In past issues, we have written about halftones from the standpoint of reproduction, different screens, laser scanning, halftones vs. PMT'S, etc. This time we'll cover how to select and present photos to your printer.
As before, I'm relying on "outside help" for this story ... namely T-S order planners and a camera person as well as several customers who do a good number of illustrated books. If you have additional tips you believe would be useful to someone planning to reproduce photos in a book, let us know what they are and we'll include them in the next issue.
Photos should be selected with good contrast and clarity of focus in mind. They are the most important factors for good-looking reproduction. The printer cannot improve an out of focus photo, and it will likely actually be a bit worse after it is printed. If your photo lacks contrast, we will automatically enhance that by making the highlights a bit whiter and the shadows a bit darker (unless you tell us not to) but there are limits to what the camera can do here. It's best if the contrast is already in the photo to begin with.
You should try to provide black and white glossies or matte finish photos for halftones. Textured finish photos can sometimes cause a problem with what looks like a moir pattern in the halftone negative. Also, your photo should not be on wavy paper as that is difficult to feed through a laser scanner.
Color photos can be used for black and white halftones although the contrast in a dark blue or dark red area may not show up well. The camera sees colors differently than the human eye. Color slides or transparencies are still greater problem causes. They must first be made into glossy prints before they can be photographed. If all you have is transparencies, it is best to get a black and white glossy made from the transparency so you can see if the black and white is going to be good enough for your purposes. If a commercial photographer does this for you, they may be able to get what you want by using color filters.
It is best if your photo can be reproduced at the same size or smaller. However, if it is in good focus to begin with, it can usually be enlarged up to 100% before the focus is affected.
You should not write on the back of a photo. The indentation it leaves will often show up in the printed halftone. A better way to identify a photo is to write or type on a label then tape it to the outer edge or corner of the photo. If you feel you must write on the photo, use a soft lead pencil and write on the outer margin of the back.
There are several ways to show how you want your photo cropped. Tissue overlays have long been popular but they are not practical if your printer uses a laser scanner to make the halftone negative. The tissue won't go through the scanner. If you do use tissue overlays, we would make a Xerox copy of the photo with the overlay in place so layout can see how it was before we removed the overlay.
Black crop marks in the margin of the photo are the most common cropping method for photos and this works fine ... if you have margins around the image. If not, you can mount the picture on a thin, flexible board and put your crop marks on the board. Try not to use boards more than 1/16" thick as thicker ones also won't feed through the laser scanner.
Other ways to show cropping and placement of the photo include sending the photos to the printer before the job is ready to go, have them make a halftone negative with the correct reduction or enlargement and then send you back a contact print of that negative.
You can crop the contact print with scissors to the exact size you want and paste it down on your final camera copy. You could, if you want, show this to the author for approval of size and cropping.
Another good way, if you have the equipment, is to make a Xerox of your photo, enlarged or reduced the amount you want, then cut out the area you want to print, just as you did with the contact print, paste it down on your copy and send that to the printer ... along with the photo, of course.
If you prefer not to paste rough prints of the picture on your camera copy, you can indicate the size and location of the picture on the text copy with four corner marks, a full outline box (or keyline) or a rubylith window. The printer isn't likely to care which of the first two you use but, at least in our plant, the rubylith window is the least desirable. If you provide a rubylith window, we would use it for position only so, unless it is free, it's probably not worthwhile.
If you use a full keyline outline box, be sure and tell the printer if the keyline is to print around the photo or not. If you want it to print, we will "manufacture" the exact size keyline to fit the photo automatically on the scanner, without using your box. If we must use your box, we have to composite the line and halftone negative together, this is a time consuming process and carries an additional charge.
If you want to reproduce an arrow on your photo, it can best be done by putting it in the correct position on an acetate overlay. If you put the arrow directly on the photo, it will print with a dot in it so it may not be as obvious. The disadvantage of the overlay is that it does necessitate a combination line and halftone shot which again adds $5.00 to the cost. The last bit of information that I can find in my four pages of notes is that when camera sizing your photos you should allow for 1/32" (on all four sides) that won't show up on the printed photo. When we strip the halftone negative, we need that much space to open the "window" around the photo on the goldenrod flat. I think that's it. Thanks to Vicki, Linda, Joyce, Emmy, Becki and Marge, for providing me with their ideas. If any of this is wrong, it's their fault.
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We are not recommending creation of an insert as it is rather an expensive addition but it can be done if it is needed.
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In 1993 we shot just under 40,000 halftones, a 10% increase over 1992. Of these, virtualiy all were scanned on one of our two 2540 DPI Laser scanners.
The scanner which is doing the large majority of all of our halftone negatives is the new Dupont Scanner. It can create halftone negatives from approximately 120 lines per inch up to 200.
In actual operation we use 150 lines per inch for halftones that go on covers, jackets, text enamel, matte text and white offset text stock. We use 133 line halftones for natural text stock. On coated stocks we can go up to 175 lines if you request it.
This scanner can also do duotones and, in the rare case that you need it, tritones. In addition to scanning direct from black and white glossies (the medium of choice), it can also make black and white halftone negatives direct from color prints or color transparencies, at no additional cost.
When our operator scans a halftone, he or she looks the photo over and decides if it needs any special enhancement. The scanner has the ability to enhance contrast by making the shadows darker or the highlights lighter or both. This is known as photo enhancement and it can actually, in some cases, make a "flat" or mediocre photo look a lot better printed than it does in its photographic form.
While we routinely make these judgments, if you have anything you specifically want done, by all means tell us. We can shoot to exactly reproduce the photo as it appears (this is what we usually do) or manipulate it if you want.
The scanner can put keyline boxes around the halftone . . . actually our ECRM Scanner does this better than the Dupont . . . for a small added cost per halftone. Another thing we can do, by utilizing Adobe Photoshop software, is remove an object after the halftone has been scanned.
Another thing the scanner can do is make a halftone negative directly from a color transparency. In the olden days you could only create halftones from a transparency by first making a black and white glossy print and this added about $12.00 to the normal halftone cost. Scanning has reduced that incremental charge to $2.00. One limitation to making halftones directly from transparencies is that the maximum enlargement is 600%.
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