I do quite a lot of low light and night photography. One irritation is sodium light pollution. I have heard that there is a sodium filter available but I cannot seem to find a Cokin p type to do this. Any users cracked this one?

Interesting topic, subscribed. I don't do a lot of night photography but I typically adjust my white balance until I get a desired effect.

I have a custom WB for sodium light saved on most cards. Subjectively, I found 12 per cent gives more accurate rendition than 18 per cent. It's not a perfect solution, but gives you a start which you can further tweak in PP

Badgerballs wrote in post #12153708
I do quite a lot of low light and night photography. One irritation is sodium light pollution. I have heard that there is a sodium filter available but I cannot seem to find a Cokin p type to do this. Any users cracked this one?

What would the filter you have in mind do for you?

Anything that you can do with filters for "white balance correction" can be done more easily in software when working with digital images - especially if you shoot in RAW mode.

Sodium vapor lights, as well as other types of gas-discharge lighting, do not have a full spectrum of colors in the light. It's impossible to get all the colors in the subject (which might be seen in daylight or with flash lighting) to show properly when the subject is illuminated with sodium vapor lighting.

SkipD wrote in post #12153856
What would the filter you have in mind do for you?

Anything that you can do with filters for "white balance correction" can be done more easily in software when working with digital images - especially if you shoot in RAW mode.

Sodium vapor lights, as well as other types of gas-discharge lighting, do not have a full spectrum of colors in the light. It's impossible to get all the colors in the subject (which might be seen in daylight or with flash lighting) to show properly when the subject is illuminated with sodium vapor lighting.

Well I need to research this more as the information I saw was on an Astronomy program. A sodium filter apparently prevents the sodium wavelengths from entering the CMOS much the such as infra red filters. White balance adjustment will only change the colour cast to match your required preference. I am looking to remove the sodium light waves completely.

The problem with adding a filter in front of your lens is you can lose some image quality.. Also,, with any colour correction filter you will lose light entering your lens, and with lowlight photography, you need all the light you can muster..

This was a huge problem with film photography where to subject was lit by artificial light.. A 80A filter was usually used to convert tungsten light to daylight. An 80A has a filter factor of 4, which will reduce light transmission by 2 stops..

Today's digital photography is much easier where white balance adjustments can be done accurately either in camera or during post processing..

Just to add,, sodium vapour lighting has and always be a pain in the arse for photography..

When you take a picture on long exposure and have sodium lights around I have noticed you get a large haze appear around it. This is obviously where the light is being absorbed into the dust etc. The theory supports that if you can filter out the wavelength apparently 589nm them the lights would in my mind appear more defined and easier to remove in PP. I found this interesting link
http://www.astronexus.​com/node/4

Badgerballs wrote in post #12153866
Well I need to research this more as the information I saw was on an Astronomy program. A sodium filter apparently prevents the sodium wavelengths from entering the CMOS much the such as infra red filters. White balance adjustment will only change the colour cast to match your required preference. I am looking to remove the sodium light waves completely.

Yes, there are astronomy filters that will remove the sodium light. I've no idea what effect they might have on ordinary photography. As long as your scene had alternative lighting then it might work.

I've always fancied trying one of these Astronomik filters. Instead of going on the front of the lens they go behind the lens, in front of the sensor.

hollis_f wrote in post #12153971
Yes, there are astronomy filters that will remove the sodium light. I've no idea what effect they might have on ordinary photography. As long as your scene had alternative lighting then it might work.

I've always fancied trying one of these Astronomik filters. Instead of going on the front of the lens they go behind the lens, in front of the sensor.

Wow that looks interesting I will have to have a read of it. Yet another avenue of photography to explore. They are endless

Badgerballs wrote in post #12154325
Wow that looks interesting I will have to have a read of it. Yet another avenue of photography to explore. They are endless

Well, I gave in and ordered one - £110 from Rother Valley.

It does muck up the colours. Here's a colour chart without the filter -

hollis_f wrote in post #12175388
Well, I gave in and ordered one - £110 from Rother Valley.

It does muck up the colours. Here's a colour chart without the filter -

And with the filter...

Then with the filter and the white-balance set in Lightroom.

It looks OK with the WB set properly.


I'll try to get some shots taken tonight to see how it does with light pollution.

Hey so did you do a follow up to this? I would really like to see pictures, I know the thread is kinda old but very beneficial for me at the moment.

hollis_f wrote in post #12175388

Interesting to see the orange being removed. Orange becomes red, but yellow becomes orange.