Articles, Helpful Information
Preparing files in Photoshop: Starting and Finishing
Estimating sharpness and quality at various print sizes
Tips to help you avoid the most common mistakes
Tradeoffs between using Photoshop (or other editing software) and on-line editing
Stitching images together to increase the pixel count and/or the field of view.
Tradeoffs between high quality ink jet (the kind we use) and traditional photography
Selling your Photos: Information you need to know
Helpful PDF documents you can download:
Preparing files in Photoshop: Starting and Finishing
Starting. For example, let's say your objective is to make a 22" x 28" poster. When we print this poster, we will expand it by pixel interpolation (at 300 pixels per inch [PPI]) to 6,600 x 8,400 pixels, or 55.44 Megapixels. If your poster contains very fine line art (e.g., 6 pt text), and you want it to look as sharp as possible, then this is the file size you should start with. (In other words, multiply each dimension by 300 pixels per inch, and that is the number of pixels you need for your starting file size.) However, if your text is larger, and/or you can tolerate a very small amount of fuzziness, you might be able to use around 150 pixels per inch.
If your poster does not contain line art, (e.g., if it is just a photo), or if the file comes to you with line art already embedded in it (and it's not a Photoshop file), then there is no good reason to expand the number of pixels. Let's say, for example, that you are starting with a 1200 x 1800 pixel (2.16 Megapixel) image. If you import this into Photoshop and expand it to, for example, 6,000 x 9,000 pixels, there is no detail which will look any sharper than it was in your original image. You might just as well have sent the file to us at 1200 x 1800 pixels. The pixel interpolation that Photoshop would do to fill in the missing pixels is no different than the pixel interpolation we will do for you when we print your photo. Moreover, the 1200 x 1800 pixel image will take about 1/25 as long to transmit as the larger file would take. (To some readers, this fact is very obvious. However, quite a few of our customers have made life unnecessarily difficult for themselves by expanding their files in Photoshop when they gained no benefit by doing so.)
Most posters contain a mixture of photos, text, and other line art. Following the above example, let's say that your 1200 x 1800 pixel photo is printed within your 22 x 28 poster at 12" x 18" (100 PPI), and the rest is text and other line art (over and around your photo), printed at 300 PPI. You might ask, Why not print the whole poster at 100 PPI (2,200 x 2,800 pixels)? Answer: That's not optimal. The world will probably forgive you for the blurriness of your image, at 100 PPI. But, they will probably not forgive you for the blurriness of your text at that same resolution. Viewers expect some blurriness in images (even the best professional images). But most people do not expect blurriness in type. You might be able to get away with, e.g., 150 PPI. But at much less than 150 PPI in a 22 x 28" poster, the result will not look professional.
For posters larger than 22 x 28, there is some leeway in the number of PPI that you need. A 5 x 7 print is typically viewed at 18" distance. The same is true for an 8 x 10, or for a 16 x 20. For posters larger than 20 or 30" in the longest dimension, people typically stand back a ways to view it. Let's say your poster is 40" x 72". For that, 75 PPI type would probably look professional, even though type at 75 PPI in a smaller poster would not look professional.
The cost of professionalism is a large file size and possibly a long upload time. If you know how to save your photos, you can save yourself a lot of time and inconvenience. If you learn to use our on-line tools, you can also save yourself a lot of upload time, and make sure that the text you add looks sharp.
Finishing. Staying with our example, above, a 22 x 28" poster at 300 PPI, the worst case scenario (in terms of file size and upload time) is that you will choose to save this file uncompressed (e.g., as a TIF file). Uncompressed, it will occupy 166 Megabytes. At 250K bits/second (a typical DSL line), in its uncompressed state, it will take 110 minutes to upload. Obviously, that is an unacceptable upload time. Fortunately, you can also choose to save it as a JPEG (JPG) file, which will take 1/10 to 1/30 as much space. Typically, that would take about 5 minutes to upload (again, assuming a DSL line). If you put a print, made with a good JPG compression, next to a print made from the original TIF file, in nearly all cases nobody will be able to tell which is which.
A "good" JPG compression, in Photoshop, means than when you click "save as" and select JPG compression, you will choose a number in the range of 10 to 12. This will give you a file compression probably in the range of 10:1 or 20:1, and the quality will be excellent. (When the program asks you for compression type, choose "baseline.") (Nearly all digital cameras use the same type of JPG compression, giving around 10:1 compression, and no visible loss of quality.) If you use lower compression numbers, the result will be JPEG artifacts, which appear as halos or waves around objects. The author has never seen a JPEG artifact in a properly compressed file.
There are other compression algorithms, e.g. BMP or GIF. BMP images are less compressed than JPG images. GIF compression is ideal for files which contain 256 or fewer colors.
You might also send files to us as Photoshop (PSD) files. Although many customers do this, we don't encourage it, inasmuch as some Photoshop files contain color table information and/or font information which our file format converter cannot process properly. (In nearly all cases, you will be able to tell from the thumbnail image in your on-line directory whether the file format conversion was successful.)
If you choose PDF compression, it is a good idea to re-import your PDF into Photoshop and check for errors. Common errors include clipping of characters and/or conversion of bullets into other characters. You may be able to make the same check by uploading the file to our web site and then check the thumbnail.
If you plan to do additional editing, later, on your file, it is best to save it in two formats -- the Photoshop format and the JPG format. You can send the JPG format to us for printing, but if you do additional editing or revising, that is best done starting with the Photoshop PSD file.
Estimating Sharpess and Quality at various print sizes.
It's not unusual for our customers to call us and ask whether they really need to follow our "300 PPI" guideline. This usually happens when they do the math and discover that they need a file size upwards of 50-200 Megapixels. About 75% of the orders we get are for prints at resolutions less than 150 PPI, and the results generally look good (albeit, not "fantastic"). The guidelines we provide are for "fantastic" prints, and many of the prints we send to our customers are easily described as "fantastic." Many applications simply do not need "fantastic" prints. In other cases, it's simply not feasible.
The digital equivalent of a sharp, well-focused 35mm slide, is 2,000 x 3,000 pixels (6 Megapixels). Some photographers would argue that 4-5 Megapixels is the equivalent of a 35mm slide, since there is no additional degredation caused by a slide scanner. Moreover, digital color is almost always better than 35mm slide color.
Traditionally, a professional photographer would use a 6 x 7 format camera for weddings, graduations, portraits, etc. The digital equivalent of a 6 x 7 format camera is about 20 Megapixels. However, many professional photographers are choosing and using good 6-8 Megapixel cameras for demanding applications, finding the advantages of the digital format (better color, absence of dust, no media costs, instant feedback, instant file availability) to outweigh the sharpness limitations.
Using a 20" x 30" poster as an example, the following is our opinion:
| 9,000 pixels in the 30" dimension, 54 Megapixels, 300 PPI | Best possible quality, seldom achievable |
| 3,000 pixels in the 30" dimension, 100 PPI | Totally acceptable for images, marginally acceptable for text. |
| 2,000 pixels in the 30" dimension, 67 PPI | Marginal for images, poor for text |
| 1,000 pixels in the 30" dimension 33 PPI | Poor, all around. However, if this is all that is available, print it. |
Tips to help you avoid the most common mistakes.
1. Use RGB, not CMYK. If you don't know whether your files are CMYK or RGB, they're probably RGB, and you're OK. CMYK is interpreted differently by various file format converters.
2. Don't expand your files (e.g., to 300 pixels per inch) if you don't have to. Our equipment will determine if your files need to be expanded, and do so by pixel interpolation. If you're making a montage or creating a poster with line art, then you probably do need to create your file at 150 to 300 pixels per inch, at the size you will be having it printed. But if neither of these is true, and your file is smaller, you don't need to make it larger.
3. Check your aspect ratio (the ratio of pixels wide to pixels tall). If, for example, you have a file with a 4:5 aspect ratio and you want to make a 20 x 30 (2:3), something will have to be stretched or cropped to make it fit. You can crop on-line, or crop the file yourself. But don't leave the cropping to our system unless you're sure that the part that will be cropped is OK to crop.
4. Don't be misled by an out-of-calibration monitor. If you take a relatively new monitor and use the default settings, you're probably in good shape. If you use a monitor calibration program, make sure you test the calibration. Some monitor calibration programs do more harm than good.
5. Use the best file format. In most cases, JPEG compression (.JPG files) works best. We're happy to receive large TIF files, but if you have problems in uploading, consider using compressed files. If even one packet gets lost, the entire upload is ruined. Most upload problems happen when customers are sending many and/or large files.
Avoid GIF files for photographic images, if possible. GIF files create the image out of just 256 colors, and usually (but not always) minimize the color problems by dithering (oscillating) between colors to simulate in-between colors. However, when GIF images are expanded, for large prints, they can look very noisy. Worse yet, if you do editing, in Photoshop or Paintshop, on GIF files, any modifications will have to be created out of the 256 colors already there. Change your files, in Photoshop, to TIF or JPEG before you start editing.
If you convert (e.g.,) Word files to PDF, be sure to check the conversion closely. If the images are large and/or complex, mistakes may occur. Even for simple files, symbols may convert to "?". For larger files, characters or even portions of lines may get truncated. Often the problems are not obvious until you look closely.
6. If you think your upload time might exceed 15 minutes, upload your files one at a time. This is particularly important at times when the internet is quite busy. If just one packet gets lost, the entire upload is ruined and must be repeated. If you have been having upload problems, usually just waiting until the internet is less busy will produce better results.
7. Check the file edges. We sometimes see files with discontinuities at the edges. This often results from Photoshop operations which start with the identification of a box which is intended to cover the entire file, but doesn't. The result is a 1-3 pixel band at the file edges. Our policy is that if the edge discontinuity is less than 1/32" (and the print is ordered 'cut to size'), we cut off the discontinuity, even though that results in a slightly undersize print. However, if the discontinuity is more than 1/32", or if the print is ordered with a border, then we have no choice but to leave it there.
Older monitors and video driver boards varied considerably from unit to unit. As a result, monitor calibration programs were devised to attempt to reduce the errors.
New equipment is very accurate. A new CRT monitor and a new computer, operated at nominal ("out of the box") settings, is probably quite accurate. If you have new equipment, using a calibration program could easily do more harm than good.
When evaluating color, keep in mind that the monitor is transmissive and the print is reflective. Room lighting is very important in evaluating a print.
What we've found is that nearly all digital cameras, with well-illuminated subjects, without any subsequent editing, produce color which looks good.
Unfortunately, the same cannot be said for flatbed scanners or slide scanners. We've found that most flatbed scanners which are sold do not have good color. One of the common problems is that the glass on a scanner reflects quite a bit (an unpredictable amount) of light, so the scanner has difficulty differentiating between dark gray and black. Worse yet, any fingerprints or dust on the glass will show up conspicuously for the darker colors. Most scanners handle this problem by simply making anything that is darker than a dark gray show up as black (red = 0, green = 0, blue = 0). This hides the fingerprints, the dust, and the reflection off of the glass, which usually varies from place to place. Unfortunately, you probably don't want to lose most or all of your shadow detail.
Another problem with flatbed scanners is that the illumination is not uniform. A perfectly uniform white piece of paper will show up on the scanner lighter in some places than others, simply because the lamp and associated optics are not perfect. The scanner manufacturer doesn't want to get complaints that white backgrounds show up differently from place to place, so the scanner makes anything lighter than a very light gray show up as white (red = 100%, green = 100%, blue = 100%). Unfortunately, you probably don't want to lose most or all of your highlight detail.
Slide scanners have similar problems, the result being that getting good results is often difficult.
The bottom line: it is best if you can do one of the following:
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Use a digital camera, and avoid the need to use a flatbed scanner or slide scanner, or
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Purchase professional equipment (a good flatbed scanner may cost more than $2,000), or
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Get a good drum scan from an imaging service bureau.
This relates to getting good artwork in the first place. What about editing? The first piece of information you need is whether your monitor will predict accurately what you will get from our printer. We recommend that you obtain from us a Free Sample. One of the prints you will get contains the image below. If this image looks very much like the sample you've received, expect other prints you order to look like what you've seen on your monitor. If not, you might consider recalibrating your monitor. If you don't want to do that, note the differences in color, lightness, and contrast between the two, and try to edit your photos to have the same tendencies.
| Noise under low-light conditions | When there's not enough light,
you are faced with the following alternatives:
In normal lighting, the camera has 256 grayshades between black and white. The way the camera simulates a faster film is by reducing the number of available grayshades between black and white, e.g., to 128, 64, 32, or 16. The result is that objects which otherwise looked very dark now look properly exposed. However, objects may look cartoon-like, with visible discontinuities between grayshades. Color may be poor. The ideal solution is to choose a camera with a larger CCD array. Chip manufacturers like to keep the chip size small so as to reduce cost. However, the size of the photodiode which captures the light for each pixel is the primary determinant of what the signal to noise ratio will be under poor lighting conditions. In general, the larger the CCD array chip, the better the quality will be under poor lighting. Camera manufacturers usually say so if they have a larger than normal CCD array chip. |
| Interchangeable, 35mm-compatible lenses | Most of the advantages of interchangeable lenses are obvious. However, a non-obvious fact is that most digital cameras cannot use 35mm lenses. |
| Digital zoom | A mostly useless feature. You can crop your photos in a photo editor. The digital zoom is not doing anything other than cropping your photo, at the expense of overall detail. |
| Optical zoom | Very useful. However, if you have and plan to use anything better than 3x optical zoom, you should either bring your tripod with you or shoot with very good lighting and fast shutter speeds. |
| Megapixels | The more the better.
However, the difference in price between 5 Megapixels and 8 Megapixels is
substantial. If you earn your living with a camera, than 8 or more is a good
choice. Otherwise, you might want to live with 4 or 5.
If you don't plan to make very many large (8 x 10 and up) prints, you can do very well with a 2-3 Megapixel camera. Viewed on the screen, or on small prints, these cameras are very adequte. |
Tradeoffs between using Photoshop (or other editing software) and our on-line editor.
For the sake of illustration, let's say you want to add some text to a 5 Megapixel photo, and print it at 20" x 30". For the text to be sharp, you should make your file at 6,000 x 9,000 pixels (54 Megapixels). On the other hand, you could send us the 5 Megapixel photo and a very small number of bytes of text and formatting information. We'll blow the image up to 300 PPI before we add the text. 54 Megapixels or 5 Megapixels. 30 minutes on-line or 3 minutes. The same result. It's an easy choice.
On the other hand, our on-line photo editor doesn't do everything that Photoshop or Paint Shop Pro will do. Also, it's easier to proof the result with Photoshop or PPP. The on-line proofs we provide are thumbnails. They don't show very well what the final result will look like.
We do, however, provide some functionality which is difficult to find elsewhere. For example, we provide calendars, complex text addition, and very professional looking composites. Moreover, we think our user interface is a lot easier. For example, try cropping a photo, adding some text, and then putting a border around it with our on-line editor. Then do the same thing in Photoshop. Our on-line editor is usually easier and faster than the alternatives.
All of our software is internally produced. That means that if someone reports a bug or has a suggestion, a software change may be published within a week or two. We welcome suggestions and comments, and appreciate the many helpful comments we've received from our customers.
Stitching images together to increase the pixel count and/or the field of view.
There is a photo, above of the Colorado National Monument which was taken with a 2.1 Megapixel camera. However, the original from which this thumbnail image was obtained measures 3,406 x 1.678 pixels -- 5.7 Megapixels. Almost the same photo could have been taken with a 6 Megapixel camera (2,000 x 3,000 pixels) with a wide angle lens and then cropped to the desired aspect ratio. However, the photographer was able to use a much less expensive camera, and get a superior result. Then, instead of purchasing expensive stitching software, he used our free on-line stitching editor. With stitching, photographers can obtain results far superior to those obtainable with even the best digital cameras. The advantages of stitching are not well known, and there is a learning curve in knowing how to take photos for stitching.
To stitch photos together using our on-line stitching editor, follow these easy steps:
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Take photos using our guidelines. Primarily, this means making sure the photos overlap somewhat.
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Upload them into your on-line directory.
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Click "stitch"
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Choose the photos to be stitched together, and indicate whether the sequence is horizontal or vertical.
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Let our editor guide you through the rest of the process. The last step is about a wait of about 60 seconds while we stitch your photos together.
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Zoom in to see the result. Keep in mind that the result you are viewing is still just a thumbnail. If you order prints, we'll redo the stitch with the same information to obtain a full-size result.
Learn more by going to your on-line account, click "stitch", and then select "examples".
Tradeoffs between high quality dye-based ink jet (the kind we use) and traditional photography.
Traditional photography is the same as Silver Halide (RA4 process). RA4 prints may be made via either digital or conventional analog techniques. Nearly all RA4 prints made today are done with digital imagers.
The type of high quality ink jet prints we provide are made with HP Designjet 5000 printers.
As we see it, here are the advantages and disadvantages of each:
| Item | Comparison |
| Production cost | Silver Halide (RA4) prints have a production cost (paper, chemicals) about 1/2 that of High Quality Ink Jet (paper, ink, print heads). However, RA4 equipment is more expensive than ink jet equipment, and there are pollution and disposal problems associated with RA4 which don't exist for ink jet. |
| Color Fidelity | Ink jet has a wider gamut, i.e., the range of all colors which can be printed. Silver Halide paper is quite complicated in nature -- being 7 layers of dyes and filters. Ink jet is inherently much simpler; the final result is just ink and (coated) paper. |
| Graininess | Ink jet does have some graininess to it. For that reason, high quality ink jet prints are usually used for 5 x 7 and larger prints. |
| Durability | Silver halide can be more durable. Dye-based ink jet prints can be damaged by water. To some extent, water drops will also cause some damage to silver halide prints (leaving a change in surface glossiness). |
| Lifetime | Sooner or later, most
prints will fade. Washed silver halide prints (as are obtained from
most commercial labs) will last longer (e.g., about 20 years in
indoor illumination) than stabilized silver halide prints (as are obtained
from all one-hour labs and many other labs). Stabilized silver
halide prints typically
start to fade, in indoor illumination, in about 5 years. The
stabilized process has a big advantage to photofinishers in that it is
easier to comply with environmental regulations. Environmental
regulators often restrict or prohibit the chemicals used in the washed
silver halide processors.
Ink jet prints fade due to (a) UV light and (b) gas oxidation. We use dye inks. The use of pigment inks reduces the rate of fading due to UV, and may reduce the rate of fading due to gas oxidation. Inasmuch as pigment inks generally have a poorer color gamut and increased graininess, and dye-based prints have a lifetime which is very acceptable in most situations, we have chosen to use the dyes. The type of ink jet prints we provide will last longer than the stabilized silver halide prints, or about as the washed silver halide prints. Lamination will extend the lifetime and durability of both silver halide and ink jet prints, at the expense of cost and appearance. We do not provide lamination of prints. |
| Acceptance | When publishers want proofs, they seldom choose silver halide prints. Ink jet prints have gained acceptance in demanding applications. The trend in large format photofinishing is towards ink jet, at the expense of silver halide. Smaller prints (4 x 6 to 8 x 10) are more often produced with silver halide (RA4) equipment, the production cost advantage being key for the smaller prints. |
Selling your Photos: Information you need to know
Most of our customers purchase photos to be sent directly to their customers (some using the "blind drop ship" option, and others using a ship address different from their own address). By watching the success or lack of success of thousands of our customers, we've been able to make some good generalizations regarding what works and what doesn't.1. Customers need to be able to relate to a photograph. Usually, they relate to a photograph because
- They took the picture
- They are in the picture
- They relate to, identify with, or know, the people in or subject of the picture
- They were once at the same location shown in the photo
- Something about the photo seems familiar
2. Photos need to be marketed. Many of our customers have their own web sites. Some are successful. Many are not. To be successful, your site needs to receive substantial traffic (hits). To get traffic,
- The meta text (the keywords) must be carefully researched. These keywords must be the same as words which are frequently used in web searches. There are various web sites which provide help in this. You can determine, for example, what the relative value of "sports composites" is relative to "sports photos".
- You must be recognized by search engines. Most search engines have a "site submission" feature. If you search some of your keywords, and find that your web site is not on the 1st or 2nd page of the search, you won't get a lot of traffic.
- If you can get links to your site, from other sites which (a) are similar in subject matter to your site, and (b) get a lot of traffic, that's quite valuable. To understand more about why this is true, visit google and get information regarding their search algorithm.
- Check out the pay-per-click search engines. Most successful web sites pay anywhere from $0.20 to $1.00 or more per click to attract traffic. Examples exist of companies paying more than $15 per click. There are small search engines which will charge less than $0.10 per click.
- Visit forums and chat rooms and discretely drop the name of your web site.
- Use conventional media advertising (magazine ads, etc).
Use care in designing your site so it becomes inststantly clear what is is that you are selling, and how someone who is interested might proceed to purchase one of your photos. It is not difficult to find web sites wherein it is virtually impossible to determine how to make a purchase.
Make the decision process easy and manageable. There is a point, beyond which, "less is more". In other words, if you have too many photos to choose from, or if there are too many other decisions to make, that's bad. If your customers are uncertain about their decision, simply because they are overwhelmed with too many choices, the easiest thing to do is to go to another web site.
At BigPhotoHelp, we've seen very successful photographers and very unsuccessful photographers. The ones who take the best photos aren't always the most successful. While photographic expertise is important, success usually has more to do with marketing expertise than it has to do with photographic expertise.
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