Tech Talk - Photos
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This page was last updated on March 12, 2017.
I have been asked to share how I produce photo images for books, magazine articles, and online photo albums. I have gone through many years of painful learning experiences, simply not knowing what to do or how to do it, and I now shutter when I see an image that I produced more than 8-10 years ago.
First action -- always, always -- is to clean the slide or negative with "canned" air, which is a pressurized can of air the is readily available at most stores. In my area that includes Walmart, Target, Costco, and Smith's Market Place.
While you are in one of these stores, head on over to the makeup section and pick up a soft-bristled makeup brush. Buy both a small brush and a large brush, as they will come in handy to physically remove the tough bits of dust.
Always, always, save the scanned photo as an uncompressed TIF file. Later, you can edit it or resize it for whatever purpose you need, then save it as a compressed JPG file.
DPI and PPI
DPI is dots per inch, and is the standard reference for printing to paper. PPI is pixels per inch, and is the standard reference for digital images. It may be wrong to say DPI when talking digital stuff, but the term is universal and understandable. I will try to use PPI.
For lack of a recognized standard, the goal is to follow (and improve on, if feasible) the general guidelines of the National Archives and the Federal Agencies Digitization Guidelines Initiative to produce digital images that are 5000 pixels along their wide dimension, regardless of resolution. National Archives recommends 4000 pixels wide for 35mm slides and film up to 4x5 inches; 6000 pixels wide for film 4x5 inches, up to 8x10 inches; and 8000 pixels wide for film 8x10 inches and larger. (see page 60 of Technical Guidelines for Digitizing Cultural Heritage Materials, link below)
A good overall goal is to produce images that can be published to paper, meaning that the image needs to be 12 inches wide and at least 300 ppi along the wide dimension, or 3600 pixels wide. I've been told by at least two editors that 400 ppi is better, so this means that a 12-inch image should be 4800 pixels wide. I default to 5000 pixels.
I found a web site called "The Megapixel Myth" written by Ken Rockwell in 2008. He explains some of the mystery about resolution and printing in the digital age. He notes that to get digital resolution that matches 35mm film, you would need a 20 MP camera. He also notes that Arizona Highways magazine, well known for its scenery photos, requires a minimum of 18 inches wide at 300 ppi, or an image 5400 pixels wide. An image that is 5400 pixels wide by 3600 pixels high produces a digital file that is 19,440,000 Bytes, or 20 Megapixels (MP).
Since I usually scan railroad-related photos, I like to be able to sort them by subject and date, and photographer. I always use dashes (--) and underscores (_) to separate the words in a file name; I never, never use a space in the file name because some internet servers insert the equivalent ASCI characters, which makes the file name very confusing (a space becomes %20).
All computer systems allow 256 characters in a file name. Use them.
Making descriptive file names that can be easily read by a human means that you don't need a separate database or document to describe the photo, except to add details for a later photo caption. I create file names using this sequence:
Railroad name (or major subject), including locomotive model and number, with underscore separators.
Date (usually dd-mmm-yyyy)
Photographer (or collection)
Example (UP GP9): UP_GP9_234_Salt-Lake-City_23-Jul-1978_Don-Strack-Photo.tif
Example (D&RGW depot): DRGW_Salina_Depot_6-Mar-1972_Ken-Ardinger-Photo_Don-Strack-Collection.tif
I use either lower case or upper case letters in the file name. Lower case letters seem less LOUD and easier to read.
I have learned to not "auto" anything during the scan, and to turn off all color correction. I use FastStone Image Viewer for 99 percent of my adjustments, which includes simple straightening, Cropping, Levels, Gamma, and very rarely, saturation. FastStone adjustments are much easier to do than any other free software, and are especially easier than Photoshop or Paint Shop Pro.
I generally use FastStone Image Viewer for the basic stuff, like adjusting gray levels on black & white photos, or color levels on color photos. It also works very well for straightening and cropping, and simple resizing. It also has a good batch conversion tool to convert TIF to JPG, for uploading to SmugMug.
Although it takes a while to load just for simple tasks, Photoshop CS6 also does a good job by using the "Straighten" feature on the new Crop Tool. In CS5 and earlier I used the Ruler Tool (right-click the Eyedropper Tool, then select the Ruler Tool), and the "Straighten Layer" button at the top. In either case, I can determine a vertical line, such as the corner of a building or a metal pole of some sort, or the corner of a locomotive cab or boxcar, or a horizontal line such as a bridge or part of a structure that is level. Trace the line with the Ruler Tool, and let go of the pointer (in CS6), or press the Straighten Layer button (in CS5), and Done!
I use Photoshop if I need to modify the image itself, such as fixing dust spots or adding a background to images where I have increased the canvas size. The healing brush and the clone brush work wonders. I also use Photoshop when I need to stitch two images together, that have been scanned as two images because whatever being scanned is too large to fit on the scanner.
I tried the Ai version of Silverfast 8, but it really is not a useful program for me.
I use Paint Shop Pro almost solely to fix the moire (dots) pattern of images scanned from publications, although using 300ppi for the original scans on the Epson flatbed seems to very good job of minimizing the dots.
Scanning Color Photos
I have both an Epson V700 flatbed scanner, and a Plustek 8200i film and slide scanner. I needed the V700 for the full-sized light in the lid. For slides, I like the Plustek. It takes less than one minute per slide, and it does a much better job with colors.
During 2014, I tried using VueScan with the Plustek film scanner, but the colors were off and inaccurate. As of March 2016 and the latest version of Vuescan, the colors are again accurate, and I am back to using Vuescan with the Plustek scanner.
For black and white negatives, and for color negatives, the Epson flatbed scanner does an excellent job. Do not try using the Epson software to adjust the colors on negatives. Turn off all color correction, and fix it later after scanning.
(The Epson flatbed did not work for the Emil Albrecht B&W 35mm negatives due to having to handle the tightly-wound rolls much more carefully; see below.)
Why Epson and not some other brand? I'm sure the other brands work just fine, but I have noticed when I visit camera stores, and when I read various online photography and photo imaging web sites and discussion forums, the one brand you see referred to is an Epson. And my own experience, at work and at home, with Canon, and especially HP, I have never had any trouble with an Epson scanner. And their software is the easiest to use. As for what the camera stores sell to photographers, I recall stacks of Epson V700 scanner boxes, and few other brands or models.
For slides, the Plustek 8200 scanner is exactly the same as the 7600 that it replaced. The difference is that the 8200 comes with Silverfast 8, while the 7600 came with Silverfast 7.
The Plustek 8200i SE was cheaper than the V700 by about $250. I bought mine from B&H Photo, which sells the 8200i SE and the 8200i Ai, as well as the 8100, which lacks the infrared feature..
After fighting with the Silverfast 8 Lite software that came with the Plustek slide scanner, I now only use the OpticFilm QuickScan basic software that also came with it. For the Epson flatbed, I only use the EpsonScan software that came with it.
I chose the Epson V700 because it has a full-size light in the lid. I had almost 150 large format 8x10, 5x8 and 4x5 negatives that I needed to scan. But most users could get by with an Epson V550 or V600, both for less than $200.00, would work just fine. These two will scan a single strip of 35mm negative film, or four 35mm color slides, or a single strip of medium-format 120-size film. The V700 has a larger light area in the lid, a better DMax resolution (meaning better detail in shadow areas), and a better quality light source. Spend some time reading online reviews, and watching reviews and how-to videos on YouTube. The recommended scanner is usually the Epson scanner, either V600 and V700.
Flatbed Scanner vs. Film Scanner
In June 2013, I did a test of scanning color slides on an Epson V700 flatbed scanner, compared to using a dedicated Plustek 8200i film scanner. A direct comparison of the same slide, and detail on the slide indicated that a dedicated slide scanner is better for color slides. But the tests also indicate that the differences can be acceptable if overall cost is a factor, and one can only afford a single scanner. If so, then a flatbed scanner for both black & white negatives and color slides and negatives is the best choice. Find the flatbed scanner that will do the size negatives you need to scan. For me, I needed the large light in the lid on the V700 for the 8x10, 5x8 and 4x5 Kennecott negatives that I was scanning.
I shared my findings with a group of railfan photographers, and one person wrote the following:
The real test of a scanner is to scan a crappy slide. One with less than perfect exposure, or lots of shadow detail. The higher D-Max of most slide scanners will produce a significantly better image than most flatbeds from a less-than-optimal original. Let's face it, a lot of us have a lot of less-than-perfect slides so a high D-Max scanner is especially useful for bringing poor originals back to life.
Also, on the V700, try scanning the same slide in different locations on the holder. Usually the ones closest to the center are sharper than the ones toward the outside of the holder. But I suppose the opposite could be true depending on that particular scanner's "sweet spot".
The light on the Plustek slide scanner started giving colors that were off by enough that I have stopped using it, so it now sits on the shelf. I now use an Epson V850 and Vuescan for most photos, including all prints, all negatives and all slides. The combination of Epson and Vuescan have been found to be easy, with accurate colors. I made my own mask to scan hundreds of 116/616-size negatives recently acquired.
Using the Epson V850 for slides, with Epson's own software, is working quite a bit better for slides. The new-design slide holder is adjustable for focus, and I am using one notch above the factory default. Surprisingly, an attempted second chance for the Plustek slide scanner resulted in out-of-focus images compared to the Epson, so the Plustek is now back on the shelf.
The Silverfast that came with the Epson flatbed scanner is the SE version, not the Ai version. Using Silverfast is incredibly versatile, which makes it also incredibly complex. Too many choices are offered, with little if any explanation what each will do. Like Photoshop, it is meant for professionals who do this sort of thing on a regular basis for publication.
I don't have much use for the "Lite" version of Silverfast that came "free" with both the Epson and Plustek scanners. It's like using Photoshop Essentials instead of Photoshop. For the Plustek slide scanner, I spent a lot of time trying to get Silverfast to do simple scans that had accurate colors, but finally gave up and now I simply use Plustek's own Quickscan program that is part of the driver software package. It forces a bit of a clunky workflow, but the colors are perfect.
I have found that calibrating a scanner is a waste of time. The photos that I scan are not fine art images, and are used for simple publishing to the web and for basic books and magazine articles. None of these photos are being enlarged beyond single-page size, and most are half-page size. In reality, most are taken by amateur and hobbyist photographers from earlier times, using basic entry level cameras. Fine tuning for absolutely accurate colors is not a requirement.
Upon the advice of a couple helpful people who have read these comments, I have tried scanning 35mm color slides using Vuescan, with the Color tab set to None. I then set the levels of the individual RGB colors and gamma with FastStone Image Viewer. These same comments included advice that we should never allow any scanning software to adjust colors, and that all colors should always be adjusted after the scan, using whatever post-scan software we choose. I use both FastStone Image Viewer and Photoshop (but mostly FastStone), and setting levels and gamma in each works equally well.
Scanning Black & White Photos
Scanning black and white photos and negatives is a whole different story than scanning color. Without having to worry about accurate colors, using the Plustek and Vuescan for 35mm negatives is by far the best route for scanning black & white negatives. It allows a very sensible workflow that is simple and fast. I use 16-bit grayscale for the scan, and 8-bit grayscale for the output. This combination seems to reduce the artifacts.
(Update, March 2016: I have started using the Plustek film holder on the Epson flatbed scanner. I like the workflow, mostly because Vuescan and Epson seem to be a better match. I was a bit concerned about focus because the different distance between the glass and the film in the Plustek holder, but it actually seems do a better job focusing.)
I use the Epson flatbed to scan medium format black and white negatives, because it came with the needed negative holders.
For black & white or color prints, I still use the Epson flatbed scanner, and Epson's own scanning software. Depending on the size of the print, I scan smaller contact and postcard-size prints at 1200 ppi, I scan 5x7 prints at 800 ppi, and 8x10 prints are scanned at 600 ppi. This is slightly better than the National Archives standard of 800 ppi for prints up to 4x5 inches; 570 ppi for 5x7-inch prints; and 400 ppi for 8x10 prints. The general guidance being 5000 pixels along the long side.
I use these higher resolutions to allow the digital image to be used for research by zooming in on an image to see finer details, like using an eye-loup or magnifying glass on the original print.
I like to scan Union Pacific's calendars, but I still have several more to add to the collection.
Union Pacific Calendars -- Information about UP's calendars, including a link to an online album showcasing more than 130 of the months showing trains.
The later calendars do not use Union Pacific photos, which is why I did not scan them.
To scan most of those that I shared in the online photo albums, I used a regular Epson V700 flatbed scanner, done in two separate scans. The two scans were then stitched together using Photoshop. Make sure you have plenty of overlap. The outside borders were cropped off, and new 50px borders added, matching the color of the bottom border, where the caption is.
The most recent images are done with a 24MP Nikon digital camera, mounted on a copy stand. This combination allows a single image, with the needed 300ppi resolution. I use sixteen Daylight (5000K) LED flood lights for lighting. Each is 18 watts and generates 1323 lumens, and sixteen of them in four groups of four generates plenty of light.
I had really bad keystoning with my earlier images taken with the 24MP camera, as well as other earlier attempts with other smaller cameras. Then, I was reading online about various things to do while taking photos with a copy stand, and one of the tips was to get a bubble level. Using a bubble level, I make sure the base of the copy stand is level; several layers of index cards took care of that. Then I make sure that the back of the camera is also level. Turns out that the camera mount on the copy stand was not perpendicular to the base, so I shimmed it with layers of the same index cards, cut into 1-inch squares. A simple tip that fixed the keystoning problem.
I use a dedicated macro lens for the camera itself, which prevents fisheye effect.
Scanning Emil Albrecht Photos
These rolls of 35mm film are in rolls that snap back like a steel spring. Since I received them in January 2012, I have tried several remedies to take the curl out them, but none worked. The negative holder for my Plustek 8200i film scanner has openings for six images, with a cover that is hinged at one end, and a snap closure at the other. I wore cotton gloves, and held the roll up to the light and unroll six images. I then cut a strip of six images off of the full-length roll, one strip at a time. I had to carefully hold each strip in the holder, and carefully close the cover. I then adjusted the position of the strip within the holder, averaging the amount of image that is visible, since they do not line up perfectly, meaning that the spacing of the images as they were taken in a 1940s era camera do not match the perfect spacing of the Plustek negative holder. I used canned air to blow off any dust or lint that may have attached itself.
I used Vuescan and scanned the negatives at 2400 ppi and 16-bit gray, with no color balance or correction, and manual cropping. I had tried 3600 ppi, but I got artifacts in the scan, and the light grays in the sky were blown out as pixelated white blotches. I have learned that this is because on the Plustek, for grayscale images, anything higher than its native 2400 ppi, is interpolated, or "upsampled." You can see this on some of my earlier scans, but it's not bad enough to make me want to re-scan them.
Each scan took about one minute to preview, crop, and scan. I then used Photoshop CS6 to straighten the image, then set the levels manually (no "auto" anything), tweaking the gamma and contrast as needed (easy in FastStone, a bit harder in Photoshop). For most of Emil's negatives, I found that using Photoshop CS6 for the first adjustments worked best. I dragged six images at a time into Photoshop, then looked to see if an image needed to be straightened. If so, I used the Straighten feature in the Crop Tool. I have found that the way Photoshop uses to adjust Levels seems to be better than FastStone, so after straightening (if needed), I adjusted Levels. Because it is easier, I then use FastStone to adjust the Gamma and Contrast (on its Adjust Colors workflow).
The finished scan is re-sized to 5000 pixels width, which is the National Archives standard, then saved as uncompressed TIFs. Each finished file is about 16MB for a 35mm negative. The images in the SmugMug online albums are converted to full-sized JPGs using FastStone's Image Re-sizer, at 100 percent quality. For the images I shared on TO, I re-size them to 120 ppi and 900 pixels wide, then save them as JPGs.
After I scan the negatives, they were placed in a snack-size Ziplock bag, on which I have used a Sharpie to write a description on the bag. Each roll came rolled in a paper wrapper that Emil wrote the information and date. I scanned this piece of paper as a label, which is uploaded with the images to the online albums. This paper sheet is placed in the Ziplock bag, and the bag was sealed.
FastStone Image Viewer -- To adjust colors, brightness and contrast, I use the (free) FastStone Image Viewer. I have Photoshop CS6, but using FastStone is much easier and quicker.
Vuescan -- I started using Vuescan in 2002 for slides.
Pearson Imaging, About Film Formats -- Link to a web site not updated since 2012, that may disappear any day.
FADGI Technical Guidelines for Digitizing Cultural Heritage Materials (PDF; 101 pages; 5.4MB)
Library of Congress, Guidelines for Personal Archiving; see also "Scanning Your Personal Collections" (PDF; 2 pages; 113KB)