www.photomacrography.net :: View topic - Early Optical sensor microchip.
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Early Optical sensor microchip.

 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Photography Through the Microscope
View previous topic :: View next topic  
Author Message
harisA



Joined: 03 Jul 2011
Posts: 387
Location: Greece

PostPosted: Thu Jan 30, 2014 4:17 am    Post subject: Early Optical sensor microchip. Reply with quote



Epi-brightfield illumination




External illumination -flash and difuser

All images were taken with a Mplan 5x objective.

Many thanks to Rik for his willingness to help me regarding the difference between "epi darkfield" and "epi brightfield" illumination methods.
Back to top
View user's profile Send private message
RogelioMoreno



Joined: 20 Nov 2009
Posts: 2953
Location: Panama

PostPosted: Thu Jan 30, 2014 2:55 pm    Post subject: Reply with quote

Interesting!

Rogelio
Back to top
View user's profile Send private message Send e-mail
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 17390
Location: Richland, Washington State, USA

PostPosted: Thu Jan 30, 2014 4:55 pm    Post subject: Re: Early Optical sensor microchip. Reply with quote

harisA wrote:
Many thanks to Rik for his willingness to help me regarding the difference between "epi darkfield" and "epi brightfield" illumination methods.

You're very welcome.

To quickly summarize for other readers...

Think about looking at a flat mirror surface with some dust on it.

With epi brightfield, the illumination light travels out through the objective lens, hits the mirror, and reflects back into the objective. In this situation the mirror appears bright; any dust on it will be dark.

With epi darkfield, illumination light travels out around the objective lens, hits the mirror surface, and reflects at an angle such that it does not get into the objective. In this situation the mirror appears dark; any dust on it will be bright.

So, epi brightfield and darkfield are named for the appearance of the mirror -- the flat featureless "field".

This is shown in the above photos.

In the first image, flat shiny surfaces are bright and everything else is dark. All we see are direct reflections. The colors are due to thin-film interference on the flat surfaces. If you look very close, small bits of the gold wires will be bright, where the surface happens to lie flat in the plane of focus.

In the second image, flat mirror surfaces are dark (the "black hole" effect), and everything else is bright. This is the illumination that we're used to seeing, so it looks the same as usual.

If we were used to looking at the world in a dark room illuminated only by beamsplitting eyeglasses that acted like light was coming out of our eyes, then the first image would look more "real".

--Rik
Back to top
View user's profile Send private message Visit poster's website
Chris S.
Site Admin


Joined: 05 Apr 2009
Posts: 2620
Location: Ohio, USA

PostPosted: Thu Jan 30, 2014 9:13 pm    Post subject: Reply with quote

Very informative post--both the images and the explanation. Interesting how each image conveys different useful information.

Studying the images--particularly the top one--I find myself curious to know more about what we're looking at and how it works. Is this a small array of photodiodes? If so, why are there apparently three? Why do two appear to be addressed twice (which makes intuitive sense), but one addressed four times? Are the fine green lines divisions between P and N regions?

--Chris
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Photography Through the Microscope All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group