Daphnia Simocephalus vetulus - Video Added

Mitch640 · Post by **Mitch640** » Fri Jun 03, 2011 10:41 am

Going by an ID from this page.

The video.

Took a trip to the river and came back with 2 gallon jars of sample water from a shallow backwater area. I needed to recharge my microbe aquarium.

1. 10x.

2. 10x.

3. 4x.

4. 10x.

5. 10x.

fpelectronica · Post by **fpelectronica** » Fri Jun 03, 2011 11:34 am

Very nice. Great detail
Francisco

Mitch640 · Post by **Mitch640** » Fri Jun 03, 2011 11:43 am

Thanks Francisco. Do you know if there is a projector lens smaller than 2.5x for the Fluophot?

So many times, I can see the whole bug with the eyepieces, but then with the 2.5x, the camera sensor cuts some of it off. It's even worse when I shoot video. I would like to get even a 1x lens if there is such a thing.

Maybe I need to check it with no lens at all?

RogelioMoreno · Post by **RogelioMoreno** » Fri Jun 03, 2011 1:23 pm

Mitch,

Very nice set!

Rogelio

Mitch640 · Post by **Mitch640** » Fri Jun 03, 2011 1:33 pm

Thanks Rogelio. I dipped out a small plastic sample cup from the aquarium this morning, to make it easier to capture a single individual, and using the new stereo scope, I saw at least 7 different species of water bug swimming around in it. The trip to the river was very productive.

fpelectronica · Post by **fpelectronica** » Fri Jun 03, 2011 1:35 pm

I think the smallest increase is 2.5 X. There are objectives, I believe, but very expensive 1X
Francisco

Mitch640 · Post by **Mitch640** » Fri Jun 03, 2011 1:40 pm

Yes, I have never seen anything smaller than 2.5x.

It is very hot right now, and I am mixing down a video of this daphnia, but when it cools off, I will try the extension tubes on the trinocular port, with no projector lens in it.

Charles Krebs · Post by **Charles Krebs** » Fri Jun 03, 2011 2:39 pm

Mitch,

Very nice!

I believe Nikon made a CF Pl 2X. Don't see it very often however. Nikon CF 2X objectives are out there.

Mitch640 · Post by **Mitch640** » Fri Jun 03, 2011 3:09 pm

Hi Charles, and thanks for looking.

I thought I had seen a 1.3x projector lens on E-bay, but it may have been for an Olympus, I wasn't really shopping at the time.

I did just do a test though, using my micrometer scale. The good news is, I can get good focus, full frame, with no PL lens at all. The bad news is, it is nowhere near parfocal anymore. Here's a couple of shots and more testing will be needed.

2.5x.

No PL Lens.

Pau · Post by **Pau** » Sat Jun 04, 2011 7:39 am

Mitch640 wrote:I did just do a test though, using my micrometer scale. The good news is, I can get good focus, full frame, with no PL lens at all. The bad news is, it is nowhere near parfocal anymore. Here's a couple of shots and more testing will be needed.

The objective image, when focused at the right distance, is formed 10mm below the end of the eyepiece tube or photo port. If you use Nikon CF objectives (no need of eyepiece corrections) direct projection is a real alternative, but you need to modify the photo tube to place the camera sensor at this position. It may be done if the tube itself can be dismounted and you can cut it (well best to make a new shorter one). In a Canon DSLR the sensor is placed 44mm behind the lens mount "flange focal distance", so you need to place the camera mount 54mm lower than the phototube end.
The tube diameter also need to be wide enough to not crop the image and well anti reflection flocked
Doing direct projection in fact the camera FOV will be wider han the eyepieces FOV. Perhaps with some objectives the image borders will be bad while with others would be OK (It's the same that to use the microscope objective on bellows)

In your test you focus the microscope very away of its desing point.

Mitch640 · Post by **Mitch640** » Sat Jun 04, 2011 7:47 am

Pau, I did some more tests this morning, and found that without the PL lens in place, depth of field was almost non-existant. The images looked soft.

I did not change the length of the tubes though, I just re-focussed in live view.

So your saying I should make the extension tubes shorter than if I used the lens? I can do that. I have two sets of extension tubes that have a total of 7 pieces of different lengths. I should be able to get something out of that.

Pau · Post by **Pau** » Sat Jun 04, 2011 8:06 am

- The DOF only will change if the magnification (or NA) changes
- Shorter would be beter, but still not parfocal, to be parfocal the sensor plane need to be placed 10mm bellow the end of the tube where the photoeyepiece sits.

Mitch640 · Post by **Mitch640** » Sat Jun 04, 2011 8:13 am

Pau wrote:- The DOF only will change if the magnification (or NA) changes
- Shorter would be beter, but still not parfocal, to be parfocal the sensor plane need to be placed 10mm bellow the end of the tube where the photoeyepiece sits.

If I understand this right, that would be impossible. I would have to cut the trinocular tube off the head???

Pau · Post by **Pau** » Sat Jun 04, 2011 8:40 am

Mitch640 wrote:If I understand this right, that would be impossible. I would have to cut the trinocular tube off the head???

Yes, this is what I tried to explain in my first reply. If the phototube can be dismounted, a shorter replica can be made, and a test with a bellows or extension tubes set holded in its place would be performed. (Perhaps possible, surely not easy

)

Mitch640 · Post by **Mitch640** » Sat Jun 04, 2011 8:55 am

Ah, OK, I understand now. No, I can not dismount the trinocular tube from the head, or shorten it. It would ruin it.

I did just do some fast tests though, first with the lens and extensions, then by removing the 2.5x PL lens, then shortening the extension, first by half, then by removing all extensions. When I had removed all extension, then mounted the Canon back on the ring adapter at the top of the trinocular tube, for some very strange reason, I was almost at parfocal again.

This made me curious, so I took the camera off the ring, placed the 2.5x PL lens in the hole and held the camera up there. If I had tried to mount it, the top of the lens would have broken the mirror in the camera. I did not measure it, but at a guess, I think the the top of the lens would be at about 20mm or less from the senor.

I have to thank you guys for sticking with me here. I learn something new every time I talk to you or read one of your threads, and today, I had a gestalt about using extensions. I have been thinking about it all wrong until you explained that part about getting the sensor closer. Other have tried, cause I know I had heard it before, but it just didn't sink in until today. Thanks for the push.

Now, if I could just learn the names of these bugs I look at.