Happy Holidays: White Lights

[ori333]

Hello UVP,

 

I'm wondering if the lights are emitting UV or is this visible light leaking into my UV camera setup?

[Stefano]

If they are tungsten-based, they will emit some UV. If they are LEDs, they will emit a tiny bit of UV in the really longest wavelengths and some IR up to 750-800 nm.

[Andy Perrin]

Ori, the top photo does not look like a UV photo in the first place? I'm voting strongly for visible and maybe other leakage.

[Stefano]

Andy, why doesn't look like UV? If he didn't white balance, the blue-violet he got is to be expected. It may be IR (deep IR shows up as pink sometimes), but I don't know why you think that.

[Andy Perrin]

Stefano, what's with all the brown? That doesn't belong in a UV photo!

[Stefano]

I don't see any brown. Is it a reflection off the screen?

[Andy Perrin]

Screen?

[Andy Perrin]

WAIT. IS THIS A PHOTO OF A CAMERA SCREEN, NOT AN ACTUAL PHOTO?

 

I think you just explained my confusion.

[Stefano]

Sometimes it happens. At least, once you see it, you can't unsee it.

[ori333]

Yes, let me get you the real photo.

[Stefano]

To see if you have UV, try the classic filter stacking method. For example, see if a IR-pass filter removes the image and so on.

[ori333]

The added the monochrome image to the top.

[ori333]

To see if you have UV, try the classic filter stacking method. For example, see if a IR-pass filter removes the image and so on.

 

Thank you! I'll get some extra filters.

[dabateman]

I think you maybe seeing uv.

Based on it being monochrome, I assume you are using the monochrome Pi HQ sensor. That thing is wickedly sensitive. So it will pick up the uv from lights.

[ori333]

I think you maybe seeing uv.

Based on it being monochrome, I assume you are using the monochrome Pi HQ sensor. That thing is wickedly sensitive. So it will pick up the uv from lights.

 

Yes, the monochrome Pi HQ sensor! I'm having so much fun with it now.

[Stefano]

So I got it wrong too! I thought it was a color image with a violet tint, maybe it actually is, but color in this case matters nothing.

 

Anyway, what kind of lights are those?

[ori333]

https://www.biglots.com/product/clear-mini-light-set-on-green-wire-50-lights/p810439856

[Stefano]

They look like tungsten but they say they are made of plastic, metal and PVC, so apparently no glass.

[ori333]

I'm learning a lot from everyone, thank you.

 

Would like to try the filter stacking method.

At the moment I only have the two filters to see UV from the monochrome both are M25.5

They don't really fit the lens, using tape.

 

https://maxmax.com/s...ilter-in-25-5mm

https://maxmax.com/s...egory_pathway-2

 

When it comes to buying more filters, what do you recommend? Stick to M25.5? Get an adapter? Or is there a set of filters to get off Amazon.

I have not yet narrowed down what lens to use for this camera either. Hope to switch to quartz at some point.

 

What I know is that I'll be sticking with the C mount sensor array.

[colinbm]

The Baader UV comes in a 1-1/4" size. You will only need one & no stacking

[dabateman]

The Baader UV comes in a 1-1/4" size. You will only need one & no stacking

 

However, that Baader U size might be the original and leak a lot of IR. So we generally avoid it and go for the 48 mm (2 inch) version. Thats a great filter but very expensive.

The 330c you have is a ug11 equivalent like u340 or a good copy of zwb1. So not too many other good options for your monochrome camera.

The others to use with your blocking filter are ug1=u360, like zwb2 or ug5=u330, like Zwb3. But you may not notice a difference for your monochrome camera.

 

The biggest difference would be if you can get a 390 band pass filter, like 390bp25 from the cheap ebay seller or a straight edge U filter.

http://www.uvroptics.com/index.php?SEUGen3

 

That will have slightly different UV appearance than your deeper 330c filter.

 

Or even go into the 400s with a wratten #47 filter. The tiffen ones are good.

 

Deeper UV filters are very expensive like 308 which goes for $1000.

[dabateman]

Actually thinking about it before you jump into another filter you might just want to get a good lens, like the one I suggested.

 

Then order one or 2 additional HQ cameras. Keep one stock and pop the CM500 filter out of the other if you order 2 from pi shop. They are only $50 each. With a stock HQ with internal CM500 filter and your 330C filter you already have, you will get some nice color UV images. The stock HQ can see from 350nm to 680nm.

[ori333]

Actually thinking about it before you jump into another filter you might just want to get a good lens, like the one I suggested.

 

Then order one or 2 additional HQ cameras. Keep one stock and pop the CM500 filter out of the other if you order 2 from pi shop. They are only $50 each. With a stock HQ with internal CM500 filter and your 330C filter you already have, you will get some nice color UV images. The stock HQ can see from 350nm to 680nm.

 

Sound advice, which led me to nailing down a focal length, and then led me to get a adjustable focal length lens (non-quartz) for testing. Thank you.

Just ordered the 4-12mm adjustable one that you recommended in:

https://www.ultravioletphotography.com/content/index.php/topic/4099-spectral-scan-of-some-c-mount-lenses/