Sodium Street lighting - Filter?

Wassup folks?

merry X-mas!!!

Anyone know if you can get a filter for sodium lighting? I love night shots, but everything seems to be polluted by sodium lighting these days? I've had no real luck compensating for it digitally.

Does such a filter exist?

The light is very red, so you could use the Tungsten setting in White Balance.

However, if you do filter out the effect of the lighting, you end up removing the very character of the light that makes a night shot attractive. It would be like "correcting" the light of a sunset to make it look like daylight. Is this what we want to do?

Personally, I would think around the positive side of it and alter the composition of a shot to include as much as possible of what I want to show and remove as much as possible of what I don't.

Just a thought!

depends... when lighting at night, I like to think in terms of how much ambient light you got, and how much light you need to add to a scene to get a shot with a particular subject...

for example, I might light a door frame with my car headlights, and set my color for that light source and let the rest go where it may..
or I may set a person in the scene and use srtobes to light them and set my color for the strobes...

also if I had to work with colored lightsource, I might wind up doin a custom white balance for the (usually red) sodiium light and add a red filter to my strobe then use the strobe to light or paint parts of the scene.



edited getting my flourecent and sodium lights mixed...need a coffee just got up

Hi there John. No the intention is not to turn a night shot into a daylight shot.

I'm staying at my Mum's at the moment ( christmas break ) and the streets here have more balanced, almost white, streetlighting, not the narrowband of sodium. I took some nightshots yesterday and they look amazing. Still got that great night shot character of course but not that hideous orange wash

You can't compensate for the sodium with a tungsten white balance setting. I think you'd need a filter that has the narrowband notches. Using a broad band EQ you end up getting rid of a lot of wanted info too.

Actually that's a though. It could perhaps be done in software. In the audio world you can all kinds of narrow band/notch filters. I wonder if such a thing exists for the light band?


Cheers for replying though.

Some interesting stuff here

http://www.nezumi.demon.co.uk/nonad/nonad.htm

more stuff here.

http://photo.net/leica-rangefinders-forum/00Ag04


Looks like a company called Singh-Ray makes one.




Singh-Ray Series 8 Lucalox Filter

I'm not sure though but that looks to me like a white balance filter.
If so then it won't have any useful effect with digital.

You could desaturate the yellow in post processing, it lose colour then but it should still have the same brightness (luminous?).
Problem is though that the yellow sodium light is the only light source so everything colours yellow since that's the only light a colour can reflect, so you could end with an almost black and white photo.

Lucalox is the General Electric trade name for Sodium Lighting

Not with you there. :

Indeed this is a problem. Although many of the shots I take have other light sources, tungsten, flourescent from shop/house windows/car headlights, etc,etc. It would require much longer exposures though.

I'm think I ight have to source one of these filters for the USA. It might not be cheap

I mean if they're a white balance filter then it won't have any effect on digital because you can change the white balance.

With film you were set on the white balance of the film so if you had day light and wanted to use it under tungsten then you need to shift the white balance from tungsten to daylight before it hits the film, you use a filter for that.

Here are some of those filters link
This is one halogen light to daylight link

Here is a nice article about artificial light and their colour link

I really don't believe that the Lee filter will work in such a way that you think, it looks like a filter for film to adjust the white balance no need for that on digital.

If I ain't clear enough I'm sure one of the veterans here from the film era can tell you all about them.

I know sodium light filters are available for telescopes to try and deal with the problem of light pollution. Maybe one of these could be made to fit a camera?? I don't know as I've never used one.

Ahhhh gotcha _ iwas confused was becuase obvisouly a filter in fron of the lens will affect the shot whether it's film or digital. But is rather pointless in digital.


The Singh-Ray Series 8 Lucalox Filter looks like it's made specifically for sodium given that Lucalox is the GE trade name for sodium lighting

but talking of Lee Filters, a photographer friend sent these linsk to me tonight ..

http://www.leefiltersusa.com/camera/products/show/ref:C4757E0C8560D4/

http://www.warehouseexpress.com/buy-lee-hps-d-specialist-filter/p1010747


However, from researcg so far, I think there's a big difference between HP and LP sodium lighting and HP lighting in that HP is more of a broadband EQ curve meaning that colour temprature change would probably cure it, whilst LP sodium is the nasty one with a few narrow band spikes.

I did come across some info on the light pollution filters for astronomy as Father Ted mentions.

After taking some shots in a village with a more natural street lighting I'm now driving around shaking my fist at Sodium street lights!!!

Cheers for the replies

maybe I should just wait for widespread use of LED lighting ??

http://news.cnet.com/8301-11128_3-10390656-54.html?tag=mncol;title

Smeggy, the lee filter is a colour correction filter for white balance for sure! It change the sodium colour to daylight.

The lee site has a big hint:
Film Type: Daylight (5500K)


And the colour looks precisely the same as the singh-ray so I really can not recommend them for digital.

Sorry I probably misinterpreted you as saying it was just a general white balance filter. I see what you are saying now.

Anyway the very idea was to notch filter out the very narrowband light from the sodium lamps in order to capture what's left. The filter won't change the scene to daylight as there is no daylight at night. As has already been pointed out there won't be much light left once the streetlights have been filtered out, but in many scenes there's still light from shop windows, car headlights, illuminated signs etc, etc

Unless I'm missing something I still dont' understand ( but am willing to learn ) ergarding it having no effect on digial.

previously you said :

I would have thought any filter has an effect on digital. After all the sensor simply captures waht comes thrugh the lens and a filter affects what comes through the lens.

I appreciate you can alter white balance post capture either in the camera or in a picture editing software but from waht I've seen so far these algorithms are broadband equalisers/filters.

The problem with sodium lighting is that it's colour spectrum is a very narrow band. So using normal methods you also get rid of wanted signal.

Here's an audio example. Lets say you have a music recording with bad mains hum on it .... A 50Hz sine wave is the most significant component in it's spectrum. Very narrow band. You could highly diminish it by turning down the bass control on the music system, but this will get rid of the bass out of the music as well. the tool is a very narrow band filter. Normally called a notch filter. I.e it removes 50Hz and ideally leaves 49Hz and 51Hz alone.

I have the tools in software for audio, but not for light. Mind you with audio you actually record the waveform so DSP using FFT techniques, etc can applied. with a still picture the light waveform isn't actually recorded but it's frequency and intensity is recorded.

Got me thinking now. I wonder if you could notch out a single freqeuncy of light from a photo. Hmmmmm?

Cheers

I used tungsten-to-daylight filters with film regularly and the results seemed far more predictable and satisfactory than setting the white balance to tungsten with digital. Sadly, I've lost my 80A filters so can't make a direct comparison now. The downside with filters is the loss of the couple of stops. Instinctively, I can see Smeggy's point but perhaps technology has overtaken us.

Al