Video of fresh water organisms from bird bath

dragonblade · Post by **dragonblade** » Sat Mar 31, 2018 8:33 am

Here's my first microscope video. All the organisms were found in a single drop of water collected from a bird bath in my backyard.

Regarding identification, I'm assuming the first organisms in the video are stentors? I'm intrigued by the contrasting sizes of the rotifers. At first, I assumed that the larger rotifers were simply more mature / older. Then again, the bigger ones have a deep red / orange midsection whereas the smaller ones don't. And there seems to be two distinct sizes with no intermediate sizes. Could they be different species of rotifers?

There's also some kind of small ciliate swimming close to one of the rotifers fairly early on in the video. It looks like a paramecium but the shape is slightly different.

https://www.youtube.com/watch?v=RXP8hN6_a6o

Sumguy01 · Post by **Sumguy01** » Sat Mar 31, 2018 8:52 am

Nice first vid.
Thanks for sharing.

dragonblade · Post by **dragonblade** » Sat Mar 31, 2018 8:56 am

Thanks Sumguy! I admit it was challenging....some of those rotifers didn't stay still for long!

rjlittlefield · Post by **rjlittlefield** » Sat Mar 31, 2018 9:53 am

Excellent -- that's some good looking pond water.

I notice there's no trace of the vignette that you were struggling with a couple of weeks ago (HERE).

What did the solution to that problem turn out to be?

--Rik

dragonblade · Post by **dragonblade** » Sat Mar 31, 2018 4:49 pm

Rik, thankyou! I guess you'd be surprised to know that this is desalinated water which I suspect is treated. So it's usually not so good at harbouring microscopic life. However, I have had good results when I find clumps of what I can only describe as reddish stuff in this water in the bird bath. I'm not sure what it is - if it's a kind of vegetation or not. Whatever it is, the rotifers love it - they clamber all over it.

I still haven't found a solution to the vignetting problem. This was the first time I shot video footage through the microscope and there was no vignetting to be seen. The vignetting problem appeared a few days later and I can't get rid of it. The odd thing is that I'm using the same equipment and the same techniques / approach as I utilised in this video - yet now I'm getting different results.

Ive been away for a week so haven't been able to take the photos you requested when I tilt the camera. Hopefully, I should be able to do that soon.

rjlittlefield · Post by **rjlittlefield** » Sat Mar 31, 2018 5:57 pm

dragonblade wrote:so haven't been able to take the photos you requested when I tilt the camera. Hopefully, I should be able to do that soon.

Sounds good. I will be very interested to see how the vignette tracks the slide contents when you tilt the camera. One other thing: when you are testing again, play also with the separation between camera and eyepiece. It is not necessarily true that the least vignetting happens when the camera lens is closest to the eyepiece. The least vignetting will occur when entrance pupil of the camera lens coincides with the exit pupil of the eyepiece. If the lens's pupil is far forward and the eyepiece is a high eyepoint design, then you may have to pull the camera back from the eyepiece to make the pupils coincide.

--Rik

dragonblade · Post by **dragonblade** » Sat Mar 31, 2018 8:44 pm

rjlittlefield wrote:If the lens's pupil is far forward and the eyepiece is a high eyepoint design, then you may have to pull the camera back from the eyepiece to make the pupils coincide.

--Rik

For the video above, there was quite a bit of space between the camera lens and eyepiece. I didn't have to get very close at all. Though since then, I'm getting vignetting at all distances - both near and far.