Blog on UV and other aspects of microscopy and imaging

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jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

Latest post - reflection microscopy of a camera sensor, in its normal state and how it looks during the process of removing the filter to form a monochrome sensor - https://jmcscientificconsulting.com/mic ... ra-sensor/
Jonathan Crowther

Lou Jost
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Re: Blog on UV and other aspects of microscopy and imaging

Post by Lou Jost »

Nice demonstration!
Oddly enough the green ones look smaller than the red and blue ones, and I’m not quite sure why that would be the case.
This is a clever design. It makes sense to equalize the AREAS of the three colors, and since there are two green pixels for every blue or red one, all colors will have more nearly equal areas if the green ones are smaller than the blue and red ones.

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Re: Blog on UV and other aspects of microscopy and imaging

Post by rjlittlefield »

Lou Jost wrote:
Tue Sep 08, 2020 7:19 am
Oddly enough the green ones look smaller than the red and blue ones, and I’m not quite sure why that would be the case.
This is a clever design. It makes sense to equalize the AREAS of the three colors, and since there are two green pixels for every blue or red one, all colors will have more nearly equal areas if the green ones are smaller than the blue and red ones.
I see the size difference also.

But then I noticed that when the Bayer filter layer is removed, all of the sensor cells then appear to be the same size.

My take is that what's different in size in the Bayer-only image is just the blocks of the Bayer filter, R and B blocks looking larger than G. Even that may be a perceptual illusion. The inactive strips between pixels are mostly covered by green, but I think we don't "see" that green because we recognize it as being inactive area. On the other hand, where the R and B blocks spill over into the inactive strips, the extra areas of R and B are very obvious and very associated with the corresponding pixel.

A more neutral view, I suspect, is provided by the image with microlenses still in place. In that image, all of the pixels (microlenses) look the same size to me. There's a lot of extra green area in that image also, but it's obviously between the pixels so it's easy to ignore.

--Rik

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

I wonder if the size is related to the order in which the colours are put down on the sensor? Presumably the colour put down second will overlap slightly with the edges of the first one, and the third one will overlap the first two. I must admit, I know nothing about the specifics of how these filter layers are made - I guess each colour is put down sequentially?
Jonathan Crowther

Lou Jost
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Re: Blog on UV and other aspects of microscopy and imaging

Post by Lou Jost »

Could you perhaps determine the order by looking closely at the partially scraped areas of the chip?

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

Lou Jost wrote:
Wed Sep 09, 2020 6:12 am
Could you perhaps determine the order by looking closely at the partially scraped areas of the chip?
Good idea. Next time I assemble the kit back together I'll take a look.

EDIT: Section removed, as it added unnecessary confusion.
Last edited by jmc on Thu Sep 10, 2020 2:32 pm, edited 2 times in total.
Jonathan Crowther

Lou Jost
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Re: Blog on UV and other aspects of microscopy and imaging

Post by Lou Jost »

then it would explain why the green is bigger
But you said green was smaller?

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

Doh, that I did. I should check things before posting them. I've removed the section because it added confusion. Thanks Lou.
Jonathan Crowther

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

My UV microscope build is coming along. The latest post summarises the work to date and brings together links to the different parts to it. Also I've swapped out some of the original Olympus optical components for UV fused silica now, and I share the initial testing of that. Here's the link - https://jmcscientificconsulting.com/uv- ... ca-optics/

When completed, the optics should be good for imaging down to around 230nm, however at the moment my cameras will be the limiting factors, and I should be able to get down to around 280nm for now. I have some final parts on order and hope to have the build completed by the end of the year.
Jonathan Crowther

Lou Jost
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Re: Blog on UV and other aspects of microscopy and imaging

Post by Lou Jost »

In case you are interested in a crazy 10x 0.37 UV (365nm) "objective" with a gigantic field size and perfect field flatness, this just came up on eBay today:
https://www.ebay.com/itm/193756315611?ul_noapp=true

This is quite unique. If nothing else, it is full of UV-transmitting lenses made from exotic materials. Probably cost hundreds of thousands of dollars when new.

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

Lou Jost wrote:
Thu Nov 19, 2020 9:34 am
In case you are interested in a crazy 10x 0.37 UV (365nm) "objective" with a gigantic field size and perfect field flatness, this just came up on eBay today:
https://www.ebay.com/itm/193756315611?ul_noapp=true

This is quite unique. If nothing else, it is full of UV-transmitting lenses made from exotic materials. Probably cost hundreds of thousands of dollars when new.
Wow that is quite a beast. I'd need a new workshop to put that in :D
Jonathan Crowther

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

Happy New Year everyone.

The UV microscope build is coming along. For the latest on how I modified the binocular head see here - https://jmcscientificconsulting.com/uv- ... d-part-ii/

I've used UV fused silica components to replace the glass parts in the route through the head to the camera.
Jonathan Crowther

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

A bit of an update on the UV transmission microscope build. Everything is now done, and I have been able to do transmission imaging down at 313nm, which is about the limit of where I can get to with my current camera and light source.

Link to the latest update here - https://jmcscientificconsulting.com/uv- ... -it-works/
Jonathan Crowther

Lou Jost
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Re: Blog on UV and other aspects of microscopy and imaging

Post by Lou Jost »

Congratulations! Very nice to see how the normalized tranmission curves and emission curves match so well at every peak. Your project is especially nice in that you have tested and quantified everything at every step. That's extremely rare, most of us don't have the intrumentation to do it.

I hope your system proves useful to you!

jmc
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Re: Blog on UV and other aspects of microscopy and imaging

Post by jmc »

Lou Jost wrote:
Sat Feb 13, 2021 9:23 am
Congratulations! Very nice to see how the normalized tranmission curves and emission curves match so well at every peak. Your project is especially nice in that you have tested and quantified everything at every step. That's extremely rare, most of us don't have the intrumentation to do it.

I hope your system proves useful to you!
Thanks Lou, yes I'm lucky enough to have the equipment to be able to test and characterise what I've been up to. To be honest, without it, I wouldn't have been able to do this. I've shared it in case it is of use to others who are thinking of going down this route.

What I need to to now is get more practice at preparing samples.

I will of course continue to optimise it. I'm hoping later this year to invest in a camera with a UV enhanced sensor which should help with improving sensitivity in the UVB region.
Jonathan Crowther

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