Slashdot Mirror

← Back to Stories (view on slashdot.org)

Beyond Megapixels - Part II

Posted by michael on from the point-and-shoot dept.

TheTechLounge writes "This is Part II of a series of three editorial articles examining current digital photography hardware, as well as my views of what is to come. In this segment I will be focusing on build, size, weight and ergonomics of camera bodies, as well as the size, weight, function and versatility of the glass strapped to the front of it. If you haven't already, you may want to read Part I first."

48 of 135 comments (clear)

  1. There making cam's to "camp" by Anonymous Coward · · Score: 4, Insightful

    I'm not expecting a military spec strength durable camera, but these comtempory cam's seem to fragile.
    I remember seeing this store clerk setting the display of new cam's; the clerk was handling them as if they were new born babies.
    Then again one those cam's probably cost a months wage for the clerk.

  2. Article is Wrong on Lenses by hanway · · Score: 5, Informative
    The article started out okay, although taking a whole page to say little more than "DSLRs are big", but on the second page I came to this statement as a justification for using smaller lenses in DSLRs:

    The sensor only receives the light that passes through the center of the lens, while the light on the outer region simply falls to the side of the sensor.

    That's fundamentally wrong. A light ray that falls on any part of the lens can be refracted to any point on the focal plane. What gets focused onto the sensor in the center of the focal plane is not just the light that passed through the center of the lens, but part of the light passing through the entire lens.

    The author is right that a range of smaller lenses would help reduce camera size, but with a smaller lens comes less light gathering ability and reduced ability to take advantage of depth of field when composing a photo, so smaller lenses would be a compromise in photo quality.

    1. Re:Article is Wrong on Lenses by dfghjk · · Score: 5, Informative

      The author also missed the point that DSLR's are an attempt to make cameras that best utilize existing lenses. He says over and over that the lenses aren't necessary for the camera but that's meaningless. The lenses come first and the bodies follow. This is the best they can do at the price point and time.

      He also stated that the 2/3" lens and DLSR lens at f/2.8 have the same light gathering ability. That's wrong. They have the same exposing rate ability but the SLR lens has greater light gathering ability because it exposes a larger image circle.

      Frankly, everyone should ignore these articles. The author doesn't know enough about the subject to do anything but damage.

    2. Re:Article is Wrong on Lenses by frdmfghtr · · Score: 4, Informative

      What may have been the point is that while a ray of light at the top of the lens may be focused on the focal plane, it doesn't land on the sensor.

      The sensor only receives the light that passes through the center of the lens, while the light on the outer region simply falls to the side of the sensor.

      This is actually true, due to the nature of focusing a round image from a round lens onto a rectangular sensor (the round plug into the square hole, if you will). Either outer parts of the circle will fall on the focal plane that is not convered by the sensor or the sensor will have areas not exposed to the image (circle fitting entirely inside the rectangle).

      --
      Government's idea of a balanced budget: take money from the right pocket to balance...oh who am I kidding?
    3. Re:Article is Wrong on Lenses by kfg · · Score: 5, Informative

      The author also missed the point that DSLR's are an attempt to make cameras that best utilize existing lenses.

      ". . . by utilizing the interchangeability of the lenses on a DSLR, you open yourself up to the use of dozens of lenses appropriate for all kinds of various uses and prices from around $60 up to, and in excess of, $8,000. For photographers switching from a film SLR to a DSLR of the same brand and mount, this means your investment in lenses does not go out the window."

      KFG

    4. Re:Article is Wrong on Lenses by guidryp · · Score: 3, Interesting

      Actually he highlights the real world compromise of using the existing lenses with smaller sensors. But this is a comopromise.

      He is actually correct. F/2.8 is essentially light gathering ability over area. Not total light gather ability. No matter what size sensor you put there within the image circle it is effectively F/2.8.

      But it ends up being a waste of lens with smaller sensor. You can use a much smaller lens and deliver the equivalent light to the smaller image circle.

    5. Re:Article is Wrong on Lenses by Zocalo · · Score: 4, Informative
      This is actually true...

      Actually, it's kind of both. You need to think beyond those over simplified line drawings of a pinhole camera with a tree or vertical arrow as the "scene". A circular lens will create a circular image on the focal plane, which is where the sensor or film will hopefully lie, and since the sensor is usually rectangular part of that projection will indeed be "discarded".

      However, for a point in the center of the image, reflected light from that point source will almost certainly be striking the *entire* front element of the lens, and being refracted back onto the sensor where they ideally will focus on a single point again. Instead of a single line from a point on the subject to a point on the sensor, you need to think of two conical objects (yes, 3D) joined at their equal sized bases (the lens).

      The fact is that there are a lot of photographers that don't understand the finer points of optics, or need to for that matter, and are under the illusion that DSLRs are only utilising the superior glass in the center of their lenses. Given that many of them have only just grasped how the field of view crop actually works, and that it's not really the "zoom multiplier" marketing told them it was, I can't say I'm surprised. If anyone knows of a web page that explains this in laypersons terms, I'd certainly appreciate the URL though!

      --
      UNIX? They're not even circumcised! Savages!
    6. Re:Article is Wrong on Lenses by jdg · · Score: 2, Informative

      Well, the article did not state it quite correctly, but the size of the sensor certainly drives the maximum diameter of the lens elements in almost all lenses of the design forms used for cameras. In real life, the diameter of the lens elements is determined by two things: 1) the speed of the lens (f-number), and 2) the coverage (field of view & sensor size).

      Think of a limiting case. If you had a lens element in contact with the sensor, that lens element would have to be larger for a larger sensor. Often lens elements are quite close to the sensor because it is helpful in correcting field curvature.

      If you are interested in this stuff, take a look at Modern Optical Engineering by Warren Smith.

    7. Re:Article is Wrong on Lenses by dfghjk · · Score: 5, Informative

      f/2.8 would be a specific rate of exposure per unit of imager area. It would expose at the same rate regardless of the size of the imager. The sensitivity of the imager is rated by ISO and is also a rating per unit area. In this way, cameras with identical ISO ratings and f-stops will require the same shutter speed regardless of imager size. That how you want it to work.

      Light gathering ability of the lens, however, is not per unit area. It means the total ability to gather light. Therefore a lens that covers a wider area at the same f-stop will have greater light gathering ability than its competitor. Whether that larger image circle is actually used is beside the point. The author was incorrect stating that the two lenses have identical light gathering ability. He would have been right had he said "exposure ability".

      Two cameras with different sensor size but identical ISO's and f-stops will require the same shutter speed for proper exposure, but the camera with the larger sensor requires more light to expose due to its larger imager area. Where does this extra light come from? Not from increased exposure time since the shutter speed is the same. It comes from the lens delivering more total light. This occurs because its lens actually has a larger physical aperture to achieve the same f-stop and the larger aperture allows more light through the lens. The "luminous flux" is unchanged, however, because it's spread over a larger area. How does the lens get away with this? The larger sensor area requires a longer focal length lens for equivalent perspective and f-stop = (focal length/physical aperture). It's all cleverly hidden in the math. Perhaps a little too cleverly.

    8. Re:Article is Wrong on Lenses by ipfwadm · · Score: 3, Insightful

      I don't think either of you are exactly right. Obviously the manufacturer wants you to buy more lenses, because that means more money for them. But they also don't want you to have to throw away all your old lenses, because that would require a huge initial investment on your part (new camera + all new lenses) which would certainly deter a lot of people.

      The happy medium? Cameras with an APS sensor size, which allow the use of the old lenses, but with a different effective focal length than when used with 35mm. You don't have to throw out all your old lenses, but because of the different performance characteristics they'll have when used with D-SLRs, you'll probably want to upgrade them in the future. You're happy because you can still use all your old lenses, and the manufacturer is happy because you'll probably buy new ones in the not-so-distant future, not to mention the fact that you also bought the camera.

      Do I think this is the primary reason for manufacturers using APS-size sensors vs. 35mm? No, but I'm sure I'm not the first one to think of it.

    9. Re:Article is Wrong on Lenses by wfberg · · Score: 3, Insightful

      OK, I meant to say a full-frame sensor DSLR, like the Canon 1Ds.. With smaller sensor, apparently the image is cropped relative to 35mm.. Still, both 35mm and smaller sensors are both rectangular..

      I wonder why they don't use a built-in lens to undo the ~ 1.5 'magnification'.

      --
      SCO employee? Check out the bounty
    10. Re:Article is Wrong on Lenses by haut · · Score: 2, Insightful

      You're right, and he also didn't even talk about the quality of the lenses. The aberrations in a 3 element, tiny zoom lens system will be much greater than in a 5+ element good sized SLR lens. This means that the geometrical spot size (which ideally would be a point, but with finite lenses would be the point spread function) will be samller on the SLR lenses. Since the 'pixel size' on the SLR will also be bigger, its much more likely there that spots will not overlap pixels. The next issue is the MTF (modulation transfer function) of the optical system. Having less aberrations, the 35 mm lens will be able to resolve higher spatial frequencies (closer together objects). While the author of this article is making a good point that megapixels are not all there is to a camera's quality, he doesn't seem fully qualified to explain why.

    11. Re:Article is Wrong on Lenses by floateyedumpi · · Score: 4, Informative
      Actually, you're wrong. Imagine a set of mile markers set off in the distance you are imaging. Now imagine you've setup the same lens on a 35mm and DSLR, side by side, to capture the exact same field of view (same number of mile markers). To get the same field of view, you'll need to zoom the 35mm camera in. To get the same f-number, you'll need to open up its pupil aperture to 1.5x as big (it's collecting more light, as someone below points out, because it needs to preserve not total luminous input, but surface brightness per square mm of film). So we have our two cameras taking the exact same picture at the exact same exposure value, but one is zoomed in and has a larger aperture.

      In order to reach the film/sensor, a bundle of rays must pass through the pupil aperture, aka the "iris". Consider the bundle for the mile marker post #123 on the extreme right-hand side of the scene. For the 35mm camera, the aperture is bigger (e.g. 1.5x as big), hence the bundle of rays accepted from that milepost is bigger, hence the actual amount of glass it traverses is bigger. If the aperture and hence bundle of rays is too big, and the field angle at the edge of the sensor is too large, part of that bundle will be shadowed by the lens hood and you'll have vignetting: again not so much of a problem for DSLRs (but a real problem for wide-angle lenses)! This is a real physical effect.

      Yes, the front surface of the lens accepts light from mile post #123 over its entire diameter, but most of those photons are rejected by the aperture stop (i.e. they fall on the iris pupil and never makes it through). For a given FOV, the aperture diameter is *smaller* for DSLRs, simply because the focal length needs to be reduced.

      The bottom line is standard 35mm lenses are overdesigned for DSLR usage, accomodating a larger pupil aperture than needed for a given field of view. Less of the lens really is used, and luckily, all problems of chromatic and spherical aberration increase drastically with field angle: in this case sticking to the "center of the lens" should be thought of the angular sense, and really does improve the image quality. The flip side of this is that DSLRs will be more forgiving when it comes to lens quality, since they don't stress the off-axis performance as much.

      If you don't believe me, take a very wide angle lens on you 35mm film camera, open up the aperture as wide as possible, and take a highly-contrasting scene. Notice how the center of the image is sharper and more color-accurate? Get out your scissors and cut out the central 1/2 of that picture. You've just replicated what a DSLR at the same lens settings would have produced. Nicer looking, eh?

      By the way, the terminology "equivalent focal length" when applied to DSLR lenses is a complete misnomer: see this comment.

    12. Re:Article is Wrong on Lenses by guidryp · · Score: 2, Informative

      This is simply arguing semantics. At F2.8 a smaller lens or a larger lens will still deliver the same amount of light to the sensor.

      Having a lens gather more light and spill it beyond the sensor is wasted and the main point of the article. The point is putting a larger than needed lens with a larger than needed image circle is only a waste. When you could build a smaller lens with a smaller image circle with the exact same specs.

      This why Nikon is building a line of lenses for the smaller APS image circle of it's DSLRs. On the smaller sensor there is NO drawback in using a smaller lens system, with the obvious advantage of it being smaller/lighter/cheaper.

  3. pixels?!?!?! Bahhh!! PINHOLES by eclectro · · Score: 2, Funny

    Back in the day we had no fancy shmancy pixels! We had no lens! We had no shutter!

    *All* we had was a pinhole. That's all we ever had. We were even darned lucky to have the pin from aunt Emma to make the pinhole with! Life was hard, and we were GRATEFUL.

    Why don't you whippersnappers grab a 'toid and make a Pintoid

    Return to where your roots are, don't be deceived by megapixel this and megapixel that. It's a myth anyway. If film was good enough for your grandpa, and your parents, it's good enough for you.

    Someday you will thank me for this.

    see what a 'toid can do here

    --
    Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
  4. What is this article trying to say? by B4RSK · · Score: 5, Insightful

    The first article in this series was reasonably well laid out and the information quite good.

    But this one? What is he trying to say? It almost seems as though the article is missing several pages...

    And a DSLR with a whole new series of lenses, presumably on a different mount? Not likely! In such a scenario anyone who eventually upgrades from a 10D-level camera to a full professional DSLR would be stuck with replacing all lenses as well. From the user-standpoint that obviously sucks, and from the camera maker standpoint there is no "brand lock in". If you have to change all your lenses anyway, then you can easily jump brands at the same time.

    What is going to happen is eventually 10D-level cameras will have full-frame 35mm sensors. Canon and Nikon might not like this idea very much, but someone else is going to do it if they don't. If Minolta/Pentax/Sigma etc move in this direction, Canon and Nikon will be forced to follow. As pixel counts increase sensor size will eventually have to follow.

    When this happens, prosumer point-and-shoots will move to APS-sized sensors, and the standard point-and-shoot models will increase to something around what the prosumers have now.

    --
    Some people are like slinkies--basically useless but they bring a smile to your face when pushed down the stairs.
    1. Re:What is this article trying to say? by dfghjk · · Score: 2, Informative
      The 4/3 system is a DSLR with a whole new series of lenses. Been out for a while now in the form of the Olympus E-1.

      Canon is the manufacturer most actively pushing full frame. That's because they lead in the manufacture of CMOS imagers so they have a distinct advantage in imager size. Still, there doesn't seem to be any race to get there. It's unlikely Canon and Nikon will be following anyone else any time soon. I should mention that Kodak makes full frame as well (the least expensive at around $4000).

      I also don't agree that P&S digicams will move to APS sensors. APS sensors are quite costly and would dictate lenses that would be too large for that class camera. There is no inevitable march to larger sensor sizes.

    2. Re:What is this article trying to say? by B4RSK · · Score: 2, Informative

      That's a very interesting point.

      When 35mm was introduced the previous formats were drastically different. It was not reasonable to use previous body/lens formats for 35mm film.

      PCI is the same -- VESA local bus was a major kludge, to be polite about it. It also could not be run at speeds other than FSB, if memory serves. This was a rather large problem for the DX-50 chips! (Not DX2-50, DX50.) Many cards would not run reliably on a 50MHz bus. But I digress...

      This situation is rather different. It is extremely difficult to make lens glass good enough to then be able pack 10 million+ pixels onto very small sensors and still get a good quality image. The cost of the glass would far exceed the savings of using a small sensor. This is a problem of optics that is not easy to overcome.

      Beyond this, the sensors are going to get cheaper and cheaper, but the glass isn't going to drop much (if at all) in price.

      Because of this it actually makes sense to have APS-to-35mm size digital sensors, and also medium format digital backs.

      --
      Some people are like slinkies--basically useless but they bring a smile to your face when pushed down the stairs.
    3. Re:What is this article trying to say? by carlislematthew · · Score: 5, Informative
      It seems that Nikon are avoiding the 35mm size sensor more than anyone else. They've come out with these crippled "digital" (or whatever) lenses specifically for their DSLR range.

      Right now, Canon actually *has* a 35mm sensor DSLR (EOS-1Ds) - it's supposed to be awesome, as well as being awesomely expensive ($9,000ish I believe). From what I've read, the problem is the low yield on making the sensors themselves and also some fancy expensive anti-aliasing filter that goes in front of the sensor.

      Unfortunately, I don't think you can compare yield improvement of expensive 35mm 12MP sensors with yield improvement (and therefore cost reduction) on things like LCD flat panels. The reason is that consumers don't *need* image quality like the Canon EOS-1Ds provides. It's almost medium format quality and 99% of consumers used crappy tiny-lensed 35mm negative film for years, printed by shitty machines on 4x6 paper that fades.

      So if it *is* the case that 35mm sensors are the future for DSLRs, I do not believe we can expect the kind of quick generational reduction in cost that we're used to for other more "commodity" consumer items like LCD flat panels, PDAs, cell phones, and so on.

    4. Re:What is this article trying to say? by B4RSK · · Score: 3, Interesting

      Yes, the 1Ds is 11MP and the quality is beyond amazing. Even my D60 when coupled with L lenses gives fantastic quality.

      We will see this happen though. CMOS sensors are manufactured using essentially the same technology that is used to make RAM. Yields will increase. Costs will come down.

      If this is not driven by Canon or Nikon in the high end, it will be driven by Panasonic, Sony, Casio, etc in the P&S market. As the P&S quality increases, the 10D-level DSLR quality will have to increase to justify their higher prices. As the 10D quality level goes up, the 1Ds level cameras will have to improve too.

      You are right that most consumers do not need a 10+megapixel camera. But they also do not need 3GHz PCs, 200+HP cars, 50" Plasma TVs... Because the technology is going to become available, the cameras are going to advance.

      --
      Some people are like slinkies--basically useless but they bring a smile to your face when pushed down the stairs.
    5. Re:What is this article trying to say? by B4RSK · · Score: 2, Interesting

      I agree that at the top end of the range there is not much to challenge Canon or Nikon, especially Canon.

      At the P&S and prosumer levels though, there is a lot of competition, especially here in Japan.

      Casio, Panasonic, Sony, Kyocera, Konica, Ricoh and others are all selling P&S digital cameras, but not DSLR. They want as much of the market as they can get, and will drive the lower end of the market up. This will in turn force the Kiss/300D/Rebel-level market up. Which will force the 10D market up... Which will... I think you see what I am saying!

      Canon and Nikon were able to control the level of the SLR market in the past because it just was not possible to pressure them from below. That has changed with digital though.

      --
      Some people are like slinkies--basically useless but they bring a smile to your face when pushed down the stairs.
    6. Re:What is this article trying to say? by dfghjk · · Score: 2, Interesting

      Yes, lots more players in the digicam market (which is much, much larger than the DSLR market). Interestingly, Canon and Nikon have quite similar market share in DSLR's, though Canon clearly has a lead in sensor development. The 1D2 looks very impressive. I personally think it caused the D2x to be withdrawn but who knows.

  5. 35mm by tooth · · Score: 4, Interesting
    I can't wait until they start making "full" 35mm sensors, that would rock. Unfortunatly it will probably only be on a $5000 pro camera that I'll never be able to afford. I don't think that a sensor that size will make it down into the "cheaper" digitals as consumers don't know what the difference is.

    It would be great to have the same bodies for film or digital and just swap the back off if you feel like changing and have it all interface with the body correctly. I know you can sort of do this with medium format, but then you getting into real $$. I guess customers not really caring is why APS film hasn't disapeared yet (oh look honey, it's such a cute camera), though hopefully digital will kill it off. One thing I'd like to see move up from APS is the magnetic media film. I don't know how badly it affects the image quality, but it would be really great to have the focus distance/lens, zoom, f-stop, shutter speed etc record when I take a picture. I always forget what lense I used by the time i come to develop the film... Of course if you're using a filter this still wouldn't let you know which filter you used.

    1. Re:35mm by hanway · · Score: 2, Informative

      Silicon Film has been promising an interchangeable digital back for 35mm SLR cameras for several years. As far as I know, it's still vaporware. One source indicates that the company ceased operations in 2001. The web site still exists, but seems to have nothing more than an "about us" page.

    2. Re:35mm by dfghjk · · Score: 2, Interesting

      The rumored Nikon F6 is a body with interchangable backs for digital and film. It will provide changable viewfinders as well. Don't expect it to be cheap, though. By the time it's available, few will care about film.

      Full 35mm sensors have been available for some time in the form of the Canon 1Ds and the Kodak 14n, 14nx, SLR/n, and SLR/c. You are right about the price, though.

    3. Re:35mm by sdr · · Score: 5, Informative
      There are two digital SLR cameras in market right now with full 35mm sensors - the Canon EOS-D1s and the Kodak DCS SLR/n. The Canon is an 11 MP camera and costs about $8000.00. The Kodak is a 14MP camera costing about $5000.00. The Canon produces the best quality pictures among digital SLRs. The Kodak is rather new. It is actually an update of an older camera using the same sensor called DCS 14n. This older model has been described as rather noisy (in comparison to the Canon at least) in all but the lowest ISO setting. It also produced bad colors in certain situations. The new model supposed to be better - but not in the same class as the Canon. The Kodak uses Nikon lenses and is based on a Nikon camera body. Kodak has also announced another body with the same sensors that take Canon lenses.

      So at least two full 35mm frame digital SLRs exist. None of them are cheap - and it it will quite possibly stay that way for some time.

      Leica has announced a digital back for their R series SLR cameras. This being Leica, it will possibly be rather expensive - not to mention the huge price tags for their lenses and film bodies. There has been some persistent rumors that Nikon is designing their next professional flagship SLR camera body (the successor to the film SLR model F5) as a camera that can take interchangable digital (and film) backs. Nikon flagship models are usually replaced every 8 years. If the pattern holds then they should come up with a new model (the F6) this year.

    4. Re:35mm by herko_cl · · Score: 4, Informative

      The Canon EOS 1Ds has a full 35mm frame, 11 Megapixel sensor. The Kodak DSC 14n accepts Nikkor lenses (for Nikon mounts) and has a full 35mm frame, 14 megapixel sensor (both links are reviews)
      The Kodak costs approx. $ 4000, and the Canon $ 7500. But at least 35mm, full frame sensors ARE here already. If you win the lottery, you can also buy medium format digital backs.

      --
      No .sig for you! ONE YEAR!
  6. Telecentric Lenses and Silicon by G4from128k · · Score: 5, Informative

    The article mentions the excessively large size of 35 mm lens for imaging on to small digital sensors, but misses the two additional problems with using film camera lenses with digital sensors.

    Standard film camera lens tend to transmit light from the subject to the sensor at the angle that it was received (similar to the way that a pinhole camera projects a bundle of rays from object space to image space). Silicon sensors suffer from two problems when light enters them at an angle. First, the high index of the material and coatings tends to reflect the angled light -- causing less light to enter the sensor and the image to have dark corners. Second, long wavelength light penetrates the sensor deeper than does short wavelength light. If the light enters at an angle, the red photons can angle down into the substrate and actualy register in pixels further out. The result is that the red and infrared portions of the image are misregistered, causing color fringing in the corners.

    The point is that the best lens for a digital camera will be different from the best lens for a film camera. A better lens design for digital cameras incorporates image-space telecentricity. Image-space telecentricity means that the light hitting the CCD is largely perpendicular to the sensor.

    --
    Two wrongs don't make a right, but three lefts do.
    1. Re:Telecentric Lenses and Silicon by jdg · · Score: 5, Informative

      I design lenses for a living.

      This statement is sort of correct. The real need for telecentricity is the limited acceptance angle of the lenslet arrays that are put on many sensors, particularly small pixel size consumer grade sensors. This is what causes the drop off in corner illumination with non-telecentric lenses in consumer grade digital cameras. Telecentricity is a real requirement, particularly in sensors which pixel sizes smaller than say 4um.

      Large pixel, higher end CCDs generally don't need the lenslet arrays because the fill factor on the pixel aperture is much larger, so there is not much of a problem with non-telecentric designs. There are no lenslets present to limit the acceptance angle. I have never seen reflections off the sensor be an actual problem. People also talk about ray bundles from one obliquity passing through the wrong filter on the color filter array in a non-telecentric design, but I have never seen this happen either.

      Longer wavelength light is generally eliminated by an infrared reject filter, so light rarely bleeds from pixel to pixel.

  7. Drop in 35mm electronic film capture by stecoop · · Score: 4, Interesting

    It would be really neat if you could drop in an electronic sensor to replace your film in exciting cameras. Have the exact form factor of current 35mm barrel film with only added electronics. The data could be stored in the film barrel and a sensor could be drawn out like you do with current 35mm strip. The mechanical film advance would "tell" the electronics that a picture was taken and save what it just saw. That would be the best of both worlds - able to have electronic pictures and able to use 35mm regular film plus all the camera hardware is already built.

    1. Re:Drop in 35mm electronic film capture by hetta · · Score: 3, Informative

      It would be really neat if you could drop in an electronic sensor to replace your film in exciting cameras.

      You can.
      WAAAY more expensive than a good quality digital camera, though. So how much money do you have?

      --
      -- Henriette's herbal -
  8. Re:Actually you are incorrect by guidryp · · Score: 3, Informative

    Smaller lenses designed for the smaller image circle will not have less light gathering ability.

    A properly designed lens for the smaller image circle will be smaller lighter and put the same light on the sensor. The larger lens is wasting light since a large percentage is dumped outside the sensor.

    And while I wont argue the where the light rays come from, the effect remains the same. The outer edges of the image circle is where the performance is worse. Softness, Chromatic Aberration and Vignetting are all worse.

    By cropping to the center portion of the image circle the smaller sensors are in the lens sweet spot.

  9. Self Advertising Concerns by Artega+VH · · Score: 5, Insightful

    There are going to be three parts to this article on the tech lounge. But really.. is slashdot going to be able to have insightful commentary for all three parts? Or will it be a case of comment rehashing and karma whoring in all three threads..

    Surely one slashdot article with links to all three techlounge articles would be more appropriate? But of course 3 separate articles on slashdot generates more advertising revenue than 1 doesnt it?

    I have mod points at this current time, but I'm sure as hell not using them in this thread... I don't want to waste my time reading part 1 and part 2 checking that noone is karma whoring...

    BAH...

    --
    groklaw, wired and slashdot. The holy trinity of work based time wasting.
    1. Re:Self Advertising Concerns by B4RSK · · Score: 2, Funny

      You just posted in this thread! It's not like you can mod here now anyway...

      --
      Some people are like slinkies--basically useless but they bring a smile to your face when pushed down the stairs.
  10. dpreview.com by Seequeue · · Score: 4, Informative

    Go look at http://dpreview.com for as much detailed, objective information regarding digital cameras as you're likely to want.

  11. Sample rules by jsse · · Score: 4, Informative

    Here is my little opinions on the subject. Not surprising I share the same view with the author.(My apology for the length and inaccurate technical details)

    Lens
    I agree with the author that the lens pays an important part of the overall quality, rather than no. of pixels. Generally speaking, lens with large aperture(F2.8>F4>F5.6>F8, etc.) can create better images. However, to compensate for the distortion near the edge, the larger the aperture, the bigger the lens size. You'd find digital camera with bigger lens(usually implies bigger aperture) cost more, regardless of no. of pixels.
    While it's true that camera with exchangeable lens is very desirable for photographers especially when you already has a good lens. However, I do not think the high price of those lens-exhangeable digital camera, especially Nikon D70, is justified(I'm a diehard Nikon film amatuer photographer myself). If you don't like those digital camera exchangeble lens, you may look at those already has good lens equipped, like Lumix DMC-LC1, which equipped with a F2.0 Vario-Summicron Lens, a legendary brand name for most film photograpers. (Mind you, some perfectists critize that the lensare not made in their original factory. Oh well.. :)

    Color
    The article touchs this topic very lightly, in fact most digital camera manufactuers avoid this. You can imagine different wave in light spectrum refract in different angle in each piece of lens. The problem is particular complicated when the lens group has more than one lens. That's why lens with more lens group is more expensive. This problem is called the chromatic abberation.

    Aspherical lens(glasses with uneven density) and coating could help solving this problem. You can see the color reflect from the surface of many professional lens are not white - usually redish or slight greenish. The less white light reflects from the lens' surface, the better the coating. (This is in fact one tip you can use in choosing a good digital camera)

    Light
    As implied in the word 'photographing', it's all about light(photo). The better the lighting condition, the better the images created - this is true for digital and film photographing. You can't control the light, but you can control how light enter the camera. Most digital camera owners would find that regardless of no. of pixels, the images quality drops drastically in low light condition.

    Guess what I'd say - yes, bigger(and high quality) lens invite more light thus create better images. What's so difficult to understand. XD

    Conclusion

    The quality of the lens outweights the no. of pixels. Well, in fact this is a most unwelcome answer, and people stop asking me for opinion on choosing digital camera, and go buy some fancy looking garblish. Luckily we've slashdot where I can find people still listening to me.....hello? HELLO???......

    1. Re:Sample rules by Zocalo · · Score: 2, Informative
      Generally speaking, lens with large aperture(F2.8>F4>F5.6>F8, etc.) can create better images.

      That could have been phrased more clearly, since it seems to imply that f/2.8 is always better than f/8. A large aperture just lets more light into the camera meaning that you can achieve the desired exposure faster, but the flipside is that you have a shallower depth of field. For landscapes, where a large depth of field is key, you will usually want to close the aperture down as far as possible and make a longer exposure to bring out the detail.

      I'm with you 100% percent on the quality of the lens outweighs the number of pixels though. If I had a dollar for every lunatic that spent about a $1000 on a DSLR body then slapped a $200 kit zoom lens on the front of it with the impression that the camera is all that matters... Well, I'd probably have a 1Ds MkII instead of my 10D to be honest, but only because I already have a good selection of expensive glass. ;)

      --
      UNIX? They're not even circumcised! Savages!
  12. See an earlier Slashdot by Darth+Cider · · Score: 3, Insightful

    Back in October 2002 Slashdot asked Digital Camera Passing Quality of Film? which referenced a field report from Luminous Landscape. Now that was a great article, full of technical info. (The Canon 1DS 11-megapixel camera surpassed 35mm film.) Why is Slashdot calling attention to an informationally empty piece like Beyond Megapixels?

  13. Dphc? by dollargonzo · · Score: 2, Interesting

    one of my friends once made a digital pinhole camera. yes, you heard me right. it was really cool. and since there is not really any concept of depth of field (everything is in focus) you can get some pretty cool pictures. did it for a undergrad honors project in photography

    --
    BSD is for people who love UNIX. Linux is for those who hate Microsoft.
  14. The Digital Camera Revolution is not in Megapixels by miracle69 · · Score: 3, Interesting

    But rather X3.

    CCDs can only recognize one color per pixel, whereas X3 can recognize each color per pixel, producing much better pictures.

    The CCD will be dead in 10 years and replaced by X3.

    --
    Linux - Because Mommy taught me to Share.
  15. How sky-hi-end benefits us... by Fringe · · Score: 3, Insightful
    The articles seem a bit lightweight, especially do what you could quickly glean from Steve's DigiCams or Imaging Resource or DP Review. I do agree with the little data in the article, specifically that above about 4MP, the average consumer doesn't benefit much. The big problem is that the lenses can't give you more than that, at the price and size range we're seeing.

    But there's a huge benefit to this tech-race. More digital cameras. People with them, use them a lot more than they did with film. No cost to take, no cost to view, low cost to print or mail. I wrote an open-source project to make building galleries free-and-easy (primarily for my family initially, see it at Picture Pager on SourceForge) and that too is a benefit of digitals... they gain from the open source world.

    So the only downside of 8MP cameras is that they're the Ferraris or Porsches of consumer-land. They push the technology, in a few years us mere mortals will benefit, but serious drivers and photographers benefit, at least slightly, now while bearing the hefty early-adopter price.

  16. Slowness is the biggest problem by truth_revealed · · Score: 2, Interesting

    The RAM transfer speeds are so poor that it takes around a second to snap a picture with many of these 5 Megapixel cameras - by that time you can easily miss the shot.

  17. What's beyond megapixels?? by photonic · · Score: 3, Interesting
    ..well, gigapixels of course.

    I recently had the pleasure of attending a talk by a guy that worked on the focal plane of GAIA, a spacecraft to be launched by ESA around 2010. It is not designed for imaging, but for very accurately determining the position of stars (astrometry).

    Their specs for the focal plane of the telescopes: size of around 0.6*0.8 meter, 180 CCD chips packed together for a total of 1.2 Gigapixels! I believe handling the thermal power alone (~100 Watt), without moving the location of the pixels a bit already was a typical case of rocket science.

    --
    karma police: arrest this man, he talks in maths; he buzzes like a fridge, he's like a detuned radio. [radiohead]
  18. dcresource.com too by haut · · Score: 2, Informative

    dcresource.com has great reviews and I tend to like their page layout more than most other sites.

  19. Did anyone find this article hard to read? by redshadow01 · · Score: 3, Insightful

    Reading this one over I found it rather hard to keep track of what was being said in a logical manner..the guy is all over the place without a logical structure to the paragraphs... Part one is better written I think, or better edited maybe...any thoughts?

  20. Aspherical Lens by ChrisMaple · · Score: 2, Informative

    An aspherical lens is one that has a surface that is not a portion of a sphere. It has nothing to do with the evenness of density of the lens.

    --
    Contribute to civilization: ari.aynrand.org/donate
  21. Good Reviews by HenchmenResources · · Score: 2, Informative

    If your interested in good reviews/information pertaining to photography and cameras you may try Rob Galbraith's web site, he tends to give good information as well as reviews of camera equipment, both digital and film, plus he has a forum if you have questions, where professional photographers can help you out. The information you'll fine will be a whole lot more accurate than that given by "The tech Lounge." For good information ask someone who works with whats being reviewed as their profession if you ask me.

    --
    "Napalm is nature's toothpaste" - Chef Brian
  22. what I want in a digital camera by brer_rabbit · · Score: 2, Insightful
    I was pretty big on digital cameras til I got a Nikon FM-3a. The FM-3a is a fully manual SLR film camera and it completely reversed my view of photography. After I got it I took an intro to photography class at the local community college and was hooked. Now I'd like to get a digital camera to take the place of the FM-3a, but I don't see that happening. Here is my wish list for a digital SLR:
    • Full 35mm sensor. Let me have a shallow depth of field, please! Smaller sensors give such a huge depth of field, it's difficult to blur the background.
    • No built in flash. Face it, if you need a flash, you're going to need a REAL flash, not some cheapo flashlight built into the camera.
    • Analog metering. By this I mean a little needle I can see thru the viewfinder for metering. I can look thru the FM-3a and instantly see how many stops I need to adjust the exposure.
    • Traditional SLR feel. I need the shutter time on the top right of the camera on a dedicated knob. No multi-purpose jog wheel, a traditional knob with full stops. 60, 125, 250, no fraction-of-a-stop BS.
    • No LCD display. Yep, you heard me right. Take this thing off and it'll lower the price & form factor. I don't need to review the shots I took, if I'm concerned about the exposure I'll bracket the shots +/- a stop. And I'm not worried about deleting a picture to save disk space when I've got a 1 gig compact flash card.
    • No bells and whistles. I can pick up any old SLR and know how to use it in 10 seconds. Try this with any modern digital.
    ok, those are my main gripes. I've got more minor ones, like screw USB and firewire, I'll just plug the CF card directly into my laptop. Wireless connection? Definetly axe that, what a waste of real estate on a camera.

    A dedicated knob for shutter time, one for ISO setting, another for white balance, and a Nikon lens mount (ok, I don't care if it's Nikon, I'll buy a new system if the camera is as above).