Help with a scientific set up

[twiddlestix]

Hi everyone.
I am not a photographer at all, so trying to put a set up together is a challenging prospect. Here's what I need it to do, and I believe I will require a lens, ring-light and a tripod, (we have a camera already) so any advice that you can give me would be much appreciated:

I am going to be looking at black 1-5 micron beads and taking pictures of them as they move slowly. Colour is not a concern. Size isn't much of a concern either as it will all be relative.

So how do i make a system that will hold the camera 90 degrees above the beads so I can see in fine detail the area that they cover (which is what i want to measure). I need the tripod to hold the weight of the camera and lens at 90 degrees all the time.

If you can help at all I would be very grateful.

Thanks!

 

[KmH]

If the beads only have a 1-5 micron diameter, you need a microscope that the camera can be attached to, not just a lens.

 

[twiddlestix]

I don't need to see each bead indivdually - sorry i wasn't more clear! I there will be many beads that clump together to make a dense area , and its that area i need to measure. I need to be able to see the difference between light and dark.

Thanks!

 

[KmH]

Most dSLR cameras have a rectangular image frame that has an aspect ratio of 3:2.

You are likely going to need a lens that has a true macro capability and that can give a 5:1 magnification factor.

That means a Canon camera and the Canon EOS (SLR) Camera Systems - Macro - Macro Lens - MP-E 65mm f/2.8 1-5x Macro Photo - Canon USA Consumer Products

If 5x magnification is not enough you're back to finding a suitable microscope.

A ring light will not be able to light that small a field and good tripods can hold the camera above the subject while pointing straight down.

Hopefully, you have a sufficient budget. The lens alone new, is $950.00

 

[fokker]

How big is the area that the beads will be occupying? ie how big is the space the camera needs to frame?

I'm not sure if the super macro lens kmh is recommending will be necesary.

 

[twiddlestix]

The area is around 5 mm squared, could go even smaller, but thats a good baseline.

 

[KmH]

The area is around 5 mm squared, could go even smaller, but thats a good baseline.

That's right about 1/5th of an inch.

Did you click on the lens link I provided and look at the image Canon has of the water beads made at 5x?

You'll need to check the dimensions of the FOV (field-of-view) for the lens I suggested to be sure that at 5x it's FOV will be large enough for your needs.

Your next problem is going to be lighting the area you want to shoot. The lens will be pretty close to your work field.

I don't do photography that close up, and have no experience lighting that small a FOV.

 

[anm90]

Perhaps try using a light underneath the surface on which the beads are placed? If the surface is white and semi-translucent you should get good contrast between the beads and their surroundings. If you don't need detail in the beads themselves this should be fine, as their upper surface will be completely in shadow.