Delderby Loc: Derby UK

From above solutions, the obvious one is to photograph the pic - as straight as you can. Then load it into a computer editor for any final straightening that may be necessary, and perhaps further editing to improve.

bw79st Loc: New York City

You don't need to do all that work. PS will piece it together for you in Photomerge. It even staightens out any sections that may have been scanned askew.

CPR Loc: Nature Coast of Florida

A correct answer, and probably the easiest one.

StanMac Loc: Tennessee

If there is a service in your area or nearby that does architectural blueprint production they may have a large scanner in shop that could handle large sheets.

Stan

therwol Loc: USA

You're brilliant. It was shot with a 55mm f/1.2 lens. That's all I had available at that moment when I went to my parents' home in Mobile, AL after the hurricane. I didn't think ahead of time that I should take my 55mm f/3.5 macro lens when the purpose of the trip was to help cut up downed trees with a chainsaw. I don't remember what film I used, possibly Tri-X. It's better to have made the photos than not. There were no consumer grade scanners and no Photoshop 45 years ago.

rcarol

You can scan sections and use a stitching program to recombine all sections into the final image.

burkphoto Loc: High Point, NC

In my 20s, back in 1979-'87, I copied thousands of book covers, book pages, stamps, coins, business forms, and photographs for slide shows. I had a professional copy stand setup, but that just made things efficient. You can get the same results with far less gear.

If you have a macro lens or close-focusing lens with no field curvature (i.e.; apochromatic, flat-field lens), a near-perfect copy can be created.

Lighting matters. Get a book on copy photography and learn the proper techniques. I learned decades ago from one of the Time-Life Library of Photography volumes. Once the principles are understood, you can get excellent results with minimal effort.

Basically, you want two identical color-accurate light sources (High CRI of 96 or better), adjusted for even illumination within 1/6 f/stop over the entire surface of the largest print you're copying. I use a couple of video light panels that we bought for interviews. They are equidistant from the center of my copy board, on either side of it, at 37° to 45° angles above the board, feathered for even exposure.

These days, I still meter a gray card, but I use a custom white balance off of a target. I also expose a frame of a ColorChecker chart for reference in raw editing. I use the camera natural picture style. And I work with raw files.

All the menu settings from the camera JPEG processor are carried forward via the JPEG preview of the raw file. They prime my post-processing software, so the image that appears on my calibrated and custom-profiled monitor is pretty close to correct. I make minor adjustments to match the original, and export a JPEG for whatever purpose I need.

Here's a reasonable facsimile of my ColorChecker chart copied on my camera with macro lens and video lights:

This can be tweaked as needed, but it is close to the original chart.

(Download)

RKastner Loc: Davenport, FL

The only problem with scanning is that it's probably only going to let you save it as a JPEG or a TIFF. Neither one is going to let you do much in Photoshop with it.

Ed Chu Loc: Las Vegas NV

I went to a Staples that had an over-sized bed, and was able to make copies of newspapers, etc.

burkphoto Loc: High Point, NC

A good scanner will save a 16-bit-per-channel TIFF, which is about as manipulable as you can ask for. The cheap ones are 8-bit output, 10-bit input if you are lucky.