle lunghezze d’onda invisibili i colori dello spettro visibile, costruendo una rappresentazione verosimile di come si presenterebbe l’oggetto fotografato se fossimo in grado di percepire tutto lo spettro elettromagnetico.
Una stessa porzione di universo può apparire estremamente diversa se la siguarda con occhi umani, nell’infrarosso o nell’ultravioletto. A fini scientifici è estremamente interessante poter disporre di tutte queste versioni della medesima realtà, senza contare che è incredibilmente affascinante poter percepire un universo
parallelo normalmente precluso ai nostri sensi, che nonostante questo sta là fuori e si agita in un ribollire impetuoso di ammassi di gas che collassano genarando stelle, galassie che si scontrano, soli che muoiono esplodendo e così via. Tutta roba che ci rimette al nostro posto, lascio a voi indovinare quale sia.
Nebulosa Granchio nello spettro visibile Fonte NASA
Nebulosa Granchio ai raggi x Fonte NASA
Nebulosa Granchio agli infrarossi Fonte NASA
Nebulosa Granchio, composizione delle tre foto precedenti Fonte NASA
Pillars of Creation (i Pilastri della Creazione) fotografati in luce visibile (a sinistra) e all’infrarosso (a destra) Fonte NASA I Falsi Colori
La terza ed ultima tecnica utilizzata per colorare l’universo è quella dei falsi colori, che serve per enfatizzare determinati elementi della scena. Per esempio se si vuole differenziare una nube di ossigeno da una di idrogeno, oppure se si vogliono distinguere zone che hanno temperature differenti. In tutti questi casi si assegnano dei colori in modo più o meno arbitrario ai diversi oggetti presenti nella scena.
La FotoCosa del Giorno | La Mossa del Cavallo Aprile 9, 2020
La FotoCosa del Giorno | Gypsies Aprile 8, 2020
La FotoCosa del Giorno | Family Love Aprile 7, 2020
La FotoCosa del Giorno | Nadar Fotografo Volante Aprile 6, 2020
La FotoCosa del Giorno | Our Life in the Shadows Aprile 3, 2020
La FotoCosa del Giorno | Martine Franck: è dura vivere accanto a un mito Aprile 2, 2020
La FotoCosa del Giorno | Robert Doisneau tra baci e processi Aprile 1, 2020
La FotoCosa del Giorno | Quando la street divenne arte: Paul Strand Marzo 31, 2020
La FotoCosa del Giorno | L’epidemia attraverso gli occhi di Alex Majoli e Fabio Bucciarelli Marzo 30, 2020
La FotoCosa del Giorno | La città più fredda del mondo Marzo 27, 2020