We know Photoshop is expensive, but it is the industry standard. The following discusses procedures that may only make sense to you if you are using it, but these observations apply to any image manipulation software you might use regardless.
Viewing your pictures on a monitor. If you are doing colour correction, adjusting hue, saturation and lightness or adjusting curves and levels then you should make the whole picture fit your screen. If you are retouching, using filters, sharpening, drawing or doing any function that involves the way fine detail will look then you must always enlarge the picture to at least 100%.
Sharpening, or unsharp mask. DON’T DO IT! Sharpening is a useful tool if you are preparing an image for use within a web page where the size is much smaller, but it should only be used for pictures that are going to be printed with extreme care, sharpening will often look much more obvious on the printed page than on your monitor. The best time to apply an unsharp mask is when the picture has been reduced or enlarged to the size it is going to appear on the page, in most cases we do not know what the size will be so it is normal for the printer to apply the unsharp mask themselves when processing the finished page, it is therefore not recommended that you apply an unsharp mask to pictures you are supplying to us. Before you contemplate sharpening you must enlarge the picture to 100%. If you reduce the picture to fit your monitor you are probably looking at it at 16.6% or 25% which means that each pixel of your monitor is representing 36 or 16 pixels of your picture. You are going to have to multiply any sharpening by a factor of six or four to see any change and you will inevitably overdo it.
The output from your camera should only need limited colour or other similar correction if you have set it up right (and made any adjustments to account for different light sources like flourescent tubes or tungsten). If your results are consistently wrong then do check the pictures on other computers to see if the problem is the same, it may be that the calibration of the computer monitor is wrong, not the camera. If the problem is consistent then look at adjusting the camera settings, this will save you time if you are having to correct every picture. I will correct what I consider to be badly balanced colour so if you happen to like very yellow pictures there is no guarantee that I will and I may take all your yellow out again! Output from scanners is more variable, but you should be able to set up your scanner with a default profile that works most of the time. If you are scanning coloured negative film you need to use a different profile for every different film stock. If you are making subtle colour and contrast adjustments then you should consider using an adjustment layer and supplying this to me, I can then see your intentions and if I think there is a better way of achieving the same result, I can go back to the original if necessary.
RAW images will probably be either 12 or 14 bit. All the normal image file formats are either 8 or 16 bit. If you import your images to 8 bit files then you are discarding some of the pixel data. This may not be a problem if your picture is properly exposed in the first place, however if you need to make any colour or brightness changes, especially to shadow areas then importing to 16 bit is much better. 16 bit files are much bigger so you may want to convert to 8 bit once you have done your corrections and they will have to be converted if you are saving as JPEG.
Resist the temptation to mess about with your scans. You may like bizarre colour effects, graduated fills in the sky and so on, but in our experience they don't sell. If you must do it then send us the original as well or do your alterations on a layer so it can be removed if we consider it unsuitable. We are not fans of graduated filters and I have become adept at removing them from scanned transparencies. If we don’t like what you have done we will not use it.
Avoid increasing the saturation or contrast, these can make the picture look nicer on the screen, but it can be a problem when the picture is printed. Magazine and book printing inks are capable of reproducing far fewer colours than your monitor. This means that there has to be more detail in the shadows than you might expect and more tone in the highlights. Overall this tends to mean less contrasty pictures will print closer to the original than high contrast pictures. If the shadows are too dark then the dots on the printing page fill in (called dot gain) and if the picture is too saturated then it may require more ink than the press can manage to put on the page (called gamut).
In an ideal digital picture the histogram for the picture (left) would make a bell shaped curve that starts between 0 and 5 (black, or very dark grey!) and finishes at nearly 255 (white). There would not be any clipping up at either end of the curve. Obviously no picture is ideal so an abrupt cut off at the black end of the curve may be unavoidable, but it is still better that the cut off point should be less than the maximum because when a picture is printed, in a book or magazine for instance, it will print better if there is still a dot in the highlights and shadows. The blacks will not be absolutely black on the screen, but more shadow detail will print. You may be able to set the black point in the options of your scanner, or it may be governed by setting a CMYK profile, though every printer has its own profile so there is no way of knowing what to set. The colour space printing presses use is called the printers gamut and it varies depending on the type of press, the paper used and the inks used. We supply pictures in RGB, if any of the colours in the picture are outside the printers gamut then they will be automatically brought within gamut by software when the picture is converted to CMYK for printing. This means that you have no guarantee that what prints actually matches the RGB original, for this reason it is better to keep your picture within gamut to ensure you get the expected results. You can check if a picture is out of gamut in Photoshop by activating the Gamut Warning, but what it warns you about does depend on which CMYK profile you are using. The best option from Photoshop’s standard list is Euroscale coated v.2, there are moves within the industry to standardise the delivery of pictures and the recommended profile, short of installing a bespoke profile for every client, is “ISO web coated” which can be obtained from The European Color Initiative web site, look for the download for ECI_offset_2004.zip.
Do not use the Brightness/Contrast window to adjust contrast, it is a very blunt tool to do a delicate job. To increase contrast you should try using the Curves window instead, if you make the RGB curve into a very flat S shape you will increase the contrast without altering the black or white points. Reversing the S will reduce contrast.
You should also use Curves in preference to Colour Balance for the same reason. Virtually all the work I do on pictures, excluding retouching, is done with Curves. Don’t use Auto Levels, it may work fairly well for a lot of pictures, but it is only an averaging tool and most pictures are not average! I have also found that it tends to make the shadows too dark which is not desirable for printing
Do not use dust removal software. Digital Ice, built into some film scanners, is a hardware based system, is great time saver and works very well (but use it in normal mode only and don’t do the post processing). All the other dust removal systems I know of are software based and simply soften the picture till the dust doesn’t show anymore. If your scan needs dust removed then you should do it manually using the clone stamp (or healing tool in Photoshop 7+). I will do some myself if necessary, but it is time consuming and I would rather not.
If you are scanning pictures from your archives then bear in mind that a lot can change in a few years, especially in cities and particularly in London where a picture can become out of date within months. We only want older pictures if they have special historical interest or the subject has not changed. Remember that old cars and fashions can date a picture even if the location hasn’t changed.
We will not use pictures if they are not sharp or have other technical failings. Digitisation does give you the opportunity to rescue transparencies that may be badly exposed, but only to a point. So don’t waste your time with originals that won’t pass muster.
Unless you insist that we do not, we will do whatever we think is necessary to a picture if we think it needs improving, this can include reducing the saturation of over saturated pictures, adjusting colours to remove colour casts, reducing or increasing contrast, lightening or darkening, cropping, straightening crooked or distorted pictures, fixing barrel distortion and sometimes removing telephone cables, bits of rubbish or other distractions from the picture. We will only do this if we think the picture is worth the effort involved and will not do anything that creates a “false” image. We will not create composite pictures from multiple photographers work for inclusion in the library. The copyright in any altered image remains the sole property of the photographer, however the altered scan is the property of Collections.
