View Full Version : Document photography

01-19-2007, 01:31 PM
I have a Olympus 3040Z camera which, several years ago, was "camera of the year." With only 3x optical zoom, 2.5x digital zoom, and 3.3 megapixels, it has been far surpassed by what is out there now.

However, I have used it extensively for document photography, and have been very pleased with the results. I use the macro setting (and also turn the digital zoom on) and if the document or photo is 8.5 inches by 11 inches in size or smaller, with print that is not too small, I can print out a clear, crisp, easily readable facsimile of the orignial document. Usually, the ambient light in a library or archives is just fine, so I normally don't use a flash.

Now, I am looking at a project where I will be photographing 12 inch by 18 inches of broadsheet newspaper pages. I tried a few trials, using various settings (high quality, super high quality, TIFF) and then printing the images out in the same 12 inch by 18 inch size as the original. The print is rather fuzzy and difficult to read.

1. Is the problem that I just don't have enough pixels here? Not enough light? Both? Do I need to upgrade to a camera with 6 megapixels?

2. If the lighting were better, I'm guessing the lens opening would be smaller, resulting in sharper focus. Flash can sometimes wash out the document, so I've heard that taping plastic from a milk jug over the flash will give more light but diffuse the flash. I don't think I can bring in a copy stand and floodlights, but I have seen small LED floodlights which can be attached to small flexible stands, and wonder if four of these would help. Has anyone tried anything like this?

3. I've also heard to NOT use the digital zoom. Why is this? I almost always do and the images come out fine. I tried turning it off for the 12 inch by 18 inch documents but it made no difference I could see.

4. If I take separate photos of the top half and bottom half of the document, they are much sharper and are readable. However this means I would have to stitch them together. Stitiching programs I have tried cannot auto stitch newsprint images together, and besides, I will probably have several thousand pages to put together.

5. What about converting color RGB images to greyscale? Again, I've heard not to use the "convert to greyscale" option, which strips out all color, but to turn the image into a red monotone first, eliminating blue and yellow, and then converting to greyscale. I tried this using Photoshop Elements, but frankly, I thought the "convert to greyscale" method gave a better, more uniform background. Many of these newspapers are yellowed so it is impossible to get a nice, clean, white background.

Any and all comments about document photography appreciated.



01-20-2007, 10:31 AM
I think you need more megapixels.

I am assuming that the camera is working correctly, specifically that it is focusing correctly on the 12x18 newspaper held further away than 8-1/2x11 typewritten pages..

You could compare those portions of the 12x18 newsprint where the print is bigger with your 8-1/2x11 typewritten pages. When you run up against the megapixel limitation, it is the size of the text relative to the height of the frame that is the specific limiting factor.

Try decreasing the compression level of JPEG (if possible). Non-lossy formats such as GIF or RAW may improve things even more.

Also the lens quality is important for this much text on a frame. If the middle of the picture is clearer (the text more readable) then the lens is at least partly an issue.

If you want to convert to grayscale, do it in the camera, not in the computer. Putting a green filter on the camera tightens up the focus a bit while still letting in the most light for the same lens opening etc. This is almost the equivalent of converting to grayscale in the camera.

Digital zoom does nothing more, nothing less than manipulating Photoshop or other editing software to magnify the picture after downloading it to your computer.

Useful digital camera hints:

01-21-2007, 06:23 PM
3. I've also heard to NOT use the digital zoom. Why is this? I almost always do and the images come out fine. I tried turning it off for the 12 inch by 18 inch documents but it made no difference I could see.

Digital zoom is basically just useless. It's (a few technical nitpicks aside) identical to taking the image without digital zoom, cropping out the middle, and then expanding that using interpolation (i.e., using software to invent the missing pixels based on the surrounding ones) to be the same size as a non-zoomed image file.

In other words, you gain size, but no actual increase in detail.

Norm in Fujino
01-23-2007, 01:39 AM
I would also avoid digital zoom like the plague.

1. Set the camera for your highest jpeg setting (SHQ),
2. Set the record mode menu adjustment for contrast to "high."
3. Set to the lowest ISO possible (100).
4. Use a tripod (or copy stand).
5. I would shoot in color and then covert to greyscale afterwards in a software program (Photoshop, etc.). There are many ways to convert, so you should try several to see which works best for your images. You can also raise the contrast at that stage, together with sharpening.

If you're shooting hand-held in dim surroundings, that's enough reason for there to be blurriness in the shots.