Plankton Portal Talk

Dirty Camera Housing?

  • WEBs_in_space by WEBs_in_space

    Image APK0008stk
    Image APK0007ahf

    Looking at a lot of the images, there appears to be dried water spots on the glass. Am I wrong in this? In some pics, they appear very linear (top to bottom), like water drops were running down and dried. Now, I would think taking these pics would be an expensive endeavor, could some time and care be taken to ensure the glass is properly cleaned before a dive? It is very distracting.



  • yshish by yshish moderator, translator in response to WEBs in space's comment.

    @jo.irisson or @cguigand will answer your question, so wait for their replies please. Here are just few facts about the images I can provide you in the meantime...

    These images we get to classify are only small fragments of what ISIIS takes, and they are rotated. What you see as up, is actually the side of the image. And what you see as margin of the image, is only sometimes the real margin, since the image is cut into many smaller images.

    Those spots, you probably meant, are rather tiny microorganisms which are too small to be displayed properly, or marine snow floating in the water, sinking down to the bottom(?). As the images are post-processed to make the creatures better visible for us, classifiers, the colours are inverted, the contrast is increased(?), and so they may appear as dried water drops(?) to you.

    If you are more interested in how the images are taken, read these few blog posts. It is quite an interesting reading:

    The first two are the most useful, but look at them all 😃 At least play the video and look at the images!

    I'll ask the scientists to look at your question.


  • jo.irisson by jo.irisson translator, scientist


    I'm not sure what you think are dried water spots on the images you link to. Those are pretty clean actually and everything you see as not black in those images are organisms or small pieces of marine snow in the water (as @yshish mentioned).

    On occasions, you can see vertical streaks across the images. We use a linesman camera, which constantly scans the same line (the image is created because the instrument moves in the water, just like the scanning diodes move on a flatbed scanner), so any speckle on the glass creates those lines. We do clean the glass of course, very thoroughly, but a scientific ship is a rough place and some stuff may damage the glass or dirty it after we cleaned it.

    I hope that helps.