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More depth!

Don't panic. The above claim doesn't refer to the intellectual depth of the Water Bear web base. The world outside is serious enough and we promise to continue our not-so-serious style of presentation.

But there is a continuous development of focus depth enhancing software on the web and we will show some tardigrade imaging results on the basis of those new developments.


[ Tardigrada, tardigrades, focus depth ]

Echiniscus tardigrade.
Side view images of tardigrades are really difficult to generate but they are still feasible. The single, not software-processed photomicrograph shown on the left can be still counted among the successful ones as it depicts the stylets and one eye - i.e. the face of the tardigrade - but the front and hind claws are already out of focus. The older readers among you will be reminded of those pre-digital, ancient portrait photographs when some focus play was a reliable proof for real artwork   ;-)


E.g. "Auto-Montage", a commercial imaging software, allows the comfortable, fully automatic or preview & lever controlled combination of many different focus levels. But it is still the task of the micrsocopist to photograph the (non-moving) object slice by slice slowly focusing/photographing from top to bottom thus preparing the image stack which is then handed over to the software.
The program choses the sharpest regions of each image slice and tries to combine them into a smooth one-layer image. One problem in this process is that an object might have crisp structures at various depth levels which cannot be properly combined. Furthermore a multiple image overlay might end up in some additional noise and blur. So it was not possible to use the automatic focus depth software for the tardigrade 'tun' image shown below. Manual selection of crisp image regions and arbitrary combination by means of a normal imaging program turned out to be the better method in this case.


[ Tardigrada, tardigrades, dry state "tun"]

Eutardigrade "tun" (tardigrade in dry state), as seen from top.
The length of the tun is about 155 micrometers, its height about 40 micrometers.
Sharp sections of the respective focus levels were cut out and combined by means of a cheap but good digital imaging software (Micrografx "PicturePublisher").


Meanwhile there are many more focus depth programs available via internet. Just keep your eyes open and perform some tests by yourself. We did like also the freeware "CombineZ" and the shareware "Astrostack". When you are lucky those programs will generate images that would have been considered as 'impossible' 20 years ago.


[ Tardigrada, tardigrades, CombineZ ]

Echiniscus tardigrade image generated by help of the freeware "CombineZ".


[ Tardigrada, tardigrades, CombineZ ]

Echiniscus tardigrade image generated out of a video section with sweeping focus by help of the freeware "CombineZ". Normally you would get either a crisp nose tip or crisp claws or crisp eyes ...


And there is a high speed imaging system commercially available that takes 1000 (!) images per second - 40 focus level slices, 25 stacks per second. The microscope objective is moved by a piezo engine which is virtually vibrating continuously through all necessary focus levels. The abundant image information then can be combined to a totally crisp video of a bulky, moving microscopic object.
So, if you should have some money left this might be the ideal solution for some of your "worm video problems". Good luck!



© Text, images and video clips by  Martin Mach  (webmaster@baertierchen.de).
Water Bear web base is a licensed and revised version of the German language monthly magazine  Bärtierchen-Journal . Style and grammar amendments by native speakers are warmly welcomed.

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