Dichroic/Microscope Florescence Filters

Has anyone used microscope type filters for photography?  I am especially interested in the ones that they use to image florescent dyes.  Where they image multiple different narrow bands.  I've seen some diving equipment that use blue lights and dichroic filters.  It seems like Macro isn't too different from Micro, has anyone used these types of filter techniques for macro photography?  I've seen UV florescent flashes, to photograph florescent bugs, but they don't really use emission filters.

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

D Cox wrote:

Matty W wrote:

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

Didymium filters have more effect on human vision than they do on most cameras. They filter out the yellow, near to the Sodium wavelength, and the narrow-band filters used in typical Bayer mosaics already have a gap there.

I think dichroic filters are different than didymium, dichroic filters work by thin film reflection, like soap bubbles.  They use them to tune very specific color bands, so that light that stimulates fluorescent dyes is filtered out.  It looks like a single color like red or green is most popular, but there are also multiband filters for using three four or five dyes, which is what I am more interested in.  Interestingly enough they come in complement pairs, one to ensure the excitation light is not in the same range as the emission light, and the complement for imaging.

D Cox wrote:

Matty W wrote:

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

Didymium filters have more effect on human vision than they do on most cameras. They filter out the yellow, near to the Sodium wavelength, and the narrow-band filters used in typical Bayer mosaics already have a gap there.

I have used a didymium filter a bit, but I was actually thinking something more similar to this:

https://enchroma.com

Which apparently is some sort of band pass filter. (Would didymium be a notch filter? I was never good at science.) If I remember correctly, the company started out when its creator noticed that microscopic imagining filters (or perhaps it was filters for viewing lasers) also enhanced color perception.

But this isn't exactly related to the OP's interest... in florescence primarily. So never mind; I think I'm after something slightly different (more perceived color saturation like with the "trichromatic back" using a color filter). But I'm curious about the OP's question, too.

Matty W wrote:

D Cox wrote:

Matty W wrote:

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

Didymium filters have more effect on human vision than they do on most cameras. They filter out the yellow, near to the Sodium wavelength, and the narrow-band filters used in typical Bayer mosaics already have a gap there.

I have used a didymium filter a bit, but I was actually thinking something more similar to this:

https://enchroma.com

Which apparently is some sort of band pass filter. (Would didymium be a notch filter? I was never good at science.) If I remember correctly, the company started out when its creator noticed that microscopic imagining filters (or perhaps it was filters for viewing lasers) also enhanced color perception.

But this isn't exactly related to the OP's interest... in florescence primarily. So never mind; I think I'm after something slightly different (more perceived color saturation like with the "trichromatic back" using a color filter). But I'm curious about the OP's question, too.

I've been using didymium filters, and the variations "enhancers" blue, green, red, warming etc.  I like them.

I think they all have a notch in the orange, where they do pretty much the same thing that the enchroma glasses are doing.  Though there are other effects in the blue and green.

SmoothOperator wrote:

Matty W wrote:

D Cox wrote:

Matty W wrote:

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

Didymium filters have more effect on human vision than they do on most cameras. They filter out the yellow, near to the Sodium wavelength, and the narrow-band filters used in typical Bayer mosaics already have a gap there.

I have used a didymium filter a bit, but I was actually thinking something more similar to this:

https://enchroma.com

Which apparently is some sort of band pass filter. (Would didymium be a notch filter? I was never good at science.) If I remember correctly, the company started out when its creator noticed that microscopic imagining filters (or perhaps it was filters for viewing lasers) also enhanced color perception.

But this isn't exactly related to the OP's interest... in florescence primarily. So never mind; I think I'm after something slightly different (more perceived color saturation like with the "trichromatic back" using a color filter). But I'm curious about the OP's question, too.

I've been using didymium filters, and the variations "enhancers" blue, green, red, warming etc. I like them.

I think they all have a notch in the orange, where they do pretty much the same thing that the enchroma glasses are doing. Though there are other effects in the blue and green.

I haven't tried the other enhancer filters, but I suspect you're right.

What I thought would be really interesting is a narrowband (I don't know the terminology) band pass filter around each chromaticity, if that makes any sense. I used to shoot a lot of Velvia and loved the saturation and remember that its spectral acceptance curves (wrong term again, I'm sure, but it's been a while since I looked at the white paper) are very narrow, whereas bayer filters seem pretty broad to improve low light performance, and I know some even prefer the color of early dSLRs to newer ones...

Phase One/Sony's trichromatic back seems to aim at something similar, but I was wondering why not a filter that has narrow acceptance peaks around R, G, and B, and blocks light elsewhere? It would essentially work as an ND filter, but would also increase perceived color saturation dramatically.

Then again, maybe something similar is possible in post:

https://www.thebrim.pictures/vivid.html

Matty W wrote:

SmoothOperator wrote:

Matty W wrote:

D Cox wrote:

Matty W wrote:

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

Didymium filters have more effect on human vision than they do on most cameras. They filter out the yellow, near to the Sodium wavelength, and the narrow-band filters used in typical Bayer mosaics already have a gap there.

I have used a didymium filter a bit, but I was actually thinking something more similar to this:

https://enchroma.com

Which apparently is some sort of band pass filter. (Would didymium be a notch filter? I was never good at science.) If I remember correctly, the company started out when its creator noticed that microscopic imagining filters (or perhaps it was filters for viewing lasers) also enhanced color perception.

But this isn't exactly related to the OP's interest... in florescence primarily. So never mind; I think I'm after something slightly different (more perceived color saturation like with the "trichromatic back" using a color filter). But I'm curious about the OP's question, too.

I've been using didymium filters, and the variations "enhancers" blue, green, red, warming etc. I like them.

I think they all have a notch in the orange, where they do pretty much the same thing that the enchroma glasses are doing. Though there are other effects in the blue and green.

I haven't tried the other enhancer filters, but I suspect you're right.

What I thought would be really interesting is a narrowband (I don't know the terminology) band pass filter around each chromaticity, if that makes any sense. I used to shoot a lot of Velvia and loved the saturation and remember that its spectral acceptance curves (wrong term again, I'm sure, but it's been a while since I looked at the white paper) are very narrow, whereas bayer filters seem pretty broad to improve low light performance, and I know some even prefer the color of early dSLRs to newer ones...

Phase One/Sony's trichromatic back seems to aim at something similar, but I was wondering why not a filter that has narrow acceptance peaks around R, G, and B, and blocks light elsewhere? It would essentially work as an ND filter, but would also increase perceived color saturation dramatically.

Then again, maybe something similar is possible in post:

https://www.thebrim.pictures/vivid.html

I agree, I'm interested in increasing color saturation around the filters in sort of an analog way.  Or at least to see what it looks like.  I am also interested in doing the complement with orange, teal, and violet.

Some very narrow single band filters might be interesting, especially if it is in a range that is non-standard compared to the bayer filter.

I've been doing UV then IR photos, I think it really sharpens my perception of color to do sort of monochrome photography.

SmoothOperator wrote:

Matty W wrote:

SmoothOperator wrote:

Matty W wrote:

D Cox wrote:

Matty W wrote:

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

Didymium filters have more effect on human vision than they do on most cameras. They filter out the yellow, near to the Sodium wavelength, and the narrow-band filters used in typical Bayer mosaics already have a gap there.

I have used a didymium filter a bit, but I was actually thinking something more similar to this:

https://enchroma.com

Which apparently is some sort of band pass filter. (Would didymium be a notch filter? I was never good at science.) If I remember correctly, the company started out when its creator noticed that microscopic imagining filters (or perhaps it was filters for viewing lasers) also enhanced color perception.

But this isn't exactly related to the OP's interest... in florescence primarily. So never mind; I think I'm after something slightly different (more perceived color saturation like with the "trichromatic back" using a color filter). But I'm curious about the OP's question, too.

I've been using didymium filters, and the variations "enhancers" blue, green, red, warming etc. I like them.

I think they all have a notch in the orange, where they do pretty much the same thing that the enchroma glasses are doing. Though there are other effects in the blue and green.

I haven't tried the other enhancer filters, but I suspect you're right.

What I thought would be really interesting is a narrowband (I don't know the terminology) band pass filter around each chromaticity, if that makes any sense. I used to shoot a lot of Velvia and loved the saturation and remember that its spectral acceptance curves (wrong term again, I'm sure, but it's been a while since I looked at the white paper) are very narrow, whereas bayer filters seem pretty broad to improve low light performance, and I know some even prefer the color of early dSLRs to newer ones...

Phase One/Sony's trichromatic back seems to aim at something similar, but I was wondering why not a filter that has narrow acceptance peaks around R, G, and B, and blocks light elsewhere? It would essentially work as an ND filter, but would also increase perceived color saturation dramatically.

Then again, maybe something similar is possible in post:

https://www.thebrim.pictures/vivid.html

I agree, I'm interested in increasing color saturation around the filters in sort of an analog way. Or at least to see what it looks like. I am also interested in doing the complement with orange, teal, and violet.

Some very narrow single band filters might be interesting, especially if it is in a range that is non-standard compared to the bayer filter.

I've been doing UV then IR photos, I think it really sharpens my perception of color to do sort of monochrome photography.

I'd be really curious to see your results. This YouTube video doesn't offer much insight, but it got me thinking:

https://www.youtube.com/watch?v=E17pETy5jqI

I don't know enough about this to even imagine the difference between one narrowband filter and the next, but would be very curious to see your results if you get anywhere with this.

My goal was to emulate the Trichromatic back with a filter:

https://i1.wp.com/www.strollswithmydog.com/wordpress/wp-content/uploads/Phase-One-Color-Vision.png

I suspect the filter needed is contingent upon the sensor, however, and way more complicated than I could wrap my head around. It's not just whatever works for your eyes, as someone pointed out before. I believe every sensor has unique chromaticities based on the dyes used in the filter array, but I have no idea how you'd translate that into wavelengths. I heard from an acquaintance on the ACES board that the earlier Red cameras, for instance, have closer green and red chromaticities than other cinema cameras, resulting in a "ruddy" look. However, the new DXL Red cameras (and the newer ones in general) have better color rendering, and the first generation of DXL Reds had a proprietary OLPF that I suspect was doing something similar to what I want to do: filter out certain wavelengths to get a "purer" or at least more saturated signal.

But I studied liberal arts so I'm not the person to pursue this. The closest thing I got to IR photography was using one of those Sony "nightshot" camcorders.

Curious to see what you find, and I suspect your results will vary based on what camera you use, not just what filter. I think Edmunds Optics sells a lot of filters that might work for your purposes, but I'm out of my depth at this point:

https://www.edmundoptics.com/c/bandpass-filters/617/

Matty W wrote:

SmoothOperator wrote:

Matty W wrote:

SmoothOperator wrote:

Matty W wrote:

D Cox wrote:

Matty W wrote:

I've never tried it, but I did attempt to buy those color blind glasses (that are apparently just band pass filters) to see if they would make my landscapes more vivid.

Didymium filters have more effect on human vision than they do on most cameras. They filter out the yellow, near to the Sodium wavelength, and the narrow-band filters used in typical Bayer mosaics already have a gap there.

I have used a didymium filter a bit, but I was actually thinking something more similar to this:

https://enchroma.com

Which apparently is some sort of band pass filter. (Would didymium be a notch filter? I was never good at science.) If I remember correctly, the company started out when its creator noticed that microscopic imagining filters (or perhaps it was filters for viewing lasers) also enhanced color perception.

But this isn't exactly related to the OP's interest... in florescence primarily. So never mind; I think I'm after something slightly different (more perceived color saturation like with the "trichromatic back" using a color filter). But I'm curious about the OP's question, too.

I've been using didymium filters, and the variations "enhancers" blue, green, red, warming etc. I like them.

I think they all have a notch in the orange, where they do pretty much the same thing that the enchroma glasses are doing. Though there are other effects in the blue and green.

I haven't tried the other enhancer filters, but I suspect you're right.

What I thought would be really interesting is a narrowband (I don't know the terminology) band pass filter around each chromaticity, if that makes any sense. I used to shoot a lot of Velvia and loved the saturation and remember that its spectral acceptance curves (wrong term again, I'm sure, but it's been a while since I looked at the white paper) are very narrow, whereas bayer filters seem pretty broad to improve low light performance, and I know some even prefer the color of early dSLRs to newer ones...

Phase One/Sony's trichromatic back seems to aim at something similar, but I was wondering why not a filter that has narrow acceptance peaks around R, G, and B, and blocks light elsewhere? It would essentially work as an ND filter, but would also increase perceived color saturation dramatically.

Then again, maybe something similar is possible in post:

https://www.thebrim.pictures/vivid.html

I agree, I'm interested in increasing color saturation around the filters in sort of an analog way. Or at least to see what it looks like. I am also interested in doing the complement with orange, teal, and violet.

Some very narrow single band filters might be interesting, especially if it is in a range that is non-standard compared to the bayer filter.

I've been doing UV then IR photos, I think it really sharpens my perception of color to do sort of monochrome photography.

I'd be really curious to see your results. This YouTube video doesn't offer much insight, but it got me thinking:

https://www.youtube.com/watch?v=E17pETy5jqI

I don't know enough about this to even imagine the difference between one narrowband filter and the next, but would be very curious to see your results if you get anywhere with this.

My goal was to emulate the Trichromatic back with a filter:

https://i1.wp.com/www.strollswithmydog.com/wordpress/wp-content/uploads/Phase-One-Color-Vision.png

I suspect the filter needed is contingent upon the sensor, however, and way more complicated than I could wrap my head around. It's not just whatever works for your eyes, as someone pointed out before. I believe every sensor has unique chromaticities based on the dyes used in the filter array, but I have no idea how you'd translate that into wavelengths. I heard from an acquaintance on the ACES board that the earlier Red cameras, for instance, have closer green and red chromaticities than other cinema cameras, resulting in a "ruddy" look. However, the new DXL Red cameras (and the newer ones in general) have better color rendering, and the first generation of DXL Reds had a proprietary OLPF that I suspect was doing something similar to what I want to do: filter out certain wavelengths to get a "purer" or at least more saturated signal.

But I studied liberal arts so I'm not the person to pursue this. The closest thing I got to IR photography was using one of those Sony "nightshot" camcorders.

Curious to see what you find, and I suspect your results will vary based on what camera you use, not just what filter. I think Edmunds Optics sells a lot of filters that might work for your purposes, but I'm out of my depth at this point:

https://www.edmundoptics.com/c/bandpass-filters/617/

Edmund's is cool, but not quite for casual consumers.  I wonder if they could make a circular version of their linear variable filter.  A linear variable would be kind of cool to play around with too, I think it would help sharpen my sense of what color is in a scene.

https://www.edmundoptics.com/f/linear-variable-bandpass-filters-5fd8f505/14865/

petrochemist wrote:

Matty W wrote:

I haven't tried the other enhancer filters, but I suspect you're right.

What I thought would be really interesting is a narrowband (I don't know the terminology) band pass filter around each chromaticity, if that makes any sense. I used to shoot a lot of Velvia and loved the saturation and remember that its spectral acceptance curves (wrong term again, I'm sure, but it's been a while since I looked at the white paper) are very narrow, whereas bayer filters seem pretty broad to improve low light performance, and I know some even prefer the color of early dSLRs to newer ones...

Phase One/Sony's trichromatic back seems to aim at something similar, but I was wondering why not a filter that has narrow acceptance peaks around R, G, and B, and blocks light elsewhere? It would essentially work as an ND filter, but would also increase perceived color saturation dramatically.

Then again, maybe something similar is possible in post:

https://www.thebrim.pictures/vivid.html

I don't think the Bayer transmission has been made wide for low light performance. The bands chosen are chosen more for accurately determining colour. The Bayer colours having considerably less overlap than the cones in the human eye.

It you use narrowband filters you'll end up with some colours not detected at all.

My Dichroic filters are relatively broad band ones. My blue dichroic filter transmits 400-470nm while the average human apparently perceives 455-492nm as blue. So my filter will pass light seen to humans as violet, but not the bit from 470-492 humans see as blue.

Likewise my green dichroic filter transmits 515-570nm, while the average human sees 492-577 as green. Incoming green light from doubly ionised oxygen (common viewed in astronomy for OIII nebulae) at 496 & 501nm would not be seen at all.

With blackbody type illumination the absence of short ranges of wavelengths may not be too significant, but with elemental light sources (sodium lights, neon lights etc.) the light can all come in a very narrow band. Old type sodium lights gave well over 95% of their lighting between 588 & 590nm and many fluorescent lights have distinct spikes in their spectral power distribution.

Yeah, that makes a lot of sense. I suspect narrower transmission peaks would result in a punchier, more saturated look at the cost of sensitivity: comparisons of the Phase One trichromatic back with the normal Phase One back indicate as much, and Velvia has infamously narrow acceptance curves. So it makes me curious about more carefully engineered enhancer filters. I suspect the DXL OLPF on the DXL Red is designed with similar goals in mind and it seems to work well.

Of course, something like that would probably result in a less accurate image, too, and would probably have to be tailored to a specific sensor. But for certain landscapes it might be interesting. I miss shooting Velvia mostly.

Matty W wrote:

petrochemist wrote:

Matty W wrote:

I haven't tried the other enhancer filters, but I suspect you're right.

What I thought would be really interesting is a narrowband (I don't know the terminology) band pass filter around each chromaticity, if that makes any sense. I used to shoot a lot of Velvia and loved the saturation and remember that its spectral acceptance curves (wrong term again, I'm sure, but it's been a while since I looked at the white paper) are very narrow, whereas bayer filters seem pretty broad to improve low light performance, and I know some even prefer the color of early dSLRs to newer ones...

Phase One/Sony's trichromatic back seems to aim at something similar, but I was wondering why not a filter that has narrow acceptance peaks around R, G, and B, and blocks light elsewhere? It would essentially work as an ND filter, but would also increase perceived color saturation dramatically.

Then again, maybe something similar is possible in post:

https://www.thebrim.pictures/vivid.html

I don't think the Bayer transmission has been made wide for low light performance. The bands chosen are chosen more for accurately determining colour. The Bayer colours having considerably less overlap than the cones in the human eye.

It you use narrowband filters you'll end up with some colours not detected at all.

My Dichroic filters are relatively broad band ones. My blue dichroic filter transmits 400-470nm while the average human apparently perceives 455-492nm as blue. So my filter will pass light seen to humans as violet, but not the bit from 470-492 humans see as blue.

Likewise my green dichroic filter transmits 515-570nm, while the average human sees 492-577 as green. Incoming green light from doubly ionised oxygen (common viewed in astronomy for OIII nebulae) at 496 & 501nm would not be seen at all.

With blackbody type illumination the absence of short ranges of wavelengths may not be too significant, but with elemental light sources (sodium lights, neon lights etc.) the light can all come in a very narrow band. Old type sodium lights gave well over 95% of their lighting between 588 & 590nm and many fluorescent lights have distinct spikes in their spectral power distribution.

Yeah, that makes a lot of sense. I suspect narrower transmission peaks would result in a punchier, more saturated look at the cost of sensitivity: comparisons of the Phase One trichromatic back with the normal Phase One back indicate as much, and Velvia has infamously narrow acceptance curves. So it makes me curious about more carefully engineered enhancer filters. I suspect the DXL OLPF on the DXL Red is designed with similar goals in mind and it seems to work well.

Of course, something like that would probably result in a less accurate image, too, and would probably have to be tailored to a specific sensor. But for certain landscapes it might be interesting. I miss shooting Velvia mostly.

It seems that there are a number of less expensive one on ebay. It is difficult to figure out what exactly they are.

https://www.ebay.com/sch/i.html?_from=R40&_nkw=dichroic+filter&_sacat=0&_pgn=2

I am kind of interested in the ones that filter/reflect different wavelengths depending on the angle the light strikes it.

It seems that this is a property of all dichroic filters but also some do this more than others.

No Filter

Dichroic Filter Straight

Dichroic Filter Tilted

I think it was a fairly successful experiment.  I was trying to take advantage of the AOI property of the filter as an effect to control the light entering a wide angle lens from different angles.

I this filter said 460-90-2.  I'm not sure what that means, I kind of figured it out by looking at the pictures in the ad.     I think it filters 460nm light at 90degrees.  I white balanced the images, and shifted the image up with a shift adapter, but if you look at the one with the straight dichroic filter, you can see the bluish light increase from bottom to top as compared to the unfiltered.  You can see the one with the tilted filter, has the yellowish cast at the top and more like the unfiltered image.

I wonder if anyone has designed a tilting filter or maybe a filter sock to prevent reflections.

I think certain polarizing filters are dichroic already.