Help with Photographing Art

Pinedale Press · Jun 29, 2009

i am photographing flat art paintings & drawings. some with thick paint lumps and spatula marks which we must capture. i invisage using two constant haligen lamps, one at 45 degrees and one nearer 90 degress tp capture the shadows made by the lumpy sureface. we will be sending the pictures direct to a calibrated computer screen. i am using a new sony a900 full sensor camera.

1. what is the best prime lens for this project to capture all the detail.

2. what is the best method for establishing white balance? will a whibal grey card do the job

musicaleCA · Jun 29, 2009

Yes, a grey card will do the job. And the best lens is the best lens that will do the job. Check out photozone.de .

Dwig · Jun 29, 2009

You'll need more than just two lights.

1. the best prime lens? You'll need a long lens with little or no rectilinear distortion. A 100mm macro might do, but a longer lens would be better. No zoom would fall into the "best" lens choice category.

2. how to WB? You will need a WB card as large as the artwork or you'll need to move the camera close to the art to fill the frame with the WB card. Either way, the WB card needs to be near the surface of the artwork. Also, anythime you are anywhere near the WB card when you do the WB you must wear only white, grey, or black clothing. Strongly colored clothing will influence the WB reading if you are just holding the card at arm's length.

Back to the lighting...

You'll want two matched lights that are both placed near 45 degrees off of the camera's line of sight. With a long copy lens, these can be somewhat closer to the camera than the classic 45 degress. These lights need to be further away from the center of the artwork than 3x the long dimension of the artwork. 5x-6x is even better.

You'll what a third light skimming the surface of the art, or nearly so, to cast the appropriate shadows to make the surface texture visible. This light needs to be dimmer that the first two, most of the time, and should be in the range of 3-4x as far away from the artwork as the main lights. Any closer an it's effect will be uneven, with a more pronounced effect on the edge closest to the light and less diagonally opposite. Also, this texture light needs to be within 45 degrees of the "top" of the artwork. In most studios, this means the art would be hung with the top to one side and the light far off to that side and somewhat above or below the center line of the artwork.

Shooting from too close, relative to the width of the artwork, will cause the viewing angle into the micro-shadows of the texture to be noticably different from one side to the other. This presents a very odd presentation that shouts "photo of painting" instead of "painting". This is why my recommendation is for a long lens. Personally I wouldn't do everything possible to use a 200mm lens at least. Under no circumstances try to make do with something in the 50-60mm range if at all possible.

The reason for the long distances to the lights is to get even lighting. As an example, if the lights are close so that the distance from the light to the center of the near edge is approximately equal to the length of that edge, the near corners will receive about 1 stop less light than the center of the edge. That's way too close as the 1 stop fall of attests to.

Jeff Colburn · Jul 3, 2009

You also want to be sure that the film plane and surface of the artwork are perfectly parallel. You can try to dead eye this, or there's a mirror device that you set on the center of the artwork and it helps you make sure everything is parallel.

Have Fun,
Jeff

Pinedale Press · Jul 6, 2009

To Dwig
Hi. Thanks so much for your excellent advice on photographing art.
We are preparing three art books for International markets and the art being photographed are oils, watercolor and pencil and mostly 12inches x 18 with some 24x36. The pencil ones have some pale tones.
1) I am about to purchase the lenses. You recommended 200mm or larger. Considering the camera is not 4/5ths APS but a full sensor 21mp, would the Tamron180mm f3.5 Macro do the job? It equates to well over 200 on APS or the other option is a 135 Carl Zeiss Sonnar T lens equates to 202mm in APS. It also focuses down to 720mm. but is not macro?

2) Will 200w constant Haligen lamps be OK? And you don't think 3 lamps will wash out the pale stuff and oil brush strokes? I would accept your advice on this.

3) Will I need dispersion screens on the lights?

4) Will the light metre on the camera be OK? or would I be better served to purchase a light meter?

3) I'm not clear on the placement of the third light?

Many many thanks. I'll take you out for lunch some time if at all possible.

Pinedale Press.

Dwig · Jul 6, 2009

Pinedale Press said:
...
1)...would the Tamron180mm f3.5 Macro do the job? ...

I have no personal experience with this particular lens, but its the type that should do the job well

2) Will 200w constant Haligen lamps be OK? And you don't think 3 lamps will wash out the pale stuff and oil brush strokes? I would accept your advice on this.

The third lamp is only to skim the surface to reveal the surface texture and brush strokes. It is intentionally place further away from the art than the main pair of lights. With proper exposure you won't was out the pale areas because of this light.

3) Will I need dispersion screens on the lights?

No

4) Will the light metre on the camera be OK? or would I be better served to purchase a light meter?

Yes

3) I'm not clear on the placement of the third light?

The third light is placed low, almost in the plane of the surface of the art, an 3-4x as far away from the center of the art as the main lights are. Its light merely skims the surface of the art and is relatively dim compared to the main lights due to its being so much farther away.