Is there a lens that will enhance the ultraviolet wave length

[JBW]

Donald's foray into IR has got me wondering if I can use my camera to show more of the ultraviolet. I'm thinking it would be interesting to see flowers and bugs as the flowers and bugs see themselves.

[xpatUSA]

Donald's foray into IR has got me wondering if I can use my camera to show more of the ultraviolet. I'm thinking it would be interesting to see flowers and bugs as the flowers and bugs see themselves.

Dr. Klaus Schmidt is the man for that, Brian:

http://www.openphotographyforums.com...ad.php?t=22205

He mentions such lenses here:

http://photographyoftheinvisibleworld.blogspot.com/

UV is difficult. Not much of it gets through lens glass and there is a UV/IR blocking filter mounted on your sensor, not to mention any daylight or haze filter that might happen to be mounted on your lens.

So, you're talking about a special lens (quartz glass?) and surgery on the sensor at least ...

[JBW]

Dr. Klaus Schmidt is the man for that, Brian:

http://www.openphotographyforums.com...ad.php?t=22205

He mentions such lenses here:

http://photographyoftheinvisibleworld.blogspot.com/

UV is difficult. Not much of it gets through lens glass and there is a UV/IR blocking filter mounted on your sensor, not to mention any daylight or haze filter that might happen to be mounted on your lens.

So, you're talking about a special lens (quartz glass?) and surgery on the sensor at least ...

surgery is definitely out.

[Manfred M]

surgery is definitely out.

In that case your project is dead on arrival. A camera with a modified sensor stack can in theory still be used for “normal “ photography by using an external IR absorbing filter and external UV absorbing filter. UV transmitting lenses require very pure silica elements that transmit UV. These are highly specialized lenses and come with prices to match.

[JBW]

In that case your project is dead on arrival. A camera with a modified sensor stack can in theory still be used for “normal “ photography by using an external IR absorbing filter and external UV absorbing filter. UV transmitting lenses require very pure silica elements that transmit UV. These are highly specialized lenses and come with prices to match.

In the bad old days I used to be a cab driver. When I needed a break I'd drop into Izzies and watch the show. Some of the ladies did some interesting routines with black(?) lights and paint. Would there be an equivalent light unit that would pick up the neat and nifty bug colors?

[Manfred M]

Are you thinking of using a “black light” as a light source? That’s different than UV photography.

I did some of that decades ago and used a fluorescent tube black light to illuminate different mineral samples. A normal camera without any modifications or special lenses should work well.

[xpatUSA]

In the bad old days I used to be a cab driver. When I needed a break I'd drop into Izzies and watch the show. Some of the ladies did some interesting routines with black(?) lights and paint. Would there be an equivalent light unit that would pick up the neat and nifty bug colors?

Plenty on eBay, Brian, for example:

https://www.ebay.com/itm/100-LED-UV-...MAAOSwqoZa7HUF

As Manfred says, no need for UV-sensitive stuff. I have a UV lamp that I bought for irradiating watch lume to brighten it up momentarily.

UV, being highly energetic can cause some materials to fluoresce, emitting photons at a different wavelength than UV. Watch lume emits green usually. Something to do with band-gaps or summat.

I once wrote an article about it:

http://www.kronometric.org/article/lume/

There's likely some stuff in your garden that might fluoresce under UV ...

[DanK]

I think it is important at the start to distinguish between two entirely different types of UV photography. One is reflected-light photography, which is the same as regular photography or the IR discussed here except for the wavelengths of light. The second is induced-fluoresence UV photography, which uses the light emitted when UV strikes some surfaces. The latter is what is you saw with "black light", which was usually UV lighting. The techniques and equipment are very different. I looked into both and decided it was too much of a pain in the neck.

[pnodrog]

To add to your troubles (add a planck to the problem?) the colours emitted by pigments or dyes in response to UV illumination have very specific wavelengths that may well fall outside the colour space you are working in...

[JBW]

It seems that this is not one of my more brilliant ideas

[Manfred M]

It seems that this is not one of my more brilliant ideas

This would be a fairly low cost experiment as all you would need is a UV light source which tend to be relatively inexpensive.

While Paul is correct that some of the colours may be out of gamut, that may or may not be a show stopper for you.

[DanK]

This would be a fairly low cost experiment as all you would need is a UV light source which tend to be relatively inexpensive.

It's been a long time since I looked at this, but I don't think this is correct. First, you need to block visible light, either by working in a darkroom or putting filters on the camera. Many people use two different filters. Then, you need the light source, which can be inexpensive if you don't need it to be powerful, but some people modify flashes. Finally, I've read that the choice of cameras matters because some have enough UV filtration to make this difficult. I am in a work crunch and can't look for links, so I can't verify my memory.

[xpatUSA]

<> Finally, I've read that the choice of cameras matters because some have enough UV filtration to make this difficult. I am in a work crunch and can't look for links, so I can't verify my memory.

That's quite so, Dan.

And silicon itself is not that good at responding to UV i.e. less than 380nm.

Here's the response for one of my cameras with no CFA, no blur filter and no UV/IR blocking filter:



As you can see, not much response below 400nm. On top of that, my cheap LED "UV" lamp puts out some visible light too maybe as high as 450nm (I do try hard not to look at it directly).

[pnodrog]

Recording florescence is not a problem as although activated by U.V. light the colours will be predominantly in the visible spectrum. Out of gamut colours will simply be displayed as the nearest equivalent depending on intent.

The ratio of visible light to U.V. light illuminating the subject simply controls the ratio of reflected light to fluorescent light being observed. Most people will have noticed how fluorescent clothing appears to have a very strong glow at dusk.

Brian it maybe worth you having a go. You never know you may come up with some very interesting images. However they will not be indicative of how bugs would see them.

Fluorescence, chemiluminescence and phosphorescence play havoc with WB corrections... (as does any light source in a photograph)

[Manfred M]

It's been a long time since I looked at this, but I don't think this is correct. First, you need to block visible light, either by working in a darkroom or putting filters on the camera. Many people use two different filters. Then, you need the light source, which can be inexpensive if you don't need it to be powerful, but some people modify flashes. Finally, I've read that the choice of cameras matters because some have enough UV filtration to make this difficult. I am in a work crunch and can't look for links, so I can't verify my memory.

Dan - when I did this some years ago I can guarantee that I did not use anything special other than a skylight filter, and that was with a film camera that did not have a UV blocking filter. What I did was to use a background that absorbed UV and had the light source set up so that it was behind the camera. The black light was the only light source that I used, so the mineral samples that were fluorescing were the main light source as was the limited amount of visible light that the UV source was emitting.

This might not have been something that a geologist would have done, but I quite liked the results. I suspect that Brian s looking to do something similar.