Understanding all the technical issues involved in scanning your slides or negatives can be daunting. We know this and we want to make life easier for you -- not more complicated. We hope that this introduction helps you to make the right choices regarding scanning your slides or negatives. If your questions are not answered here, we encourage you to contact us with your questions or refer to our tutorial pages or the additional resources listed on our links page.
Digital ImagesDigital images are composed of pixels. A pixel is one small point of color. When thousands of these very small points of color are put together, an image results. The image on the screen you are looking at is composed of pixels. If your monitor is about average in size, there are about 800,000 pixels on the screen in front of you. Each pixel is able to show one of more than 16 million colors. When many pixels are placed close enough together and they can convey a wide enough range of colors our eye can no longer perceive the individual dots. Rather, we see a continuous picture. Slide and negative films function in a similar fashion. The "pixels" in the film are the grains of chemicals which hold the image. These grains are not infinitely small. Therefore, if a negative or slide is magnified enough, the grains are discernable (more on this later). Unless you are doing very large prints or you shoot with fast film (or film of low quality) you likely will never have noticed the presence of this grain. However, you have probably noticed the use of "pixelation" in the work of some artists, such as Georges Seurat. In the visual arts, pixelation is called "pointillism". For example, in the painting "A Sunday Afternoon on the Island of La Grande Jatte", Seurat uses thousands of dots to compose a beautiful canvas. It only becomes evident that he used discrete dots of paint on close examination. |
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 Printing and Viewing Digital ImagesWhen digital images are printed, the pixels in the image are sized to fit into area being printed. If there are enough pixels per square inch of paper, our eye cannot tell that the image was printed from a digital file. We measure the density of pixels in a printed image in dots-per-inch or DPI. As DPI decreases, we see higher and higher degrees of pixelation - or the effect of the pixels becoming visible in the print. Generally speaking, we would like to print at a minimum of 300 DPI to avoid obvious pixelation effects. For example, if you have a 300 pixel by 300 pixel image and you print it on a piece of paper that is 1" square, the 90,000 pixels of the image all may be used to generate the final printed image. The resolution of the printed image is 300 DPI. If, on the other hand, we have a 100 pixel by 100 pixel image and we print it on a piece of paper 1" square, the resulting image will have a resolution of 100 DPI. We will likely be able to see significant pixelation in the printed image. This same analysis applies to viewing digital images on a monitor screen. It is usually less of a concern here, however, because even the highest resolution monitors are approximately 1600 pixels by 1200 pixels or about 2 megapixels. Most all digital images today (from scanning or from digital cameras) exceed this pixel count significantly and therefore display well on a monitor. Even at the lowest scanning resolution we offer, scanned images are approximately 2750 pixels x 1750 pixels -- more than sufficient for viewing on standard monitors or televisions (no matter how big the display is physically). |
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Scan ResolutionThe resolution of a scanned image refers to the number of pixels in the resulting digital image for each square inch of the original material. The resolution determines the dimension of the resulting digital image. Scanning resolution is commonly measured in pixels-per-inch, or PPI. However, most of the time, we do not say pixels-per-inch but rather use the term dots-per-inch just as in the measurement of the resolution of a printed image. For example, if you have a 1 inch square original image (slightly smaller than a 35mm slide or negative) scanned at 4000 PPI, the result is a 4000 pixel by 4000 pixel image (or 16 megapixels). This is similar to the number of pixels in images shot with high-end digital single-lens reflex (SLR) cameras available today. Not all scanners are created equal. Some scan at higher resolutions than others. However, this is not the only factor to consider when deciding which scanning service or which scanner to use. Scan quality is not the same across different scanners even if resolutions match. Steps taken during and after scanning can have a significant effect on the quality of the final digital images. In general, you want to scan your slides or negatives at the highest resolution possible, as long as you understand a number of important issues up-front. Not all original images need the highest resolution. If your slide or negative film is fast (e.g., 400 ISO), of questionable quality (stored in a shoebox for how many years?), shot on less than top notch equipment or with less than top-notch technique, you are unlikely to see significant improvement in scan quality by going to very high resolutions. What you do get from the higher resolution is all the detail in your film, down to the film grain. This resolution may allow you to create slightly larger prints, but it is no panacea. Digital image file sizes grow geometrically with resolution. Are you prepared to deal with 50MB image files? These beasts can take a good deal of time to load and process on average PCs. If you have a lot of images, you need lots of storage space and you have to be concerned with backing up and maintaining a large database of images; this can be a challenge if you do not have a lot of free disk space. These issues clearly diminish in importance as time passes. Computers get faster and faster, memories get larger and larger and disk drives seem to grow without bound. Large file sizes should not automatically turn you toward lower resolution images, but you have to be prepared for what you receive! Scan resolution is not the only quality factor. We use scanners that we believe provide consistent, excellent quality at their highest resolutions of 4000 PPI. Scan resolution alone is not sufficient to assure a high quality digital image. We employ a variety of technologies in our scanners that aid in producing high quality scans. We have rigorous procedures which assure that your scans are as good as they can be. We discuss these features of our service below. We believe that the scanning methodology we employ ensures you the highest quality at a reasonable price. The table below details the print sizes and storage requirements for various scanning resolutions. You can see more detail, including examples of images at the two resolutions at which we scan here. You can indicate your desired scan resolution to us on our order form (accessible after you create a Pixmonix account and login). |
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TIFFTIFF files represent each pixel in a digital image explicitly. There is no compression or loss of image data. For this reason, TIFF files are significantly larger than other formats (like JPEG, discussed below) but represent the most complete image data. We recommend using these TIFF files for long-term archival storage or if you are doing extensive manipulation of your photos. TIFF files commonly have a file extension of ".tif". JPEGJPEG is a standard format used on the World Wide Web and by all digital photo printing and sharing services. JPEG files can encode images of any pixel dimension (i.e., number of pixels). JPEG files compress well (using a compression mechanism that gives up some image detail to achieve smaller file sizes) and provide good image quality even at fairly high compression levels. JPEG files that we provide to you are saved at high quality settings (i.e., with low compression settings that result in relatively little loss of image data) for a given image size. Hence they are not as small as they could be (if we compressed them more) but do not lose as much quality in the transformation to JPEG format. JPEG files commonly have a file extension of ".jpg". Successively higher levels of compression on a JPEG file result in successively higher levels of artifacts to be introduced. These artifacts may take the form of distortion of color accuracy, pixelization and loss of clarity and detail. You can see these effects in the simple example shown below; as compression levels increase, the file size decreases drastically, but there is an obvious loss of quality. For this reason, we do not compress JPEG files that we provide to you at all. Using the JPEG format still saves considerable disk space over TIFF even at very low compression levels. The image in this example is approximately 135KB when saved as a TIFF file.
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 Print Sizes, File Sizes and Storage RequirementsAfter we scan your slides or negatives, we burn the resulting images onto CD or DVD to ship to you. Choosing between CD and DVD is based on your uses of the images, your computer system, the number of images you are having scanned and the types of files you are receiving with your order. A CD holds approximately 640 MB. A DVD holds approximately 4.7GB. In other words, a DVD holds about seven times as much information as a CD. You can therefore store about seven times as many digital images on a DVD as on a CD. This can be important if you need to store a very large number of images or you are storing the large TIFF files. Scanning resolution and file types determine the amount of storage required for a digital image. The table below indicates a number of facts and figures based on resolution and file types.
For many of our customers, the most important figure in the above table is the print size possibilities. At 2000 PPI, a scan from a slide can be printed reasonably large (up to approximately 6" x 9"). Going to 4000 PPI allows for larger print sizes (assuming that the source slide or negative is of high enough quality to realize a benefit from scanning at the higher resolution). When you fill in our order form, we estimate, based on the scanning resolution, file formats you desire, and the number of copies of the final product you desire, the number of CDs or DVDs required to store the images. When we process an order, you are charged for the media required for your images, as detailed in our pricing information and estimated on our order page (accessible after you create a Pixmonix account and login) when you place an order. The cost per CD or DVD is not high and, as you can see above, lots of images fit on each CD or DVD. Media costs will not break the bank! Generally, if you are scanning only a handful of images, a CD will do the trick. But if you are scanning a large number of slides or negatives or you are receiving TIFF files with your order, we suggest that you choose DVDs. |
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We do not scan rolled (uncut) 35mm film or home movies (8mm or other format). We are happy to selectively scan single frames from 35mm negative strips, though we do charge for a minimum of two images per strip. We do not scan photos from prints. Note that we are adding services regularly, so we may provide new services in the future. Please contact us if you have questions or would like to be informed if we add any of these services in the future. |
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Inventory and Assessment Reception Notification Dust Removal Handling of Your Slides or Negatives |
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ICE"ICE" stands for Image Correction and Enhancement. This is the technology in our scanners and software that effectively removes the effects of minor scratches and dust contamination on your slides or negatives. ICE works on color films and C-41 processed B&W films; it will not remove the effects of scratches or dust on traditional B&W films (such as Tri-Pan or TMAX). We apply ICE on all slide and negative scans where it is effective. This service is included in all of our prices - not a costly extra. ICE works using a combination of hardware and software technologies. The scanner hardware scans the film using infrared light to illuminate the film. This allows the sensors in the scanner to pick up the imperfections on the surface of the film - such as dust particles and scratches in the film. Software then electronically "subtracts" the effect of the imperfection from the digital image. It sounds a bit like magic - and it works like magic! However, ICE is not perfect. It can't recover very badly scratched or seriously dirty films. But for average films it does an amazing job. ROCSlides and negatives fade over time. To complicate things, film fades at different rates in different areas of the color spectrum and differently in shadow areas compared to highlight areas. "ROC" is the technology in our software that restores the color of your faded slides or negatives. ROC works by analyzing the differences between the red, green and blue colors in slide film (yellow, magenta and cyan dyes in negative films) to determine a model of the original film stock. Using this model, the software then restores the original colors by selectively increasing or decreasing components of the color in the final digital image. This fantastic blob of mathematical algorithms can have absolutely amazing results. However, ROC works great on some slides and terribly on others. We apply ROC on slides and negatives that will benefit from it; this is included in our scanning prices - not a costly extra. We apply this technology selectively based on the condition and age of your film and our experience with the effectiveness of the technique. GEMWhen scanning film at high resolutions (e.g., 4000 PPI), the grain of the film being scanned can become apparent. "GEM" is the technology in our software that reduces the perceived effect of film grain during the scanning process. We apply GEM on any slide or negative that will benefit from it; this is included in our prices - not a costly extra. Like ROC, GEM works by doing a complicated mathematical analysis of the different colors in the scanner data to produce a model of the film and grain patterns and then applies the model to reduce the visible effect of the grain. It is far more effective than simple software techniques such as filters which introduce noise into the image in order to blur the grain patterns -- and you lose less of the fine detail in the image as a result. An example...Shown below is an example of the effect of these technologies on a small part of a scan of a 35 year old slide. We have scanned the same slide three times to show the effect of ICE and ROC. The differences are remarkable! (Those are beads on a baby stroller circa 1969 shot on Kodak slide film.)
Benefits of ICE, ROC and GEMWithout ICE, you will not be happy with the resulting scanned images. Even very "clean" negatives and slides have some dust and scratches - and these imperfections will show up on the scans. Most film has not spent its life in pristine conditions and hence has finger prints, dust, dirt, fungus and scratches. For most films, the use of ICE will remove the need for you to spend hours in your photo editing package manually removing these effects of age and handling from your scanned images. Like ICE, the benefit of using GEM and ROC is that you will spend less time manipulating your scanned images to produce good prints. Applied correctly, these are amazingly useful tools. We are not slaves to this technology, however. We have the knowledge and experience to utilize these tools effectively when we scan and process your images. We always use our experienced eyes before we use these tools. "Digital ICE4", "Digital GEM" and "Digital ROC" are brand names of products from Applied Science Fiction (now a Kodak company). Please see the Kodak/Applied Science Fiction website* for lots more details. Noise ReductionEven after applying GEM, many images still show significant grain noise, especially in dark areas of the photos. We apply a set of noise reduction techniques to scanned images to reduce the effect of particular grain structures in some films. This benefits many films when the "traditional" use of GEM does not. However, applying these techniques blindly or too aggressively can do more damage than good. Like ICE, ROC and GEM, we apply these techniques only when they will benefit your particular images, based on our experienced eyes and careful analysis. Shown below are two example images showing the benefit of these techniques:
SharpeningSharpening is the process of removing some of the "softness" that may result from the scanning process. In short, software in the computer attempts to make edges in your image stand out more strongly -- essentially improving the focus of the image. |
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RotationSlides and negatives are fed into a scanner with a fixed orientation. This means that images coming out of the scanner may not be oriented the way the photographer intended (e.g., a landscape photo at Mt. Rushmore is turned 90 degrees by the scanner). We manually examine each scanned image and rotate it to the proper orientation. (Note, however, that there are some cases where our technicians will not be able to determine the correct orientation if you provide a particularly abstract image.) CroppingCropping is the process of trimming the outer portions of the image to remove unwanted areas at the side of the image. In our case, we may trim images to remove the visible part of the slide mounting or negative edge. Another reason to crop images is to make them conform to a particular aspect ratio - such as 4" x 6". The images below illustrate the effect of cropping. If cropping is done to a particular aspect ratio, some of the image area is lost. Since 35mm film is basically a 4" x 6" aspect ratio, this crop loses the least of the image. Note the rocks at the bottom of the image are lost in the 5" x 7" crop. When you get prints of your images, you can crop the images yourself or rely on the printing service to automatically crop them (as happens when you have prints made from negatives). The choice is yours to make!
If we provide your images in TIFF file format, we do not crop them at all. This provides you with the full image data for archiving of the digital images. If we provide JPEG format images, however, we will crop them to remove the visible slide or negative border. We do not crop images to a specific aspect ratio. You will do this cropping when you decide what size prints are needed from your images (note that a crop for 4"x6" aspect ratio has different proportions than a crop for a 5"x7" aspect ratio) -- or, just let the photo printing service do a standard crop just as they would if you had prints made from a negative. Color Balance ChecksAs each image is examined by our technicians, they verify that the color balance determined by the scanner is accurate (by comparing to the original slide on a light table, if necessary). If a particular scan is not correctly balanced by the scanner, the image will be rescanned with necessary adjustments made during the scan process. This assures that the images you receive are true to the original sources. Our computers, monitors, scanners, and printers are fully color calibrated. You can see examples of images showing the color correction that we perform here. Generation of Final FilesFinally, we generate files in various formats and sizes, according to your wishes. By default, we provide full resolution TIFF files and JPEG images in three sizes: full resolution (for prints), email sized (~640 pixels x 480 pixels) and thumbnails (~100 pixels square). With these three sizes, the bulk of our customers do not need to generate files for various uses. This saves you time and headaches when making use of your digital images which is our whole reason for being! You can indicate your desired file format(s) to us on the order form (accessible after you create a Pixmonix account and login). ShippingWe only ship using reputable, reliable carriers such as FedEx® and UPS®. We will only ship your materials back to you. All return shipments require a signature upon delivery to assure that your precious slides or negatives are not left with someone you do not trust or left unprotected on your doorstep. We will not deviate from this important security step. We will generally return your materials and the completed scans in the same packaging you used to ship them to us, unless we determine that the shipping materials you used are not large enough or reliable enough for the return travel. We are aware of the effect of our business on the environment and we attempt to minimize our impact. We will reuse packaging material as much as possible but rest assured that your slides and negatives will be safe and secure for the return journey. |
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 Digital Image Storage, Security, and LongevityDigital image files can last forever. However, it does take some care to achieve this feat. First, it must be understood that storage media will not last forever. Hard drives fail. CDs and DVDs get scratched. Fires and floods happen. It is also important to understand that CDs and DVDs have finite lives, even if they are not damaged due to abuse or mishandling. The materials used in their manufacture do not last forever. In particular, exposure to heat, cold, sunlight or moisture may significantly shorten the lifetimes of these disks. The wonderful thing about digital media is that the data itself can be easily reproduced and stored in a number of locations simultaneously. Try that with your slides! We suggest that you make multiple copies of your digital images and store one or more copies away from your "primary set". For example, store a set of your DVDs in a safety deposit box. Give a copy to members of your family for safekeeping (they probably want the images anyway!). We use only archival grade CDs and DVDs to store your images. These products have very long lifetimes. Our links page has pointers to detailed information on archival quality of DVD and CD storage. Our order form (accessible after you create a Pixmonix account and login) provides you with the opportunity to order multiple copies of your digital images. We encourage you to do so (not because we make lots of money on these, but because it gives you further assurance of the longevity of your digital images). You can also order additional copies of your images after you receive your order from us. Please contact us for pricing (and note that we will only retain your images for a fixed amount of time, as detailed in our terms and conditions). |
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