I have many requests from ebay sellers about creating perfect white backgrounds.
People usually want these to go behind products for display on websites. Usually they have purchased a light tent over the Internet and have come to believe that this bit of proper photographic gear will solve all of the problems. Light tents can solve some problems if their use is fully understood.
For many years camera manufacturers have been pedalling the myth that an automatic camera can solve all photographic problems. In many situations they can be very successful but not in all situations. Usually, well lit subjects that are stationary, and of even tonal value, turn out okay. As it happens, this is what fine weather photographers choose to take pictures of most of the time with their cameras set to auto. The exceptions to average lighting conditions don’t do as well. Objects on paper white backgrounds are not average pictures as the white background is at the lightest extreme of the tonal range. They are technically very difficult: the sort of thing you would go to a professional photographer to do. To do good web photographs requires some understanding of basic photographic processes to achieve a consistent success rate.
This is the approach I would make:-
1. Its important to achieve consistent colour accuracy on your website, To achieve this a room with controlled lighting is important. You want your whites to always look neutral, not warm and creamy in some pictures and bluish in others, then you must understand how colour works in modern cameras.
2 Most of us work with a mixture of different light colours without thinking about it. Daylight coming through windows changes its colour temperature throughout the day. Then most rooms will have additional lighting from strip lights, tungsten, and possibly led lights too.
In order to do consistent work switch off all of the room lights and obscure any windows.Exposure should be done exclusively by illumination from the photographic fluorescent light bulbs bought for use with a light box. All other lighting should be switched off during exposure. Clearly this will be impractical in some situations especially where there is shared usage of a space.
Most better quality digital SLR cameras allow you to make a custom light balance. It is very good practice to do this for this type of work. The light balance can be locked into a camera menu setting and easily switched on for this type of shoot.You can also balance the colour in many photo editing programmes but it can take a lot of time to do it. Get it right in the camera first.
The second major problem is how you set up your objects to photograph. You need a good work area with a bit of space to move your lights around. It might be a good idea to think what is the largest size object that you are trying to photograph and work from that size downwards. Most light tents are designed for very small objects much smaller than the interior of the tent. Often small light weight objects need to be propped up to photograph at the right angle. This can be tricky and fiddly work using lumps of wood and blue tack concealed behind the thing to be photographed. Light tents ca be very unstable and move with the slightest touch. Personally I have always found a table to be more convenient to work on. When a tent is needed (only for very reflective products like chrome plated kettles) I’ve improvised wirth sheets of muslin and soft boxes.
Good light tables are normal table height, of stable construction, and have a translucent plastic surface (Perspex) that is replaceable. The background is a single piece sheet bent without sharp corners. It allows diffused light to pass through to illuminate the thing being photographed.The idea is to put a light under the table shining upwards through the plastic. The effect,when properly adjusted, is the lighten shadows cast by the thing to be photographed. Other lights can be put at the sides and top as needed. For small matt surfaced objects and most glossy surfaced objects this is all that should be needed. Very glossy surfaces such as cellophane packaging,blister packs,chromed metal, and polished stainless steel might still be too reflective. Deal with these as follows. Alternaive much of the work could be done in Photoshop if you have the relevent skills.
Spray lightly with a matting spray obtainable from a professional photographic dealer(e.g.Calumet) Do not over spray this material as some glossiness is usually needed to maintain the character of the subject. Difficult subjects are surprisingly common: blister packs present a formidable challenge for any professional photographer. Where time is pressing removing the thing from the cellophane or blister pack is the quick solution. Some improvement might be gained by using extra diffusion material between the lights and the subject. Adjustment of images in Photoshop can help assuming the photographer has sufficient knowledge of the programme.
Camera stability is also important in this kind of work. You camera should be on a very stable tripod. Always use a cable release. Better cameras have a mirror lock up facility usually buried in the custom menu. This should always be used if you have it as it stops the vibration of the camera occurring when the mirror springs up,
Modern lenses will focus down to 18 inches giving a close enough image for normal work. If you find that you need to get closer then it would be advantageous to buy a proper macro lens. Cheap ones are 55mm in focal length. The snag is that the lens has to be very close to the object to be depicted. Buy a 105 mm macro and the photo will be the same size but the camera will be twice the distance from the object. Longer focal length lenses are more convenient to work with when dealing with very small things.
Understanding how a light meter works is the next skill to acquire.Use a light meter to get an incident reading of the light (that’s the light falling on the object ) Background area should be slightly overexposed to burn out any distracting detail. If you wish to get rid of all detail you might still have to do a little work in an image editing programme.
Achiving the magic white backgroung is the simple part. You just overexpose the background so the white is at the top of the tonal scale. If you overexpose too much you will get a halation effect where the edges of you object begin to dissolve in light.
Finally check that the image is suitable for Internet use. Seventy two dots per inch, of the quality suitable for its degree of enlargement and the right sharpness for Internet use. There is often an action to do this work in editing programmes.