Para los que llevan en mente la Sony A7

Esto me recuerda la siguiente definición de Robert Cicala (LensRental) :

Sharpness – The amount of fine detail visible in an image before it is compressed to 1/10th its original size to post online.

La lista completa de definiciones es la siguiente :

The Cynic’s Photography Dictionary

Aberration – Something that is wrong with the lens by design, as opposed to something wrong with the lens by accident of assembly or use.

Action photography – The use of very large, expensive lenses to make rapidly moving objects appear immobile.

Aperture – The opening of a lens, identified by a number that gets larger as it gets smaller.

Bokeh – the look of the picture in the parts where you can’t tell what you’re looking at.

Build Quality – How heavy the metal barrel, on the outside of all the important parts of the lens, is. For example, any lens weighing more than 2 pounds has great build quality.

Corner – The edges of an image, generally known for lower image quality. They begin at the 4 points furthest from the center of the image and, depending upon the equipment and photographer, comprises between 20% and 100% of the image.

Decentered – An image showing very poor quality. This is usually assumed to be caused by the equipment mounted to the front of the camera, but is often actually caused by what is behind the camera. See also, Sample Variation

Depth of Field – The part of an image that is in best focus, traditionally placed just in front of, or just behind, the subject See also, Autofocus.

Genre – Broad categories of photography such as landscape, action, glamour, wildlife, and portrait, all of which taken together are less common than the most popular genre, the ‘selfie’.

Glamour – A type of photography practiced by many and mastered by few, with the purpose of creating images of creatures not found in nature.

Image Stabilization – a technologic triumph consisting of lenses, magnets, position sensors, springs, and electric motors that is nearly as effective as 3 sticks of wood attached to a base plate. See also, Tripod.

In Spec – Slang term meaning both ‘we can’t make it any better before we go on break’ and ‘you probably can’t tell the difference anyway’.

Lens coating — thin layers of of substances applied to clear glass that makes it clearer. In the 1600s people were burned at the stake for claiming things like this.

Minimum Focal Distance – How close an object may be to the front of the lens, yet still be in focus. Historically of importance for macro photography, but today used to make certain arm’s-length ‘Selfies’ are in focus.

Phase Detection Autofocus – a method to approximately put the plane of focus somewhere near an object approximately selected by a point in the viewfinder that approximates the location of a dedicated sensor in the camera which is approximately calibrated to the camera’s image sensor. See also, Depth of Field.

Render – from the German ‘Render’. Something an expensive lens is said to do, especially when it doesn’t do anything else exceptionally well.

Sensor – The device that actually takes an image. Its most important attribute is the number of megapixels unless yours has fewer, in which case dynamic range, high ISO performance, microlens effectiveness, color accuracy, and other characteristics are more notable.

Sharpness – The amount of fine detail visible in an image before it is compressed to 1/10th its original size to post online.

Silence – The response of many wives and at least one camera company when an obvious problem arises.

Sample Variation – The difference between this lens and that lens, even though both of them are the same lens.

Stop Down – To move the f-number up.

Technique – The methods that let someone else make pictures I couldn’t afford to buy, using equipment that I would throw away, and vice versa.

Tripod — A stabilizing device with three legs that everyone agrees would improve the sharpness of images taken by others. See also, Image Stabilization.

Vignette — A technique used by lens designers to make the image very dark in the places where the lens is very bad, based on the principle that if things are dark enough you won’t notice how bad they are.

Weather resistant – A term that consumers falsely define as ‘weather proof’ and camera companies accurately define as ‘the warranty doesn’t cover water damage’.

Wedding Photography, n. – A complex form of photography that consists of first of making hysterical people appear calm and joyous, and later making sloppy-drunk people appear pleasantly tipsy. The purpose is to create a beautiful album of images that statistically has a 54% chance of being ripped into little pieces within 5 years.

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Acabo de decidir que abro un post aparte con la lista

Geniales estas definiciones. Creo que muchos deberíamos aprendernoslas de memoria.

Leo esto de Alías:

yo he probado el Leica M super-elmar 21mm 3.4 asph, con una A7 y una A7r. En la A7 no hay problema de magenta en las esquinas, pero en la A7r si que las hay. Con la A7 en las esquinas falta nitidez y la A7r no, pero la mejor de todas para este objetivo que también he probado es la M240, la foto es practicamente perfecta.

No he mirado ninguna prueba afondo, pero.. entiendo que la A7 no da tanto magenta pero menos nitidez y que la A7r da mas nitidez pero magenta el las esquinas.

para mi esto tiene corección en la A7r y no tiene posible corrección en la A7 pues el detalle no se puede sacar si se ha perdido.
no obstante la A7r tendrá siempre mas nitidez porque tiene mas resolución.
La M240 tiene unas tablas de corrección para sus objetivos, por eso dará siempre mejor.
Aparte, no conozco mucho ese objetivo, pero suena a moderno, con lo que irá mejor que los antiguos.
Sigo sin saber cual es mi cámara, la A7 o la A7r.
me voy a esperar hasta que lo tenga muy muy claro.

MisterX, he probado las 2 y la diferencia de nitidez no me preocupa pero si el magenta, no me compro una cámara para tener el 21mm en el cajón, prefiero sacrificar la nitidez, pero ya te digo en 21mm si no lo amplias a nivel de pixel, poca diferencia, con el magenta es horrible, cada uno tiene su prioridad. Si vas a utilizar el 35,50,75,90 o 135mm la A7r pero del 28mm para abajo no te la recomiendo, a mi a veces tanta nitidez me molesta, no quiero abrir ningún debate pero la A7 es una gran cámara, si yo hubiera visto tanta diferencia me habría comprado la A7r.
Saludos.

alías escribió: Si vas a utilizar el 35,50,75,90 o 135mm la A7r pero del 28mm para abajo no te la recomiendo

Lo que hay que hacer es comprarse una u otra en función de los objetivos que se tengan y sean irrenunciables. Pero si no se tienen yo aconsejaría comprarse la A7R y despues seleccionar cuidadosamente que objetivos angulares se compran.

Por ejemplo, en la A7R los Elmarit 28 preasph van perfectos, el Trielmar 16-18-21 también, y los summilux 21 y Voigtlander 21 1.8 también.

Lo del trielmar y el summilux es una putada porque son carísimos pero los elmarit 28 preasph III y IV y el Voigtlander 21 son opciones angulares relativamente económicas y de una calidad óptica brutal, capaces de sacarle todo el partido a esos 36 mpx sin filtro AA.

Toshiro, no voy a cambiar ni la cámara ni el objetivo, seguro que dentro de un año Sony sacará una cámara mejor que la A7 y A7r, y con el problema resuelto para el Leica M super-elmar 21mm 3.4, si me convence me la cambiaré. Repito he probado las 2 cámaras con el 21mm y yo no veo esas diferencias. También tengo que decir que el obturador de la la A7r es más ruidoso que el de la A7, si tengo que comprar un objetivo será el AF Zeiss 35mm 2.8 hechas para estas 2 cámaras, me han dicho que el AF también es mejor el de la A7, y es posible que algunos tengan prioridad sobre el AF y no la nitidez.
Saludos.