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Thread: Virgin IR

  1. #1
    Moderator teerex's Avatar
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    Default Virgin IR

    First attempt at IR. Please give comments and advise.

    Shots have a very shallow DOF as have to shoot at f2.8 and handheld 1sec exposure

    Virgin IR Shots

    Thanks for viewing

  2. #2

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    may i know ... where do u buy the IR from ?

    is it a filter or a beam of light like those from sony's cam for nightshots ?

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    erm, did you know that you have 3 dead pixels on your CCD?

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    Quote Originally Posted by dennislim
    may i know ... where do u buy the IR from ?

    is it a filter or a beam of light like those from sony's cam for nightshots ?
    It's a filter, bought from CP $37/-. You need very strong sunlight to use it.

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    Quote Originally Posted by wacko
    erm, did you know that you have 3 dead pixels on your CCD?
    Thanks for highlighting, did not realise it. I found 2 can't find the third one.
    Can you advise what can be done about the dead pixels? Appreciate any help.

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    they are all on the left side

    what's your cam anyway? i think some olympus dc can auto-map or something like that, not too sure entirely.

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    Wacko - the pictures were shot with a Nikon CP5700. Think I will have to check with Nikon Singapore on Monday.

    Thanks anyway.

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    have you confirmed the dead pixels with a lenscap on shot?

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    Quote Originally Posted by wacko
    have you confirmed the dead pixels with a lenscap on shot?
    Shot at the dark sky about an hour ago, could only see one very prominent dead pixel.

    Perhaps I should shoot with lens cap also to confirm.

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    Quote Originally Posted by teerex
    Shot at the dark sky about an hour ago, could only see one very prominent dead pixel.

    Perhaps I should shoot with lens cap also to confirm.
    it might be hot spots ...

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    could be hot pixels, take lens cap on pictures at various shutter speeds (in RAW if possible), if even at the fastest shutter speeds there are abnomalies, then it's a dead one.

    something like that lah

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    Thanks wacko and dennislim, will take some pictures as advised.

    What's the difference between hot spots and dead pixels?
    Can they be rectified?

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    for hot pixels, they only come about with a long shutter speed, e.g. > 1/4s, reason being the CCD/CMOS literally gets hot, thus some pixels starts to act funny. whereas for dead pixels, they are there no matter what shutter speed you take, 1/2000s or 8s.

    something like that lah

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    Quote Originally Posted by wacko
    for hot pixels, they only come about with a long shutter speed, e.g. > 1/4s, reason being the CCD/CMOS literally gets hot, thus some pixels starts to act funny. whereas for dead pixels, they are there no matter what shutter speed you take, 1/2000s or 8s.

    something like that lah
    As advised did some tests this afternoon. Set the cam at a constant aperture f=2.5 and changing shutter speed for every shot with lens cap on. Listed below are the results:

    Shutter Speed Hot/Dead Pixels
    8 secs yes
    4 secs yes
    2 secs yes
    1 sec yes
    1/2 sec yes
    1/4 sec yes but seems smaller
    1/8sec yes, smaller still
    1/15 sec no
    1/30 sec no
    1/60 sec no
    1/125 sec no
    All the way to 1/4000 sec, no pixels seen. So from your explanation, my problem should be hot pixels and not dead pixels, right?

    Can hot pixels be rectified? Should I send the cam back for check?

    BTW, there's only 1 hot pixel, the others you see in the posted pictures I think are dust particals on the filter (I hope).

    Thanks again wacko and dennislim for your help

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    Sorry, typo error in the previous message:
    aperture set at f=2.8 not 2.5

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    that's good news then. don't think any digicam warranty out there covers hot pixels, it's part and parcel of today's technology. you just have to invest a little more time in post-processing longer exposure shots then.

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    Ya, it's a relief that the problem is hot and not dead pixel.

    Thanks again wacko

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    Quote Originally Posted by wacko
    that's good news then. don't think any digicam warranty out there covers hot pixels, it's part and parcel of today's technology. you just have to invest a little more time in post-processing longer exposure shots then.
    Wacko,
    Brought my cam to Nikon workshop this morning. Told them about the hot pixel, they said "no problem, we can re-map the CCD for you".

    Receptionist brought the cam into the workshop and the technician appeared 10mins later and said he had done the re-mapping and the hot pixel is gone.

    Got home, did same test shots again at all shutter speeds. It's true, the hot pixel is fixed.

    So there's a remedy for hot pixels. Anyone with hot pixels problem bring your cam to the workshop before your warranty expires. It's going to save you a lot of money.

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    good for ya! apologies for my rubbish post regarding hot pixels not being covered by warranty...


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    Quote Originally Posted by wacko
    good for ya! apologies for my rubbish post regarding hot pixels not being covered by warranty...

    No problem. Anyway you have been a great help in highlighting the hot pixel and I've learnt from you in our discussion.

    You're right, hot pixels are not actually covered by warranty. The workshop can do the re-mapping, but still does not guarantee that it can be fixed. If after re-mapping and the hot pixel is still there, the owner will have to live with it.

    Thanks again wacko

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