Tips for Fireworks Photography
From time to time I receive emails asking me for technical information on how I create my fireworks photos. My colleague Paul Marriott also receives these enquiries and after discussing with him the problems associated with trying to answer each and every one of them, we hit upon the idea of posting a Tip Sheet on his website for any and all to read and use. This was originally written for those who use film cameras, so at the end I have added additional information that addresses the use of digital cameras and image formats. But whether film or digital, much of the information related to composition, exposure, etc. relates to both camera types.
Choice of Film
For some reason, many people assume that you need a high-speed emulsion such as a 400 ASA film in order to photograph fireworks. In fact, just the opposite is true. It is the "slow" emulsions that provide the best results. My personal preference is Fujichrome Velvia 50 slide film, which seems to yield the best colors throughout the whole spectrum. If anything, colors are rendered just a bit on the "warm" side. Agfa CT-50 is another choice and also yields good colors, but it leans a bit toward the "cool" side - making it a better choice for blues and violets. One can also use 100 ASA films, including most of the Fuji color slide varieties, the Kodak slide films in this range, and other brands too.
Some people prefer to shoot negative film such as Fujicolor or Kodacolor. The advantage of negative film is that it is far more "forgiving" than slide film. Negative film has a "latitude" of plus or minus two stops, meaning your exposure can be off by a wide margin and the negative will still yield a printable result. Slide films, on the other hand, are far less forgiving, with a latitude of only plus or minus a ˝ stop, meaning that your exposure must be "right on". However, the range of available slide films provides a much wider variety of choices - and in general, slide films reproduce colors much better than negative films.
My preferences therefore are:
- Fujichrome Velvia 50 ASA — slide film
- Fujichrome Velvia 100 ASA — slide film
- Kodacolor Gold 100 ASA — negative film
However, you should feel free to experiment with different films to see what you like best. But stay with emulsion speeds of 50ASA or 100ASA for the best results.
Choice of Camera
Digital vs Film: In our new age of "digital everything" some people want to use a Digital camera for everything they photograph. There is no problem with this except for the choice of camera. Most of the lower priced models have automatic diaphragms and auto-exposure features that you cannot override. These cameras will not yield good results since you cannot control the aperture of the lens nor the amount of the exposure time.
To use a digital camera, you will need one that has "manual mode" settings that include the ability to manually set the aperture and the shutter speed. However, there are some ways to get around this. Please refer to the end of this essay for additional information on using Digital Cameras.
Whether you are using a traditional camera or a digital one, you will need a tripod and a cable release. The tripod is necessary for stability so that the trailing lines and curves of the illuminated stars, etc. will leave pleasing curves and trails on the film. If you try to hand-hold the camera, these lines will become wiggly and erratic. The cable release enables you to trip the shutter without physically touching the camera. Even the slightest vibration will impart "wiggles" to the trailing colors on the film.
The subject of exposure entails two separate elements - the aperture setting (the opening in the lens that determines how much light enters the lens and falls on the film plane) and the time of the exposure (which can vary greatly with fireworks). We will first limit our discussion to aperture settings since the length of time for the exposure depends on several things.
As a rule, if you are using 50 ASA film, the majority of your exposures will fall into the range of f9.5 to f16. An important thing to remember with f-stops is that the higher the number of the f-stop, the less light is getting through. Each f-stop effectively doubles or halves the amount of light reaching the film. Thus, going from f8 to f11, you are allowing half the light to enter the lens and reach the film. And going from f11 to f8, you are doubling the amount of light entering the lens and reaching the film. Many lenses on 35 mm and medium format cameras also have half-stop settings between the main stops. These are useful for subtle adjustments of exposure. I use f9.5 (halfway between f8 and f11) as the starting point for any show. The wide range of shells that includes most standard colors - large flowers, trailing comets, etc. and multi-break shells that feature color changes - will probably fall into this 9.5 aperture setting.
Candles tend to be a bit brighter, so you will want to reduce the light entering the lens by a bit. For candles, you should use f11 or f 12.5 (halfway between f11 and f16) and even f16 at times. If the show features a lot of candles, you can make several exposures, trying each of the settings mentioned above. That way, at least one of them will be correct.
Magnesium and titanium shells are extremely bright and will require exposures at f16 and even f22 (if your lens has a setting that high). This also holds true for strobing shells that will result in trails that look like "silvery rain".
Some colors are very faint such as many of the blues and violets that are used in today's fireworks and carbon-based shells such as willows. These will require exposures of f8 and even lower at f5.6 to allow even more light to enter the lens.
Here is a table for quick reference, depending on whether you are using 50 or 100 ASA film.
|Type of Fireworks||50 ASA||100 ASA|
| Most 3,4,5,6,8,10,12 inch standard color shells.
Standard colors of red, green, blue, white, yellow
|f9.5 – f11||f12.5 – f16|
|Fountains and Gerbs - Exploding mines||f8 – f9.5||f11 – f12.5|
|Titanium and Magnesium Shells (including strobes)||f16 – f22||f22|
|Candles - bright mines and nautiques||f11 – f16||f12.9 – f22|
|Soft blues and charcoal-based shells (willows)||f5.6 – f8||f6.3 – f9.5|
|Pattern shells (hearts, stars, orbits, etc)||f6.3 – f8||F8 – f11|
"Painting with Light"
Whether you are a professional photographer, a serious amateur or a novice, FORGET EVERYTHING you know about the length of time for your exposures. Your shutter speed for taking photos of fireworks will ALWAYS be "Bulb" - usually marked with a "B" symbol on the shutter speed selection dial. Bulb means that once you depress the cable release, the lens and shutter will stay open until you release the plunger - which then closes the shutter. So set your shutter to Bulb and leave it there for everything. The ONLY adjustment you will make to your camera throughout the entire process of creating fireworks photos will be the aperture settings on the lens. (and perhaps changes to the focal length if you are using a zoom lens)
Think of yourself as an artist who is about to "paint" colors onto a pitch-black background. That piece of film that is now being exposed to a black night sky is about to become your canvas. You need not be concerned with things such as a ˝ second exposure or a 1 second exposure since each trail left by a star or other element of a fireworks shell becomes a streak of light on your film canvas. Each of these streaks or trails is painting itself upon a black background and as such they can overlap without affecting exposure.
The length of time to use for your exposure will vary with each fireworks situation you encounter. Esthetically, a nice high 10 or 12 inch shell with a comet trail will produce a pleasing photo if you shoot just one single shell. The end result will probably resemble a palm tree effect. Even several such shells together will probably make a nice photo. You are literally painting the shell onto the black background that the film is also recording while the shutter is open.
Timing is everything. You will probably hear the mortar fire, which is your cue to be ready to open the shutter and catch the comet trail - keeping the shutter open until the shell explodes, and still keeping it open as the stars slowly fall downward and paint in the trails. As the shell dies out, you close the shutter.
Congratulations - you have just created your first Fireworks Masterpiece!
There is always the question of "horizontal vs. vertical" when taking photos of fireworks. Personally I shoot just about everything as a vertical. My exceptions are for "ground-based" displays, especially when they are fired near water - as is the case at the Montreal International Competition held each year. The lower displays, especially those with many arcing candles and mines just naturally lend themselves to a horizontal format, while the higher shells tend to be better framed in a vertical format.
Choice of Lens
You will note that I have said nothing up to now on what lens to use. This really depends on just how far away you are from the action. Personally I use a short zoom with a range from 28mm to 135mm focal length. If you are very far from the fireworks staging point, perhaps even a 200mm lens will be appropriate. One thing you do want to avoid is constantly fiddling with your lens to change the focal length, since you lose valuable time and "some of the good ones will get away". If you are shooting fireworks at a venue that you visit each year (let's say, your local 4th of July display in your home town) you will know just how close you can get to the firing point. A little experience will enable you to know which lens you should use. For events that you are visiting for the first time, consider taking several lenses or a zoom with a wide range so that you are covered for any situation.
Personally I like to zoom in on the heart of a shell and I am not concerned with getting all the edges of the shell in the photo. Some people call my style "In Your Face" fireworks. One reason I use this style of composition is to be able to sell my shots as "Stock Photography". Most people who are looking for fireworks photos for use in advertising or other applications are seeking "generic" shots that could be from anywhere. But it is also a challenge to integrate some famous landmark into your photos so that you incorporate not only the spectacle of the fireworks, but also the place where the display is being held - such as the Washington Monument in Washington DC or the Statue of Liberty in New York. But if you intend to sell these photos as "stock", they have more limited applications and thus fewer potential buyers. I mention all this merely to explain my own particular style.
The vantage point
Deciding just where to take your photos from is likely to be determined by a number of factors. You may in fact, have only limited viewpoints and be forced to set up at one of these areas. Remember to take into account a few factors. Bridges and some boardwalks, etc. are not necessarily the best places to set up a tripod since people walking around will always create vibrations. For example, on the Jacques Cartier Bridge in Montreal that overlooks the fireworks venue, there is only ONE place where there is no vibration - and that is the spot adjacent to the concrete pylon tower on the south side of the bridge - a spot that only one or two photographers can fit into and use. Also try to consider a point where no one will be able to get in front of you, such as a promenade with a railing. Remember this: no matter how early you arrive and get set up, people are basically rude when it comes to fireworks. Latecomers will always push and shove and attempt to get the best vantage point. They will have no concern about your tripod and will kick it and knock it about without any regard to how long you have been patiently waiting before they ever arrived. So select your vantage point carefully! Where possible, try to contact a PR person for the event to see if there are any areas set aside for Media/Press people and photographers. You might be able to wrangle a pass out of them and make your experience much more pleasant.
The Imaginary Canvas
Even once you've selected a good spot to shoot from, you know what kind of lens you will use, and you're all set to go - you still need to do a little more planning that requires some imagination. From experience you may already know within what field of view the display will likely take place. This also helps determine your choice of lens. It's best to let a display begin and actually look through your camera to see where the shells are going and whether you have enough framing to catch most of what is going on. Once you have done this, you can then lock down the angles on your tripod and already know what your camera will be "seeing" when you open and close the shutter for each composition. Remember - when you are taking photos of fireworks, you will not be looking through the lens. On SLR cameras, the mirror locks upwards during the exposure so you will see nothing through the viewfinder. The mirror stays in this position until you release the cable release and complete the exposure by closing the shutter again. Therefore you need to preconceive and pre-frame your shots since you can't see what the camera is seeing.
This ability and talent to visualize what is ultimately going to appear on the film is also of paramount importance to what you decide to "paint" on each piece of film canvas that you are creating. YOU are the artist and even though two photographers may be standing side by side, their photographs of the same thing will likely be very different. This is where your sense of timing and composition will come into play. Remember that you are an artist who is splashing brush strokes of light onto a black canvas background. You want enough material on the film to "fill in the black space" you pre-visualized, but you also don't want to "clutter" up the canvas with too much stuff. This will only come with practice, but even on your first venture into creating fireworks photos, you will probably get great results.
I find that anywhere between 1 or 2 and even up to 5 or 6 shells can nicely fill up a frame. I rarely shoot longer than that. Of course if 5 or 6 shells all go up and break within 4 seconds, the exposure time will be 4 or 5 seconds - but if 5 or 6 shells go up at intervals that span 12 or 15 seconds, then the exposure time will be 12 or 15 seconds. This is why I told you to forget everything you know about the length of the exposure time. In the example above, the results will be virtually the same, because the number of shells is the same. Only the interval has changed, because the interval is determined by the people firing the show.
During the finale of any display, there are often many shells being fired simultaneously. When a situation like this reaches a "saturation" point, I just don't shoot any more, since the result will be way too cluttered and pointless. Besides, it's more fun to just relax and watch a finale in all its splendor and glory!
Just a few other items you might want to consider that really don't fit into any other category.
There is a strong temptation to "shoot everything" when you are photographing fireworks. However, in my experience, "white" shells tend to become boring rather quickly. This is also true of multiple salutes and salute barrages. They wind up just looking like splotches of white light on film and have no esthetic value. And in displays where one color is fired again and again, such as a whole volley of red shells one after another, the same holds true. You might want to make 2 or 3 shots, using a slightly different aperture setting each time, to ensure you have one really good exposure. I tend to be most active when I see lots of colors being mixed together.
I have noticed that most pattern shells (exploding hearts, starfish, Saturn orbits, etc,) tend to be a little less bright. Use f8 for 50 ASA and f11 for 100 ASA. Don't expect pattern shells to look anything like the patterns you actually saw. On film, while the effect is pleasing, they become very abstract.
Wind and Weather
Ideally you will have a jet black sky with perhaps a 5 to 10 knot wind that will carry the smoke away. Personally I don't like having a moon in my shots since it always ends up looking like a mistake of some splotch of white light that doesn't belong. The moon rarely ends up looking like a moon in fireworks photos. Hopefully the wind is blowing laterally left or right - or away from you. If the wind is blowing towards you and is brisk, you will get "smoked" and run the danger of high-falling shell remnants raining down upon you (and sometimes including flaming remnants). Always remember "Safety First" at a fireworks event and make sure you have something to protect your eyes - even reading glasses will do - if you encounter these conditions. At the opposite end of the spectrum, "no wind at all" will spell disaster for your photos. The smoke builds up and builds up, effectively blotting out new shells and looking terrible on film. If you encounter conditions like these, relax and watch the show and don't bother wasting film.
How much Film?
I find that during particularly active displays, I tend to shoot one roll of 36 (35mm film) about every 10 minutes. This varies, depending on how many white shells are being fired and whether or not I like the overall theme of the moment. When processing slide film at a lab, I find it best to use a custom professional lab versus a drugstore or standard camera store lab. Always insist that the roll be "Process Only - Do Not Cut". This is because technicians often make mistakes and cut your roll on the wrong sprocket hole, meaning they will ruin every single shot if they are using an automated slide-mounting machine. When you get film back that is uncut and not mounted, it comes as one long continuous roll about 4 feet in length. Using cotton gloves and slide mounts that you can purchase at a camera store, you can then cut and mount the slides yourself and make sure you are cutting them on the correct sprocket. In 35mm film, it's 8 sprocket holes to a frame, so you can find the line between frames by counting sprockets. And now if you mess it up, you can't blame the lab!
Water and Reflections
By all means, if you have a vantage point for a show that includes a water foreground, experiment a bit and try to catch some of the reflections of the shells in the water. The wiggly lines will vary in width depending on how much wind is blowing and disturbing the surface of the water.
Remember to take a small flashlight with you as part of your standard camera gear for fireworks photography. It's especially useful for sneaking a quick peek at where your aperture is set to, finding things you drop (such as lens caps, etc.) and for changing rolls of film.
Now we come to the question of digital cameras. Essentially there are two types of digital cameras on the market today. The Point and Shoot variety usually has a built-in lens and a rangefinder with a display screen. The rangefinder viewing area provides only an approximation of the scene being viewed, while the display screen offers a better option for framing the composition.
The second variety is the SLR where what you see through the viewfinder is very close to what you get in the finished image (in terms of area and composition). SLRs also have the option of interchangeable lenses, offering you additional options for nearly any occasion. Another difference between the simpler Point and Shoot types and the SLRs is better control over diaphragm settings and shutter speeds. There are other differences too that make SLRs a bit better for controlling exposure, plus the fact that some of them offer extremely large file recording that permits enlargements of up to 16x24 inches or more.
Point and Shoot Digital Cameras
Many of these cameras now come with increased file size - usually in the range of from 6 megapixels all the way up to 14 megapixels. Anything from 8 and up will let you make fairly large prints of 11 x 14 inches or larger (depending on the megapixel resolutions). And one of the advantages of these newer cameras is their size and portability. Most can be carried in a coat pocket. But of course, you still need a tripod. One drawback is that very few of these cameras have a socket for a cable release, but many do have remote controls, which can serve the same purpose (using a wireless remote to trigger the shutter). If your camera has neither of these abilities, you will need to be especially careful when tripping the shutter with your finger so as not to impart any vibrations to the camera.
Earlier I discussed the types of film and the ASA speeds (or ISO exposure index) of these films. In digital photography there is no film, but basically the same rules apply. You can dial in or select a speed on an electronic menu, but these P&S cameras generally offer speeds starting only at 100 all the way up to 6400. You will recall earlier in the discussion on film that I prefer 50 ASA. Since this is usually not an option in the menu selection, there are two ways to fool the camera into thinking it is 50 ASA. Both the Point and Shoot varieties and the SLRs usually have an "under" and "over" exposure control in the electronic menu. These controls are available in half-stop increments (some cameras use thirds of a stop). By setting the camera on -1 under-exposure, you are effectively dividing the 100 ASA setting in half, thus achieving the desired 50 ASA index.
Another way to do it is to use a neutral density filter over the lens. If your lens does not allow for a screw in filter of this type, you can simply hold an oversized one in front of the lens while exposing your shot. A neutral density filter does not affect the color or quality of the image. They are usually available in 2x and 4x values - with 2x equalling one stop and 4x equalling two stops. Using a 4x ND filter will give you an effective ASA index of 25 (from a menu setting of 100), while using a 2x gives an index of 50. If you cannot obtain an ND filter, you can also use a polarizing filter, which is also 4x or two stops.
The use of an ND filter, however, only applies to cameras that are not fully automatic. You need to manually set the diaphragm (determining the amount of light entering the lens) and manually set the shutter speed: to bulb. Since most of the Point and Shoot cameras do not have the bulb feature, you can try using the settings for one second, two seconds or four seconds, etc. And since all the digital cameras have playback functions, you can immediately determine if you are getting decent exposures. All of the rules discussed earlier in this essay regarding composition, distance, exposure, types of shells, etc. still apply; so refer to the above if you need to.
SLR Digital Cameras
As mentioned above, there are significant advantages to SLR cameras, including interchangeable lenses, manual diaphragm settings and manual shutter settings. As in the case of the film type SLR, you should always use the manual bulb shutter setting and a cable release unless you have a fancier model that comes with a wireless remote control. The information about ND filters stated above also applies here since very few digital SLRs have menu options lower than a 100 ASA or ISO index.
In digital photography, noise refers to "Image noise" and is the digital equivalent of film grain for analog cameras. Alternately, one can think of it as analogous to the subtle background hiss you may hear from your audio system at full volume. For digital images, this noise appears as random speckles on an otherwise smooth surface and can significantly degrade image quality. Although noise often detracts from an image, it is sometimes desirable since it can add an old-fashioned, grainy look to an image, which is reminiscent of early film. Some noise can also increase the apparent sharpness of an image. Noise increases with the sensitivity setting (ASA or ISO) in the camera, length of the exposure, temperature, and even varies among different camera models. Some degree of noise is always present in any electronic device that transmits or receives a "signal." For digital cameras, the signal is the light, which hits the camera sensor. Even though noise is unavoidable, in fireworks photography it is generally so small relative to the signal that it appears to be nonexistent.
A camera's "ISO setting" or "ISO speed" is the standard that describes its absolute sensitivity to light. ISO settings are usually listed as factors of 2, such as ISO 50, ISO 100 and ISO 200 and can have a wide range of values. Higher numbers represent greater sensitivity and the ratio of two ISO (or ASA) numbers represents their relative sensitivity, meaning a photo at ISO 200 will take half as long to reach the same level of exposure as one taken at ISO 100 (all other settings being equal). ISO speed is analogous to ASA speed for different films, however a single digital camera can capture images at several different ISO speeds. This is accomplished by amplifying the image signal in the camera, however this also amplifies noise and so higher ISO speeds will produce progressively more noise. This is yet another reason to use the lowest possible setting on the menu when selecting the ISO or ASA.
Some cameras have a feature called a "noise suppressor". Make absolutely sure that this feature is turned OFF when shooting fireworks photos. The suppressor acts as an additional image processor and will make your downloads to the storage card take forever. This is because the suppressor is analysing all the black pixels in the image and filtering any noise out of them. Since fireworks take place on a black background, the suppressor takes forever to process the image - up to 10 seconds and even longer. In any case, you wouldn’t need the noise suppressor to be on anyway since you have already selected the lowest ISO available on the digital menu of the camera.
Digital cameras produce three common types of noise: random noise, "fixed pattern" noise, and banding noise. Random noise is characterized by intensity and color fluctuations above and below the actual image intensity. There will always be some random noise at any exposure length and it is most influenced by ISO speed. The pattern of random noise changes even if the exposure settings are identical. Fixed pattern noise includes what are called "hot pixels," which are defined as such when a pixel's intensity far surpasses that of the ambient random noise fluctuations. Fixed pattern noise generally appears in very long exposures and is exacerbated by higher temperatures. Fixed pattern noise is unique in that it will show almost the same distribution of hot pixels if taken under the same conditions (temperature, length of exposure, ISO speed). Banding noise is highly camera-dependent, and is noise that is introduced by the camera when it reads data from the digital sensor. Banding noise is most visible at high ISO speeds and in the shadows, or when an image has been excessively brightened. Banding noise can also increase for certain white balances, depending on the camera model.
Although fixed pattern noise appears more objectionable, it is usually easier to remove since it is repeatable. A camera's internal electronics just has to know the pattern and it can subtract this noise away to reveal the true image. Fixed pattern noise is much less of a problem than random noise in the latest generation of digital cameras. However, even the slightest amount can be more distracting than random noise. The less objectionable random noise is usually much more difficult to remove without degrading the image. Computers have a difficult time discerning random noise from fine texture patterns such as those occurring in dirt or foliage, so if you remove the random noise you often end up removing these textures as well. In any case, noise removal (if it does occur) can be accomplished using software like "Neat Image" or "Noise Ninja" at a later date.
File Format Selection
There are a variety of file formats that you can select for digital SLR cameras. This also applies to the Point and Shoot cameras, although fewer options are available. The most popular are JPEG and TIFF. If you intend to make enlargements, then you will want to select either TIFF or the highest quality JPEG modes. One drawback of the TIFF format is that it uses up a lot of disk space (on your storage medium). I find that high resolution JPEG is adequate and you can immediately convert the JPEG files to TIFF on your home computer. Chances are you will not be saving everything that you shoot, so this task is not as time consuming as you might think.
An important concept, which distinguishes many image types, is whether they are compressed. Compressed files are significantly smaller than their uncompressed counterparts, and fall into two general categories: "lossy" and "lossless." Lossless compression ensures that all image information is preserved, even if the file size is a bit larger as a result. Lossy compression, by contrast, can create file sizes that are significantly smaller, but achieves this by selectively discarding image data. The resulting compressed file is therefore no longer identical to the original. Visible differences between these compressed files and their original are termed "compression artefacts."
JPEG File Format
JPEG stands for "Joint Photographic Expert Group" and, as its name suggests, was specifically developed for storing photographic images. It has also become a standard format for storing images in digital cameras and displaying photographic images on Internet web pages.
JPEG files are significantly smaller than those saved as TIFF; however this comes at a cost since JPEG employs lossy compression. A great thing about JPEG files is their flexibility. The JPEG file format is really a toolkit of options whose settings can be altered to fit the needs of each image. JPEG files achieve a smaller file size by compressing the image in a way that retains detail which matters most, while discarding details deemed to be have less visual impact.
JPEG does this by taking advantage of the fact that the human eye notices slight differences in brightness more than slight differences in color. The amount of compression achieved is therefore highly dependent on the image content; images with high noise levels or lots of detail will not be as easily compressed, whereas images with smooth skies and little texture will compress very well.
TIFF File Format
TIFF stands for "Tagged Image File Format" and is a standard in the printing and publishing industry. TIFF files are significantly larger than their JPEG counterparts, and can be either uncompressed or compressed using lossless compression. Unlike JPEG, TIFF files can have a bit depth of either 16-bits per channel or 8-bits per channel, and multiple layered images can be stored in a single TIFF file. TIFF files are an excellent option for archiving intermediate files, which you may edit later, since it introduces no compression artefacts.
Many cameras have an option to create images as TIFF files, but these can consume excessive space compared to the same JPEG file. If your camera supports the RAW file format this is a superior alternative, since these are significantly smaller and can retain even more information about your image. Very few Point and Shoot digital cameras offer the RAW format, but it is a standard feature on many SLR types.
RAW File Format
The RAW file format is digital photography's equivalent of a negative in film photography: it contains untouched, "raw" pixel information straight from the digital camera's sensor. The RAW file format has yet to undergo final processing, and so it contains just one red, green, or blue value at each pixel location. Digital cameras normally "develop" this RAW file by converting it into a full color JPEG or TIFF image file, and then store the converted file in your memory card. Digital cameras have to make several interpretive decisions when they develop a RAW file, and so the RAW file format offers you more control over how the final JPEG or TIFF image is generated.
A RAW file is developed into a final JPEG or TIFF image in several steps, each of which may contain several irreversible image adjustments. One key advantage of RAW is that it allows the photographer to postpone applying these adjustments, giving more flexibility to the photographer to later apply these in a way which best suits each image.
Our eyes perceive differences in lightness logarithmically, and so when light intensity quadruples we only perceive this as a doubling in the amount of light. A digital camera, on the other hand, records differences in lightness linearly-- twice the light intensity produces twice the response in the camera sensor. In order for the numbers recorded within a digital camera to be shown as we perceive them, tone curves need to be applied.
Color saturation and contrast may also be adjusted, depending on the setting within your camera. The image is then sharpened to offset the softening caused by further image processing. The high bit depth RAW image is then converted into 8-bits per channel, and compressed into a JPEG based on the compression setting within your camera. Up until this step, RAW image information most likely resides within the digital camera's memory buffer.
There are several advantages to performing any of the above RAW conversion steps afterwards on a personal computer, as opposed to within a digital camera. The RAW file format uses a lossless compression, and so it does not suffer from the compression artefacts visible with "lossy" JPEG compression. RAW files contain more information and achieve better compression than TIFF, but without the compression artefacts of JPEG.
- RAW files are much larger than similar JPEG files, and so fewer photos can fit within the same memory card.
- RAW files are more time consuming since they may require manually applying each conversion step.
- RAW files often take longer to be written to a memory card since they are larger, therefore most digital cameras may not achieve the same frame rate as with JPEG.
- RAW files cannot be given to others immediately since they require specific software to load them, therefore it may be necessary to first convert them into JPEG.
- RAW files require a more powerful computer with more temporary memory (RAM).
One problem with the RAW file format is that it is not very standardized. Each camera has their own proprietary RAW file format, and so one program may not be able to read all formats. Fortunately, Adobe has announced a digital negative (DNG) specification that aims to standardize the RAW file format. In addition, any camera, which has the ability to save RAW files, should come with its own software to read them. Good RAW conversion software can perform batch processes and often automates all conversion steps, except those that you choose to modify. This can mitigate or even eliminate the ease of use advantage of JPEG files. Many newer cameras can save both RAW and JPEG images simultaneously. This provides you with an immediate final image, but retains the RAW "negative" just in case more flexibility is desired later.
Which is better: Raw or JPEG?
There is no single answer, as this depends on the type of photography you are doing. In most cases, RAW files will provide the best solution due to their technical advantages and the decreasing cost of large memory cards. RAW files give the photographer far more control, but with this comes the trade-off of speed, storage space and ease of use. The RAW trade-off is sometimes not worth it for sports and press photographers, although landscape and most fine art photographers often choose RAW in order to maximize the image quality potential of their digital camera. In the case of fireworks photography, it is only the most discerning connoisseur who will be able to detect the minor variations. Unless you have vast amount of portable card storage capacity and infinite time to spend tweaking the RAW files, it’s probably not worth the effort. Most photographers will be perfectly content with the results from TIFF or JPEG formats.
Well that's about all I can think of at the moment. If and when I think of any other little details that might be useful, I will send them along to Paul Marriott to add to this page.
So for all you budding Rembrandts out there, try my techniques and I guarantee you will have good results. I would also encourage you all to write to Paul using one of his message boards to report your successes (or failures) and to make suggestions of your own. Happy Shooting!