Opinions on Film and Digital Photography.

Spatial Resolution

Numerous measures can be used to assess the quality of still photographs the most discussed being the pixel count, presumed to correlate with spatial resolution. This is measured by the quantity of picture elements (pixels) in the image sensor, usually counted in millions and called “megapixels”. Measuring the resolution of both film and digital images involves numerous issues. For film, this issue depends upon the size of film used (35 mm, medium format or large format), the speed of the film used and the quality of lens fitted to the camera.

Similarly, digital cameras have a variable relationship of resolution to megapixel count; other factors are important in digital camera resolution, such as the number of pixels used to resolve the image, the effect of the Bayer pattern or other sensor filters on the digital sensor and the image processing algorithm used to interpolate sensor pixels to image pixels. In addition, digital sensors are normally arranged in a oblong grid pattern, making images susceptible to moiré pattern artefacts, whereas film is not affected by this because of the random orientation of grains.

Guesses of a picture’s resolution taken with a 35 mm film camera vary. Greater information may be recorded if a finer grain film and or developer are used. Conversely, less resolution may be recorded with poor quality optics or with coarser-grained film. A 36 mm x 24 mm frame of ISO 100-speed film is estimated to contain the equivalent of 20 million pixels.

The working commercial photographer would often opt for the use of a higher quality product being that in the medium format or large format films. Because of the size of the imaging area, they have higher resolution than the current top-of-the-range digital cameras. It is estimated that a medium format film image can record around 50 megapixels, while large format films can record around 200 megapixels (4 × 5 inch) which would equate to around 800 megapixels on the largest common film format, 8 × 10 inches, without taking into account lens sharpness. A medium format DSLRs provides from 42 to 50 megapixels, which is relatively similar quality to the medium format film quality.

When choosing between film and digital and between different types of camera, it is necessary to consider the medium which will be used for display and the viewing distance. For example , if a picture will only be viewed on a television or computer display , (which can resolve only about 0.3 megapixels and 1-2 megapixels, respectively, as of 2008. HD sets of 1080p are around 2.07mp), then the resolution provided by a very low-end digital cameras may be sufficient. Print mediums work to far greater qualities of around 300 dots per inch (dpi).

Noise and Grain

Thermal noise is a condition that affects shadow areas of electronic images with random pixels of the wrong colour. Grain and film sensitivity are linked, with more sensitive films having more obvious grain. Likewise, when used at high sensitivity settings, digital camera pictures show increased noise than those made at lower sensitivities.

Currently available technology contributes random noise to the images taken by digital cameras, produced by heat and manufacturing defects. For very long exposures it is necessary to operate the image sensor at low temperatures to avoid noise impacting the final image. Film grain for visible light is not affected by exposure time, although the apparent speed of the film does change with longer exposures, a condition known as reciprocity failure.

Dynamic Range

The topic of dynamic range (DR) is complicated. Comparisons between film and digital media should consider:

 

 

What film? For example, low-contrast print film has greater DR than slide film’s low DR and richer gradation in recorded tones.

 

 

 

 

What film format? Larger formats record larger images, so grain is less detectable at film’s limits of exposure and images require less enlargement for a given image size.

 

 

 

 

What size sensor? As with film, smaller sensors produce smaller images which require greater degrees of enlargement for a given image size. The more convenient pocket digicams use smaller sensors than professional-quality cameras.

 

 

 

 

Which scanner? Variations in optics, sensor resolution, scanner DR and precision of the analogue to digital conversion circuit cause variations in image quality.

 

 

 

 

What counts as image and what is noise? This question defines the limits of DR within a single photograph, and may vary with subject matter.

 

 

Just one comparison cannot provide enough information to show that digital or film has a smaller or greater dynamic range. Some amateur authors have performed tests with inconclusive results. R. N. Clark, comparing a professional digital camera with 35 mm film, reached the conclusion that – Digital cameras, like the Canon 1D Mark II, show a huge dynamic range compared to either print or slide film, at least for the films compared.

The digital camera industry is attempting to address the problem of dynamic range for both the amateur and professional photographer. Some CCDs like Fujifilm’s Super CCD combines photosites of different sizes to give increased dynamic range. Other manufacturers use in-camera software to prevent highlight overexposure. Nikon calls this feature D-Lighting.

Effects of Sensor Size

All compact digital cameras and most digital SLRs have sensors that are smaller than a 36 mm x 24 mm frame of 35 mm film. This affects aspects of the captured image and the way the camera is used. These effects include:

 

 

Increased depth of field;

 

 

 

 

Decreased light sensitivity and increased pixel noise;

 

 

 

 

For digital SLRs, cropping of the field of view when using lenses designed for 35 mm camera;

 

 

 

 

Lenses may be smaller because they only need to project their image onto a smaller area;

 

 

 

 

Increased degree of enlargement of the final image.

 

 

The depth of field of a digital camera and lens combination increases as the imaging area decreases, for a given f-number. This may have advantages for amateur compact cameras since they are intended for taking snapshots. More of the image will be in focus than with a larger sensor and the autofocus system does not need to be as accurate to produce an acceptable image. Conversely, commercial photographers often limit the depth of field to create certain effects, such as isolating a subject from its background. Cameras with imaging areas smaller than 36 mm x 24 mm require a wider aperture on the lens to achieve the same degree of selective focusing.

Light sensitivity and pixel noise are both related to pixel size , which is in turn related to sensor size and resolution. As the resolution of sensors increase, the size of the individual pixels has to decrease. This smaller pixel size means that each one collects less light and the resulting signal is amplified more to produce the final value. With a smaller signal, the signal-to-noise ratio decreases. More noise is present in the image and the higher noise floor means that less useful information is extracted from the darker parts of the image.

Many digital SLRs use lens mounts originally designed for film cameras. If the camera has a smaller sensor than the lens’ intended film frame, its field of view is cropped. This crop factor is often called a “focal length multiplier” because the effect can be calculated by multiplying the focal length of the lens. For lenses that are not designed for a smaller imaging area whilst using the 35 mm-compatible lens mount, this has the beneficial side effect of only using the centre part of the lens, where the image quality is in some aspects higher.

Normally only expensive digital SLRs have full-frame sensors that are 36mm × 24 mm, which eliminate depth of field and crop factor problems when compared to 35 mm film cameras.

The smaller sensor size of consumer compact means that prints are a massive enlargement of the original image and that the lens must perform well in order to provide enough resolution to match the tiny pixels on the sensor. Most digital compacts have sensors that exceed the maximum resolution that the lens is capable of delivering. Increased sensor resolution may even have a negative effect on the overall resolution because of increased noise reduction and in camera processing.

Cleanliness

DSLR cameras are especially prone to dust problems because the sensor remains in place, where a film advances through the camera for each exposure . There is a risk of debris in the camera, such as dust or sand, scratching the film; a single grain of sand can damage a whole roll of film. As film cameras age, they can develop burs in their rollers. With a digital SLR, dust is difficult to avoid, but easy to rectify using a computer with photo editing software available. Some digital SLRs have systems that remove dust from the sensor by vibrating or knocking it, sometimes in conjunction with software that remembers where dust is located and removes dust-affected pixels from pictures.

Compact digital cameras are fitted with fixed lenses; dust is excluded from the imaging area. Similar film cameras are often only light tight and not environmentally sealed. Some modern DSLRs, most notably are the high end Nikon models, use extensive dust and weather seals to avoid this problem.

Integrity

Film produces a first generation image, which contains only the information admitted through the lens of the camera.

Film images are very difficult to falsify , thus in law enforcement and in cases where the authenticity of an image is important , like passport or visa photographs, film provides greater security over most digital cameras as digital files may have been modified using a computer. However, there are digital cameras that can produce authenticated images. If someone modifies an authenticated image, it can be determined with special software.

SanDisk claims to have developed a write once memory stick for cameras and that the images once written cannot be altered.

Archiving

The archival potential of digital photographs is less well understood because digital media have existed for 50 years. Three issues are involved for archival storage: physical stability of the recording medium, future readability of the storage medium and future readability of the file formats used for storage.

It is important to consider the future readability of storage media. Assuming the storage media can continue to hold data for prolonged periods of time, the short lifespan of digital technologies often causes the drives to read media to become unavailable. For example, the first 5¼-inch Floppy disks were first made available in 1976. However, the drives to read them are already extremely rare 30 years later.

The ability to decode the data is important. Digital cameras save photographs in JPEG format, that has existed for approximately 15 years. Because the instructions on how to decode this format are publicly known, it is unlikely that this files will be unreadable in the future.

Most professional cameras can save in a RAW image format, the future of which is less certain. Some of these formats contain proprietary data which is protected by patents, and could be abandoned by their makers at any time for economic reasons. This could make it difficult to read these ‘raw’ files in the future, unless the camera manufacturers were to release information on the file formats.

Additionally many companies take an active approach to archiving rather than relying on formats being readable decades later. This takes advantage of the ability to make perfect copies of digital media. For example, rather than leaving data on a format which may potentially become unreadable or unsupported, the information can typically be copied to newer media without loss of quality. This is only possible with digital media. Digital images may be printed and stored like traditional photographs.

Convenience and flexibility

Flexibility and convenience have been the main reasons for the widespread adoption of digital cameras. With film cameras, film is normally completely exposed before being processed. Only once the film is returned is it possible to see the photograph. Most digital cameras incorporate a liquid crystal display that allows the image to be viewed immediately after exposure. The photographer may delete undesired or unnecessary photographs, allowing the photographer an immediate opportunity to repeat the image. When a user desires prints, it is only necessary to print the required photographs.

With digital imaging, images may be conveniently stored on a personal computer for modification. Professional-grade digital cameras can store pictures in a raw image format which stores the output from the sensor directly rather than processing it immediately to an image. When edited in suitable software, such as Adobe Photoshop or the GNU program GIMP (which uses dcraw to read raw files), the user may manipulate certain parameters of the image, such as contrast, sharpness or colour balance, before producing a final image. Alternatively, users may retouch the content of recorded JPEG images; software for this purpose may be provided with consumer-grade cameras.

Digital photography allows the collection of large amounts of archival documents in a short period of time which has many benefits for the researcher including convenience, saving money and an increased flexibility in using the documents.

For large format and ultra large format photography, film may have some advantages, both over price and flexibility – at least outside of a studio – as large format digital cameras use scanners rather than a single sensor, these cameras are extremely expensive and not very portable.

Price

Film and digital imaging systems have different cost basis . With digital photography, cameras tend to be significantly more expensive than film equivalents. With digital cameras, taking photographs is effectively cost-free. The price of digital cameras continues to drop and using film may be seen as more expensive than digital.

High quality film cameras are less complicated and therefore less expensive. The major expenses are ongoing film and processing costs. The professional photographer will only identify unsuitable images after developing and printing have been paid for.

Film offers the photographer more control over the depth-of-field than a DSLR with an APS sensor, and the price of full-frame sensor cameras may be very high. 35 mm single-lens reflex cameras may be purchased for a fraction of the price of a full-frame DSLR. Some lenses are interchangeable between digital and film cameras; film can be an attractive introduction to photography because of this.

The costs associated with digital photography are specialist batteries, memory cards, paper, printer ink cartridges and long-term storage.

With many photographers switching to digital, film cameras and lenses are now available on the second-hand market at often much-reduced prices, allowing for semi-professional and even professional film cameras to be owned by people who would once never have been able to afford them.

Review of the Canon EOS 40D

The Canon EOS 40D is a 10 megapixel SLR digital camera that saw a lot of hype prior to its release. According to users who have bought this camera, it lives up to the hype – and then some. Its DIGIC III image processor and large 3 inch LCD make it a favorite among casual photographers and professionals alike.

Users have nothing but lavish praise for this camera. The Canon EOS 40D consistently gets 5-star ratings and plenty of glowing reviews from owners. Some laud the camera’s impressive light sensitivity and its hefty size. The camera feels substantial, not like something fragile that might break with rough treatment. With the EFS 17-85 IS in place, the camera weighs in at two and a half pounds! But it does fit into the photographer’s hands naturally, and handles very well.

Professional action photographers use this camera for outdoor work and enjoy its sharpness and color identity. The camera even cleans itself every time it is turned off, thanks to an automatic sensor cleaning feature.

Some users feel that the Canon EOS 40D is more suited to advanced camera users. The sheer number of features can be intimidating. Customers recommend a lot of patience and exploration, or even the purchase of special training DVDs to help new photographers learn the ins and outs of the 40D.

Here are just a few of the Canon EOS 40D’s many features:

* 10.1 Megapixel CMOS Sensor
* DIGIC III Image Processor
* RAW, JPEG File Format
* Canon EF/EF-S Lens Mount
* Auto and Manual Focus
* Auto and Manual Exposure
* ISO 100-1600 (3200 Enhanced)
* 3.0-inch LCD
* Compact Flash Memory
* Lithium-ion Battery
* USB Cable
* Video Cable
* Neck Strap
* Battery Charger

The Canon EOS 40D is an SLR professional grade digital camera with image resolutions of 3888 x 2592,  2816 x 1880, and 1936 x 1288. It has a minimum shutter speed of 30 seconds, and a maximum shutter speed of 1/8000 seconds. Pictures can be snapped rapid-fire for excellent action shots. The EOS 40D does up to 75 images in burst mode. Its exposure controls include Auto, Manual, Daylight / Sunny (Preset), Cloudy (Preset), Fluorescent (Preset), Tungsten (Preset), Shade (Preset), and Flash (Preset).

A few critics voice disappointment that the camera kit doesn’t come with a lens hood as would be expected from a camera of this caliber. But complaints are few and far between. The Canon EOS 40D would be a great gift for a photography student, journalist, or anyone who is ready to move away from point-and-shoots. This is a real camera for real photographers.

The Canon EOS 40D retails for about $1,200 US.

How to keep memories alive

I always thought the idea of a scrapbook was dumb.  That is until I was given one that recorded a bunch of photos and news clippings of an important time in my life.  It meant so much to me and is great to look at from time to time.  These days there is a huge industry surrounding the idea of scrapbooks and digital scapbooks.

Digital scrapbooking is an interesting concept.  These days with the digital camera taking over, it is much more affordable to keep your scrapbooks in digital format. There are also some great artists who have turned their art work into digital scrapbook materials so all you have to do is copy their art work into your digital scapbook document.

You will need to use a photo editing program, preferrably one like Photoshop or Fireworks.  This way you can combine as much text, images, and artwork as your heart desires in one file.  A great thing about this is that you can choose to print any of your pages as well.  There are some great online printing services that are reasonably priced.

So while you at it, why not create a Blog about the person or events that are the subject of your scrapbook, then combine the two into an interesting website that can be shared with anyone you wish.  If you are not familiar with setting up a blog, contact a blog consultant who can help.

Although many people still like the process and the feel of creating scrapbooks with their own hands, some people preffer to get rid of the clutter and mess and go digital.

Digital Cameras & Digital Photography

When dealing digital photography – like most electronic devices, digital cameras need extra care when being handled. They have sensitive components that may be damaged by improper handling. We therefore came up with several tips to help you maintain your camera so that you can use it for a much longer time.

1. Keep your digital camera from getting wet unless it is indicated that it is waterproof. Otherwise, moisture will build up inside it which will destroy your camera’s internal
components.

2. If you are using a rechargeable battery for your digital camera, the time will come when it no longer works as well as it used to. Typical Lithium Ion batteries last up to 500 cycles after which a decline in its performance can be noticed. Dispose of your batteries properly and replace them with new ones.

3. Always keep your lens clean. This is especially the case if you have a digital SLR as its lens is more complex and need better maintenance. Read your user’s manual on how to
maintain your camera’s lens.

4. Avoid dropping your camera. As mentioned earlier, your camera contains sensitive equipment which may be destroyed due to excessive shaking or impact and when you look at the digital camera comparison you will see which deals with shock the best.

5. When shooting pictures in the sea, make sure to protect your gear by waterproofing it well. Salt water can corrode your camera. Therefore, you should gently wipe its surface with a cloth dipped in fresh water to rinse off remnants of salt water on your camera. Wipe it dry after.

Buy Digital Camera Tips

Looking to buy a new digital camera?  Here are a some suggestions on how to buy the digital camera that’s perfect for you.

Shop by Brand

Do your research for a digital camera under one specific brand.  Switching back and forth between different brands can create unnecessary confusion.  Brands do share common basic functions, but obviously they don’t all share the same technological features which make a brand different or unique… maybe even better for what you want from a digital camera.  For example, the SD 750 has a feature that automatically focuses in on a subject’s face.

Megapixel: Is More Better?

Don’t let megapixels be the only deciding factor for choosing your digital camera.  More megapixels in a digital camera doesn’t necessarily mean better picture or print quality.  Although the trend has been for digital camera manufacturers to offer 8, 10 or 12 megapixel digital cameras, Consumer Reports research shows that a 7 megapixel digital camera is adequate for the average digital camera user.  The Canon PowerShot Camera has a resolution of 7.1 megapixels and has many favorable reviews.

Optical vs. Digital Zoom

Just remember the most important thing about zoom on a digital camera; optical and digital zoom are not the same.  Digital zoom or magnification is achieved through the software within camera.  Whereas, optical zoom is magnification through the camera lens and is higher quality that what can be achieve from digital zoom.  Consider what types of pictures you will be taking.  Automatic point and shoot digital cameras such as the Canon SD750, have 3x optical zoom and regular or hobbyist camera users will be happy.  Anyone who will be taking sports or nature pictures may want a camera with 10x optical zoom lens or more.