photographing documents

Slon · 08-14-2008, 05:24 PM

I need to photograph documents with the IstDL. Any suggestions that you can give me? I already have a tripod, some lighting, set the ISO to 200 (lowest), shooting in flash off mode, have a USB and power adapter (and waiting for remote). Any other settings suggestions?

RioRico · 08-15-2008, 04:14 AM

I'll assume that your documents can't be shoved into a copier-scanner, eh? Before I got a scanner, I'd photograph documents after borrowing my in-laws' copying outfit, which had an enlarger-type camera mount, dual side-mounted lights, and a heavy non-glare plexiglas plate to hold the documents flat. Whatever camera I used, I shot B&W, used a polarizing filter, and did my best to increase contrast & DOF.

Your settings depend on what you're shooting -- text only, mono or color images, IR/UV forensics, etc. Do you want your images to be flat or textured? Are you shooting typewritten pages, old publications, ancient hand-lettered & illuminated manuscripts, kindergarten drawings, or what?

StarDust · 08-15-2008, 04:28 AM

Good points there. A scanner is preferred but sometimes that's not possible. I think a high f-stop is good so the photo is sharp out to the edges.

Slon · 08-15-2008, 11:14 AM

Originally Posted by RioRico

I'll assume that your documents can't be shoved into a copier-scanner, eh? Before I got a scanner, I'd photograph documents after borrowing my in-laws' copying outfit, which had an enlarger-type camera mount, dual side-mounted lights, and a heavy non-glare plexiglas plate to hold the documents flat. Whatever camera I used, I shot B&W, used a polarizing filter, and did my best to increase contrast & DOF.

Your settings depend on what you're shooting -- text only, mono or color images, IR/UV forensics, etc. Do you want your images to be flat or textured? Are you shooting typewritten pages, old publications, ancient hand-lettered & illuminated manuscripts, kindergarten drawings, or what?

It is a textbook. Unfortunately, scanning is not feasible because it would take an enormous amount of time and/or require a lot of manpower. It has some pictures and is typewritten. I can mount some regular lights on the tripod. However, after I did that, the photo didn't get lighter, it got tinted red. I don't happen to have any plexiglass on hand. I'd rather not shoot B&W. How do you do the polarizing filter and increase contrast? DOF?

graphicgr8s · 08-15-2008, 01:42 PM

On a regular flatbed, you're right. Very labor intensive. Go to a printshop. Most if not all the new copiers can "scan to archive" in other words scan it to a pdf file. You get about 600 dpi resolution at full size. And textbooks aren't all that difficult. What part of the world are you in?

Slon · 08-15-2008, 02:03 PM

Originally Posted by graphicgr8s

On a regular flatbed, you're right. Very labor intensive. Go to a printshop. Most if not all the new copiers can "scan to archive" in other words scan it to a pdf file. You get about 600 dpi resolution at full size. And textbooks aren't all that difficult. What part of the world are you in?

US, eastern. Sure, I can do that, but it would be too costly.

*gokenin* · 08-15-2008, 04:22 PM

just curious why are you photgraphing a textbook? is it an old manuscript?

PDL · 08-15-2008, 10:50 PM

Get - make - yourself a copy stand, sort of a tripod in reverse. Just look at B&H, Adorama or any other decent photo equipment vendor - they sell them.

Get a 18% grey card to set your exposure with either the flash or lights used on the light stand.

Get a remote shutter.

If the documents have color - get color control patches and shoot them in each frame.

Focus any old way you want - remember to disable the AF from the shutter button - why refocus for each shot?

Blast away - take notes, do not rely on EXIF only - embed the notes in the EXIF

Be ready and willing to do some shots over and over until you are satisfied. This is essentially a lab - so take control of everything.

The Elitist - formerly known as PDL

Nico · 08-16-2008, 01:06 AM

Good instructions by PDL. I just want to add few details. Two light source either flash or light bulb need to be at about 45 degrees. If you shoot with light bulb make sure that there are no outside light interference for even exposure from beginning to the end. Advantage of light bulbs is the ability to visually adjust the light source for minimal glare quickly. Make sure that the camera is perfectly parallel to the surface below to minimaze distortion (not an issue with copy stand). From my experience the exposure does not need to be adjusted once set with gray card.

If you are going to be doing this more than once, used copy stand with lights is recommended. You will need to set everything only once for consistant results.

Slon · 08-16-2008, 02:04 AM

Originally Posted by PDL

Get - make - yourself a copy stand, sort of a tripod in reverse. Just look at B&H, Adorama or any other decent photo equipment vendor - they sell them.

I was thinking of making one by simply making a hope (for the lens) in an old table and just inserting the camera that way.

Get a 18% grey card to set your exposure with either the flash or lights used on the light stand.

18% grey card? You mean just a shade of gray? I can probably print that with my greyscale laser printer.

Get a remote shutter.

I have a wired one on the way that is supposed to work with this camera.

If the documents have color - get color control patches and shoot them in each frame.

What is the point of that?

Focus any old way you want - remember to disable the AF from the shutter button - why refocus for each shot?

Should I just use AF the first time?

Blast away - take notes, do not rely on EXIF only - embed the notes in the EXIF

My camera only has JPEG and RAW (I use RAW).

Be ready and willing to do some shots over and over until you are satisfied. This is essentially a lab - so take control of everything.

The Elitist - formerly known as PDL

One more thing. Can anyone confirm/deny if the IstDL has tethered shooting capability? That is, can I hook it up and control or even automatically view (without having to use it as a card reader or camera, one at a time) images via computer? I have the USB cable. I tried pkremote (basic install) on openSUSE 11 and pentax remote software 1 and 3. None recognized the camera. I can only view the memory card when connected.

Also, can you tell me the camera SETTINGS (IstDL) to set? You say a lot of terms but I don't recall seeing them in the camera.

Slon · 08-16-2008, 02:05 AM

Originally Posted by Nico

Good instructions by PDL. I just want to add few details. Two light source either flash or light bulb need to be at about 45 degrees.

I have 3 yellow light lamps (basic light) that I can attach readily anywhere. I also have a UV lamp.

If you shoot with light bulb make sure that there are no outside light interference for even exposure from beginning to the end. Advantage of light bulbs is the ability to visually adjust the light source for minimal glare quickly. Make sure that the camera is perfectly parallel to the surface below to minimaze distortion (not an issue with copy stand).

You mean perpendicular?

From my experience the exposure does not need to be adjusted once set with gray card.

How does one use a gray card?

If you are going to be doing this more than once, used copy stand with lights is recommended. You will need to set everything only once for consistant results.

flyer · 08-16-2008, 04:17 AM

To use the gray card, you just put it under the SAME light as your subject, do a light meter reading, adjust the exposure according to that reading, then you take off the gray card and you take your picture. You don't have to do a gray card reading for the next pictures if your lighting is consistent, since nothing will have changed. I dont suggest you do a gray card with your computer, since, if you don't have perfect control of everything, you can end up with a color cast in the gray. The color control patches are positioned just outside the image you want to photography, but still visible on the picture. They are used to adjust/balance color in post processing. Very useful in repro.

Nico · 08-16-2008, 04:21 AM

Originally Posted by Slon

I have 3 yellow light lamps (basic light) that I can attach readily anywhere. I also have a UV lamp.You mean perpendicular?How does one use a gray card?

Regular tungsten bulbs are fine. You might need high wattage bulbs. I used use two 250w bulbs.
Sorry, film plane patallel to the surface below which is equal to the lens beeing perpendicular the the surface.

Probably I am not the best person to explain the 18%gray card but I will give a go. Camera exposure system is based on light reflected from a 18% gray. Metering should be done based on amount of light that is available. Grey card send back/reflects exact amount of light that is available. You probably have seen light meter placed at the face of a model to measure available light from the flash not what is reflected off the face.

Gray card: Place it where the document is going to be and set the proper exposure. You should be able to use the same exposure obtained with the gray card for light or dark pages.

Color reference patch : Take a test shot and adjust the white balance until the colors of the reference patch from the image matches the color of actual reference patch.

Personally I do not see the need to include the color reference patch for every frame. Once set, exposure and white balance should not change in a controlled environment. If you move the tripod or lights, you should recalibrate all over again. That is why if you are going to do this more than once copy stand will come in handy. There is no need to recalibrate anything unless the bulb changes.

Nico

(if my description of the gray card is incorrect in any way, please feel free to correct me. Thanks)

PDL · 08-16-2008, 07:29 AM

You do not need to refocus each time - back in the old days I used to use all manual stuff - if you use AF associated with the shutter button - there could be the issue of "hunting" as the stupid AF computer tries to decide on what it wants to focus on. This is a lab - take control.

As for the Grey card - shoot manual not autoexposure - each page of the document will have a different "color" and that can vary the exposure. Again - take control - go manual.

As for the color control - put it on each image that has color. It is difficult to correct for color variences (there will be some - trust me, with film every time you changed rolls you had a slightly different color response - unless you bought all the film with the same batch number) if you have to scroll back to your "reference" image. Put it on the edge so you can just catch it - you might even want to put a B&W scale with a 18% grey patch. In post processing you can use the eye dropper to set grey point, white point and black point to get the most out of the image.

When you convert the image from RAW to JPEG, or in some cases have create a sidecar file, embed discriptive information IN THE IMAGE for future reference. Notes can get lost - if the information is in the image --- well, you just have it.

The Elitist - formerly known as PDL

Slon · 08-16-2008, 03:28 PM

I think I'll just put my tripod on the side, attach it to something so it doesn't fall, and go from there. Otherwise, it's practically impossible to get the camera perpendicular to the document without having the tripod legs getting in the way.