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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wheel - Tuesday, September 26, 2006 - link
Thanks for your reply.Regarding the Canon 50mm 1.8, I think most people would agree that the 1.4 is better since it has full time manual focus and also a silent USM motor, plus 8 aperture blades instead of 5 for nicer, smoother looking bokeh (out of focus areas in an image). Of course when you consider the cost differential most people choose the f1.8 and for many it is the smarter choice! However I still believe your sentence in the article suggesting that it happens to be the sharpest lens in the lineup a little misleading. Not a big deal I guess.
If I can make some comments on the following paragraph:
There are plenty of Digital Camera Review sites out on the web, so you may ask why AnandTech is re-launching a Digital Photography section. It appears that current sites are rarely on target with what computer enthusiasts want to know about digital cameras. Some sites make the assumption that the reader knows a lot more about photography than our average reader, which often leads to much of the review being gibberish to a non-photographer. Other sites dwell on tests of things like "start-up times" that were important in early digital, but have become all but meaningless in today's digital SLR market. Still other sites, which are very well-grounded in traditional photography show an obvious lack of knowledge about computers and computer tools that make digital photography so flexible today. It is our sincere belief that we can do it in a better way for our readers and computer enthusiasts everywhere, but please help us as we try to reinvent this wheel. Some of our readers may not like AT delving into Digital Camera Reviews, and to them we say you just can't ignore digital photography any more. Today's digital imaging is nothing more than an optic stuck on a computer, and there is very little left of the mechanical gems that once ruled the world of photography.
A few points:
"Some sites make the assumption that the reader knows a lot more about photography than our average reader, which often leads to much of the review being gibberish to a non-photographer."
So a 'non-photographer' will find a technical review on the big digital camera sites gibberish? I don't think that is a problem, because such reviews aren't really aimed at non-photographers. I would guess that non-computer users are going to find articles on Anandtech about ram timings difficult to understand too!
Other sites dwell on tests of things like "start-up times" that were important in early digital, but have become all but meaningless in today's digital SLR market.
See my comments re: sports / action photography in my previous post. Start up times, shot to shot times and file flush times are quite important to me! Other sites have (very comprehensive) standardised tests that include these timings. I wouldn't say they dwell on the subject though, unless a particular camera is unusually bad at it. If it is not something that is relevant then a reader can easily skip it.
Still other sites, which are very well-grounded in traditional photography show an obvious lack of knowledge about computers and computer tools that make digital photography so flexible today.
In my years of reading the major photo review websites, I haven't encountered this. Without asking you to be specific, can you mention general examples of what you mean?
Cheers,
Ian
tagej - Tuesday, September 26, 2006 - link
The reality is that most computer geeks (myself included) are not photography experts, but are overall tech-savy and interested in things like digital SLR cameras.Sure, I can go to sites like dpreview and the like, and they do an excellent job of reviewing cameras from a pro or prosumer perspective. I could sit and read a bunch of stuff on those sites and educate myself to the point of becoming very knowledgable about cameras... Most of us don't want to do that, or we would have already done so. Instead, AT hit it right on the head with this article, it's a look at digital photograhpy for the tech savy who are not photography experts.
arswihart - Tuesday, September 26, 2006 - link
I totally agree with "wheel." If you feel the need to review cameras, go ahead, but thats not what I come to Anandtech for.aeternitas - Monday, September 25, 2006 - link
" The artistic types distrust turning their vision into cheap Adobe Photoshop tricks, and the tech-savvy are so enamored of technology and editing that they often don't have a clue about what makes a good photograph and what lens to use in a given situation. "I stopped reading there. If you want respectable people to respect you, its a good idea not to be a fucking jackass and insult the readers in the second paragraph. Get some common sence.
Resh - Tuesday, September 26, 2006 - link
Have to side with Wes on this one. Nothing in his words are offensive. He is simply stating the view point of two extremes of the population who both hold very valid positions.Wesley Fink - Monday, September 25, 2006 - link
These are comments from discussions I have had on Forums and in emails with readers. They were not meant to offend, but to point out the fact that the art and technical don't always mix well. This is particularly true when the market, and not the people affected, is forcing changes in the way people work.ksherman - Monday, September 25, 2006 - link
since we have had a camera review on AT! Kudos!To those that say no, I also like to read reviews from multiple sources. AT- dont try to be dpreview, make your reviews a little less technical, easier to understand. Not to fault them, but you need to have some pretty serious photography knolwedge to get their reviews. I would welcome an easier to understand set of reviews. (I do still enjoy reading about my level :-))
On another note, on the last page, you called canons new camera the Rebel XT1, its actually the XTi.
Also, take a gander at the Panasonic Lumix DMC-FZ50, its a sort of pre-digital SLR camera. It basically is a digital SLR, but with an attached lense. Its looking to be my next camera purchase since I am too poor to afford the "real" DSLRs.
saiku - Monday, September 25, 2006 - link
I am a hobbyist photographer (Canon 350D) who likes to do macros/scenery when I can. What I'd love to see are guides for people who want to get into DSLRs and don't know which camera system to buy into. For example, if a person is interested in macros, should he buy into a Nikon system? What about the guy who wants to shoot lots of indoor shots of his baby? Lens choices are very tough for newbies to make and a hefty dose of attention to what lens to pick would be great.PokerGuy - Monday, September 25, 2006 - link
Wes, thanks for the great article. I'm a grizzled vet when it comes to PC tech, but when it comes to photography I'm pretty much a noob. I appreciate the article and look forward to reviews, especially since I'm about to purchase my first digital SLR camera.One dumb question: are lenses for SLR cameras "standard" in terms of connecting to the camera body? ie, can I take a Canon EOS Rebel 2000 SLR lens and hook it up to some other digital SLR camera?
Resh - Monday, September 25, 2006 - link
Also, Canon EF-S lenses only fit certain cameras (Digital Rebels, 20D, 30D), but EF lenses work on all current Canon bodies, digital or film.Third party manufacturers like Tamron and Sigma will make lenses for both Canon and Nikon.