Monday, March 5, 2007

HPL-97-164. Professional Portrait Studio for Amateur Digital Photography

HPL-97-164. Professional Portrait Studio for Amateur Digital Photography

The information in technical papers is very different from information in product brochures, magazines, or how-to Web sites. When you search information on a product, you can count on the vendor giving you current and relevant information. When a product is updated, the information about it is also updated. When a product is obsoleted, its information is made a little harder to find, and when the product is no longer supported, most information about it disappears.

This is not so for technical reports and papers. Research is built on previous research and that previous research must remain available forever so people can always go back to previous work and reproduce results. When you do a search, your engine will give you all links it finds, but does not evaluate them for you. If you are not a researcher be aware on how researchers use links. They typically use a search engine like Medline, Web of Science or Google Scholar to find all papers citing that first paper, and then consider only the last result, not that in the first paper they find.

Now to Professional Portrait Studio for Amateur Digital Photography. In 1996 our project did the technical demos at the HP Analyst event in Montreal. Among others there was portrait studio for executives manned by a famous local photographer, using HP's new first generation digital camera with 6 second shutter lag. People with big egos are very hard to portrait, and there is no tolerance for failure. The the portrait has to be flawless.

Compared with the cameras you buy these days, the first generation cameras were really bad. The 6 second shutter lag meant that the photographer had to think 6 seconds ahead, and then everything had to be perfect.

At that time, cameras really had only about 6 bits per pixel, the rest was just sensor noise. This means that the illumination was critical. There had to be plenty of light and the difference between highlight and dark shadow had to fit in the 6 bit dynamic range.

The only light technology that would allow a consumer camera of 1996 to get professional quality was to use a high frequency D65 light source as it is used in TV studios for example for the news. With today's cameras you do not do it that way. You no longer need a high frequency light source, you no longer need D65, and you have 12 or more bits per pixel to play with.

So please, do not use the instructions in this technical report to build a portrait studio! There used to be about 150 downloads per month, but all the sudden in February it jumped up to about 500. That is scary!

When a year ago I had to shoot some important portraits in difficult light situation for my neighbor, I went to the nearest camera store to find current literature. I bought a DVD made by world-renowned photographer Joe McNally. I am sure you can find it in a photography store near you. The title is The Speed of Light and I highly recommend it. If you came here through a link, please use the comment field below to let me know about it, maybe I can put the genie back in the boc or at least muzzle it.