a DallasArtsRevue Photo Pages Banner DallasARtsRevue.com Photography Banner Index of DallasArtsRevue.com Photography Pages
Home  Index  Calendar  Member art  Join  Resources  Feedback  Contact Me  Reviews  Submissions  Search
OTHER PAGEs  How to Start Showing Your Art   How to Design & Distribute an Invitational Postcard   Canon s90 Journal
My D800e Journal  My G2 Journal  Cameras & Lenses I Have Known   Cameras & Lenses: Past & Future


How to photograph art
that's behind glass, is glass
or is glossy like glass

This is a work in progress. I have deleted almost all of the info about shooting art glass and glossy art from How to Photograph Art

All Contents Copyright 2007-2015 by J R Compton. Do Not Reproduce this page, just email them the link. This page is updated and corrected often. A copy won't be.

When I say command, PC-users should translate the word "command" as "control."

Alex Troup - Zooamorph 1988 - copyright JRCompton. All Rights Reserved.

Alex Troup   Zooamorph   1988   mixed media with butterfly, beetle,
wasp nest, cork, feathers and dictionary pages   10 x 32 x 4 inches
 

The best way to photograph art behind glass is to take off the glass.

That's not necessarily easy or practical, but it makes photographing art much easier and more direct, unless the art includes glass, like this box. When it's not possible to remove the glass, there are, as we shall see, other ways around the problem.

Light the art through the glass obliquely from above and/or one side or the other and aim the camera and lens straight into the surface of the glass, so the art's shapes are not distorted. It appears that the soft light I shot this one with was aimed down from the top right, where the shadows are darkest.

Often when I photograph into boxes, I use a bright, white sheet of cardboard to bounce light back into the dark shadows, but I don't think that happened here, and I was lucky the light-source was not very bright or contrasty.

Glass is not always transparent. Sometimes when something is photographed through glass, the glass distorts the image from a little to a lot, or you see ripples. Especially when it is lighted at angles, glass adds its own blue-green color. Note how greenish the interior of this box appears.

Make sure the glass is very clean. Vinegar and water is probably better than the famous blue spray.

Glass is not entirely clear, steals focus, distorts your images and reflects light back at you.Many cameras focus on the first thing they're aimed at, not necessarily what you want sharp behind the glass. That happens a lot. You've got to watch for it, and sometimes it's subtle. I once had a client who had built a large and elaborate Dark Tent that occupied a lot of space in his studio, but his camera insisted upon focusing on the glass and ever so slightly defocusing the art behind it, and it took us awhile to figure out why.

It gets worse, the front surface of glass can act as a mirror to reflect light from behind the camera, back into the lens — and dark art behind glass shows more reflections than light art.
 

Six ways to photograph art through glass

1. Move the light(s),
2. Re-aim the glass,
3. Use a telephoto lens,
4. Poke your lens through a black reflector,
5. Photograph it crooked to avoid reflections, then un-distort the image using Photoshop.
6. Measure the diagonal's angle, extend its length and create a larger rectangle.
7. Create a dark tent.

Then there's

Avoiding Glare or reflections.
If art is translucent (duplicating the same small section on the full How to Photograph Art page)
Using Photoshop.

   

1. Move the light.

Mixing room light and daylight coming through the windows to illuminate art can be problematic, because you can't really aim it, and its color may be difficult to adjust back to white. Usually, it's better to have your own light on a light stand, with all other light sources turned , curtained or walled off, so you can control the color, amount and direction of light on the subject.

Often, one light, aimed just right, will do it. Unless you do it just right, however, using more than one light source tends to flatten out texture and shape, or confuse the image by creating multiple shadows, but you gotta do what you gotta do.

Using more than one light makes lighting from a little to a lot more complex. You still need just one main light, so you don't get double shadows, or get shadows in the wrong places. But if you aim it / them right, the second light partially fills in the shadows created by the first one. That may be great for sculpture but it can be problematic for framed or matted flat art or art that's purposely bumpy with lumps of paint or objects.

When I photograph art in galleries or museums, there's often a dark shadow obliterating the tops of paintings, caused by frame or mat shadows, because light is aimed almost directly down, which avoids viewers casting their own shadows onto the work.

On this planet, we expect light to come from above and left. That's probably a good place to have your main light aimed slightly down. But because of reflections and shadows and the need for even lighting over the surface of mostly flat art, you might want to move it around up there. Or have someone else move it while you watch its effects on the art.

By far the best, easiest way is to shoot at night, use only one light, and move it until it doesn't shine in the art but evenly illuminates your subject.
  

2. Re-aim glass.

Cecilia Thurman    Fish Gotta Swim, 2009   oil on paper collage diptych   34 x 32 inches
 

3. Use a telephoto lens.

Compared to normal or wide-angle lenses, telephoto lenses tend to render less depth of field. So the art can be rendered sharp (make sure it is the art you are focusing on, not the front surface of the glass, while any reflections (which are optically some distance away) are not.

The wider aperture (lower numbers) you set on the lens, the less depth of field you'll have to deal with. Some cameras have Depth-of-Field Preview Buttons. Others have Live-View LCDs. Sometimes just being able to see what is and is not reflected in the glass, is all you need, because then you can do something about those reflections. I've more often accomplished this technique in large, brightly lit galleries, but it works. Again, a tripod helps, but they are usually prohibited.
 

4. Use a black 'reflector.'

Sometimes, when I know I'll be photographing reflective art or photographs behind glass, I'll bring a large sheet of dull black mat board with a lens hole in the lower middle, and tape it to the lens or camera.

Then photograph the art holding the cardboard parallel to it or tilted toward the art, so either the dark cardboard or its shadow reflects in the glass instead of anything bright.

The size needed depends on how many and where the room's lights are, whether you are using a wide angle, normal or tele lens, and how close to the camera the art is.

I usually use as large a piece of dull black card- or fiber-board as I can find, afford or easily carry and use.

Cut a lens-sized hole in the lower middle (because light usually comes from above, and we often have to shoot up into art)

Sometimes you can take off the lens hood, push the lens through the hole, replace the hood, and aim the cardboard so it's either parallel to the plane of the artwork or the top of the board is angled slightly forward, to create its own shadow.

If you use a lens shade / hood, which shades the glass elements of the lens, it is less likely the lens front will reflect, but sometimes, no matter how careful you are, something on the lens or hood or you shows in the image. Check your images carefully. Often the only way to get rid of those reflections is to black-tape them over, or carefully use Photoshop later.

Tape might help hold it in place. What color the tape is doesn't matter on your side, but on the art side it might reflect.

Watch the glass' surface to make sure nothing but dark reflects in it, and you will probably have to adjust the distance from camera to art, and except for wide-angle lenses or wide zooms that distort, fill the frame with the artwork, not the frame.
   

5. Photograph It Crooked, then un-distort the image.

Before I concocted this simpler and more visual un-distortion method, I used the technique described in Number 6 [below] that sounds more complicated, but is actually easier.

Make two images:
 

Paul Rogers Harris - My Father - Photograph Copyright 2013 by J R Compton. All Rights Reserved. No Reproduction in Any Medium Without Specific Written Permission.

"Bad Image:" Photographed Artwork (an unframed digital photo collage by my friend Paul Rogers Harris) with one large glare on the left and one tiny sliver of glare from a bright light reflecting off its shiny surface.
 

My Father from an angle - Photograph Copyright 2013 by J R Compton. All Rights Reserved. No Reproduction in Any Medium Without Specific Written Permission.

Future Good Image: Photograph shiny art from an angle — in this case, from low and left — that does not show the glare anywhere in the image. It doesn't matter yet that the contrast, colors and tonalities have not yet been corrected, but be sure the entire image area is in focus, so don't get too close.
 

My Father - with yellow line

Since this artwork did not have an obvious top left corner to align to the top left corner and the top margins, I created a new layer in Photoshop (so I wouldn't get the line in the actual image), drew a solid yellow line that extended the angle of the top edge from the upper right corner.

 

Adjusting the Edges

Click-and-dragging the top left corner to align the left edge to the cyan guide

In Photoshop:

Select-All (command a — PC users will have to translate command as control) or click-and-drag all or part of or the image,

Select the Edit menu, then Transform, then down the pop-down menu to Distort,

which creates a marquee (pronounced mar-key) of pulsing dotted lines (like the flashing lights around the marquee of old movie theatres) around the selected portions.

In the marquee's corners are little squares to be clicked and dragged to alter the shape or align them to the guides clicked-and-dragged from the rulers

Adjusting each succeeding corner once around the image (doesn't matter whether you go clock- or counter-clockwise or choose opposite or adjacent corners) often is not enough, because each time you move one, the others re-adjust. Usually but not always, twice around is enough. Sometimes it seems endless.

Note: Sometimes it's helpful to hide (command h) the marquee to avoid the distraction or more precisely adjust the corners.

While still in Photoshop, adjust the other image aspects that need it: light/dark, color, contrast, size, sharpness, etc. and crop it precisely, so only the artwork shows.
 

Paul Rogers Harris - My Father corrected and cropped

Paul Rogers Harris   My Father   digital photo collage   corrected and cropped

 

6. Photograph it crooked, then undistort the image using proportions.

I use full-bull (expensive) Photoshop. Photoshop Elements doesn't have guides to drag out of the rulers, and even though they're not absolutely essential, guides within the document make everything easier, quicker, straighter and more accurate when there's guides to align art's edges to, although I have dragged other windows along the edges in Elements.

Several decent Photoshop alternatives are linked on my How to Photograph Art page.

Photograph the piece twice, A. straight-on and B. from an angle so glare and/or reflections do not show— like above

Take a head-on pic (bad image) of the art object with all the reflections, being careful to render the art as squared as the original (Using a tripod helps.) by aiming the lens into the center (left, right; up, down and diagonally), so the corners render as near to true right angles, and the edges are as straight and parallel to each other, top and bottom, left and right, as you can manage.

If not, adjust the edges and corners till they match the original (just like we did above.) All that really matters with the bad image is that its corners and edges are squared, so the diagonal accurately shows the proportions.

If you can see the corners and edges; and the corners and that it is a photo of the correct artwork, that's enough. Other aspects of image quality don't matter. The only purpose for this image is to establish the correct proportion to copy onto another image to be adjusted.

How to Copy Proportion

In a new or different layer from the artwork, paint or pencil (Photoshop tools) a diagonal line from bottom left to top right corners of the linearly-corrected bad image.

Copy that diagonal line from the Bad Copy to the Good Copy.

Unless you or your client absolutely needs the frame in the image, crop it out when you shoot, because frames take up valuable image space and resolution. 

Next, make a good, full-resolution, low-ISO copy from some angle in the room, where reflections don't show. This will be the good image, even if it's distorted now. Shoot it at at least three different exposures (varying the shutter speed). Then choose the image with the best exposure, focus, etc.
 

Measure, then Apply the Proportion.

The simpler (though not necessarily easier) way to undistort an image is to measure it, then use the ratio of its height to width to constrain its dimensions. I shoot a lot of images of art, but I almost never measure them, because the following procedure, seems like the long way around, while the above method has become second nature to me.

The difficult part of creating this page of instructions was to break down what has become a natural progression of steps into their component parts. From 'just do it' to 'step-by-step.' 

Open the undistorted, bad image (with reflections) in Photoshop, and drag one vertical guide and one horizontal guide to intersect at the bottom, left corner of the image.

Paste the distorted, good image, into another layer. You can adjust its exposure, levels, etc. later, when you get it undistorted.

Create a new layer that's transparent (nothing in it yet) and draw a diagonal starting with the smallest diameter you can still see at your screen size, using a round pencil tool (hard-edged dot), by clicking once at the bottom left-most corner of the artwork in the new layer.

Don't click the pencil anywhere else yet.

(It will look like a dot). The smaller the dot, the thinner the line and more accurate the proportions will be, but probably nobody will notice if it's a little off.

Then, holding the shift key down, click another point, using the same dot size but at the top right corner of the bad (undistorted) image. That creates a straight diagonal line on a separate layer. That diagonal will determine the final photograph's proportions. Use as much of the vertical and horizontal image space to create the diagonal line.

Turn off or delete the undistorted bad copy layer used to create the diagonal, and select the distorted, good image (high resolution, excellent tonal range and without reflections) so it'll be near-perfect when you undistort it.

Leave the diagonal line in the top layer, so it will be visible over the artwork you want to undistort, but activate the good image layer, so you can operate on it. Select all in the diagonal line layer, and move it (without distorting it), so the bottom left of the diagonal is on the bottom left corner of the distorted image.

Then, with the distorted good image layer still active, Select All, go to the Edit menu, and under Transform, choose Distort and drag the top right corner of the good image to align someplace along the diagonal line.

Then drag vertical and horizontal (one each) guides out from the rulers (command or ^ r to make the rulers visible) at the top and side of the image, adjust the exterior edges, by moving each succeeding corner around the artwork until all four of the good image's corners are right angles and all four edges are parallel (even though the image is probably still distorted.

Make sure the diagonal line is still visible.
 

Select All on the distorted (but now squared and paralleled) good image's layer, then click onto the tiny adjustment box at the top right corner, and drag that top right corner to a place at the center of the diagonal.

That might distort the image some, so do the select-all and distort process again until all four corners and edges are square and aligned perfectly with your four guidelines, so the guidelines' corners are square, and the edges are parallel and the top right of the piece is on the diagonal. It usually takes two or more trips to adjust each selection box.

Saving the document at that time makes sense.

Select All to create the marching-ants selection area of the entire good, but still-distorted, image. Go to the Edit Menu, and down to Distort on that menu. Then grab the top right box on the selection 

the vertical and horizontal edges (starting from the left bottom) vertical and horizontal (zero and 90 degrees) and by dragging the top right of the image that needs to be adjusted, so the top right corner is somewhere along the diagonal, I have the right proportions.

Most photographic images of art need at least slight straightening, anyway. I should probably explain the non–proportional method for un-distorting images, too, but right now I'm exhausted from writing this over the last three days.
 
   

7. Use a dark tent.

A dark tent puts non-reflective darkness where it would otherwise reflect in the glass over the artwork. I have seen set-ups as complicated as a ten-foot long corridor of soft, black material hung from the sides and the back, like a hallway of curtains, open at the top for light.

I usually go for the easier methods above, because using a dark tent takes building something that takes up a lot of space and will be in the way most of the time.
 

Avoiding Glare

Sonia King - Pathfinder

Art as mirror

The trick for photographing glossy or reflective art is to remember that the piece is acting like a mirror, so you have to angle the glare away from the camera and lens by either moving the light or the photographer. When I'm standing in a gallery and want to photograph a reflective piece of art (like the gilted glass tile in the piece above), I photograph it straight on, with all its reflections showing, so I'll know its exact proportions.

I photograph the piece from an angle using direct flash (because there's usually one of those on my camera).

At home I'd use light on a stand and re-aim the light not the piece.), making sure the camera doesn't see any flash glare in the glass or reflective paint, and that the entire piece is evenly illuminated and in sharp focus. Then, if need be, I can square the work up in Photoshop or other image-manipulation software that allows us to "distort" the image back to its original shape, using the head-on reference image to correct the proportions. Relative dimensions are often not obvious from angled photographs.

Photoshop Elements does not, but the full, expensive version of Photoshop lets us drag guide lines out of the rulers, so we can "distort" the work to align with the guides, thus rendering the piece as correctly squared or rectangular. It's usually best to crop out the mat or frame (when you photograph it) anyway, so your work uses more of the resolution of your camera's sensor.

When photographing shiny art in a studio, move the main (preferably only one — using multiple lights if you don't know what you're doing is asking for trouble. If you know what you are doing, multiple lights add to the confusion.) light until it reflects its illumination away from the camera. It may take some experimentation, but keep the lamp higher than the art, so its little paint bumps and other internal shadows fall down, where we expect to see them, so our minds will perceive the piece as "normal."

Then use a reflector (simpler and subtler) or another lamp (more of a challenge, since it can create more glare), to partially fill in the shadows created by the main light.
 

the onion

Pierre-Auguste Renoir   Onions   detail   1881   oil on canvas   15.4 x 23.9 inches
photograph copyright 2012 by J R Compton. All Rights Reserved.
 

This detail of a famous painting was photographed on the wall during a press opening at the Kimbell Museum of Art in Fort Worth, Texas for The Age of Impressionism exhibition through June 17 2012.   Photographed in an unavoidable mix of diffused and reflected daylight and tungsten light, with a Panasonic Lumix G2 and my 20mm (40mm equivalent) f1.7 lens at f2.8 and ISO 500.  More pics of the work in that show are in my review of it.

I didn't mind shooting medium-high ISO, because I shot it for a review to be published online at 72 dpi (as it is here), and I knew I could get away with it.
 

A little paint glare is not necessarily a bad thing if the piece has thick piles of paint (impasto), and the image still accurately reproduces the work, but you can also bring the fill light or reflector in closer to the artwork or angle the main light more directly into the piece, or photograph it outside in cloudy bright sunlight (but get the colors right — cloudy bright is not the same color as sunshine daylight), or shoot it inside with a couple of even-brightness and even-distance lights. 

I almost always prefer using one light and one reflector, because they're easier to move, position and aim, and if you accidentally knock it over, nothing explodes, although a reflector can knock over small, fragile pieces of art.
 

 

If art is translucent (light passes through it) — like glass, stained glass, film or sheer material, photograph it with light passing through it. The light source should be behind the art, perhaps aimed up or down into the art, but the source should probably not be visible, because compared to the light source, everything else will seem too dark. The light should be the same color as the light illuminating the rest of the art, and don't let anything else show through the translucent parts, unless you really want them to.
 

Diana Chase - Jump Right In - photographed by J R Compton

Diana Chase   Jump Right In   cast and fused glass   16 inches diameter

I was photographing work in The Back-room Invitational trying to avoid a large bright area of sunlight from one of the high windows when I realized the light was coming through this piece as I had recommended above.

Using my Nikkor 50mm f/1.8 lens with the camera on a tripod, I moved in on the piece, composing so it showed about this much background and the sunlight glowing through the glass. I cropped most of the black area at the top of the original shot. Later in Photoshop, I darkened the bottom left corner to match the bottom right, cropped out most of the wood stand and darkened the rest of it. 

 

My latest email address is always on the Contact us page. I do answer reader questions. This page is the result of one of those, although I've known for awhile that I'd have to write it, even if I procrastinated the task about as long as I could. I appreciate questions and suggestions.

Support this site. Become a Supporting Member to get your own
web page, entry in DARts shows & other benefits,

DARts Index
Art Calendar

top

 

 since July 21 2013