[UV SAFETY WARNING] Reaspberry Pi HQ affordable Fast UV sensitive Sensor!

[dabateman]

Warning UV-C should never be taken lightly. Wear protective gear and cover up your skin. You will damage your skin and can get seriously hurt yourself.

 

I was able to convince Dan at MaxMax (LDP) to convert a Raspberry Pi HQ camera to Monochrome. Its an exciting camera and he now has them for sale. You can see them here:

https://maxmax.com/maincamerapage/monochrome-cameras/raspeberry-pi-cameras/raspberry-pi-hq-12mp

 

Mine arrived today and the first thing I tested was my 254nm light with 25mm single fused silica element with the 254.3bp25 filter on front. This sensor is very sensitive to UV-C!!!!!

 

Direct from camera Jpeg, resized for posting. ISO equivalent 320, F4 (cut a 6mm disc behind the lens), 1/16 second shutter speed!

 

Direct from camera Jpeg, resized for posting. ISO equivalent 320, F4 (cut a 6mm disc behind the lens), 1/16 second shutter speed!

 

Using DCraw for Raspberry Pi HQ camera with -d -6 -T switches and resizing for here ISO 160, 1/16, F2 (cut 1/2 inch hole behind lens):

 

I just missed the focus on where I want for that one.

 

This sensor is fast and can capture movies.

 

So for under $1000, UV-C imaging at 12 Mpixels is in our hands (my hands). This should be fun. Its only Monochrome but still, great.

[colinbm]

Good on you Dave...have fun....& get focus sometimes too....

[enricosavazzi]

Edit: I originally asked about the type of conversion, but got my answer from the Maxmax page.

 

Most likely a better alternative to a converted GoPro, although some coding is probably required. It might be a good idea to make an open-source basic imaging software available for those who do not code (unless it already is available).

[JMC]

Very interesting David. Thanks for sharing.

[Stefano]

Yes, very interesting. Try stopping down the lens, you will gain sharpness. Sensitivity seems not to be a problem.

 

In the future, if I will ever do UVC, I will definitely consider this.

[WiSi-Testpilot]

Thank you for the information. That's very interesting.

Best regards,

Wilhelm

[dabateman]

The camera has been monochrome converted with the coverglass, microlenses and color filter array removed. Its a naked back side illuminated sensor, so you can't touch it. Its also tinny, so my 25mm lens is effectively a 140mm focal length.

Dan does have a M12 board quartz lens that is 6mm that fully covers the sensor. That would be roughly 35mm equivalent. But focusing would be screwing it in and out.

 

The Raspberry pi thread has the code I use and images. Not too hard to code in the pi to get a fully working camera. But may be a steep learning curve for some. Main problem was during the time I was learning and trying to get the software to work, the pi software got broken twice by the development team. So I would say once you get it working and doing what you want, don't ever update it. Something might get broken that you use in your code, within an update. Just look at the current Windows 10. The same keeps happening. One of the Windows 10 updates killed one of my old laptops. If this continues in Windows I might just lock down into a specific Linux build.

 

So I have pi 4B 8GB board, but I would recommend the 4Gb. Fewer problems and if your not doing image editing on the camera, you don't need 8Gb.

 

A UPS HAT that takes two 18650 batteries to power it.

 

A 4.3 inch HDMI touch screen. Don't get a DSI screen as they will conflict with the camera port. You must get a HDMI screen or cable to run into a standard monitor.

 

I use the CSI to HDMI adapter, as the camera cable is fragile and like to just swap HDMI cables to switch between camera modules. There are 2 in a pack. One goes on the main board. The other on your camera module, then use easy removable HDMI cables for connecting.

 

I have my full spectrum module on my microscope, so just use long HDMI Cable to connect to the board.

 

This will be fun, but will have to carefully use compressed air to blow off that dust on the sensor.

 

 

[dabateman]

All above images taken with single 15W germicidal 254nm bulb.

I still need to try the candle test and compare it to my KSS imager.

 

Also just found I need to code in:

-awb greyworld

So that my jpeg's will be monochromatic. That should also help.

 

Dan said the DNG that gets output from PyDNG works in the DNG2monochrome software for Windows computers. I still have to test the output DNG in RawTherapee.

[Stefano]

David, I think you have a quartz or fused silica lens, not the plano-convex, but a complete lens made for UV photography. I know it isn't easy, but can you attach it, in some way, to the camera? It will probably crop a lot, since the sensor is small, but at least it is corrected.

[dabateman]

Yes I have a 60mm macrol, which is really 75mm focal length and an 85mm.

However, with 5.6x crop of the Pi HQ camera that makes them both extreme telephoto lenses.

I have 25mm, 39mm, 50mm biconvex single lens elements. And planoconvex lens elements. Still trying to work out what will be best for this.

A 12mm quartz lenses would be nice.

[Andy Perrin]

David, edmund lenses on eBay are very common...

[dabateman]

For Stefano, here are some of the fast movie shots. I was able to screen grab something from the fast video.

 

No explanation needed, but fast read out is possible with the HQ sensor:

[Andy Perrin]

Is that your finger in UVC? It looks as dark as in SWIR!

[Stefano]

Yes, it really does! That's what I would have expected, UVC is well absorbed by most materials.

 

David, thanks. Although I don't really advice trying this, those images are interesting and rare. I would take a UVC selfie, eyes open, if I had the equipment AND UVC wasn't so bad... I guess even my sclera (the white of the eye) would turn dark, just like in SWIR. My hair would not turn white though, I am sure of that.

[dabateman]

All I will say is for safety, make sure you have turned off your lights before you make minor focus adjustments. Make sure they are off with a switch, definitely don't look at them.

 

I had forgotten to turn off my light for one adjustment. Fortunately, I hit movie record, instead of focus adjustments in my application. So I got a 30 seconds video. These are the best frame grabs using VLC from that video. The light is mostly behind. The frame rate is about 1/30 seconds shutter, maybe even a little faster. The aperture was about f4 and I have only anolog gain set to 4, roughly ISO 320. Impressive, grabs. But will not be repeated.

 

We got more Nitrile gloves, so will be protected incase I forget again to hit my kill switch.

 

I still need to program in monochrome capture. Colors go all over the place with a CFA removed sensor. It doesn't know not to mess with color. I think best test will be coolor effects switch with 128:128 for monochrome. Need to compare that to greyworld switch in white balance.

[Stefano]

If you want to be sure your UVC lights are turned off when you don't want them to be on, you may use something like a dead man's switch, that will be closed only if you are "alive" (vigilant). If you let it go, it will open. If you want to turn on your lights for a long time or simply leave the room while they do their nasty things, it wouldn't be a good solution, but if you use them for quick experiments you may consider this.

[ori333]

Hey,

 

I got the same camera from Dan.

 

[dabateman]

For your raspivid code you can add the switch:

-cfx 128:128

 

This will give you a monochrome (grey scale image) rather than seeing everything in magenta like the USA.

 

Its an amazing canera.

[ori333]

Thanks. My next step is trying this camera outside with natural sunlight. I'm not using a quartz lens (yet).

[ori333]

I'm very excited about this camera too. It's a first step to many possibilities. Especially if you have a solid programming background (or if we create enough tools for others). Currently just shooting first and asking questions later, but at some point I would like to do the math on frequency response on camera sensitivity, sunlight light intensity, all the lenses and filters to have an engineered result.

 

For now just having access to the RAW data in real time is good enough.

[ori333]

Battery operated Pi.

[dabateman]

This is what my pi camera looks like:

https://www.ultravioletphotography.com/content/index.php/topic/4023-corrected-raspberry-pi-hq-review-to-335nm/page__view__findpost__p__38069

 

I have a 4.3 inch touch screen for control, a UPS hat that takes two 18650 batteries and I connect the HQ camera using CSI to hdmi adapter cables, so that I can swap out cameras with specific filters.

 

I have a HQ with Zwb2 and S8612 behind the C-mount as a dedicated UVa module.

 

I have a HQ with zwb3 for IR.

 

I have the MaxMax monochrome module for UVc and monochrome.

 

I have a full spectrum one without any filters.

I also have a stock normal one for regular UV/visible as the stock glass can see 350nm to 600 something.

[Stefano]

David, you didn't miss one! One for every occasion. ZWB3 lets in UV too, so you have something like enriched IR on that one.

 

You should try to see the 185 nm line on the monochrome one. A silicon sensor should be capable of 190 nm, at least that's what they say, but I have not seen anybody actually push a sensor that far.

[dabateman]

Yes I went with zwb3 for IR instead of lp720 as I get blue sky'sand white trees.

 

Dan was thinking it maybe sensitive to x-rays. As the first pi camera he converted was. The problem is really getting a pure light source. If I had a good 185nm light it may work better than the phosphor screen imager. But my best ozone lamp blew up and after COVID the cost went up 10 fold. So can't afford a good one again.

The cheap 3W ones all are mostly 254nm.

 

If your careful and exit the software, you can hot swap out HQ cameras. Thus why I bought the others for quick spectral changes. Also being less than the cost of a filter made that choice easier. One filter module where you can screw in any lens just makes sense. Only down side is 5.6x crop on your selected lens. So 12mm is my preferred almost 70mm equivalent focal length. But a 25mm, roughly 135mm equivalent is also nice.

[ori333]

Interesting: HQ with Zwb2 and S8612 for UVA. I didn't know we can do that without removing the Bayer filter.

Like your hot swap idea. Can you still change the ISO and the shutter speed that way?

 

Instead of hot swapping my plan was to use this:

https://www.arducam.com/product/b0195-synchronized-stereo-camera-hat-raspberry-pi/

 

at the moment I'm still trying to get the right UV video camera and only testing the MaxMax one.