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Camera's - mega pixels

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  • Camera's - mega pixels

    Not wanting to hijack Fastracks post I thought I'd start a new thread before I caught swine flu.

    Now I know sod all about camera's, I'm the original point and shoot guy and to me any picture is better than none.
    My first Digital was a Sony DSC something or other, bought in in SF when i was over there and it cost me about $450 at the time, mind you they were double here.
    2.1 mega pixel and it took ace pics, problem was technology caught up with it and battery's and memory cards cost more now than new camera but I still like it.

    Bought a Fuji 3500 to replace it and it was a pile of $hit, impossible to take a picture in the workshop without the flash on, welding at the same time and lightning outside, ate battery's like a cordless MiG and was bulky.
    Gave it away to a guy I don't like..........

    Used Gerts little Nikon for a while, 4.5 mega pixels, easy on battery's and took decent pictures.

    Then bought a Panasonic DMC-LS75 with 7.2 mega pixels when it was on offer. Nice camera, easy on batteries and takes oodles of pics on the 2 meg card.

    Now the question, why did the old Sony at 2.1 MP take better pics than this one at 7.2 ?

    Seeing as I have to crop most pics to 600 x 600 for inclusion on forums what is the reason for these massive megapixels when the old Sony proved, at least to me, that they weren't necessary.?


    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.

  • #2
    Most of the current low cost cameras have low cost sensors. It isn't the megapixels that make the difference, it's the type of sensor used. Your old camera had a high quality CCD sensor, the new cheap cameras have a low quality, low cost CMOS sensor and the quality difference is very apparent in the images. More crap doesn't do a damn thing to improve crap.

    You won't find a cheap camera with a good sensor with the possible exception of the Canon lineup since Canon has a patent on a way to make CMOS sensors that are much higher image quality than what the other vendors may use.
    Free software for calculating bolt circles and similar: Click Here


    • #3
      Inside I sometimes take pics in the pitch dark with flash to avoid going down the menu to find the white balance crap.

      your shops lights are to blame, half the time in confusing the camera .

      you end up with yellow or green tinged hazy pics if you use the shop lights and don't correct the white balance.

      always use the macro function... flower symbol, even when up to 3 feet away .

      mines only 2.1 mp and excels at close ups ..

      very old Olympus c-2040-z

      each camera has different set ups for different things cant expect to use one as the other ..and expect the same results.

      all the best.markj


      • #4
        Yep, the quality of the sensor is the key. I run away when I see a compact point and shoot with a 12 mega pixel sensor...


        • #5
          My experience of Fujis has been much better than yours, John, at least as regards picture quality.
          I've had two with what they call their 'super CCD', first was a 6900 ('SLR style'), second an F180 compact. Actually had two of those, managed to smash the screen on the first, by that time they were obsolete so found one s/hand on ebay. The 6900 started to lose all the fancy functions just at the age when it wasn't economic to repair. Still works as a point and squirt but too bulky for that. Anyway my point is that I've been very happy with the picture quality even though rarely used at full resolution.
          Before the Fujis I had an early massive 1Mp Olympus SLR, bought s/hand from a friend, that could produce some very acceptable printed pics even at 1 Mp which rather supports your point.



          • #6
            Marketing... blame the marketing!

            Somebody said early on in the digital camera craze that more megapixels = better camera. The sales associates at any electronics store chant this mantra whenever they're ont actively serving a customer (and most of the time that they are, for that matter).

            So as every product cycle went by the manufacturers had to keep up in a megapixel race, just because John Q Public sees that at the single defining factor in camera design.

            More megapixels is not better, nor does it mean you can blow up your images further. Many things contribute to a good picture... I believe the single most important thing is the chunk of glass in front of the sensor, but how does a company advertise the quality of their lenses in simple numeric terms??? (well, you could stick names like Nikkor or Carl Zeis on the lens, but that's not as easy as a megapixel number anyway)

            As mentioned before, the more pixels you pack into a tiny little sensor, the more noisy the image gets... and the noiser an image gets, the more the in-camera software has to smoothe out the image. They do this primarily by washing out individual pixels to be averaged with its neighbors, which, of course, defeats any gain you might have gotten by increasing the pixel count. So while pixel count may be a good thing, pixel DENSITY is a very very BAD thing.

            Now, in order to keeps costs down, the manufacturers have to keep lenses small (they're expensive to grind etc) and a small lens projects a small image, so you're stuck with a small sensor.

            Small sensor dictated by economics + Large pixel count dictated by marketing = crappy pictures compared to your older 2.1MP camera.


            • #7
              Besides that, each camera (or brand, anyway) has a different way of converting the raw data coming out of the sensor, to the finished image file recorded to the card.

              Lots of cheap cameras tend to oversharpen and oversaturate, because that makes even mediocre pictures look better to the typical snapshooter. A printed copy looks pretty good, but when shown on your computer monitor, it can look pixelly and jaggy up close.

              Ditto file compression; Most cheap cams save the image as a JPG, which has varying levels of compression- the more compression, the smaller the file size (and thus, the more photos per card) but the more pixellized the photo looks.

              It's entirely possible your old camera used a low compression, while the new camera was set for a higher compression. It's usually adjustable/selectable, at least to a limited degree.

              And besides the sensor issue Evan mentioned, there's also the lens- that's why I typically recommend a pocket cam from a camera maker, not a general electronic-goods dealer. The quality and design of the lens has a huge impact on image quality; Canon and Nikon understand this, places like HP and Dell figure hey, if it makes a recognizable image, that's good enough!

              Now, as for overall megapixels:

              If you print a standard 4x5 photo from your camera, most photo printers (especially the "one hour" type places) typically print at something like 300 DPI. So for a 4x5 photo, that's just 1.8MP. Some print as low as 220dpi, some go to 600dpi.

              But the point is, unless you're cropping a lot or enlarging a lot, even at "just" 4MP, a lot of that image data is essentially wasted when it comes time to print the photo. So something like a 7MP camera has little benefit over a 4MP, other than the card fills up faster.

              That's not to say, of course, that the image data is useless- as I said before, if you're blowing up the shot, or want to crop out sections to reframe the image, or simply want a large image to produce a widescreen monitor wallpaper or something, that extra resolution is handy.

              Doc's Machine. (Probably not what you expect.)


              • #8
                what causes white orb like circles on photographs taken with a digital camera seems when you change the batteries it becomes ok again sorry didn't mean to steal this thread ??Alistair
                Please excuse my typing as I have a form of parkinsons disease


                • #9

                  Like you what I know about digital cameras and how they work can be written on head of a pin.
                  So I've followed a blindingly obvious approach that seems to have worked so far. I've bought Nikon for the simple reason that they have massive equity invested in optics - not in cd players, mp3 players or whatever. Nikon birdwatching binoculars are good, as are their telescopes, as have been their 35mm cameras. So why would they trash that good reputation with a crap digtal camera?

                  Doesn't answer your question though (but Evan's here for that!)



                  • #10
                    Originally posted by Alistair Hosie
                    what causes white orb like circles on photographs taken with a digital camera?
                    -The flash and dust.

                    In cheap pocket cams, the flash is at a very close axis to the lens, and typically the lens has little "extension" away from the body of the camera.

                    So the bright flash illuminates dust motes, either actually floating in front of the camera, or stuck to the lens. Also insects, sometimes.

                    You can test it yourself: Take a flash photo of darkened room, and chances are, you'll get some white "orbs". Now use a 3x5 card or something similar, to hold between the lens and the flash, as a sort of short 'wall" separating the two.

                    The lighting in the shot will be off a bit, due to the shadow of the card, but you won't see any- or at least significantly fewer- white spots.

                    Doc's Machine. (Probably not what you expect.)


                    • #11
                      Nikon's optics are absolutely superb. My Nikon 4300 with 4.3 megapixels is able to resolve Ganymede, one of the moons of Jupiter as it made a transit. That was with no telescope, just 3 times optical zoom. That is incredible in such a small lens and not coincidentally means the sensor pixel size is perfectly matched to the minimum object size that the lens is able to resolve.

                      That's the good side. The down side is that it is a CCD sensor. They draw a lot of power and that means short battery life. CCD sensors are uncommon now because in the large megapixel sizes they would need a car battery to take a reasonable number of images on a charge.

                      CMOS sensors require far less power than a CDD but are inherently noisy. They are also optically inefficient as each pixel in the sensor is surrounded by an amplifier transistor which means that light that falls on that area is not recorded. A CMOS sensor requires more light and more pixels to capture the same amount of information as a CCD sensor since some of the information that falls on a CMOS isn't recorded because it falls between pixels.

                      It is nearly impossible to make a CMOS sensor produce images as well as a CCD. If they both have the same number of pixels the CCD wins hands down. Older good quality brand name cameras are most all CCD sensors while most new cameras are CMOS. You cannot rely on the advertising or even the spec sheets. I have seen on numerous specs the sensor called a CCD when it is in reality a CMOS sensor. The abbreviation CCD is being used as if it is a generic term for an image sensor when in fact it most certainly is not. Calling a CMOS sensor a CCD is false advertising and it matters because of the very big difference in image quality.

                      Where a CCD really shines is in low light performance which is where a CMOS sensor is nearly useless with the singular exception of the Canon CMOS sensors which are made using a proprietary in-house process.
                      Free software for calculating bolt circles and similar: Click Here


                      • #12
                        10 meg cannon

                        IOts great but i cant send pictures cause they are too large. Oh well i dont like sending pictures any hows.


                        • #13
                          I though you had that figured out Mike. Call me right now and I will talk you through the easy fix for that. No more excuses. If you don't I will post the picture of you wearing your special "holster".
                          Free software for calculating bolt circles and similar: Click Here


                          • #14
                            So if moggy pixies are a blind, what about the storage media?? Cos we decided that we should be dragged into the digital age of photography, a few years ago we dived in with the purchase of a "Reduced" {(????) QVC} price Fudgy Finepix 4700. OK, I know, but I do like steam engines, but yesterday I went to a computer fair and enquired about SM cards. "Oh yes, about £20". Not f'in likely.

                            Why all the different formats?? A shrewd bit of marketing and market saturation again?? VHS/BETA? , CD/DVD/BLUE RAY? Widescreen/HDTV?

                            Regards Ian.
                            You might not like what I say,but that doesn't mean I'm wrong.


                            • #15
                              Originally posted by Circlip
                              Why all the different formats?? A shrewd bit of marketing and market saturation again?
                              -Yeah, pretty much. Every company wants theirs to become the standard, so they can make a bundle off of licensing that standard.

                              Right now, it's looking like the CompactFlash and SD are moving towards a standard, so anything that takes those is pretty safe for a few years yet.

                              Smart Media is pretty much defunct, and the format, from a physical size standpoint, is pretty limited. I think Sony's Memory Stick is falling out of favor, though holding what it has simply because Sony insists on putting it on everything they have.

                              CF is still very popular, despite the rather dated pin-type IDE connector, simply due to physical volume: a larger card will always be able to hold a larger storage capacity. CF's are up to what, 24GB now? I remember when an 8GB came out- for almost a thousand bucks- and nobody but Superbowl and National Geographic photographers bought 'em.

                              SD is popular thanks to it's much more compact size, and more trouble-free sliding contact interface.

                              There'll always be a few different formats- CF for max space, micro-SD for tiny cellphones, etc.- but for a camera, again, anything with either CF or SD is pretty safe format-wise for a few more years.

                              Doc's Machine. (Probably not what you expect.)