IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
Interesting camera design for future microscopic imagers?, Future imaging
hendric
post Jun 22 2011, 07:38 PM
Post #1


Director of Galilean Photography
***

Group: Members
Posts: 713
Joined: 15-July 04
From: Austin, TX
Member No.: 93



Found this on Facebook:

http://blog.lytro.com/news/the-light-field...tion-by-ren-ng/

His dissertation is available here

http://www.lytro.com/renng-thesis.pdf

Being a non-expert, I only skimmed it for the pictures, but it looks like that it uses the extra resolution available in today's camera chips to increase the focused depth of field using light rays.

Microlenses are placed in front of a group of pixels, say 8x8 or 64, and now the mini-picture formed on that 8x8 array can be used to extend the Depth of field by a factor of 8. This can be done without needing a high F/ratio, as is usual to increase the DoF. Plus, it allows for choosing to put near, far, or everything in between into focus.

For space, this looks the most interesting for microscopic images. It would allow a single-shot to capture a whole 3d microscopic image, with focus at a very wide distance range. You could create the large DoF picture on the imager, and upload only the processed image, or upload the full image, and choose where to focus back on Earth. It would reduce your effective number of pixels, but would remove the need for focusing apparatus, aperture control, or focus steps as you bring the imager closer to the object under study.


--------------------
Space Enthusiast Richard Hendricks
--
"The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke
Mother Nature is the final inspector of all quality.
Go to the top of the page
 
+Quote Post
jekbradbury
post Jun 22 2011, 07:59 PM
Post #2


Member
***

Group: Members
Posts: 101
Joined: 1-June 08
Member No.: 4172



The conceptual idea has been around for about 20 years, but it's only now that sensors with the required resolution (around 100 megapixels to get a resulting focused image at a reasonably high resolution) have become available. Unfortunately, such a large amount of data (around the size of a full-resolution MER panorama, if I'm not mistaken, for a single image) would make the mission limited quite severely by downlink bandwidth.
Go to the top of the page
 
+Quote Post
djellison
post Jun 22 2011, 08:05 PM
Post #3


Administrator
****

Group: Chairman
Posts: 13806
Joined: 8-February 04
Member No.: 1



MAHLI will generate an single extended DOF image and a height map, on the back-electronics for the camera, before transmitting those to the ground. It need a focusing mechanism, but it doesn't need a month to download it smile.gif
Go to the top of the page
 
+Quote Post
hendric
post Jun 22 2011, 10:17 PM
Post #4


Director of Galilean Photography
***

Group: Members
Posts: 713
Joined: 15-July 04
From: Austin, TX
Member No.: 93



Well, I was thinking the DoF processing could be handled on-site, as an overnight activity. After all, if you're going to need heaters, might as well use the power to run CPU cycles to generate heat.

I guess one possible issue would be 100+ MP chips are going to require pretty small pixels dimensions, and smaller pixels are more likely to suffer with CR hits etc. But to offset, the pictures would be much shorter; the examples in his thesis are F/4, with comparable DoF as F/22. Shorter exposures would limit the number of CR hits, right?


--------------------
Space Enthusiast Richard Hendricks
--
"The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke
Mother Nature is the final inspector of all quality.
Go to the top of the page
 
+Quote Post

Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 25th October 2014 - 04:47 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.