Showing posts with label HDR. Show all posts
Showing posts with label HDR. Show all posts

Saturday, September 16, 2017

iphone 8, iPhone 8 Plus et iPhone X pas cher, détails; Apple Watch "Series 3"; Apple TV 4k HDR; IOS 11


Les iPhone 8 et Phone 8 Plus sont enfin proposés à la précommande pour une livraison le 22 septembre 2017 en France.

Apple a présenté trois smartphones lors de sa keynote du 12 septembre : iPhone 8, iPhone 8 Plus et iPhone X (équipés  d'iOS 11). Côté prix, ils seront respectivement commercialisés à partir de 809, 919 et 1 159 euros. Les deux premiers seront en vente à partir du 22 septembre.
L'iPhone X ne sera lui disponible qu'à compter du 3 novembre.
Vanté comme la plus grande révolution depuis l'iPhone, l'iPhone X est équipé de deux caméras de 12 megapixels, d'un système de reconnaissance faciale Face ID, d'un système de recharge sans fil.
Il disposera de 2 heures d'autonomie de plus que l'iPhone 7 et accueille des animojis, emojis animés que les utilisateurs pourront se partager exclusivement via iMessage.

"L'iPhone X est le plus grand saut depuis l'arrivée de l'iPhone", a annoncé Tim Cook.
Cet iPhone X (à prononcer "ten" en anglais) sera proposé dans deux coloris "gris" et "noir" et doté d'un écran "Super Retina Display" de 5,8 pouces.  L'iPhone X est équipé de deux caméras de 12 megapixels et du système révolutionnaire Face ID pour déverrouiller son écran (et payer) grâce à la reconnaissance faciale. La lentille bénéfice de 36% de lumière de plus que l'iPhone 8 et va permettre des prises de vue grand angle. La batterie de l'iPhone X va avoir deux heures d'autonomie de plus que l'iPhone 7. Il sera possible de le recharger avec des chargeurs partenaires sans fil, par induction. Il est doté d'une puce A11 bien plus puissante que ces prédécesseurs. L'appareil intègre du machine learning et de l'intelligence artificielle pour de meilleurs rendus photos.
---

iPhone X

Comme attendu, le bouton Home disparaît. Pour allumer son iPhone X, il suffit juste d'appuyer sur son écran et pour aller sur l'écran d'accueil, de balayer son doigt de bas en haut. La reconnaissance faciale fait aussi son arrivée avec Face ID, un système de déverrouillage du  smartphone qui fera sans doute date.
Phil Schiller, VP marketing d'Apple, annonce que la technologie, qui fonctionnera avec Apple Pay, est encore plus fiable que l'ancien système digital du Touch ID. L'iPhone X sera vendu à partir de 1 159 euros et proposé avec deux capacités de stockage : 64 Go et 256 Go.  Cette dernière coûtant la coquette somme de...  1 359 euros.

iPhone 8

Les iPhone 8 et iPhone 8 Plus sont désormais disponibles en précommande, pour livraison le vendredi 22 septembre, depuis le site d'Apple et d'autres e-commerçants.

Avec son écran de 4,7 pouces, l'iPhone 8 est proposé dans trois coloris argent, gris et or. Il est équipés d'une puce d'A11 avec six coeurs qui est 70% plus rapide que la puce A10.
Deux capacités de stockages sont proposées : 64 Go et 256 Go. Il sera vendu à partir de 809 euros pour la version 64 Go et 979 euros pour la version 256 Go. Il dispose d'un système de recharge sans fil compatible avec le standard le plus populaire au monde, Qi. Comme attendu pas de chargeur Apple.... mais des partenaires comme Mophie ou Belkin dont les produits seront proposés au sein de l'Apple Store. L'iPhone 8 s'ouvre à la réalité augmentée, "une fonctionnalité amenée à devenir de plus en plus importante dans les smartphones". Ses capteurs permettent de donner tout son sens à cette technologie via la reconnaissance de la lumière et de la profondeur pour intégrer des éléments virtuels dans le réel.

Proposé à partir de 919 euros dans sa version 64 Go, l'iPhone 8 Plus est, comme son petit frère, proposé avec trois coloris (argent, gris et or) et deux capacités de stockage (64 Go et 256 Go).  Il est vendu 1 089 euros dans sa version 256 Go.

Son écran, plus large, compte 5,5 pouces. Si l'iPhone 8 n'est doté que d'un capteur photo, l'iPhone 8 Plus en embarque lui deux. Ils ont chacun une capacité de 12 megapixels qui permettra à ses utilisateurs de prendre des photos et vidéos au rendu inégalé. "Aucun smartphone n'égale Apple sur ce terrain là", annonce la firme à la pomme.

Apple Watch

L'Apple Watch "Series 3" intègre une carte sim et devient donc indépendante de l'iPhone.
Ses utilisateurs pourront désormais passer des appels directement depuis leur montre connectée, le numéro restant celui du téléphone. L'intégration directe aux cartes d'Apple permettra aux utilisateurs de se balader sans soucis. L'autre nouveauté c'est l'arrivée de la musique et la possibilité d'écouter plusieurs dizaines de millions de chansons. L'Apple Watch Series 3 sera d'abord disponible dans 9 pays dont la France. Elle sera commercialisée à partir de 329 dollars et il en coûtera 399 dollars pour se procurer la version cellulaire qui permet de passer des appels.

Apple TV

 "Nous sommes très fiers d'avoir amélioré l'expérience de la TV", a par ailleurs annoncé Tim Cook. La dernière version de l'Apple TV sera compatible avec les contenus 4K, HDR, HD-10 et Dolby Vision. Dans son cœur, la même puce que celle de l'iPad Pro et un processeur deux fois plus puissant que celui de l'ancienne Apple TV.

IOS 11

La marque à la pomme a livré la date de lancement officiel de son nouvel iOS 11 et présenté ses dernières innovations, en particulier Face ID.


Wednesday, July 19, 2017

all features of sony alpha 77 65: A77 features not found in A65 and tricks for A65. In 2012, the first World’s highest megapixel for an APS-C sized sensor, fast AF when shooting HD video


A77 features not found in A65

1) Magnesium alloy body
2) Weather sealing
3) Rear control wheel
4) Joystick control
5) Microfocus adjust
6) LED AF assist lamp
7) Customizable upper and lower Auto ISO limits
8) 19 point AF w/ 11 cross type vs. 15 point AF w/ 3 cross type
9) 1/8000 vs. 1/4000 max shutter speed
10) 1/250 vs. 1/160 Flash Sync
11) Flash sync socket
12) Sony vertical grip available
13) Top LCD
14) 3 way tilt rear LCD
15) 12 fps vs. 10fps
16) Extended exposure bracketing
17) Extended AE compensation
18) ISO settings start from 50 vs. 100 and offer 1/3 stop increments
19) External focusing mode switch
20) AF/MF switching button
21) Direct Manual Focus
22) Manual control for pop-up flash
23) JPEG Extra Fine option
24) 3 user memory locations
25) Release priority option
26) AF drive speed option
27) AEL button vs. Function menu for slow sync
28) Pop-up flash GN12/16mm vs. GN10/18mm
29) Additional Creative Styles
30) 'M' shift capability

FINDING BUTTONS, DIALS, AND CONTROLS ON YOUR SONY ALPHA A65/A77






http://www.dummies.com/photography/cameras/sony-alpha-slt-a65a77-for-dummies-cheat-sheet/

a very good intro (in french)

http://alpha-numerique.fr/index.php/materiel/boitiers-sony/128-alpha-65/791-sony-alpha-65-le-reflex-semi-expert-translucent-accessible

Books about Sony alpha 77 and 65

The Complete Guide to Sony's Alpha 65 and 77 SLT Cameras B&W Edition
Volume I
https://books.google.fr/books?id=afiWAwAAQBAJ
Volume II
https://books.google.fr/books?id=R_mWAwAAQBAJ
Version 1.2
ISBN 978-1-105-52519-3 B&W Vol. I
978-1-105-52578-0 B&W Vol. ll

Sony Alpha SLT-A65 / A77 For Dummies
https://books.google.fr/books?id=bFa3sUiL0xIC

From Vol I

only the beginning on google books
Geez, where do I start? The specs for these cameras looked so perfect that
the entire world waited anxiously for them to be released: World’s
highest megapixel (for an APS-C sized sensor, that is), world’s best
Electronic Viewfinder, a design that allows fast AF (or full manual
control) when shooting HD video, Olympic-paced shooting speeds, and
probably the best “kit” lens ever produced.

the translucent mirror

Traditional SLRs (which stands for
Single Lens Reflex) had a mirror
behind the lens that swung out of
the way the moment you took the
picture (Figure 1-2). The mirror
was there to ensure that the
composition you saw in the
viewfinder was identical to what
ended up on the film. (Yes, FILM.
It’s an old design!) And moving
that mirror up and down five
frames per second (or faster with
some high-end sports cameras) is a
mechanical engineering challenge
which can also induce a lot of in-
camera vibration.
But what if the mirror remained
fixed in place‘? Or, more
specifically, what if the mirror was
a semi-transparent variety, which
let most of the light through but
reflected about one third of that
light up to some autofocus
sensors? That would solve two of
the biggest problems with most
other DSLRs that try to shoot video: 1) you would now be able to add fast autofocus while you’re shooting video, and 2) you would be able to shoot many more frames-per-second (10 in the ease of the A65; 12 in the case of the A77) than what a consumer-grade moving mirror would normally be
able to allow. AND you wouldn’t have to give up autofocus in this mode!
The SLT was conceived to give you a full-time Live View function with HO compromises.
Sony’s marketing department says that it took a collaboration of five different technology companies to produce this 2nd-generation thin polymer mirror laminate. (They also incorrectly label this semi-
transparent mirror as being “translucent”. Semantics. I’ve gotten over it.)
The new mirror is so good that dprevicwcom tried andfailed to produce a “ghost” (unwanted internal reflection of a specular highlight) in their review of the camera.

Worlds Best Electronic Viewfinder

It’s not just hyperbole - l’m serious. Everyone who has ever picked up these cameras looks at the EVF and says, “Wow!”. (This is especially true of those who have used this camera’s predecessors, the A33, 35, and 55.) What makes it different‘? It’s an Organic L.E.D. (OLED) display — the same kind used on high-end smart phones. They are brighter, have a wider color gamut, and have a faster refresh rate than the camera’s rear LCD. And unlike the A55’s liquid crystal-based EVF, this one doesn’t employ a polarizer, which means you can use this camera while wearing polarized sunglasses without fear of screen blackout.
The EVF is the other essential ingredient (the first being the translucent mirror) that bring all of the benefits of SLT design to you: in addition to the fact that you can have fast autofocus during video mode, you can also see how your image will look before you shoot (exposure and white balance), plus it gives you tools for focusing manually (Focus Magnifier and Peaking Level functions) that just weren’t available using the old design.
The EVF isn’t perfect, though. When shooting under any kind of fluorescent light (whether it be the older tubular bulbs or the newer compact fluorescent variety), the white balance you see in Live View
fluctuates and doesn’t always match the final image. Eyeglass wearers shooting outdoors on a bright day say they have to shield the sun which comes in between their face and the eyeglasses. David Kilpatriek at photoclubalpha.eom mentions that the EVF doesn’t show you enough detail in the blacks (he says that to save energy the camera turns off any LED pixels if the value is below a certain threshold, something I never would have noticed. And some extreme sports shooters have complained that they have trouble panning in the fastest shooting modes (although I personally haven’t experienced any problem during any experiments).

Furthermore, unlike other cameras which shoot this quickly, the Sony can actually autofocus between shots, helping to kccp that sprinter in focus from shot-to-shot. Sony calls this feature "Continuous Advance Prioritv AE”.

 3-D Panorama mode

Sony’s programmers have pulled off (what is in my mind) a software miracle by also including a 3-D Panorama mode. Using no special hardware or lenses, the software actually compares the geometry
and perspective of adjacent 2D shots and infers the relative distance from the camera in software. (This was clearly the result of several Ph.D. dissertations.) It then generates a 3-D image in an industry-standard .mpo file which can be viewed on the new breed of 3-D TVs. There are also
free programs available for viewing these files on your computer. (You’ll
have to provide your own red/green eyeglasses, though.)

In camera Lens Corrections

If you’re a lens perfectionist, then you’ll probably appreciate this feature:
Your camera has the ability to correct for the three most common types of optical deficiencies in consumer-grade lenses: vignetting, distortion, and chromatic aberrations. And it does this the same way that high-end and expensive desktop workflow software does: inside the camera is a database of a small but growing number of lenses and their optical characteristics (and the corrections needed) at different focal lengths. As of this writing, the cameras know about 6 popular lenses; with more to be
added via future firmware updates.

Handheld Twilight and Multi-Frame Noise Reduction

There are other features that use Sony’s ability to do multiple-image alignment in-camera. The first actually has two names and appears in the menus in different places: “Handheld Twilight” (HHT) and “Multi-Frame Noise Reduction” (MFNR).
Shooting in low light and don’t have a tripod handy‘? Hate noisy pictures, whether in good light or bad? For years professional photographers (astrophotographers in particular) had a trick up their sleeves when it came to reducing noise in static images — they would take several different
shots in succession, and then merge them all in Photoshop. The underlying principle here was that each frame had the same subject but completely random noise (sensor's noise & atmosphere/transmission), and by combining the images the noise would just get “averaged” away, while the subject, which appeared consistently in each shot, would be reinforced.
Using the same intelligence found in the panorama stitching algorithms mentioned above, your A65 or A77 camera can use this very same technique, except you don’t need a tripod and you certainly don’t need a computer. Using either Handheld Twilight mode or the Multi-Frame Noise-Reduction function, the camera will take six handheld shots in rapid succession, line them all up (in case your hand wasn’t perfectly steady), merge them all together, and produce one high- resolution, low-noise, low-light image — all in-camera!
Three Low-Light Modes Compared So it tuns out that these cameras offer you not one but THREE different features designed to tackle low-light shots:
  • Handheld Twilight, 
  • Multi- frame Noise Reduction, 
  •  a 3“ one called "Night Scene" mode  which as far as I can see doesn’t do anything different than AUTO mode with the flash disabled. 
This seems like as good a place as any to compare all three.  

Conclusion: While Handheld Twilight is a great feature for point-and- shoots that gives amateurs a fighting chance of getting a sharp shot without using tripods (AND it reduces noise about three stops’ worth), the results arc not nearly as good as using an old-fashioned tripod with a lower ISO. And using MFNR  actually makes the low ISO tripod shots look even less noisy!  

Handheld High Dynamic Range (HDR) 

The last multiple-image, in-camera alignment feature is another great timesaver: High Dynamic Range (often abbreviated HDR). I’ll also talk about the limited dynamic range of the digital sensor, and how our eyes can see a greater range of light (bright to dark) than what the camera can see. Over the past century there have been lots of attempts to correct this intentional artifact of photographic representation of real light, trying to render the image so it looks more like how we saw it. The latest technique for trying to achieve this wider dynamic range comes in what’s become known as High Dynamic Range (HDR) photography. The time-honored way to create an HDR image is to put the camera on a tripod and take 3 (sometimes more) pictures of the same scene, each at different exposures — some darker, some lighter. Then, you merge them all in your computer so it sort of looks like the way you saw it in real life.
Up until now, HDR photography was labor-intensive and unintuitive — in fact, I once wrote a whole article on the subject and gave real-life examples of how to create these images in my Advanced Topics 2 e-booklet (available from www.FriedmanArchives.com/ebooks). That was HDR the old way. With the A65/77 cameras, Sony has made this useful feature easier to use. For starters, there’s no need for a tripod anymore. With the feature enabled (page 162), you just point the camera at your subject, and press the shutter release button once. The camera will take 3 sequential pictures at different exposures (one lighter, one darker, one “normal”) and merge them in the camera for you. No computer needed. What’s more, this feature can shoot up to a six-stop range. “But what if you had a shaky hand and the camera moved slightly between the first and third exposure?”, I hear you ask. Just as with the Handheld Twilight function mentioned earlier, the answer is the camera will automatically try to align the three images for you before merging them into a single .jpg image. Again, pretty impressive stuff.

Peaking Color

Peaking Color As mentioned earlier, these cameras also provide two great manual focusing aids. The first is the Focus magnifier (which shows you a magnified area of the image so you can fine- tune your manual focusing), and the other is a pretty innovative feature called “Peaking Color” (and its counterpart, “Peaking Level”). As you tum the manual focusing ring of your lens, areas that have high contrast (which equates to sharp focus) will be highlighted in the color of your choice. Faster than using the superior ground-glass focusing screens of l960’s era film-based SLRs!

 Built-in GPS 

I predicted this back in 1994. In my NASA days I invented the “Trustworthy Digital Camera” (http://tinyurl.c0m/6bhlw9g); if you took a picture with this camera you’d be able to prove in court that the image had not been manipulated by computer. (I was on a mission to restore the credibility of the photographic image!)  


From Vol II


Forum

HDMI live

Is the HDMI output from A57 and or A65 live during recording mode? I would like to use an external HDMI monitor with larger screen size while composing.
https://www.dpreview.com/forums/thread/3193603

A65 - Taking time lapse

https://www.dpreview.com/forums/thread/3893577

use triggertrap ("intervalometer")
https://medium.com/triggertrap-playbook/triggertrap-for-ios-and-android-is-now-open-source-a194350e9cfc

http://stephane-mottin.blogspot.fr/2017/07/hdr-high-dynamic-range-problem.html

HDR, EDR, wides gamuts DCI-P3, 10bits for each RGB-Transparency and screen


"HDR (High Dynamic Range)" video describes pixels using three different criteria:

  • Greater resolution (“more pixels”)
  • Greater color saturation (“fatter pixels”)
  • Greater shadow and highlight range (“brighter pixels”)--> only this criteria for classic HDR.

DCI P3 (Digital Cinema Initiative P3) falls into the “greater color saturation” section. It sets the white point at 6500° Kelvin and is more saturated than traditional HD video, but not as deeply saturated as the ultimate goal of Rec. 2020. Apple calls this “wide color,” or “wide color gamut,” media.

None of the new Macs have HDR screens. They offer a wider color gamut and higher resolution than previous gen Macs, but they are not HDR.

Timing DCI-P3

DCI-P3 was defined by the Digital Cinema Initiatives (DCI) organization and published by the Society of Motion Picture and Television Engineers (SMPTE) in SMPTE EG 432-1 and SMPTE RP 431-2.
In September 2015, Apple's iMac desktop became the first consumer computer with a built-in wide-gamut display, supporting the P3 color space.
Normal white LED backlights produce a lot of blue light, but not as much red or green light. Late 2015 iMacs are using the not-that-new GB-r LED backlight technology. This creates a much stronger green and red spectral component to match the already strong blue. The larger gamut can reproduce more vivid greens, reds, and their derivatives (cyan, yellow, magenta). http://www.astramael.com/
In August 2016, the Samsung Galaxy Note 7 shipped with an HDR display with 100% DCI-P3 color gamut.
https://en.wikipedia.org/wiki/DCI-P3
In September 2016, Apple's iPhone 7 shipped with a wide-gamut display, supporting P3.
In October 2016, Apple's new MacBook Pro notebook computers were released with P3 displays.

DCI-P3

Traditionally, the folks that cared the most about extended color spaces were professional still photographers. This is because, in the past, HD video created the significantly lower resolution images where a 1080p frame contained 2.1 million pixels at 8-bit depth, while a 4×5 inch digital negative could contain up to 40 million pixels at 16-bit depth.
In the world of still photos, Adobe RGB (and its close cousin sRGB) reigned supreme as the color space of choice because of its color range and dynamics.
From what I read, the DCI P3 color space is optimized for projection systems, not for monitors. Why? Because P3 was the color space designed for use by digital cinema projectors in theaters.
This means that many photographers are puzzled about why Apple chose a video standard for its monitors, rather than a stills standards. Apple hasn’t responded to these questions, but my guess it that consumers are embracing video in all aspects of their life – both socially and professionally – and it makes sense to support them with greater video quality. Also, the P3 spec has more reds and warmer colors than Adobe RGB.
https://larryjordan.com/articles/configure-the-new-macbook-pro-to-p3-color-space/

To view or change the color space setting for your monitor, open System Preferences > Display and click the Color tab. The top option – Color LCD – isn’t labeled “P3,” but it is. When you compare the Color LCD setting with the Display P3 setting, you’ll see they are essentially identical.

There’s a great way to explore the differences between Adobe RGB, HD (Rec. 709), P3, and HDR (Rec. 2020) color spaces. It’s called ColorSync and its already installed in the Utility folder on your system.
Open the Utility folder inside Applications (shortcut: Shift + Cmd + U), then open the ColorSync Utility. This program allows you to view and modify color profiles.
Click the Display P3 profile and, on the right, is a visual representation of the colors that can be displayed in the P3 color space; illustrated above.
One of the hidden features of ColorSync is the ability to compare color spaces, so you can easily see the differences between them.

Mac OS

Sierra & EDR, In  french, En français

macOS Sierra supporte  une technologie de type pseudo-HDR, qu’Apple nomme EDR.
L’idée du "pseudo-HDR" est d’augmenter fortement le contraste pour obtenir des images plus naturelles. La méthode typique, proposée par Apple, consiste à abaisser la valeur du noir et d’augmenter fortement la luminosité de l’écran pour créer un éblouissement. Actuellement, le "HDR" est essentiellement utilisé dans les films, Netflix (dans certains cas, comme la série Marco Polo) ou certains Blu-ray Ultra HD proposent des effets de ce type. Le HDR améliore l’immersion avec un soleil vraiment éblouissant, des lumières plus réalistes, etc.

Le support dans macOS Sierra semble limité pour le moment : ça ne fonctionne qu’en OpenGL ou avec Metal (l’API graphique maison) et uniquement sur les iMac 27 pouces Retina (5K). On peut supposer que la vidéo devrait tirer parti de cette possibilité avec la version finale, en même temps que les couleurs encodées sur 10 bits, les dalles wide gammut (même si c’est déjà le cas) et (j’espère) le codec HEVC (alias H.265).

http://www.journaldulapin.com/2016/07/07/macos-sierra-supporte-le-hdr/
http://www.journaldulapin.com/2017/04/25/wide-gammut-os-x/

Pour faire simple, le monde de l’informatique travaille généralement avec des couleurs codées sur 8 bits, soit 256 valeurs possibles pour chaque canal (rouge, vert, bleu et la transparence, soit 32 bits). Dans les moniteurs, les premiers LCD travaillaient sur 6 bits, les modèles modernes évidemment sur 8 bits, mais depuis quelques années des modèles 10 bits (1 024 valeurs) arrivent sur le marché. Avec OS X El Capitan (et évidemment macOS Sierra), le support a été ajouté et il est donc possible de brancher un écran “10 bits” sur un Mac (écran HDR vrai).

carte vidéo

Sur un MacBookPro2016 la carte vidéo est une Intel Iris Graphics 540.
https://www.notebookcheck.net/Intel-Iris-Graphics-540.149939.0.html
The revised video engine now decodes H.265/HEVC completely in hardware and thereby much more efficiently than before. Displays can be connected via DP 1.2 / eDP 1.3 (max. 3840 x 2160 @ 60 Hz), whereas HDMI is limited to the older version 1.4a (max. 3840 x 2160 @ 30 Hz). However, HDMI 2.0 can be added using a DisplayPort (DP) converter. Up to 3 displays can be controlled simultaneously.
https://www.intel.com/content/www/us/en/support/graphics-drivers/000022440.html

Safari accepte les images 10 bits

L’intérêt de l’affichage sur 10 bits est de notamment améliorer les dégradés entre les couleurs, étant donné qu’il existe plus d’intermédiaires possibles. Les écrans 10 bits utilisent aussi souvent un espace de couleurs plus large, ce qui permet d’afficher des couleurs qui n’existent pas dans l’espace de couleur classique. En clair, une image comme celle présentée sur ce post de blog chez Webkit (https://webkit.org/blog/6682/improving-color-on-the-web/) apparaît complètement rouge sur un écran 8 bits classique, mais montre un logo sur un écran 10 bits avec un espace de couleur étendu. Le rouge du logo utilise des valeurs qu’un écran classique interprète comme la valeur maximale du rouge, alors qu’il s’agit d’une teinte distincte pour un modèle moderne. Certains écrans peuvent d’ailleurs combiner des couleurs 8 bits classiques avec un espace large (wide gammut) et afficher le logo, c’est le cas des MacBook Pro 2016.

Une image prévue pour un affichage sur un écran wide gammut,
sinon que du rouge pour les autres


Le support des écrans 10 bits a de l’intérêt dans le monde de la photo, car beaucoup d’appareils peuvent photographier en RAW en 10, 12 ou même 14 bits.

Les wides gamuts sont plutôt à partir de l’espace AdobeRVB (https://en.wikipedia.org/wiki/Wide-gamut_RGB_color_space) et dernièrement P3 chez Apple.
Cependant, chose rare pour un sRVB, il supporte les couleurs 10 bits par le displayPort.
Le logo au centre est hors de l’espace sRGB. Y a pas besoin de 10 bits pour le voir, juste un écran wide gamut (P3 par exemple, comme certains Mac) ou un profil de couleur bizarre. Sur mon écran *pas* wide gamut, certains profils ICC affichent bien le logo.
Il s'affiche dans chrome safari mais pas Firefox des versions de Juin 2017 sur mac sierra et macBook Pro 2016.
Le profil de couleur est dans l’image jpeg, mais tous les navigateurs le chargent pas...




Monday, July 17, 2017

HDR high dynamic range, problem avantages and photo, raw, DRO, video, game, science, computer, screen, camera, web platform, understanding SONY auto-HDR


Intro

https://en.wikipedia.org/wiki/High-dynamic-range_imaging

I will focus on the example of the Sony alpha 77 and 65 (the first with built-in auto-HDR).

Tone mapping

The method of rendering an HDR image to a standard monitor or printing device is called tone mapping. This method reduces the overall contrast of an HDR image to facilitate display on devices or printouts with lower dynamic range (LDR), and can be applied to produce images with preserved local contrast (or exaggerated for artistic effect).
https://en.wikipedia.org/wiki/Tone_mapping

The main problem is the dynamic ranges of common devices:
Dynamic ranges of common devices
DeviceStopsContrast
LCD9.5700:1 (250:1 – 1750:1)
Negative film (Kodak VISION3)138000:1
Human eye (static)10–141000:1 – 15000:1
High-end DSLR camera 14.828500:1
Human eye (dynamic)20
1000000:1
https://en.wikipedia.org/wiki/High-dynamic-range_imaging

In our case (camera), the CMOS sensor and its electronic is limited. For example:
The dynamic range is typically limited by the readout process of the CMOS imager pixel. Techniques have been developed in the past to cope with this, usually by non-linear compression of the signal.
ams Sensors Belgium developed a new CMOS image sensor pixels that allows readout of a photodiode with a wide dynamic range, which maintains a linear response to light. After exposure, the photodiode is read out via two transfer gates to two sense nodes. Two signals are then read from each pixel. The first signal only reads charge transferred to the first sense node, with maximal gain. This sample is used for small charge packets and is read with with low read noise. The second sample reads the total charge transferred to both sense nodes, with a lower gain. Pixels with a read noise of 3.3 electrons and a full well charge of 100,000 electrons have been demonstrated, resulting in a linear dynamic range of 90 dB.
http://www.cmosis.com/technology/technology_overview/high_dynamic_range_pixels

DRO, auto-HDR, Raw

In fact you have 5 possibilities:

  • DRO (how DRO works: https://www.dpreview.com/articles/3798759501/apical)
  • auto-HDR
  • shooting a bracket 3-5 exposures (well within the camera's reach) and RAW then doing the HDR work on the computer (function "Merge to HDR"),
  • research domain with you own software (macro photo, fluorescent photo, photo with very high contrast, 3D photo)
  • one Raw and manual or semi-automatic processing with specialized software (raw converters):


see Merged HDR with many Preset
https://www.hdrsoft.com/

HDR auto from Sony

in french: Le mode HDR automatique des Sony Alpha 450, 500 et 550 (2010)
http://www.alpha-numerique.fr/index.php/technique/elements-techniques/426-le-mode-hdr-automatique-des-sony-alpha-450-500-et-550

Auto HDR of alpha 65 and 77 (2012)
http://blog.william-porter.net/2012/01/sony-a77-expanding-dynamic-range-with.html
This excellent post shows the difference of DRO, HDR, and raw.
The best is to select HDR with you own contrast decision.

In-camera HDR ("high dynamic range") is a different way to solve the problem. Like on-the-computer HDR, in-camera HDR starts with several different exposures of the same scene, then combines them into a single output file in which the well-exposed bright areas from one shot have been combined with the best-exposed dark areas from another, and the composite file has been adjusted to make things look natural. Sony's programmers have written programs that seem to do a very good job — sometimes — of combining the exposures. But a key factor in getting good results, is providing the processor with good source images. The new fixed-mirror (SLT) cameras from Sony are especially well suited to gathering the multiple exposures because, lacking a moving mirror, these cameras can take more shots per second than their traditional reflex (moving) mirror competitors.

Raw file, unprocessed. and clipping region  (no contrast)
The red is where the scene is brighter than the camera could capture (with these settings) 
and the blue is where the scene is too dark for the camera (with these settings) to retain detail.
It's when you turn on Lightroom's "show clipping" feature.


 Raw file, unprocessed.

 Sony auto-HDR
The HDR AUTO has preserved detail outside well 
but surrendered detail in the shadows.
It's the choice of Sony's programmers.
 Sony auto-HDR 
with knowing that the dynamic range of this scene 
was fairly extreme, I set HDR to its max (6 EV). 

The raw data file has a lot more latitude than a jpeg. To compare what I can get from the raw file with what Sony's in-camera DRO and HDR offer, I reshot the scene, saved the raw file, and processed it myself in Lightroom or other software.
I used an adjustment brush to bring the bright areas (the windows) down 1.5 stops, and a separate brush to bring the shadow areas up 1.5 stops. Even so, the result was pretty good. See the original RAW file at the beginning.

Morever, because in-camera HDR takes multiple exposures and then processes them, achieving a single HDR result in the camera takes about five or six seconds. And you simply can't use it if anything in the scene is moving quickly. Finally, the A65 or A77's processor saves the HDR file as a jpeg, by necessity. The HDR file is a composite, a processed result. There is no raw original of the HDR result.

And if you really want to hedge your bets, shoot RAW + JPEG with DRO AUTO enabled. You may find that the raw file is badly exposed but the jpeg is usable and you won't have to fuss with the raw file on the computer.
 sony auto-DRO
sony DRO LV5;
Sensing that there was at least a five to six stop gap between the darks
and the lights here, I then changed the DRO setting from Auto to "Lv5".

 The feature is called "Auto HDR" and it has seven possible options: levels 1-6 plus an option called, confusingly, "auto." Sounds tautological to say "put the Auto HDR feature on auto," but it's not.

But a word or two further about raw might be pertinent here.

There is never a question about shooting raw or not. We all shoot raw always, willy nilly. Raw is how the camera works. The question is simply, where does the raw data get processed? Your choices are

  • (a) let the little processor with the no-choice software in your camera do it and hope you're happy with the results, because you lose the chance to do it over; or 
  • (b) keep the raw data, then process and reprocess as many times you like on a full-blown computer, using as many different raw converters as you like or as many different programs as you can afford. If you put it this way, it's not hard to see that, if you really need to get it right, you're better off shooting raw and shooting a bracket 3-5 exposures (well within the camera's reach) then doing the HDR work on the computer.


That said, while in-camera HDR might not produce the best results possible, I will readily admit that is that its results are pretty darned good. I'm still not quite sold, but I do acknowledge that Sony's done a tremendous job here and with MFNR multi frame noise reduction.
HDR image has less noise in the shadows.
One of the downsides to shooting and processing HDR in-camera is that you have no control over the tone-curve applied. 

See also

https://www.dpreview.com/reviews/sonyslta77/12
https://www.dpreview.com/reviews/sonynexc3/7
The Complete Guide to Sony's Alpha 65 and 77 SLT Cameras B&W Edition Volume II:
https://books.google.fr/books?id=R_mWAwAAQBAJ&pg=PA456&lpg=PA456&dq=HDR+automatic+Sony+Alpha+65&source=bl&ots=-ajGH13gZg&sig=UkvJtQ1KE5laUZ7vKgPGtd0KTcc&hl=en&sa=X&ved=0ahUKEwiap-Gw4o3VAhWBB8AKHVuzAmIQ6AEIYjAJ#v=onepage&q=HDR%20automatic%20Sony%20Alpha%2065&f=false

Process

The 'HDR' mode can be set to Auto, or can be manually set from 1 stop to 6 stops EV. This is the mode that takes 3 frames quickly, and merges them together in camera to deliver a single HDR merged photo.

This is different than bracketing, and manually taking your own set of photos to merge in software after the fact, which is what most other folks on the web are talking about. For this, you need to see what the maximum bracketing range is for the camera in the exposure bracketing mode...with most Sony cameras, it is indeed only + -0.7 EV. The A77 being an exception. Also of note: you don't HAVE to use bracketing mode to take manual HDR exposures to blend - if you set up the camera on a tripod and take a series of photos where you manually adjust the exposure by a stop or two at a time, you can take any EV range you want and any number of photos you want - bracketing is what people use when they are trying to eliminate motion blur between a series of shots from handheld action, as it takes 3 photos relatively quickly. Sony's HDR mode does the same, but also does the blending of the HDR in the camera so the output is a single, final HDR photo.

Page 129 of the A65 Handbook states, You cannot use the Auto HDR function on RAW images. And, when the exposure mode is set to

  • AUTO, 
  • AUTO+, 
  • Sweep Panaroma, 
  • 3D Sweep Panaroma, 
  • Continuous Advance Priority AE 
  • Scent Selection, 
  • when Multi Frame Noise Reduct. is selected...

you cannot select Auto HDR.

I think that the delay between the 3 photos is around 150ms (frequency 1.6 Hz; or "speed process"=1/6.6), "speed of all the shooting process"=1/3.3then be careful when you have a moving part in your photo. The sound between the 3 photos indicates this tempo...
After the computer processing is around 5s and your camera is blocked.

JPEG, RAW and high iso.

http://www.photographyblog.com/reviews/sony_a65_review/image_quality/

List of all cameras and Auto Exposure Bracketing option

Auto Exposure Bracketing Settings by Camera Model
list of all cameras
https://www.hdrsoft.com/resources/aeb.html
Camera Model Auto-bracketed frames Max EV step increment Max EV range in AEB Max burst rate
Sony Alpha A65 3 0.7 1.4 10 fps
Sony Alpha A77 3 or 5 3 (3 frames), 0.7 (5 frames) 6 12 fps

Many digital cameras include an Auto Exposure Bracketing (AEB) option. When AEB is selected, the camera automatically takes three or more shots, each at a different exposure.
Auto Exposure Bracketing is very useful for capturing high contrast scenes for HDR. However, AEB wasn't intended for HDR initially, but for ensuring that one of the shots taken is correctly exposed. This means that some camera models only offer a maximum of 1 EV spacing, or even less, in just three auto bracketed shots.
Unfortunately, three shots spaced by one EV are often not sufficient for capturing high contrast scenes.