Equal Exposure

Hi,

I'm currently building a new website for my school. Our Bookstore

wants to be able to take pictures of their merchandise and send it to

the webmaster for posting. They have a very simple digital camera. I

was wondering what steps could I give them so the exposure in the

pictures are similar and colors accurate -- I?m not talking about

ultimate color accuracy.. just something that seems close enough -

they are not picky.

 

I would be gratefull about any pointers.

 

Thanks Alot !

The key is ensuring consistent lighting. You can construct a makeshift copy stand using a pair of anglepoise lamps with identical tungsten bulbs placed on the floor either side of the area which will form the stage for the books, well away from any window so that the lamps are the dominant (almost only) source of light. They should be aimed toward the centre of this area, at an angle of about 45 degrees. This will minimise unwanted reflections from any shiny surfaces. For repeatability, it's handy to measure the separation of the lamps and the height at which you set them.

 

The camera needs to be mounted on some sort of tripod/support (a cheap tabletop tripod lashed to a wooden batten held in place from a desk surface by a pile of books will do). The camera should be set for time delayed exposure (2 secs works well), or triggered by remote, and preferably using manual exposure mode so that exposures are consistent regardless of the colour of the subject. Flash should be set to off. If you can control ISO, it should be set to the lowest value available. It's probably a good idea to use the camera's custom white balance option if it has one, or at least to ensure that white balance is set to tungsten. Do some exposure bracketing of a test subject using the smallest intervals of shutter speed you can, and pick the best one after viewing them on your computer. You may get better sized-for-web images by shooting at the camera's best quality and doing the downsize on the computer, rather than having the camera do it.

My first digital camera (Largan Mega Chameleon - free with computer purchase) had no provision for changing the exposure or white balance. Colors were rendered best in sunlight, so you my try photogaphing the products near a window with available light for best color reproduction. A cheap clear shower curtain could be used as a diffuser, if needed, as well as a white foamboard as a reflector.

One other tip - you should probably use the middle of the zoom range, since any distortion that you might get (which will show close to the edge of the frame with a rectangular subject like a book) will be minimised. Crop the images to size on the computer, rather than zooming to try to fill the frame. Another reason for using the camera's best quality/resolution setting and doing the resizing on the computer.

constant lighting is useless as long as there is a automatic white balance doing what it wants.

 

I once tried to shoot various types of eyeglasses in front of a white background under color proofing light source, with a autowhitebalancing Powershot 70Pro. A frame of eyeglasses isn't much material to fill a piocture, but the colortaint of the background looked very different if I shot a red or a blue frame.

 

Using the built in flash might help. At least the ****ing canon had a fixed white balance with external flash.

 

O.K. you can't usse built in flash on a copy stand, but well, a copy stand wouldn't show how thick the book is.

 

tell them to shoot ahead, or let them capture stills from a old camcorder, which might offer a fixed custom white balance.

 

It's hard to gain professional look from something far below prosumer equipment in the digital world.

The simple answer is to press the button and without doubt the camera will ignore all the professional requirements and take excellent shots ....I used a Coolicam for several months until a freind told me it wasn't doing my skills justice. With a 320x180 sensor it gave me 4x3 inch photos in the club magazine of bold subjects. I added a plastic 1 dioptre [hobby glasses lens] so that I could take shots closer.

Where there's a will there's a way. If they use a sheet of white card as a background, then even if the camera lacks white balance controls, there are lots of image processing programs that will allow white balance to be reset by highlighting a portion of the white background. The trickier problem is if the camera doesn't allow manual exposure, but even here, some software also allows a black point to be set in addition to the white point, so including a small area of black paper at the edge of the frame would allow the exposure to be corrected.

 

In my view flash should be avoided because it creates specular reflections and hot spots from glossy book covers, and shooting using daylight requires similar weather conditions (e.g. same kind of clouded sky or just blue sky) and time of day (even time of year in higher latitudes) to produce consistent lighting. You can only use flash if it's a pair of off camera flashes set up at an angle as with the anglepoises - an unlikely solution for a cheap digicam.

Thank You very much guys. That gave alot of ideas on how to set them up, Luckly theyr camera has costom white balance, but on the other hand no manual exposure.. Well I'm sure that with your tips we will get it set up fine.

 

Thanks Alot !!!