Concursos

22 February, 2018 - General - Comment -



Concursos de Fotografía


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Collision of water droplets

18 December, 2016 - Colision de gotas de agua - 2 Comments -

      First, say, that this tutorial is the result of a long tour of instruments (drippers, timed relays, Arduino boards), techniques, devices, methods, tests, queries and a long etc. Which have resulted in what I am going to show here.

 

      A simple hospital dropper that dropped drops of water on a regular basis at indeterminable intervals of time, was as I began. With this method, I obviously could not adjust the drip time or the size of the drop of water. Little by little, investigating and asking people who were far ahead of this was the way to capture with the camera the collisions of water droplets.

 

Indeed, doing this type of photography requires a lot of patience but also a varied endowment of means to be able to capture that magical moment that the eye is unable to retain.

 

If you can afford it, I would advise you to have a space dedicated just to make these photographs, since mounting and dismantling takes time so it is convenient to mount it and to have it there just for this.

 

What I intend with this tutorial is to give you the starting point to take photos of drops collisions and from here, either by modifying values of height, times, water densities, etc. experience and get incredible photos.

 


Equipment 


 

CAMERA

Most are made with a Canon 40D.

 

Of a time to this part I do with a Canon 5D Mark III.


Usually the exposure times are very long, which causes a significant noise in the photos but the 5D has a very good treatment of noise, which improves the quality of the photo incredibly.

 

 


LENS


You can choose the lens you want (as long as it is not an angle), I use the Canon EF 100mm f / 2.8 USM Macro.

 

We all know that the sharpness provided by a macro over short distances is not obtained with another type of lens. The problem with which we find is that the depth of field is very small and that is why I always make these photos with a fairly closed diaphragm between f / 14 to f / 22.

 


FLASH


Since the diaphragm is very closed for the reason I explained earlier, it would be logical to think that the flash illumination should be at maximum power to compensate for such a small light input. Nothing is further from reality. If the flash we put to the maximum power, the time of light is too long to freeze the image and this one would leave us moved. Therefore I use two or three flashes at a power of 1/32, 1/64 and even 1/128. What we get with this is to have enough light so that the photo does not come out dark and with a very small light time with which the photo will freeze.

 

 

     It should be noted that this type of photography is made, as I say, only with the light of the flashes while the camera mirror is raised. And this is why the shutter speed is NOT a determining factor, but it is the time that the flashes are illuminated. That yes, the room must be dark or dim to avoid undesirable lights.

 

 

     We have to think very well what flashes to buy because the price would have to be multiplied by two or three according to the number of flashes we are going to use.

 

 

     There are those who have the Yongnuo Speedlite YN560-II and say they do very well.

     I bought a Vivitar 285 to which I made a modification to be able to vary the intensity to my liking.

 

In this link I leave the instructions to make these modifications:

 

https://www.dropbox.com/s/oncxeiok5okoicp/Vivitar%20285%20Tutorial.pdf?dl=0

(It was sent to me by Markus Reugels and does not have it translated.)

 


CONTROL AND DRIP ELEMENTS


The StopShot controller is the device I use to control all dripping elements, flashes and even the camera trigger.

      Of the configuration of the times will depend the success of the collision of drops.

      This controller has an input for the infrared sensor (which I show below) and three RCA outputs where I connect the solenoid valve, the flashes and also the camera.

      It also has a microphone input. Sometimes the time counting, we need to be done by sound instead of by cutting a beam of infrared rays, but this would be for other types of photographs.

 

StopShot Controller

 

The drops are produced by the opening of a precision solenoid valve which is about 55 cm high. This height is variable, you will have to do multiple tests until you find the height in which you produce the effects that you want.

      The opening time of the solenoid valve, of course, is configurable. The more milliseconds of opening, the bigger the drop of water.

      The solenoid valve is this:

 

solenoid valve

And it is the one that you have to screw in the siphon of Mariotte:

 

siphon of Mariotte

 

The function of the siphon of Mariotte is to always maintain the same pressure in the water tank even if this is gradually emptying.

 

 

      The next element is an infrared sensor:

 

 

sensor

When the solenoid valve releases a drop of water, we pass it through the sensor arc which sends the information of the exact position of the drop of water as it falls to the controller to begin the cycle we have programmed.

 

Support

Of course, these last three elements, can be placed in a tripod with a support thought for it.

 


THE WATER


 

      If we did these photos with only water, the moment of the collision would be an endless number of microdrops that would not give us the result we expect. Therefore I add between two and three capsules of guar gum per liter of water. (This is variable and to your liking):

 

 

The guar gum gives the water a sufficient viscosity so that it does not "break" the drop of water when colliding with the column that creates the first one when falling.

      To mix the guar gum with water, I advise you to dissolve the capsules separately in a little alcohol and then throw it into the water. This will avoid problems with lumps.

      Once mixed, you will have to strain it with a cloth or a fabric strainer to remove the turbidity.

      The color is given with food coloring:

 

When I want to make two color collisions, what I do is put a dye in the water of the siphon of mariotte and another color in the water of the container below. With this we obtain that the column up that creates the first drop is of one color and the second drop, that is the one that collides against the column, of another one.

 

 

 

 


OTHER USEFUL ITEMS


 

      Focus is an important point and you have to be constantly watching. Of course, the objective you have to put the manual. I use one of these two elements as an aid to the focusing:

 

 

The one on the left is the tip of a silicone cartridge to which I screwed a screw and the one on the right is a very thin tube attached to a solid and heavy base.

      Once you have everything installed (Controller, valve with siphon, water, container where the drops fall) you will have to drop a drop of water so that it hits just the tip of the screw or the thin tube, and once you have Achieved, you'll have to make a focus adjustment as accurate as possible right there.

      From here, obviously you can no longer move the tripod. Keep in mind that it is easy to stumble with a paw and goodbye to focus. I tell you from personal experience. However, it is necessary to be constantly monitoring the approach. It's fundamental.

 

 

      Other elements that will be very useful to you are the pressure clamps and / or the sergeants. Always hold paperboards, plexiglass plates, cables, etc.

 

 

 


 

PROCEDURE

 


 

Diagram of a typical setup

(1) Remote flash trigger (emitter)

(2) Container full of water

(3) White opaque plexiglass sheet

(4) Flashes

(5) Remote Shutter Receiver

(6) Water tank with siphon from Mariotte

(7) Solenoid valve nozzle

(8) Precision Solenoid Valve

 

As I told you at the beginning, this tutorial is a starting point and of course, the diagram I show you can vary it to your liking.

      The setup of this diagram would result in this type of photo:

 

While the camera in Bulb mode is triggered for approximately 0.5 seconds, at the time the collision occurs, the flashes that pass through the opaque white plexiglass plate that works as a light window are triggered.

 

 

     You can go playing with the position of the flashes and the position of the camera to obtain different results. Even in many cases it is advisable to illuminate the collision sideways so we will have to distribute the flashes around the container where the collisions occur.

 

 

     You will observe in the diagram that to avoid too much wiring I use a remote flash trigger (1) with receivers in each of the flashes (5).

 

 

     The StopShot comes with a manual where it explains perfectly its operation and the way of putting the different Triggers (exits for solenoid valve, flash, camera), like saving a configuration, etc. So I will not dwell on it.

     If you want to have a look, the link to the manual is this:

     https://www.cognisys-inc.com/downloads/StopShot%20Manual%201.8%20English.pdf

 


      YOUR FIRST COLLISION


 

- Starting from the base we have the siphon filled with water with guar paste, the flashes connected, the StopShot on, the manual trigger connected to the camera, the focus well done, etc.

 

 

     - Firstly, I place the solenoid valve perfectly vertical, this is important because otherwise the columns will not be vertical (they will lean towards one side) with which the collision will not occur.

 

 

     - The distance between the lower tip of the nozzle (7) and the surface of the water in the container (2) is 54 cm.

 

 

     - The distance between the lower tip of the nozzle (7) and the infrared sensor is 13 cm. (The diagram does not show the sensor)

 

     - On Trigger 1 of the StopShot, connect the solenoid valve.

 

 

     - On the Trigger 2 of the StopShot I connect the remote flash trigger. In the diagram, the trigger is placed on the camera. We would have to make an RCA-flash shoe cable to place the trigger here.

 

 

     - Program the StopShot as follows:

          T1 --------------> Manual (For the driver to wait for the Up / Down button to be pressed)

          #PULSE --------> 2 (Number of solenoid valve openings 2 drops)

          PULSE 1 --------> 50.0 ms (First opening of solenoid valve, first drop)

          TOFF 1 ---------> 76 ms (76 millisecond wait)

          PULSE 2 --------> 25.0 ms (Second opening of solenoid valve, second drop)

          TOFF 2 ---------> 16.0 ms (Default)

          T2 --------------> 275 ms (Standby time of 275 milliseconds and flash fires)

 

 

     - The camera would shoot me with a manual trigger. The trigger sequence would be:

          1) With the camera in Bulb shoot with the manual trigger.

          2) Press the Up / Down button to execute what we have programmed.

          3) Release the manual release

 

 

     - Admire your creation

 

 

All these values are orientative and you will have to change them quite frequently. Keep in mind that working with time values so small, any environmental condition can cause you to have to modify some values that in principle were working well but suddenly stop. It's a lot of patience and trial / error work.

 

 

 

 

      I have a tutorial for adjusting the sharpness in Photoshop in which there is a video of Markus Reugels that does this same thing I just told you but with three solenoid valves and another controller, look at it, it is interesting to illustrate more this tutorial. The link is this:

http://www.enriqueizquierdo.com/lang/es/blog/ajuste-de-la-nitidez-con-el-filtro-paso-alto

 

 

 


  *** (If you have arrived here, leave me a comment giving me your opinion, whether you liked it or not.


 

Enrique Izquierdo

 

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Colisión de gotas de agua

05 April, 2016 - Colision de gotas de agua - 25 Comments -

     En primer lugar, decir, que este tutorial es el resultado de un largo recorrido por instrumentos (goteros, relés temporizados, placas Arduino), técnicas, aparatos, métodos, pruebas, consultas y un largo etc. que han dado como resultado lo que aquí os voy a mostrar.

 

     Un simple gotero que soltaba gotas de agua de forma regular a intervalos de tiempo indeterminables, fué como empecé. Con este método, obviamente no podía ajustar el tiempo de goteo ni el tamaño de la gota de agua. Poco a poco, investigando y preguntando a gente que estaba muy por delante de esto fué la manera de captar con la cámara las colisiones de gotas de agua.

 

     El mayor problema estaba en conseguir soltar gotas de agua en el punto exacto y en el momento exacto, al tiempo que se dispare la cámara y se disparen también los flashes en el momento justo. (más tarde explicaré porqué digo flashes y no flash)

 

     Efectivamente, hacer este tipo de fotografía requiere mucha paciencia pero además también una variada dotación de medios para poder lograr captar ese momento mágico que el ojo es incapaz de retener.

 

     Si te lo puedes permitir, te aconsejaría disponer de un espacio dedicado solo para hacer estas fotografías ya que montar y desmontar todo lleva su tiempo por lo que es conveniente montarlo y poder tenerlo ahí sólo para esto. 


     Lo que pretendo con este tutorial es darte el punto de partida para hacer fotos de colisiones de gotas y que a partir de aquí, ya bien sea modificando valores de altura, tiempos, densidades del agua, etc experimentes y obtengas fotos increíbles.


 



EL EQUIPO

 



CAMARA


     La mayoría están hechas con una Canon 40D.

 

 

     De un tiempo a esta parte las hago con una Canon 5D Mark III.

     Normalmente los tiempos de exposición son muy largos, lo que provoca un ruido importante en las fotos pero la 5D tiene un tratamiento buenísimo del ruido, lo que mejora increíblemente la calidad de la foto.

 



OBJETIVO


     Puedes elegir el objetivo que quieras (siempre que no sea un angular), yo utilizo el Canon EF 100mm f/2.8 USM Macro. 

     Todos sabemos que la nitidez que proporciona un macro en distancias cortas no se obtiene con otro tipo de objetivo. El problema con el que nos encontramos es que la profundidad de campo es muy pequeña y es por lo que yo siempre hago estas fotos con un diafragma bastante cerrado entre f/14 a f/22.


 


 

FLASH


     Puesto que el diafragma lo pongo muy cerrado por la razón que he explicado antes, sería lógico pensar que la iluminación por flash debería ser a la máxima potencia para compensar esa entrada de luz tan pequeña. Nada más lejos de la realidad. Si el flash lo ponemos a la máxima potencia, el tiempo de luz es demasiado largo para congelar la imagen y ésta nos saldría movida. Por tanto yo utilizo dos o tres flashes a una potencia de 1/32, 1/64 y hasta de 1/128. Lo que conseguimos con esto es tener la suficiente luz para que la foto no nos salga oscura y con un tiempo de luz muy pequeño con lo que la foto se congelará.


     Hay que tener en cuenta que este tipo de fotografía está hecha, como yo digo, solamente con la luz de los flashes mientras que el espejo de la cámara está levantado. Y es por lo que la velocidad de obturación NO es un factor determinante pero SI el tiempo que los flashes están iluminados. Eso si, la habitación debe estar oscura o en penumbra para evitar luces indeseables.


     Tenemos que pensar muy bien qué flashes comprar porque el precio habría que multiplicarlo por dos o por tres según la cantidad de flashes que vayamos a utilizar.


     Hay quien tiene los Yongnuo Speedlite YN560-II y dicen que les van muy bien.

     Yo compré unos Vivitar 285 a los que les hice una modificación para poder variar la intensidad a mi gusto.

     En este enlace te dejo las instrucciones para hacer estas modificaciones: 

https://www.dropbox.com/s/oncxeiok5okoicp/Vivitar%20285%20Tutorial.pdf?dl=0

     (Lo siento, me lo envió Markus Reugels y no lo tiene traducido.)



 

 


 




ELEMENTOS DE CONTROL Y GOTEO


     El controlador StopShot es el aparato que utilizo para gobernar todos los elementos de goteo, flashes y hasta el disparo de la cámara. 

     De la configuración de los tiempos va a depender el éxito de las colisiones de gotas.

     Este controlador dispone de una entrada para el sensor de rayos infrarojos (que te lo muestro más abajo) y tres salidas RCA en dónde conecto la electroválvula, los flashes y también la cámara.

     También tiene una entrada de micrófono. En ocasiones, el conteo de tiempo, necesitamos que se haga por sonido en vez de por corte de un haz de rayos infrarojos, pero esto sería para otro tipo de fotografías.

     


controlador StopShot


     Las gotas se producen por la apertura de una electroválvula de precisión que sitúo a unos 55 cm de altura.  Esta altura es variable, tendrás que hacer múltiples pruebas hasta encontrar la altura en la que se producen los efectos que tú deseas.

     El tiempo de apertura de la electrovávula, por supuesto, es configurable. Cuantos más milisegundos de apertura, más grande será la gota de agua.

     La electroválvula es esta:

electroválvula




    Y es la que tienes que enroscar en el sifón de Mariotte:

 

sifón de Mariotte


     La función del sifón de Mariotte es mantener siempre la misma presión en el depósito del agua aunque este se vaya vaciando poco a poco.


     El siguiente elemento es un sensor de rayos infrarojos:


sensor

Cuando la electroválvula suelta una gota de agua, ésta la hacemos pasar por el arco del sensor el cual envía la información de la posición exacta de la gota de agua al caer al controlador para que éste comience el ciclo que le hayamos programado.



soporte

 

Por supuesto, estos últimos tres elementos, pueden ser colocados en un trípode con un soporte pensado para ello.

 


 


EL AGUA

 



     Si hiciésemos estas fotos con sólo agua, el momento de la colisión sería un sinfín de microgotitas que no nos darían el resultado que esperamos. Por tanto yo añado entre dos y tres cápsulas de goma guar por cada litro de agua. (Esto es variable y a tu gusto):


goma guar

     

     La goma guar le da al agua una viscosidad suficiente como para que no se "rompa" la gota de agua al chocar con la columna que crea la primera al caer. 

     Para mezclar la goma guar con el agua, te aconsejo que disuelvas aparte las capsulas en un poco de alcohol y después lo eches al agua. Esto te evitará problemas con los grumos.

     Una vez mezclado, tendrás que colar con un paño o con un colador de tela para quitarle la turbieza.

     El color se lo doy con colorante alimentario:


 

colorante alimentario

Cuando quiero hacer colisiones de dos colores lo que hago es poner un colorante en el agua del sifón de mariotte y otro color en el agua del recipiente de abajo. Con ello conseguimos que la columna hacia arriba que crea la primera gota sea de un color y la segunda gota, que es la que choca contra la columna, de otro.


 


OTROS ELEMENTOS UTILES

     El enfoque es un punto importante y hay que estar vigilándolo constantemente. Por supuesto, el objetivo lo tendrás que poner el manual. Yo utilizo uno de estos dos elementos como ayuda para el enfoque:

ayuda para enfoque

     El de la izquierda es la punta de un cartucho de silicona al que le he enroscado un tornillo y el de la derecha es un tubo muy fino adherido a una base sólida y pesada.

     Una vez ya tengas montado todo (Controlador, válvula con sifón, agua, recipiente donde caen las gotas) tendrás que dejar caer una gota de agua de manera que impacte justo en la punta del tornillo o en el fino tubo, y una vez lo hayas conseguido, tendrás que hacer un ajuste del enfoque lo más preciso posible justo ahí.

     A partir de aquí, obviamente ya no puedes mover el trípode. Ten en cuenta que es fácil tropezar con una pata y adiós al enfoque. Te lo digo por propia experiencia. De todas formas, es necesario estar constantemente vigilando el enfoque. Es fundamental.


     Otros elementos que te serán de mucha utilidad son las pinzas de presión y/o los sargentos. Siempre hay que sujetar cartulinas, placas de plexiglas, cables, etc.


pinzas de presion 

sargento

 

 

 

 

 



PROCEDIMIENTO


 




 

Diagrama de un montaje típico



     (1)  Disparador remoto de flash (emisor)

     (2)  Recipiente lleno de agua

     (3)  Lámina de plexiglass blanco opaco

     (4)  Flashes

     (5)  Receptores del disparador remoto

     (6)  Depósito de agua con sifón de Mariotte

     (7)  Boquilla de la electroválvula

     (8)  Electroválvula de precisión


     Como te dije al principio, este tutorial, es un punto de partida y por supuesto, el diagrama que te muestro lo puedes variar a tu gusto.

     El montaje de este diagrama daría como resultado este tipo de foto:

     


     Mientras la cámara que está en modo Bulb se dispara aproximadamente 0,5 segundos, en el momento en que se produce la colisión, se disparan los flashes que atraviesan la placa de plexiglass blanco opaco que trabaja a modo de ventana de luz.


     Puedes ir jugando con la posición de los flashes y la posición de la cámara para obtener diferentes resultados. Incluso en muchas ocasiones conviene iluminar lateralmente la colisión por lo que tendremos que distribuir los flashes alrededor del recipiente donde se producen las colisiones.


     Observarás en el diagrama que para evitar demasiado cableado yo utilizo un disparador de flash remoto (1) con receptores en cada uno de los flashes (5). 


     El StopShot viene con un manual en dónde explica perfectamente su funcionamiento y el modo de cómo poner los diferentes Triggers (salidas para electroválvula, flash, camara), como salvar una configuración, etc. por lo que no voy a extenderme en ello.

     Si quieres echar un vistazo, el enlace al manual es este: 

     https://www.cognisys-inc.com/downloads/StopShot%20Manual%201.8%20Espanol.pdf


 



     TU PRIMERA COLISION


     - Partimos de la base que tenemos el sifón lleno de agua con goma guar, los flashes conectados, el StopShot encendido, el disparador manual conectado a la cámara, el enfoque bien hecho, etc.


     - En primer lugar, coloco la electroválvula perfectamente vertical, esto es importante pues de lo contrario las columnas no serán verticales (se inclinarán hacia un lado) con lo que la colisión no se producirá.


     - La distancia entra la punta inferior de la boquilla (7) y la superficie del agua en el recipiente (2) es de 54 cm.


     - La distancia entre la punta inferior de la boquilla (7) y el sensor de rayos infrarojos es de 13 cm. (en el diagrama no aparece el sensor)

 

     - En el Trigger 1 del StopShot conecto la electroválvula.


     - En el Trigger 2 del StopShot conecto el disparador remoto de flash. En el diagrama, el disparador, está puesto sobre la cámara. Tendríamos que fabricar un cable RCA-zapata de flash para colocar aqui el disparador.


     - Programar el StopShot asi:

          T1 --------------> Manual   (Para que el controlador espere a que se pulse el botón Up/Down)

          #PULSE --------> 2  (Número de aperturas de la electroválvula. 2 gotas)

          PULSE 1 --------> 50.0 ms  (Primera apertura de la electroválvula. Primera gota)

          TOFF 1 ---------> 76 ms  (Espera de 76 milisegundos)

          PULSE 2 --------> 25.0 ms  (Segunda apertura de la electroválvula. Segunda gota)

          TOFF 2 ---------> 16.0 ms  (Por defecto)

          T2 --------------> 275 ms   (Tiempo de espera de 275 milisegundos y se dispara el flash)


     - La cámara la dispararía yo con un disparador manual. La secuencia de disparo sería:

          1) Con la cámara en Bulb disparar con el disparador manual.  

          2) Pulsar el botón Up/Down para que se ejecute lo que hemos programado.

          3) Soltar el disparador manual


     - Admira tu creación




     Todos estos valores son orientativos y los vas a tener que ir cambiando con bastante frecuencia. Ten en cuenta que el hecho de trabajar con valores de tiempo tan pequeños, cualquier condición ambiental puede hacer que tengas que modificar unos valores que en principio te estaban funcionando bien pero que de repente dejan de hacerlo. Es un trabajo de mucha paciencia y de prueba/error.     



     Tengo un tutorial para el ajuste de la nitidez en Photoshop en el cual hay un video de Markus Reugels que hace esto mismo que te acabo de contar pero con tres electroválvulas y con otro controlador, míralo, es interesante para ilustrar más este tutorial. El enlace es este: 

http://www.enriqueizquierdo.com/lang/es/blog/ajuste-de-la-nitidez-con-el-filtro-paso-alto


 



 ***(Si has llegado hasta aquí, déjame un comentario dándome tu opinión,tanto si te ha gustado como si no. Gracias)***


 



Enrique Izquierdo

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HDR photography

19 March, 2016 - HDR - Comment -

HDR photography

     

We all know that the pupil of the human eye constantly expands and contracts when we are looking around. When we look at an area or an object that has a lot of lighting this shrinks, however, it expands if the lighting is poor or dark.

 

 

     To understand well what is HDR photography is necessary to strongly emphasize that this process makes the human eye, it does so because the eye can only look at one point at a time and not to an environment as does the camera . For this reason the pupil is constantly varying in size.


     Making an analogy with the diaphragm of the camera, we can say that by the photometer that the camera is fitted and measures the amount of light entering the diaphragm will expand / open or contract / will close depending on the amount of light who "sees" at the time of shooting.

 

 

 

     The "problem" with which we are when taking a picture is that, since the photometer makes a single measurement of light (either specific or weighted) shall fix a value for the diaphragm to be the same for all decision points as well are very bright or very dark. Therefore this diaphragm will be suitable for some points decision but too open or too closed to others, so for those points where the diaphragm is correct picture will look good, but those for which the diaphragm should be more closed, the image will we overexposed or too light or "burned" and on the other hand, at those points where the diaphragm should be more open because the lighting conditions are poor, you will leave us this underexposed area, dark demasidao or black directly.

 

 


     What we try to do the HDR technique is precisely "correct this problem," causing both light, medium and dark areas look perfectly fine in terms of lighting in a photograph, which makes it somewhat unreal. But this is just my opinion, what makes it attractive to HDR photography.

 

 

 

     Therefore, to take a picture HDR, I do five to nine pictures obviously letting in more light for dark areas and less light to get clear.

     In a camera, we can do this in two ways:

     - Leaving sets the shutter speed (ie the time it is open the curtain) and varying the diaphragm, more open to more light.

     - Leaving the fixed diaphragm and varying the shutter speed. A longer with open curtain will come more light and vice versa.

     Either of the two options would be worth, but in HDR, we use the second, ie, varying the shutter speed for some reason I mention below:

 

 

Diaphragm more open = less depth of field
Diaphragm more closed = more depth of field

 

     Since the work we will do with several equal, equal but different illuminations photos, apart from using a tripod for pictures leave us exact as the frame is concerned, we need everything in one take us out crisp, also focused us out crisp and focused on all others. And this we can only achieved by maintaining the same aperture diaphragm at all because if we change, we vary the depth of field or frame in which the captured image is sharp.

     Therefore we have no choice but to vary the shutter speed. Actually, as we have the camera on a tripod, shutter speed will not matter too much, but we use the diaphragm.

     Keep in mind that if you are going to photograph a landscape we have to put a very closed so that the depth very large diaphragm and thereby obtain clear to the horizon. Additionally, if we put a closed diaphragm, we may have to put very high exposure times (1 sec., 1/2 sec. Etc) for the purpose of camera movement does not affect us as I said but possibly if you affect us about the picture will get more "noise" the longer you put it.

 

 

                                                                    Sample photo with Long exposure noise

 

 

To take pictures HDR story with the following material to the pictures then at home will process:

 

                                                             Tripod, manual trigger and of course a camera.

 

 

And to make the story with Photomatix HDR process and Photoshop. (Versions to individual taste.)

 

                                                                                         Photomatix

 

 

                                                                                          Photoshop

 

 

For this tutorial I chose this photo:

 

 

 

                                                             --------------------o--------------------

 

 

Shooting:

I made six shots with the camera on the tripod and manual shutter cable.
Data of six shots, except the speed, (they are placed under each photo), were:

Camera: Canon EOS 40D
Objective: Sigma 10-20mm
Focal Length: 14 mm
Aperture: f / 16
Priority: Opening
ISO 100

 

1/200 sec

 

 

 

1/100 sec

 

 

 

1/50 sec

 

 

1/25 sec.

 

 

 

1/13 sec

 

 

 

1/6 sec

 

 

     The day was quite cloudy as you can see. The first photo is too dark because, although a speed of 1/200 is a very normal speed, I used a fixed aperture of f / 16 for much depth of field as possibly so that the photo had gone well luminosity it would have been necessary to put an f / 5.6

     When we do a series of photographs how are you known by the name of "bracketing" or "bracketing".

     Most of SLR digital SLR cameras have a system by which we can put the minimum and maximum exposure and, depending on the make and model, we make consecutive shots and the camera alone we will doing different shots you see here up. In this case it is called "Auto bracketing" or "Bracketing".

     For convenience, the camera can be put in burst mode, although the Puritans say you should not do so because every time a shot is fired must wait a few seconds for the camera stops moving because the movement produced by the mirror when the curtain rises and may impact on the next shot due to a microbalanceo produced. (This I leave to individual taste)

     For this work I put a three-shot bracketing (which is the maximum allowed my camera) separated by a difference of 1 point exposure between shots, and the camera in burst mode.

     Having made the first three and carefully turned the wheel speeds to bear the photometer 1 point above the last picture taken and made the remaining three.

     This same process we could have done with two, three, four, twenty ... .. they want, from a totally black photography to a completely white but then do not we use, in fact, I personally do not usually use all what I do.

     Once we have the pictures, and we can only make the process of obtaining HDR photo following steps:

     1. We open our Photomatix and select the photos that we will try, File> Open, we mark the files, and click Open:

 

 

     First I open all the pictures of the series and do all the procedure that follows. However, I often repeat but selecting only some photos instead of all. For example with the 1st, 3rd and 5th or the 2nd, 4th and 6th or what I please and make processing them. You have to know that in this post-processing plays a lot with trial and error to get what we want, so it is necessary to take it with patience and time left to do more the better tests.

 

     2. Then do: HDR> Generate> We mark Use opened images> OK
     On occasion, it is possible that pressing OK similar to this screen qppears:

  

 

     The explanation is that assuming that 0 is the correct exposure, Photomatix expected to exhibit interval is the same for all photos, both underexposed (negative values) to the overexposed (positive values).

     In the event that does not happen we will leave this window showing us what Photomatix believes, where he let us change the values ​​if we consider that Photomatix has not played well or leaving it as if it really shows us is right.

     In any case we will press OK.

 

3. It appears this window:

 

 

     I usually leave it alone and press OK. Align source images labeled leaving Photomatix we correct any small misalignment that exists between all selected photos. If we made shots in which there are objects or people moving logically between takes these have moved, in which case tildaremos also reduces ghosting artifacts Attempt to.

 

     4. After clicking OK in the previous window, we see a new window with our photo HDR:

 

 

     5. If you move the cursor over our picture, we can see in the small window Viewer HDR photography as will in all areas after doing next step in Tone Mapping. If we think it is too light or too dark can raise or lower the exposicióncon HDR> Adjust View> Exposure Up to increase exposure F12 or F11 Exposure Down to decrease it. Generally you do not have to do anything and we will continue with the next step.

 

     6. Now we will access the last step is the Tone Mapping. We click HDR> Tone Mapping and leave us the following window:

 

 

     ... And here dear friends, I leave you to your fate. All you see will slip to give you more or less force to the photo, color saturation, softness of light, brightness, etc, etc.

     For reference, there are certain adjustments that I almost always I put more or less the same as are:

                        Gamma: 2.0
                        Black Clip: 0.00%
                        White Clip: 5.000%
                        Light Smoothing: 0 or 1
                        Strength: (above 50, even reaching 100)

 

     7. After several hours :-)) touching the sliding press OK and will appear as the final work on the main window Photomatix:

 

 

     Once here we can save nuetra picture. I usually save in TIFF format for a simple reason. We all know that the JPG format is a compressed format and how the next thing we will do is open the file in Photoshop to make a few tweaks and re-save and possibly return to open to retouch and save again ... and more the quality of our picture is deteriorating more and more when saved since it has to compress each time you save the file running the danger it leaves us the typical bands JPG.

     Therefore File> Save as ...> (choose TIFF) and click Save

 

     8. And, as a final step, open the photo with Photoshop to put the finishing "touches" such as:

 

 

          Image> Adjustments> Levels

          Image> Adjustments> Curves ...

          Image> Adjustments> Hue / Saturation ...

          Filter> Sharpen> Unsharp Mask ...

       etc etc

 

I hope it's helpful for you.

 

 

Enrique Izquierdo

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Ajuste de la nitidez con el filtro Paso Alto

16 March, 2016 - General - Comment -

La primera parte, explica cómo Markus Reugels hace las fotografías de colisiones de gotas de agua.

El post-procesado está en la parte final del video en dónde explica como trata con Photoshop las imagenes obtenidas haciendolas más nítidas con el filtro Paso Alto.. 

 

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