Canon 20Da Introduction

Discussion in 'Canon EOS' started by pto189, Feb 15, 2005.

  1. Dennis Hissink : February 14th 2005 - 09:08 GMT<br><p>
    Canon EOS 20Da introduction : Out of the blue? On the Japanese Canon
    website a new version of the Canon EOS 20D appeared. The new Canon
    EOS 20Da seems to be almost identical to the Canon 20D, accept for
    features like 'Live View' mode which enables the user to manual
    control the focus by using the LCD display. This is very handy when
    using the Canon 20Da for astrophotography. The subject can be viewed
    enlarged on the LCD display (5x or 10x magnification). Furthermore a
    special filter that normally is used to block infrared information
    is removed. The Canon EOS 20Da is equipped with a more transmissive
    mirror which makes the new Canon 20Da 2.5x times more transmissive
    compared to the Canon EOS 20D.<br><p>
    The Canon EOS 20Da is compatible with the timer remote controller
    Canon TC-80CN3. This accessory enables long exposure times
    especially for night shots or astrophotography.<br><p>
    Canon EOS 20Da major features:<br>
    - CCD: 22.5x15.0mm<br>
    - Canon EF lens compatible<br>
    - CompactFlash type I and II slot<br>
    - 8.2 effective Megapixels<br>
    - JPEG and RAW (12bit) format<br>
    - Highest resolution: 3504x2336 pixels<br>
    - Lowest resolution: 1728x1152 pixels<br>
    - Color space: sRGB and Adobe RGB<br>
    - Interface: USB 2.0 Hi-Speed and Video out<br>
    - ISO 100, 200, 400, 800, 1600 and 3200<br>
    - Shutter speed: 1/8000 - 30 sec.<br>
    - 1.8-inch TFT LCD display - 118.000 pixels<br>
    - Li-Ion battery<br>
    - Dimensions: 144x105.5x71.5<br>
    - Weight: 685g<br>
     
  2. Philip - I'm afraid you (or your source) been mislead by a couple of websites with inaccurate info. I was fooled myself briefly, but I went to the original source (Canon Japan webpage) and checked out some of this stuff.
    "Furthermore a special filter that normally is used to block infrared information is removed" - actually it turns out that the filter isn't removed, it's just changed for one with greater transmission at 656nm but which still seems to reject most of the IR.
    "The Canon EOS 20Da is equipped with a more transmissive mirror which makes the new Canon 20Da..." - Nope, despite what a fairly well known website is reporting, this doesn't seem to be the case. The mirror in the 20D is also partly transmissive, it needs this for the AF system to operate. The 20Da locks it's mirror up when used in the "live LCD preview mode".
    Actually what the website says (machine translated!) is: With EOS 20Da you kept in a state where the mirror is lifted, live image of the image pickup element the enlargement color it can be indicated to the liquid crystal monitor loaded "live view mode".
    BTW. the "2.5x" refers to the increase in sensitivity at 656nm (the hydrogen alpha emission wavelength).
    Some people seem to think the 20Da has a fixed pellicle type mirror (like the EOS RT). This isn't the case. Pellicle mirrors cause light loss, and the last thing you want in a camera designed for astrophotography is the loss of any light.
    I have a page on my website with what I believe to be the correct info. The URL is http://www.bobatkins.com/photography/digital/eos20da.html.
    It only takes one publication of incorrect info on the internet for that info to be repeated all over the place, and once the info escapes, you can't ever get it back! Just goes to show that you can't believe everything you read these days.
     
  3. Hey Bob, got my Japanese wife (^_^) to kindly help me translate here:

    Price is gonna be approx ~$2400 USD (250,000 yen at whatever the exchange rate):


    The order process is for Japan only, roughly goes as follows:
    http://www.canon-sales.co.jp/camera/eosd/20da/sale.html

    (mentioned right up at the top in that blue box, 250,000 yen)

    You order on the form below:
    https://entry.canon.jp/question/form22/eos20da/eos20da.cgi

    After it reaches them, they send you an e-mail within a week, at which point you decide how to pay, then you pay them, and they ship you the camera within 3 months or so.

    *The sale is only valid to Japanese customer addresses only.*

    -cs
     
  4. Thanks Carlos, I'll add that info.
     
  5. The live view on the 20Da has got many people's interest for this feature right up.

    I am afraid that I only see problems with using the feature a great deal. A working CMOS/CCD is like a dust magnet; the live view used for any length of time will, just like the long exposures (used typically in astrophotography) give more time for dust to pollute the sensor.

    I guess with astrophotography its a necessary evil; but it would only exacerbate the dust problems of most people on SLR cameras.

    Regards.
     
  6. Not to sound dense since I am not IR expert, but wouldnt these changed mean that the 20Da is a good candidate for IR photography with the right filter? Just curious...
     
  7. Read my review as cited above for comments on IR. As far as I can tell the filter has simply been replaced with one allowing 656nm transmission, not removed. This would suggest that IR is still blocked, though perhaps not quite so effectively at near IR wavelengths as with the standard filter.
    I'd expect perhaps a slight improvement in IR performance, but if you want true IR performance you can get a 20D with no IR blocking filter at all for around $2000, you don't have to wait 3 months and you don't have to order it from Japan. There's a link from my 20Da webpage.
     
  8. I am big fan of Infrared photography, mostly with film - Kodak EIR (color slide film).
    So I have been waiting for some Canon digital DSLR with IR capability. This one is the first one, but only for Japan, which is very sad.
    Practical use can be determined after field test and some time on the market.
    To get Infrared image I think we would need to put Infrared filter on the lens. This filter will block most of the visible spectrum and result should be an infrared image. This is nothing new, it is the same process as with infrared films. I just want to clarify, that even if this sensor on 20Da is more sensitive to infrared portion of the spectrum, there is still need for expensive infrared filter in order to filter visible light. So this camera actually needs filters even for regular images - (portraits, landscapes, macro...) to block infrared light.
    At least this way I understand this camera would work. That means the filters would be quite expensive. I am curious how would unfiltered images looks and if there is any use for them except astronomic photography.
    It is still better to have 20Da than nothing, but I a sure, that better cameras are coming next year even for US/Europe market.
     
  9. It has CCD instead of CMOS sensor? Is this right?
     
  10. No thats not right. Check out the other discussion. here the sensor is a refined process later generation identical cmos 8.3 megapixel, the front AA/rgb/linear to cirle polarised correcting filter has a narrow band H-alpha or Hydrogen emissions color spectrum passing filter which enables the NIR band to pass approximately 2.5 times more than the standard 20D front filter, so you can photograph the emission nebulas.. Most deep IR and Near IR frequency band is still blocked. On canon/japans website you can see the results in their daylight photograph test showing their model wearing a cardigan sweater that is BLACK and shows RED reflection compared to the normal 20D photo.
     
  11. hmm. /www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00B8sk>here
     
  12. well, that html thing isn't for me... http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00B8sk
     
  13. Hydrogen-Alpha--this means it has about the same IR response as Tech Pan, right--
    enough to sometimes do odd things to skin tones, not enough to turn foliage white?

    Actually, wouldn't this camera be MUCH WORSE for pictorial IR photography?

    With a standard digicam's IR block filter there's pretty good overlap between what the
    blocker blocks and the IR pass passes, so the net is just that your IR response is a few
    stops slower than it otherwise would be.

    This camera used with a standard IR-pass filter would give a couple stops more exposure
    to the nearest part of the IR range than to the 800+ nm range--your spectrum response
    would be skewed in such a way that it might be completely impossible to get the "white
    foliage" effect.
     

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