BARCELONA /.JOAN MIRÓ’S WOMAN AND BIRD

PRACTICAL EXERCISE WITH DIFFERENT FOCAL LENGTH LENSES

I decided to do another practical photo experiment related to Antonio Espejo’s picture and Joan Miró’s statue Dona I Ocell (Woman and Bird). It is an exercise sometimes my pupils do to understand what happens working with different lenses with different focal length. Focal length is the distance between the optical center, inside the lens, and the plane where the image appears, focal plane (where is the film or the sensor in digital cameras). The focal length and angle covered are in an inverse relationship: the longest the focal length the lesser the cover angle and vice versa.

I have photographed the Miró’s statue in several occasions, of course. The best known this 1991 image of two different captures in the same shot (There wasn’t Photoshop yet), the sculpture and the full moon. This photo ran full page in a Paris Match about Barcelona and the 1992 Olympic Games. I’ll explain better this technique in a coming post.

The practical exercise consists in taking a particular object as a reference, in this case la Dona i Ocell (Woman and Bird), and while changing the lenses focal length keeping it always in the same size. The difference with the first exercise with Espejo’s picture that consisted also in using different lenses but always from THE SAME PLACE, in this case you HAVE TO MOVE.

NIKKOR 300 mm
NIKKOR 180 mm
NIKKOR 70 mm
NIKKOR 50 mm
NIKKOR 18 mm

It is very convenient start with the longest focal length and continue forward. If we do it the opposite way we ran the risk to find and obstacle to our back and to have the experiment stopped there.
In my classes we chose simpler exercises: a reference object not too big on a clear environment. In this case the statue is 22 meters high, there were obstacles all around and the point of depart was half a kilometre away. But all this made the experiment far more interesting. The lenses I used were a 300, 180, 70, 50 and 27 mm on a digital Nikon factor 1,5 , so the real focal lengths were 450, 270, 105, 75 and 27 mm. In the second photo the sculpture is nearly hidden by the white offices of the Bullfight Arena works, very close to Joan Miró’s park. The interesting part of the exercise is to observe how the planes in front and behind the statue change with the different lenses used.

Map showing where the photos were taken.

PERSPECTIVE CONTROL IN ARCHITECTURE PHOTOGRAPHY

The photography of architecture requires the control of the lines; we have to maintain the verticality and horizontality of the buildings we photograph. The way to achieve this is to get the camera perfectly levelled, but this is often impossible and we have to move it upwards to cover the building. For these cases, there are the lenses called PC (perspective control), also called shift lenses, that enables the photographer to offset the lens from its normal optical axis in relation to the sensor plane, either horizontally or vertically, or by a combination of the two movements. This rise, fall or lateral shift of the lens gives the 35 mm photographer control similar to that possible with a view camera, as the case of the second photo of this Romanic church of Andorra. These lenses are expensive, but now we have in Photoshop Cs2 and CS3 a command called correction lens that enables us to achieve similar effects.

This is another photo taken from my window with a Nikon D700 and 20 mm lens using an ISO of 1600. By using a wide angle and focus down there is an obvious distortion. The way to correct it is in Photoshop is to go to filters, open distort and choose the command lens correction (Photoshop CS2 yCS3).

In the Transform box (towards the bottom) just move the Vertical Perspective and Horizontal Perspective sliders until the lines are straight. For this image I simply slid the Vertical Perspective slider until it looked right, which was at +50.

Click OK, and now we have to cut part of the picture, what we do by using the cutting tool. Before saving the image, we have to go to layers and apply the command flatten image, which is below.

To correct the distortion and crop the picture we've lost some of the original image, but the end result is very similar to what we would have achieved through a PC lens and we have saved a lot of money.

PICTURES FROM MY WINDOW. DEPTH OF FIELD

NIKON D80 50 mm, 1/1000, F:2,8, 400 ASA

NIKON D80 50 mm, 1/15, F:22 ,400 ASA

This is a practical exercise on depth of field that I ask my students to do: to photograph the same subject with very little and with great depth of field, using the same lens, at the same distance and changing only the aperture. I took the photo of the plant in my terrace without leaving home. For that reason I started the series Pictures from my window, among other ones: I can prepare some examples for my classes without leaving home. By the way, thanks to readers of the blog I already know that the plant is from the sucus (Latin) family, which stores water and does not need to be almost watered. And I used to do it, at least, once a week.

TECHNICAL EXPLANATIONS.

DEPTH OF FIELD is the distance between the farthest and closest elements in the picture in relationship with the point we focus. Depth of field depends of three factors that can be controlled by a photographer who works in manual mode:
1) Lenses focal length. The longest the focal length the shorter will be the depth of field and vice-versa.
2) The distance. The distance between the camera and what we want to photograph. The longest the distance the longer will be the depth of field and vice-versa.
3) F-number. The smallest the f-number (less light entering through the lens) the longer will be the depth of field.
I used a large aperture f: 2.8 for the picture with little depth of field and a very small one f: 22 for the image with great depth of field.

EXPRESIONS OF MOTION IN PHOTOGRAPHY

MONICA SELES. 1/1000 F.4 100 ASA

There are basically three ways to represent motion in photography: Freezing the motion, panning and motion blurr. We must take into account several factors: the shutter speed, the camera movement and direction of the moving subject towards the camera.

1) FREEZING THE MOTION: The subject or object is perfectly sharp and its movement frozen. The shutter speed must be high, the greater the faster the subject moves. The direction of the subject influences the shutter speed we need.If it moves parallel to the camera requires a higher speed than if it moves perpendicular to it, but considering this premise, its trajectory with respect to the camera is irrelevant, unlike in the panning, and it doesn’t matter if the camera is moving or is steady. The closer the subject, the higher the shutter speed needed to freeze it. This same principle applies to the focal length of lenses used. The longer the lens’ focal distance, that gets us closer to the subject, the higher speed needed to freeze the motion subject and viceversa.

1/500 F:4 400 ASA

1/1.000 F:2,8 100 ASA

2) PANNING: The subject in motion is acceptably sharp and the background blurred. The shutter speed needed is lower than in the case of the, motion freezing, but also depends on the motion speed of the subject. To achieve this effect is essential that the subject moves parallel related to the camera, not away from or approaching it. To achieve this effect you must move the camera following the subject and shoot when it is in front you.

1/8 F:2,8 200 ASA

LEICA 1/15 F:8 100 ASA

3) MOTION BLUR: (ghost image): The subject in motion is blurred and the background sharp. The shutter speed is lower than in the freezing motion case and also than in the panning case, but also depends on the speed of movement of the subject. The trajectory of the subject is irrelevant, unlike the case of the panning, but we must remember that we need a lower shutter speed to achieve the desired effect if the subject or object moves perpendicular to the camera, than if is moving parallel to the camera. Unlike in the freezing motion and panning techniques is essential that the camera remains stationary; the use of a tripod is usually recommended.

MARATON BARCELONA 2009. 1/4 F.11 100ASA

RÍO MUNDO. 2' F:16 50 ASA

ZARAGOZA. 1/15 F:8 50 ASA

ALL PHOTOS ARE COPYRIGHTED BY PACO ELVIRA

/ PICTURES FROM MY WINDOW. ILLUMINANCE

In photometry illuminance is the total luminous flux incident on a surface, per unit area . It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception. Similarly, luminous emittance is the luminous flux per unit area emitted from a surface. Luminous emittance is also known as luminous exitance.In SI derived units, these are both measured in lux (lx) or lumens per square metre (cd·sr·m−2).
Both the illuminance and the lighting level are measured with the photometer. There are objects capable of producing their own light like the sun or the light bulbs: they are the light sources. Other objects reflect the light and direct it toward our eyes. This is the case of the house opposite my window: it looks like a chameleon. Framing is always the same, but the light is constantly evolving. And this is a basic lesson in photography: take advantage of the good lights.

WHICH IS THE SHARPEST APERTURE?

It is known that the best aperture, which will give us sharper images if we don’t have to play with depth of field for photos with great depth of field or very short, lies somewhere between the largest aperture-the smaller F number- and the smallest aperture-the largest F number. Normally the photographers were using the f/8 for the sharpest images.

But the other day surfing the Internet I found this interesting article by Ken Rockwell entitled Selecting the sharpest aperture showing this table:

For Nikon, Canon, Leica, Pentax and most 35mm cameras:

If the maximun aperture is.................The best aperture is

f/1.4.....................................................f/5.6

f/2.......................................................f/6.7

f/2.8...................................................................f/8

f/4..................................................................... f /9,5

f/5.6...................................................................f/11

f/8......................................................................f/16

So if I want maximum sharpness with my f1.4 Summilux I’ll shoot to f/5.6. With most of my f/2.8 fixed lenses to f / 8. With my 300 mm f / 4 tele lens at f/9.5, and with a zoom that opens at f/5.6 to f/11.

How Ken Rockwell did calculate this? I'm not going to argue but take pages and pages of numbers and mathematical formulas. For those crazy about math, not my case, this is the original page.

ANTONIO ESPEJO / THE POWER OF TELE LENSES 3

A PRACTICAL EXAMPLE OF DEPTH OF FIELD AND FOCAL LENGTH.

Following my search for spectacular Barcelona photos taken with tele lenses I remembered one image standing out. There was a picture shot by Antonio Espejo using a colossal tele.

CANON 1.200 mm COPYRIGHT ANTONIO ESPEJO

Espejo worked many years as El Pais staff photographer and, as Alguersuari, came from the Sports Photography field; because of this he was an expert in taking the maximum advantage from long distance lenses. Antonio was working in a book titled “Barcelona de bat a bat” for Lunwerg editors. Nikon and Canon professional’s services lend special equipment, during a limited period of time, to the photographers members of their professionals clubs. Espejo got a real “monster”: a Canon 1.200 mm. tele lens. In the image, taken from the steps below the MNAC (Catalonia’s Art Nacional Museum) you can see the Venetian Towers, the central monument and the Plaza hotel clock, all in Plaza España, and Joan Miró’s sculpture “La Dona i l’Ocell” (The Woman and the Bird). To all who know Barcelona , the image is surprising. All is together in the same plane. For those who don’t know Barcelona so well I looked for the distances in a city map. The Miró sculpture is…400 meters away from the Venetians Towers! But, due to tele lenses effect (the greatest the focal distance the greatest the effect) of flattening all the planes, the final result is simply amazing.

The tele lens used was of 1.200 mm. The so called “normal lenses” (similar to the human view) are the 50 mm, so in this case Espejo took the photo with a lens with a focal length that is twenty four times the 50 mm !I decided to take the same photograph using different lenses. I live very close to Plaza España so I took my tripod, my D80 Nikon and a bag full of lenses and climbed the steps that go from Plaza España to the MNAC. You have an exceptional Barcelona view from there that I have used in many occasions. And those are the results. I used three Nikon lenses: a 18-70 zoom, a 180 f:2,8 and a 300 f:4. In the captions I multiply the focal lengths by the 1,5 digital conversion factor to compare them with Antonio Espejo’s 1.200 mm lens.

NIKKOR 105 mm

NIKKOR 270 mm

NIKKOR 450 mm

CANNON 1.200 mm COPYRIGHT ANTONIO ESPEJO

TECHNICAL CONSIDERATIONS

Antonio Espejo needed to solve several technical problems to get his photo. A tele lens of such a long focal length needed to be shot using a high shutter speed or fixed to an extremely sturdy tripod. Espejo told me that he got a 15 kilos tripod from the Canon Professional Service. The second challenge was to get all the planes sharp, a greath DEPTH OF FIELD known as the distance between the farthest and closest sharp elements in the picture in relationship with the point we focus. Depth of field depends of three factors that can be controlled by a photographer who works in manual mode:
1) F-number. The smallest the f-number (less light entering through the lens) the longer will be the depth of field.
2) Lenses focal length. The longest the focal length the shorter will be the depth of field and vice-versa.
3) The distance. The distance between the camera and what we want to photograph. The longest the distance the longer will be the depth of field and vice-versa.
To get all the planes sharp in the image Espejo had two fixed variables, one positive and one negative. The positive one was that the distance of the subjects in the photo was very big. The first elements appearing, the Venetian Towers, were about 700 meters from the point the camera was, as I calculated on a Barcelona map. The negative and fixed variable was that the 1.200 mm focal length was very big.
Antonio could only play with the third variable left: the number f. Usually he should had used the smallest f-number and the correlative slow shutter speed allowing the right amount of light needed to get the right exposure. But there was a problem as Antonio told me:” I couldn’t use a slow shutter speed because, in spite of having the camera on the tripod, the focal length was so huge that the photo would be blurred, so I have to use a middle f-number and a pretty high shutter speed with Velvia 50 ASA slide film".
The photo was taken on a sunny day (a must to get this result) at 14h 8 minutes (Guess how I know that?).
The final result was fantastic. Chapeau Antonio!