Off camera flash

Técnicas de iluminación en fotografía

Steinberg, Miró, Haring and friends

Some photographic works are truly difficult to perform in the digital era, and one of them are reproductions of works of art. The color fidelity should be high and reaching them is a task of high precision throughout all phases of the assignment. But let’s first talk about lighting, which is what this blog is about. When photographing a work of art – or anything else – our main concern in terms of lighting is its brightness, color and contrast.
Saul Steinberg 1971  Saúl SteinbergSteinberg, Miro, Haring and friends.pdf

I often take reproductions of works of art for A34 Gallery Barcelona, besides working for other clients on this issue, as when I made reproductions of the work of my dear friend Yamandú Canosa for the Suñol Foundation or when I worked for CCCB photographing Pegaso cars.

Isarrualde Photography Gallery  A34
Many works are framed and glass becomes the main problem. We must avoid seeing the resulting reflections and it is therefore necessary to pause on the concept of “families of angles that produce a direct reflection”.

Isarrualde Photography Direct Reflection

The picture above shows a direct reflection. Here, reflected on the glass, we see the direct reflection produced by the light boxes that I used to take the picture. In this sense it is very important that from the position of the camera we won’t see any direct reflection of the light sources used to take the picture.

Family of Angles

Isarrualde Photography

Any light located outside the family of angles that produces direct reflections of the light source, will be well placed to start the job. It is important to position the camera away from the subject because if we have to place the camera close to the artwork, the family of angles that produces direct reflections will be higher and will force us to put the light in a grazing angle with the artwork and the frame shadows will be bigger.

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Another essential aspect is that the same amount of light should reach the surface of the artwork. In this regard it is important that the light source is located further from the work so that the light is distributed evenly. The law of “inverse square of the distance” reminds us that at further distance there will be less light and we should avoid degraded light on the subject. On the other hand, diffuse reflections become brighter as the light approaches the reflecting surface. We should try to have distances a and b on the following image be as similar as possible. In the excellent book by Hunter, Biver and Faqua you can see this theme developed to a greater extent.

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If we’re working on drawings with no relief, I prefer to work with bigger light boxes so that the shadows casted by the frame would be soft and low contrast. Otherwise if the frame is very deep the shadows will be very notorious and if the light we use is hard, there will be no transition between light and dark areas on the work and it will be more difficult to tweak in post production. An important detail when artworks have a glass is to place in the plane of the camera a black velvet cloth to ensure that all the reflections from the room that could appear on the glass will be absorbed.

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Sometimes we may be lucky and artworks don’t have any frames with glass. If on top of that they were done on matte paper we just need to set the light well. Two symmetric lights, equidistant from the work and at the same angle of incidence, will be enough. In my case, for these works, I normally use Wafer light boxes and Bowens flashes.

Torres-García Joaquín Torres García

I remember a few years ago I did a report on the exhibition of the works of Keith Haring at the Whitney Museum in New York, where I could not illuminate the work and only had one hour for the assignment. The artworks were very well lit but several of them were made on glossy canvas. Sometimes you cannot do what you know you should do and you have to solve the problem with whatever scarce resources you have in hand. In this case I chose to get away from the artworks and look for shooting angles that would avoid direct reflections, although it was not possible for all the artworks.

Whitney-Museum Whitney Museum © Marcelo Isarrualde
Keith-Haring Keith Haring © Marcelo Isarrualde

Color management in the digital age

Color management in the reproduction of artworks is a fundamental issue and in the digital age it is not easy. Firstly, you should know what light sources you will be going to work with and generate a profile for the sensor of the camera and those lights. At the time I was lucky that my friend Hugo Rodriguez prepared it for my equipment when I had to make some very difficult reproductions of the work of Joan Miró. Part of the red and blue tones of his works were outside the reproducible color range in a printing press and we had to know what decisions to make about the color management.

Hugo Rodriguez With Hugo Rodriguez

This type of work involves shooting a “bracketing” of exposures, revealing the raw file with the developed profile and with a linear response curve. In these circumstances we also have to make a white balance and evaluate the best resulting histogram for the development. We should also compare the values of the Gretag Macbeth Color Checker CGI card with the real card photographed bearing in mind that both should be in the same color space. The purpose of the color representation in the development program of the raw files is also very important, as well as choosing the histogram more shifted to the right, as it will ensure solving the noise level in the black textures, a greater tonal separation in highlights and a greater dynamic range. Choosing the right histogram is very well developed in the last book of Hugo, Digital Capture and Raw Revealed.

Isarrualde Photography Gretag Macbeth Card

We should also assess the values in a space of Lab color when the photography is converted from RGB to CMYK, etc, etc. This whole issue goes beyond the aim of this lighting blog. Hugo explains it brilliantly in his various articles on the subject, among which the article on the color chart IT8 he developed for the laboratories EGM in Barcelona, where he also tells how he did the profile of my equipment.

IT8 card  Art work by Joan Miró with IT8

Steinberg, Miro, Haring and friends.pdf

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No partial or total reproduction is allowed without the written consent of the author.

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