Digital Photography from 20,000 Feet
by Wesley Fink on September 25, 2006 12:05 AM EST- Posted in
- Digital Camera
Digital Challenges: What Needs to be Improved
Despite the huge leaps in digital technology in the past few years, there are still a few issues remaining. Most of the sensor makers and camera/lens manufacturers are working on these issues. You should keep them in mind when looking at digital SLRs, because they are the areas where development is needed.
Dynamic Range
Compared to film SLRs, digital SLRs still cannot match the dynamic range of film. Dynamic range is the difference between the brightest highlights and darkest shadow detail in an image. Most manufacturers are working very hard to provide improved dynamic range, but there is no consensus yet on what works or will work best to fix this problem. Solutions vary from the extra set of pixels designed just to capture highlight detail in the Fuji S3 PRO (for Nikon lenses), to the Bionz image processor in the new Sony A100 electronics, and the D-Lighting feature in the new Nikon D80 that can be used to improve shadow or highlight detail.
Most users are not really aware of this issue, and sensor and camera makers are not making a big deal about it unless they have a feature that improves this weakness. However, if you examine a high contrast image from film next to the digital image you will see highlights blowing out on the digital image and less shadow detail in the digital image. Digital has improved greatly in this area, and will no doubt continue to improve, but the dynamic range difference is still about 1.5 to 3 stops better with film than digital.
In shopping for a digital SLR you might pay attention to those that claim to address this issues and what they have done.
Dirt on the Sensor
One of the early problems identified by users of digital SLRs with interchangeable lenses was that the sensor could easily get dirty in the process of changing lenses. Unlike film cameras, where this issue went away with a film change, a dirty sensor will make all future photographs spotted with specks. This issue is particularly troublesome in digital cameras, because the sensor coatings are very delicate and the SLR needs to be returned to the manufacturer for cleaning dust from the sensor.
Most manufacturers have software tools to minimize this problem, mathematically "removing the spot and filling in with calculated pixels", but the first manufacturer to address it on the prevention end was Olympus with their wave filter. They provided a protective coating on the sensor and also used ultrasonic vibrations to clean the sensor on start-up to remove any dust that may have gotten through.
Sony also introduced a protective coating and start-up vibration feature to protect from and remove dust on their new 10.2 megapixel A100. Pentax and Samsung have apparently licensed the Sony system, as they have announced similar mechanisms on their new 10.2 Sony-sensor cameras. Even Canon, who denied for quite a while that there was a dust problem, is now providing the "EOS Integrated Cleaning System" on their new 10 megapixel Rebel XTi. The XTi uses special antistatic sensor coatings and an ultrasonic cleaner much like Olympus.
Auto White Balance
White Balance was not really discussed in this introductory guide, but digital cameras, unlike film, allow the user to set the color temperature or color balance of the sensor. With film you had to choose daylight (or flash), tungsten, Fluorescent, and other color balances when you selected film. In digital imaging you select the "color temperature" when you shoot. You can also leave the color temperature on Auto and let the camera choose - or be really fancy and measure color temperature (most SLRs have this capability) and set a Custom temperature.
Most users leave it on Auto, but we have yet to see a digital SLR that does a decent job with common indoor lamps and lights (tungsten) on the Auto setting. Almost all Auto settings seem to leave an orange cast in the images shot under indoor light. This can normally be corrected in images shot in RAW and some images shot as JPEG, but the easiest solution by far would be an Auto setting that really works. The best solution today is to move off the Auto White Balance setting to Tungsten (Indoor Light) when shooting indoors. Today's cameras do generally apply the correct temperature when the tungsten white balance is selected. Until this is fixed in the majority of Digital SLR cameras we plan to test the Auto setting under indoor lighting in our reviews.
Lens Confusion
This guide should help with confusion about lenses and lens factors, but the problem won't go away until camera and lens makers decide on a standard. Right now digital SLRs are still basically fed with 35mm lenses, even though the sensors are APS C and DX size and have a smaller image circle. It appeared for a while that the industry would settle on this APS C/DX size and eventually name lenses by their equivalent APS C/DX focal lengths once 35mm faded away. Now the outcome is less clear. Some now predict the SLR market will move to two tiers, with APS C/DX SLR cameras as mainstream and full-frame 35mm-size sensors at the Pro end. This certainly would maximize the existing 35mm lens line of the big camera manufacturers and still provide an upgrade path for advanced amateurs. This is the path that Canon appears to be following, but Nikon is still committed to the pro APS C/DX sensor size.
If you look closely at the new lenses Sony introduced you will see even more confusion. Sony does not make 35mm film SLR cameras, so there is no reason for them to introduce new lenses designed for 35mm just for the current Minolta film owners. Yet 2 of the 3 new Sony Carl Zeiss lenses are designed for a 35mm image circle. This leads observers to believe that Sony, one of the largest sensor manufacturers in the world, may be hedging their bets on a full-size 35mm sensor Sony SLR. It is also interesting that the major camera makers that have extensive lens lines seem to have slowed their introduction of lenses designed for APS C/DX sensor size. There is no crystal ball, but it will be interesting to see where the digital SLR industry goes in the near future.
The lens confusion and format confusion is likely to continue for a while, since none of the manufacturers except Olympus, with their all-new digital 4/3 system, have truly committed to a new sensor size. If Sony or Nikon introduce a new Pro full-size 35mm sensor in the near future, you can expect the industry to segment as Canon has now done with their 35mm sensor Pro EOS 1D Mark II and EOS 5D versus the rest of the Canon line whish uses an APS C sensor with a 1.6 lens factor.
Gaps in the Lens Lines
Perhaps because of the lens confusion, there are still gaping holes in the lens lines of the APS C/DX format digital SLR cameras. Due to the 1.5/1.6 lens factors the 35mm wide angles are pretty useless on a digital SLR. There is still a need for additional wide angle lenses that are wide angle on APS C/DX. The Sigma 10-20mm and Tamron 11-18mm help, but pickings form the majors are very slim. So are DT size lenses from the majors that address the need for fast fixed-focal-length wide-angles and fast normal lenses. Pentax recently introduced 21mm f3.2 and 40mm f2.8 pancake (flat) lenses for their digital line. Samsung recently announced they would introduce a 35mm F2.0 lens for their digital cameras. These three lenses will bring new options to digital photographers shooting with the Pentax KA mount.
Despite the huge leaps in digital technology in the past few years, there are still a few issues remaining. Most of the sensor makers and camera/lens manufacturers are working on these issues. You should keep them in mind when looking at digital SLRs, because they are the areas where development is needed.
Dynamic Range
Compared to film SLRs, digital SLRs still cannot match the dynamic range of film. Dynamic range is the difference between the brightest highlights and darkest shadow detail in an image. Most manufacturers are working very hard to provide improved dynamic range, but there is no consensus yet on what works or will work best to fix this problem. Solutions vary from the extra set of pixels designed just to capture highlight detail in the Fuji S3 PRO (for Nikon lenses), to the Bionz image processor in the new Sony A100 electronics, and the D-Lighting feature in the new Nikon D80 that can be used to improve shadow or highlight detail.
Most users are not really aware of this issue, and sensor and camera makers are not making a big deal about it unless they have a feature that improves this weakness. However, if you examine a high contrast image from film next to the digital image you will see highlights blowing out on the digital image and less shadow detail in the digital image. Digital has improved greatly in this area, and will no doubt continue to improve, but the dynamic range difference is still about 1.5 to 3 stops better with film than digital.
In shopping for a digital SLR you might pay attention to those that claim to address this issues and what they have done.
Dirt on the Sensor
One of the early problems identified by users of digital SLRs with interchangeable lenses was that the sensor could easily get dirty in the process of changing lenses. Unlike film cameras, where this issue went away with a film change, a dirty sensor will make all future photographs spotted with specks. This issue is particularly troublesome in digital cameras, because the sensor coatings are very delicate and the SLR needs to be returned to the manufacturer for cleaning dust from the sensor.
Most manufacturers have software tools to minimize this problem, mathematically "removing the spot and filling in with calculated pixels", but the first manufacturer to address it on the prevention end was Olympus with their wave filter. They provided a protective coating on the sensor and also used ultrasonic vibrations to clean the sensor on start-up to remove any dust that may have gotten through.
Sony also introduced a protective coating and start-up vibration feature to protect from and remove dust on their new 10.2 megapixel A100. Pentax and Samsung have apparently licensed the Sony system, as they have announced similar mechanisms on their new 10.2 Sony-sensor cameras. Even Canon, who denied for quite a while that there was a dust problem, is now providing the "EOS Integrated Cleaning System" on their new 10 megapixel Rebel XTi. The XTi uses special antistatic sensor coatings and an ultrasonic cleaner much like Olympus.
Auto White Balance
White Balance was not really discussed in this introductory guide, but digital cameras, unlike film, allow the user to set the color temperature or color balance of the sensor. With film you had to choose daylight (or flash), tungsten, Fluorescent, and other color balances when you selected film. In digital imaging you select the "color temperature" when you shoot. You can also leave the color temperature on Auto and let the camera choose - or be really fancy and measure color temperature (most SLRs have this capability) and set a Custom temperature.
Most users leave it on Auto, but we have yet to see a digital SLR that does a decent job with common indoor lamps and lights (tungsten) on the Auto setting. Almost all Auto settings seem to leave an orange cast in the images shot under indoor light. This can normally be corrected in images shot in RAW and some images shot as JPEG, but the easiest solution by far would be an Auto setting that really works. The best solution today is to move off the Auto White Balance setting to Tungsten (Indoor Light) when shooting indoors. Today's cameras do generally apply the correct temperature when the tungsten white balance is selected. Until this is fixed in the majority of Digital SLR cameras we plan to test the Auto setting under indoor lighting in our reviews.
Lens Confusion
This guide should help with confusion about lenses and lens factors, but the problem won't go away until camera and lens makers decide on a standard. Right now digital SLRs are still basically fed with 35mm lenses, even though the sensors are APS C and DX size and have a smaller image circle. It appeared for a while that the industry would settle on this APS C/DX size and eventually name lenses by their equivalent APS C/DX focal lengths once 35mm faded away. Now the outcome is less clear. Some now predict the SLR market will move to two tiers, with APS C/DX SLR cameras as mainstream and full-frame 35mm-size sensors at the Pro end. This certainly would maximize the existing 35mm lens line of the big camera manufacturers and still provide an upgrade path for advanced amateurs. This is the path that Canon appears to be following, but Nikon is still committed to the pro APS C/DX sensor size.
If you look closely at the new lenses Sony introduced you will see even more confusion. Sony does not make 35mm film SLR cameras, so there is no reason for them to introduce new lenses designed for 35mm just for the current Minolta film owners. Yet 2 of the 3 new Sony Carl Zeiss lenses are designed for a 35mm image circle. This leads observers to believe that Sony, one of the largest sensor manufacturers in the world, may be hedging their bets on a full-size 35mm sensor Sony SLR. It is also interesting that the major camera makers that have extensive lens lines seem to have slowed their introduction of lenses designed for APS C/DX sensor size. There is no crystal ball, but it will be interesting to see where the digital SLR industry goes in the near future.
The lens confusion and format confusion is likely to continue for a while, since none of the manufacturers except Olympus, with their all-new digital 4/3 system, have truly committed to a new sensor size. If Sony or Nikon introduce a new Pro full-size 35mm sensor in the near future, you can expect the industry to segment as Canon has now done with their 35mm sensor Pro EOS 1D Mark II and EOS 5D versus the rest of the Canon line whish uses an APS C sensor with a 1.6 lens factor.
Gaps in the Lens Lines
Perhaps because of the lens confusion, there are still gaping holes in the lens lines of the APS C/DX format digital SLR cameras. Due to the 1.5/1.6 lens factors the 35mm wide angles are pretty useless on a digital SLR. There is still a need for additional wide angle lenses that are wide angle on APS C/DX. The Sigma 10-20mm and Tamron 11-18mm help, but pickings form the majors are very slim. So are DT size lenses from the majors that address the need for fast fixed-focal-length wide-angles and fast normal lenses. Pentax recently introduced 21mm f3.2 and 40mm f2.8 pancake (flat) lenses for their digital line. Samsung recently announced they would introduce a 35mm F2.0 lens for their digital cameras. These three lenses will bring new options to digital photographers shooting with the Pentax KA mount.
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silver - Monday, September 25, 2006 - link
I think this is one tidbit that you might write on when you're realy bored. My images are backed up using Verbatim UltraLife Gold DVD-R media. You also need to make sure that they stay cool and dry much as you do with film. They're not as sensitive to humidity but as certainly far more sensitive to heat.Googer - Monday, September 25, 2006 - link
Panasonic is makeing and selling cameras based on good old Leca Lens. If you have a leica lens from any point in the last 55+ years, it will be compatable with a Panasonic/Leica Camera.
Wesley Fink - Monday, September 25, 2006 - link
The Pansonic Lumix DMC-L1 digital SLR uses a Leica lens built with a four thirds mount. This is the new digital only mount pioneered by Olympus. The LMC-L1 is mentioned in the guide.silver - Monday, September 25, 2006 - link
One of my friends has one of these and the images are simply incredible. He states that the Opticla Image Stabilization is simply the best he could find.wilburpan - Monday, September 25, 2006 - link
As someone used to shooting with film cameras, I can say that I still notice some shutter lag when using digital SLRs, even with current models. To write this off as "Virtually none of the lags of early digital cameras remain" is to ignore a real factor when it comes to the use of any camera.To put this another way, if a digital camera website stated that the choice of CPUs was unimportant in buying a computer because all modern day CPUs were fast and powerful enough, the readers of this site probably would bust a gut.
There are also speed issues involved with other uses of a digital camera that need to be addressed. The Nikon D80 takes about 1.4 seconds to store and then display an image after the shutter has been pressed. The speed of this process varies widely from camera to camera. Similar variances in speed and performance come into play when performing tasks such as playback of pictures taken, the time that it takes to process bursts of photos when shooting in continuous mode, etc.
silver - Wednesday, September 27, 2006 - link
Regarding shutter lag, digital cameras will always be slower than film. There's no way around that. My FM2n's have near instantaneous shutter release and are quite the opposite of my admittedly dated Fuji S602. What manufacturers need to do is to have separate power sources (batteries) for lens focusing and camera functions other than CCD/CMOS/memory charging. Obviously this would complicate the camera so they probably aren't considering this option.Wesley Fink - Monday, September 25, 2006 - link
This is where we start to get into questions about what test is real. The file flush time on a Nikon D80 is 2.0 seconds for a fine jpeg and a little less than 3s for a RAW+jpeg. However, you never encounter this becuase of the memory buffering built into the Nikon D80 and every other digital SLR camera. The D80 can do 3 fps for a little over 30 seconds shooting raw+jpeg, and with fine jpeg it can shoot 3fpm until you run out of flash card room or battery.I consider the D80 time of 160ms viewfinder blackout (0.16s), and a less than 0.1s from off to shot negligible for almost any users. Even the Sony, which has a 1 second start-up, is using almost all that time to clean the sensor before shooting, while shot-to-shot is very competitive with the best SLRs around. Some users might be happier if you could turn off the cleaning on start. While this may be very important for some users, it is doubtful that the small differences in recent digital SLR cameras will really be noticable or matter to most users.
dpreview is an excellent and respected digital review site, and I have sent many readers there with their questions. They often come back with more questions than answers, which usually means they found the technical level too far above their skills and needs. We can't be all things in Digital Camera reviews so we will likely err toward the more basic side.
We'll consider your suggestion about start-up times, but I'm not convinced yet.
yacoub - Monday, September 25, 2006 - link
I appreciate your article but I don't know: I think that folks into digital photography, no matter what other hobbies they have, including computer hardware or gaming, are knowledgable enough (or are competent enough to gain the knowledge needed) to make good use of a site like DPReview, which offers about all the info most need to make an intelligent purchase of a digital camera. Plus that being their primary focus (and has been for years), they automatically get much more credibility than a computer hardware site can hope to achieve by writing content basically saying "look we can do this too!" and writing what most good highschool photography classes are teaching today anyway.I guess my question is, why not stay focused on computer component hardware? All branching out does is reduce the chance of the main hardware getting the attention it needs. There are umpteen motherboard, videocard, and RAM reviews and guides yet to be completed or even begun, yet you're going off into digital photography land? That's kind of disappointing. For that hobby there are already many strong resources for folks who are into that, and many more for folks who want a simple pocket-sized point-n-shoot (which is the majority of folks). Why not focus on being the strong resource in computer hardware that folks in this hobby need?
fanbanlo - Monday, September 25, 2006 - link
Maybe AnandTech can explain to use what are the new technology built into the sensor rather than meaningless marketing terms givin to them.Different algorithm used? what's their computational power?
Why shoot RAW? RAW-enabled software review!?
Thx
Heidfirst - Monday, September 25, 2006 - link
For the lower end DSLRs (D50,350D,K100D etc.) I think that you should also review the standard kit lens as the majority of buyers will probably be buying it with the body as a package.By the time that you start hitting EOS30D type level imo most people will probably have lenses already or be buying a better lens than the entry level kit lens. Also if they are paying that for a body they quite probably are reasonably knowledgeable photo enthusiasts & maybe Anandtech isn't going to be the first place that they look for reviews so sticking to the lower end at least initially sounds reasonable to me.
The idea of a standard test scene is interesting but it would have to be reproducible which means in the studio & that means that it's less representative of the conditions in which most people will use them (I imagine that the % of even current DSLR users who shoot in the studio is in single figures & probably low single figures at that).