Brown sky at night!
 

I've been experimenting with some long-exposure night shooting recently with some mixed results. One thing that I can't figure out is why I often get a brown cast, particularly to the sky. Sometimes it looks quite neat but I'd like to also be able to achieve the nice crisp colours as displayed in Yelvertoft's photos of the cloth hall in Ypres. Can anyone explain what is happening?

Thanks.

Sean

If you post an example of the effect you are describing, it would help in analysing what's going on. On first reading, light pollution from sodium lamp street lighting springs to mind but an example would help.

Thanks for the compliment on my shot. Apart from a bit of perspective correction, and subsequent crop, I didn't do anything with this shot, it's "as taken".

Duncan

Thanks Duncan. My shot of St Pauls is an example.

Sean

This is light pollution and is brown or really orange from low pressure sodium street lights. Duncans photo may have been more rural or lighting of the church may have overridden this pollution. I took almost the same St. Pauls photo and posted in the critique forum back in Feb 2006 with the same orange sky.

I agree with Stephen. You are recording the light from the city scattered from clouds and dust in the sky. The solution is to wait for a clear sky, then it will be black, at least in shortish exposures. Also, if you want a bit of colour, you can wait for a nice sunset. If you take a look at the postcards sold in central London newsagents you will see some good examples of this. Of course it is easiest if you live in London, as you can never be sure quite how the conditions will turn out. I suppose these days we should all be taking pictures close to home to avoid needlessly burning fuel.

The lighting in Ieper is far lower intensity than London, it's a small provincial town in rural Flanders. What you have in the St. Paul's picture is light pollution from the vast urban spread that is London. Even on a clear night, you are going to get the orange sky effect.

Sorry, there is no cure except to take pictures in less urban environments.

Duncan

Some years ago I took some pictures of the Houses of Parliament and Big Ben at night with a clear sky and the sky came out black. I've attached two examples. They are not particularly good pictures, but they are quite good illustrations of technque. The first was taken long after sunset, and the sky is black. Any colour in the sky is electronic noise from the scan and is not present in the slide. (Yes this was pre-digital.) The second was taken just after sunset, and the sky has some colour. If you are really lucky you can get a lovely red sunset as the background. Sadly those are quite rare.

The air will be cleaner on a fine night after rain but light pollution will still be there. Its often recommended to shoot while there is still a bit of light in the sky as per yelvertofts second shot i.e. at dusk rather than when it is truly dark. I think a that makes for a more interesting shot but it makes the photography more weather dependant.

It was Leif who took the two pictures above, not I. And very good they are too.

I wonder how much difference there is with digital vs. film in picking up the orange tint? I've shot many cityscapes on film at night. I've just gone and had a look at one hanging on my wall, it has negligible orange glow.

Sorry to have given the credit to the wrong person Leif. Yes they are very good shots. Interesting question, you would have to set up a film and digital camera up side by side so the conditions were identical. Different films would make a difference too so its a bit complicated!