Gary's Beginner's Guide to Digital Photography & FAQ

What is this page for?

Why are my photos so grainy?

There are many settings for resolution and quality -- which ones should I use, and why?

How many megapixels should my camera have?

Why does my photo look ok on the screen, but blurry when printed?

How do I match the color of my prints to what I see on the monitor?

Why are my photos so blurry?

How can I increase detail?

How can I make a picture better, once it has been taken?

How can I make better enlargements?

What are "Hot Pixels" and should I be worried about them? -- Under Construction

How do I create a slide show from the camera with photos edited on my PC?

What is this page for? Who is the intended reader?

Just getting into digital photography? Want to get more out of your photos? This might be a start. I've discovered a number of things, particularly from experimentation and my knowledge of computers and how digital data works, as well as assimilating tips from elsewhere.

I'll assume that you've read your camera's manual, taken photos, and even printed them, and are now looking to make improvements.

I'm an amateur photographer, not an expert, so I only feel qualified to cover the basics. Once you're beyond the basics, you'll have to look elsewhere, particularly for info. on photography in general. I'm going to focus on the more computer-related aspects of digital photography.

If you're looking for a one-size-fits-all description of what to set your camera to, well, this isn't it. It's just not that simple, at least not all the time. Often, you will be in situations with low light, or running out of space on your memory card, and will need to modify what you do from what is optimal, to what is necessary for a given situation. This will be more clear by the end of the document! Most of us can just set the camera to "auto" and not worry about it, but some of us are going to want to stretch and get the most out of our tools.

Why are my photos so grainy?

The Causes

There are multiple ways that your photos can look grainy, but here are a few reasons:

  1. Low light. The camera can compensate for low light by turning up the sensitivity of the light sensor, but at the cost of more grain. This is similar to how film can look more grainy when you use higher ISO ratings.
     

  2. JPEG compression. In order to fit more pictures on the memory card, the compression can be increased. However, increased compression introduces artifacts, or odd-looking areas. These areas can look "blocky", or around edges, you can notice excessive "noise".

    Below is an example of what compression artifacts can do to your picture. In the blown-up section, you can see fuzzy areas beyond the edge of the car (see arrows).



    This photo was originally taken at the "normal" (medium) setting of my camera. Using higher compression ("low" quality), the noise may be more visible, and areas may take on a "blocky" or cross-hatched appearance. Normally, unless the compression is very high, the noise is slight enough that you will not notice the errors much in a typical 4x6 snapshot.
     

  3. Low Resolution. A 1-megapixel photo may have enough detail to fit on the screen, but when printed, the individual pixels which make up the picture may be visible. The look may be more "blocky" (such as the magnified section above) than "grainy". (Alternatively, the photo may instead look blurry, from the printer software attempting to fill in some intermediate values between the original pixels in order to avoid the obvious blocks. "Blurry" is better than "blocky", but you may still feel that there is something lacking in the detail.)
  4. Too much Sharpness. Setting the sharpness control too high will enhance any noise that is otherwise in the photo. Also, excessive sharpness produces other artifacts, such as halos, or borders, around objects, which will create even yet more noise if you use higher compression. The JPEG compression scheme does not deal well with all of the added edges. Also, since it makes the JPEG compression work harder, your file sizes may be larger (meaning fewer photos per storage card).

So, how do you compensate for the above problems?

  1. Here are three ways to handle a low-light situation:

    Increase the light. Simple, eh? Turn on the flash if your subject is close. In many situations, you may not have any control over the light, and will have to find other ways to work around it.

    Decrease the ISO setting. (For example, change it from "AUTO" to "100".) Note that in a low light situation, this means that the shutter speed may be very long, increasing the chance that you will blur your photos. You may need a tripod or some way to steady the camera, else you're just trading noise for blurriness (from the camera-shaking from your hands).

    In some cases, it is worthwhile adjusting the brightness (EV setting) lower, to get a darker picture. See below.
     
  2. Increase the quality settings (reduce the compression). If you do not have the room for enough photos, consider buying a larger memory card. The ones that come with the cameras are usually inadequate.

    You may want to try reducing the "sharpness" settings. Excessive sharpness creates more edges (and sometimes halo effects), which forces the JPEG compression to work harder, causing more artifacts and/or larger file sizes (which means fewer photos).
  3. Photo editing software can increase the number of pixels in a photo, but they cannot create detail that was not already there, so the best you generally will get is a slightly blurry picture, if you print a photo that does not have enough resolution (pixels). If you have a lot of detail in normal prints, but want to blow up the picture to a large size and wish you could get more out of it, you could try Genuine Fractals, which does a good job of manufacturing detail, or similar software.

    Let's say that you are low on memory and you must do something to fit more photos into your storage device. If you have to make the choice, it is better to increase the JPEG compression (a.k.a. less quality) rather than reduce the resolution. Use the largest-sized pixel format your camera will allow. Even though you will introduce JPEG artifacts if you lower the quality setting, slightly erroneous pixels are better than no pixels at all!
  4. Try lowering the sharpness setting. Determine if you really need sharpness turned on at all! You can always add it back later with photo editing software.

You'll notice that you're often trading off one limitation for another one.  This can sometimes be a hassle, as you switch settings on-the-fly, to try to choose the best settings for the moment.

There are many settings for resolution and quality -- which ones should I use, and why?

If possible, you would always want the highest quality photos, just on principle. So, why does the camera have so many settings for resolution, file type, and quality? Mostly because of the limited space of your memory cards (and partially because of the time to write the photo to that card).

The short answer is to use the highest resolution that you can get away with. If you are low on memory card space, sacrifice the compression quality first. In other words, if you have a choice between 640x480 at high quality JPEG or 2048x1536 at low quality JPEG, with either choice giving you the approximately same sized file in memory, choose the 2048 pixel version at low quality.

The reason for this is that JPEG is optimized to give more detail at those high resolutions, even though the detail is not perfect. In the lower resolution photo, that detail wouldn't just be non-perfect, it would be absent.

If you are away from home on vacation and it looks like you will be running out of memory space, don't be afraid to go from "fine" to "normal" or "basic" quality settings. Printed at 4x6, most snapshots will be perfectly acceptable even at "basic" quality.

On the other hand, if you are planning a particular shot of a single subject, you do not need more than a few photos, and you plan to enlarge it to an 8x10, then you may want to save it in TIFF mode, which will preserve as much quality as possible. These files will be huge, however!

How many megapixels should my camera have?

Two to three megapixels is probably sufficient for most people who generally only print 4x6's. 3MP will give you a bit of extra room for when you want to print an occasional large print (often even 8x10s are not unreasonable), but also for when you need to crop. With 2MP, you don't have many pixels to spare, so cropping will be a problem -- your resulting image will have a low resolution.

So, what about newer cameras with 4 and 5 MP? Hey, the more pixels the better! But if you have a 3MP camera, I wouldn't necessarily say to trade it in just yet. There is more to a camera than just the number of pixels (the size of the chip, quality of lenses, etc.), and the bottom line is, if you're happy with the results from your camera, that is all that matters. There are those that say that increasing the number of pixels is a case of diminishing returns; one person pointed out that if the size of the chip is not increased, your 4MP pics may have more noise than an equivalently-sized 3MP one. This is outside of my expertise, so I can't say one way or the other on this issue, but the point does seem worth considering. Also, new chips are coming onto the market by Foveon which have superior results using the same number of pixels. In other words, a 3 megapixel Foveon chip could be as good as having a camera with a 6 mp conventional design.

Why does my photo look ok on the screen, but blurry when printed?

For display on the monitor, you do not need as many pixels. 72 pixels per inch looks great on the monitor, but is not nearly enough for the printer. Try only using low resolution (1 megapixel or less) modes when you know that you only want the pictures for viewing on the web or computer.

However, even low-resolutions will look OK printed, if the printout is small enough. When you print, you may need to set the DPI (dots per inch) in the printer settings, along with the type of paper you are using. 300 dpi may look fine for everyday text, but is probably not going to give you a photo quality printout. Try 720 or 1440 with paper that the manufacturer indicates is for photo printing. At 2880 dpi with photo paper, your output should rival film snapshot prints.

Why does my photo look blurry?

Camera shake is the most likely culprit. It's easy to have slow shutter speeds when the light is low. Assuming that you have no control over the lighting, here are some other ways to increase the shutter speed:

  1. Steady the camera by bracing against something, or use a tripod.
  2. Increase the ISO rating. Note that this will increase the grain or noise level.
  3. Decrease the brightness setting (EV, exposure). Actually, you may want to do this more often than you think -- see below.
  4. Increase the aperture (lower f number). For the Nikon CoolPix series, use "Aperture priority" mode.

These tips are also valid if you're trying to get less blur when photographing action.


Another occasional problem may be in the auto-focus, if most of your photos look fine. Most cameras will focus on what is in the center of the display, rather than what you would prefer to be the subject. Most cameras will let you set focus with a half-press of the shutter, and allow you to reposition the camera and press the rest of the way to take the actual shot.  You may want to set the camera to "landscape" or "infinity" to focus on distant objects and not need to worry about the camera attempting to focus on something closer; try this when taking pictures through a screened window. Also, your camera may have a setting to allow you to manually target a spot for focusing, helping you better frame your photo the way you want.

How can I increase detail or make other general improvements using the camera's settings?

Watching out for the problems outlined elsewhere in this document, here are some thoughts.

Decrease the ISO setting to reduce graininess. If you leave it at auto, it will often use higher ISO settings as soon as the light dims. (See warnings about low-light situations, however.)

Decrease the JPEG compression to reduce graininess. Use the highest resolution your camera allows. These actions will create larger file sizes, so you may want to buy a larger memory card (see your camera's manual).

Reduce or disable the "sharpness" setting. Despite its name, it's really an "edge enhancement" function, but it does not really add detail -- past a certain point, it actually reduces detail. (Use your photo software to zoom into a sharpened picture. If there are "halos" around objects, then you have sharpened too much.) If your photos look blurry, try to steady the camera, rather than use sharpness to compensate for camera shake. Note that sometimes photos can use a bit of "sharpness" for display on the monitor (probably to compensate for the low resolution), however, it may not be as necessary for printing. (Some printer drivers sharpen before printing anyway.) Experiment! Print some photos both ways. You can always use photo software to add sharpness, but once added, it can not be taken out. The bottom line is that you should use whatever you believe looks best, but my advice is to consider the case of "no sharpness". Compare both methods side by side, and if you feel that added sharpness looks better, then use it, but my advice is to avoid it.

If your camera has a "histogram" function, use it, particularly if the photo you just took looks like it might have areas that are washed out. On the Nikon CoolPix series of cameras, you can call up the histogram when playing back a photo. In that camera, any areas that have been "blown out" or over-exposed will flash; these areas will have lost all detail (and will print completely white). If those areas are important to the detail of the photo, you may want to reduce the exposure settings, and shoot again. Alternatively, you may want to allow certain areas to be blown-out, in order to pick up more detail in the darker areas. Taking a photo of someone with a light source behind them, you may want to increase the exposure to ensure that the subject is properly exposed. (Taking that example, the window in the background isn't important information, so you may not mind if you lose detail there.) If you want to get both the bright and the dark shots into one photo, there are techniques you can use; basically, you take multiple shots using different exposure settings, and combine them with photo editing software (but this is beyond the scope of this document -- there are various web pages and books explaining this and other techniques of editing).

How can I make a picture better, after it has been shot?

Let's face it -- most of us take some pictures that we look back on and realize that something went horribly wrong. Sometimes editing in photo software can bring a decent picture back out. There are some operations that are nearly "automatic", but if you're a total control freak, the way to go is a full editing package, such as Photoshop or Paint Shop Pro. These products not only have the basic operations, such as adjusting contrast or color saturation, but you can edit specific areas of your photo independently. Don't like the tree that appears to be growing out of someone's head? If you have the patience, you can often edit out such irregularities in the composition. Also helpful is selecting one particular object in your photo, and only adjusting that one object for brightness, etc. Another idea is selecting everything except your main subject, and adding blur, in order to give an advanced photographic look, even if you just use a point-and-shoot. Quite a few things can be done not only to salvage a poor shot, but even make a good photo better.

My only concern here is to not overdo it! Think twice before oversharpening (see above), or getting too crazy with the contrast or color adjustments, if you want your photo to look natural. If you're going for an artistic effect, then go for whatever effect that you're after.

How do I match the color of my prints to what I see on the monitor?  Or why is the color off at all?

Virtually all monitors (and TVs for that matter) will need some adjustment so that you see the same image that others will see.  If your monitor shows images too darkly, you might be editing all of your photos incorrectly; if you modify a photo and put it on a web page, it will be too light for everyone -- except you.  Similarly, if you print that photo, it will be too light, while looking great on your monitor.  Ideally, your monitor should be calibrated to display colors and shades reasonably close to some standard.  Only then should you attempt editing your photos.

Similar to your monitor, your printer will print according a predefined standard.  If we can get all of the devices to reproduce color and shading according to the exact same standard, everything should work!  In theory.

You might be thinking that this is too much of a hassle, but it's very important that you be able to see accurately, if you'll be making any modifications to your photos.  Without the proper calibration, you can't trust any modifications to your photos because you will probably do more harm than good.

How do you change the settings for the devices?

Professional photographers and videographers may be willing to spend hundreds of dollars for a gadget to measure the color of the screen and adjust easily. For cheap, you can do a pretty good job with what you have with a bit more effort.  Keep in mind that I'm not a professional graphics artist or photographer, so my methods are not going to be as exacting.

How does the computer handle differences with colors for devices?  The operating system provides a mapping (from one set of colors to another) using something called a "color profile".  Without changing the actual data that makes up the photo in memory, the colors from anything onscreen are changed as they are sent to the device (monitor, printer, etc.).  This may fix differences in the range of colors, but I'm not sure that it fixes the gamma or certain other settings.  Still, if your device comes with a color profile, it seems to me like setting that up would be a good first step.

I started by setting my display color profile to the one that came with my monitor.  (See the monitor settings inside the display settings in the control panel.)  I then had to find test screens for gamma and brightness. (See http://www.aim-dtp.net/ as one example of test screens and good info.)  They were way off, so I adjusted the gamma settings.  (Check your Display settings (advanced), and see if your video card has adjustments for Gamma.)  If you fix it here, it'll work in all of your programs automatically. Remember, you want to compensate for the screen's errors so that all programs come out displaying the colors and shadow detail more accurately.

Also, I personally go into the monitor and adjust the color temp. to "warm" (better for photos & movies) and control the brightness and contrast with the monitor controls, because I feel like it is more precise to use the settings from the monitor.

Similarly, you can set a profile for your printer in your printer settings from the control panel.  However, in my case, this is a generic setting, and does not compensate for bias in my printer, so some fine-tuning in the printer driver's settings is necessary.

When you make these settings from the control panel, it takes effect in all programs.  The programs, therefore, do not need to be individually adjusted.

For advanced photo editors, you may need to delve further into color profiles and their use in your software.  There are items that are beyond the context of this article, however.  It gets complicated when files are saved with a profile, and I'm not sure that I'm ready to deal with that myself.

If you are ambitious, you may want to calibrate your scanner, but that requires specialized software and a test pattern.

A reason to leave your monitor calibrated incorrectly!

Ok, maybe not a good reason, but one web site suggested that photos intended for the web be edited assuming that others will be using uncalibrated monitors.  The problem as I see it is that there is no way to be sure how far out of whack anyone's monitor will be, or even in which direction!  My CRT monitors usually needed the gamma value increased, but my LCD actually needed the gamma to be decreased.  If I upload pictures to the web, should I cater to only the CRT viewers or LCD?

How do I create a slide show from the camera with photos edited on my PC?

Most digital cameras allow you to show off your photos onto a TV, or at least on the LCD on the rear of the unit. You can set up an instant slideshow! This is great for showing off to family and friends, but what of photos you took at an earlier date (and are currently on your computer)?

If you haven't edited the pictures, you could simply copy them into the proper folder on the CF card. You can even change the order by renumbering, as long as you stay consistent with the naming scheme used in your camera. (WARNING: only do this with copies of your original files! Otherwise, you may overwrite files that use the new numbers that you've chosen!)

The biggest problem is that your memory card has limited space, and you may want to create a larger slideshow. Perhaps you want to make use of a smaller CompactFlash card that you are not currently using for anything else. By resizing the pictures to a smaller size, you will get far more pics, and they'll look OK displayed in the LCD monitor or TV, as long as you don't plan to zoom in on details. Also, you may wish to edit the picture, in order to rotate, crop, fix the brightness, etc. With any modification, the camera may no longer recognize the photo and will refuse to display it. For these reasons, you may want to use a utility. There are third-party utilities available, but you might first try the software that came with the camera. The photo must be saved in a very particular format, not just any JPEG format.

Using NikonView 4 for slideshows (click here)

Using NikonView 6 for slideshows (click here)

WARNING: if at all possible, back up your original photos from the camera onto a CD-ROM before trying to do any modifications. Make sure you have a safe backup before starting to play around with resizing or other modifications. It is not difficult to miss a step and accidentally down-size your original copy; if you do that, it will lose detail!

If you didn't understand my warnings, you may want to review the operation of the software to ensure that you know that your photos are being copied correctly to the computer, and what pixel and file sizes you should expect to see. You may find that the cost of a third-party utility is worth it for the assistance in managing these kinds of details. A popular choice is "TV Writer" by David Taylor.

Glossary

Pixels -- one point of color in a photo.

Resolution -- the amount of detail in a picture. The more pixels, the higher the resolution.

Megapixel -- one million pixels. For example, a picture that is 2048 pixels across by 1536 down is about 3.1 megapixels.

Artifact -- something that was not in the original scene, but ended up in your photo due to the way one or more areas of the technology behave.


This page last edited on Sept. 29, 2004.