Dichroic/Microscope Florescence Filters

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/