Infrared light though Calcium

[Charlie_Brown]

Hi!
I would like to know if the infrared light of a led would pass through CaCO3. I would like to "see" the inside of an egg and CaCO3 is the basic compound.
Thanks

 

[kender]

850nm IR goes through bone, which has substantial amounts of CaCO3. It should go throuh egg shell too.

 

[mkh]

what about ultrasonics?

 

[kender]

what about ultrasonics?

IR and ultrasonic sound propagate (and get absorbed) differently through tissue and blood. Also, ultrasonic scanner is much harder to build.

 

[rikie_rizza]

I have done some experiment using IR led to view an egg of a duck. My technique is,
- use 12 IR led in matrix configuration.
- Give about 30mA for each led.
- Shield half of the egg with with aluminum foil.
- Take a picture with IR film (shutter speed 1/60, aperture 5.6).
And I can the egg yolk, but its not clear.

 

[kender]

Here's a image of a human (my partner's) hand in IR. The hand is between the light source and the camera. Notice that the blood vessels are absorbing, and the bones are not absorbing.

 

[rikie_rizza]

Wow that's clear. Mine is a bit less contrast. Maybe because the density of the yolk and the... other yucky smelly thing that i don't know the name in English, is about the same. Do you remember the apperture and the speed of the shutter?

 

[kender]

Wow that's clear. Mine is a bit less contrast. Maybe because the density of the yolk and the... other yucky smelly thing that i don't know the name in English, is about the same. Do you remember the apperture and the speed of the shutter?

That picture was done with a CCD camera and a lot of tricks that I can't write about (the photo itself is public though).

 

[platonas]

Although I am not an expert, you can try a digital camera to take the picture in a dark or very low light room.
The CCD of all digital cameras is sensitive to IR and even to UV-A.

Personaly, I test the IR remote controls whether they transmit by viewing the IR LED through the cameras LCD. It glows blue on the screen. Almost always I do tests of remote controls with my mobile phone's camera and it is very reliable.

So, with the setup you stated before, you can use a digital camera instead of a film one and just play with thw apperture speed. Use manual settings since the camera's meter cannot measure IR light reliably.

Anyway, it is a nice idea to take such kind of pictures, I would appreciate if in the future you can post some photos.

Good luck