Friday, December 19, 2014

Blogging for Freya: The Little Things

Poinsettia leaf under the microscope stand
It's been an exhausting week, Spiders. My dog had emergency surgery and his recovery is not going well. I found out that I didn't get a job I was really hoping to have for next semester. I'm still waiting to hear back about a grant for 2015, and I haven't heard anything from the admissions people at one of the graduate programs I want to apply for in the fall. It's just not been a great time lately.

But, I have still been working. For my birthday, my family helped me put together a microscope platform for my cell phone. It's a cool little project that I found on IFLS. The original video and instructions are available on Instructables. There are some limitations, and it certainly cost more than $10. It was about $30, total, though some of that was because I had to use alternate parts, and needed some springs to help stabilize the specimen stage. Still, $10 isn't a good estimate for this project.

Keep in mind that I'm saying it was $30 to build a microscope for my cell phone. That's pretty nifty. Yes, you can buy cheap digital microscopes for about $40, and there is actually a purpose-designed cell phone attachment for $15. This set up is fairly customizable, and you can add or substitute lenses for different effects. So, I'm fairly pleased with the concept. The results.. eh.

The platform, with slides.
A big issue with high magnification, using any format at all, is focal distance and focal length. The subject needs to be right up next to the lens to be seen, and your depth of field is practically two dimensional. We're talking way under a millimeter for this set up. I can focus on the top of a cube of loose salt, but not the entire cube. Yeah, I can't get a whole grain of salt in focus. It's too big. So that is a consideration, certainly.

The lens I used, stolen from a $2 laser pointer, is a bit smaller than the lens of my cell phone, meaning I only have a limited field of view. The edges of the laser-lens is visible in the cell phone images, causing extreme vignetting. Maybe the center 30% of the final photo is in focus. Zooming in at all causes severe distortion and pixellation. You can see that in the photo of the text from a US quarter, over on my Instagram. I've been tagging all the photos with this rig as #cellphonemicroscope.

It is theoretically possible to stack lenses for greater magnification, which actually allows plant cells to become visible. I haven't tried that myself, but all the issues with depth of field, vignetting and focus would be doubled along with the magnification. I really doubt the final result is worth the trouble, but I may experiment with it later.

Generally, I think this was a fun project, and I do enjoy playing around with it. I'm glad my family helped me put the stand together, and it made for a great birthday present. The image results aren't anything to write home about, at least not yet. It's certainly worth exploration, though.

No comments:

Post a Comment