what is the best Light pollution filter for me?

[sambarber]

Ive got a 70mm refractor with a short focal length. im an astrophotographer. most of my images aquired get washed out in light pollution when i stack them. ive been looking for the best filter to help me with this problem. the baader Uhc-s nebula filter looks nice. all i need are some nice opinions on this topic. thanks!

[ronin]

I have no idea what lights are used in the US, however unless your problem is with the yellow sodium lights then there is likely little that you can realistically do.

The yellow sodium lights were "convenient" in their manner of pollution, they emitted in a narrow set of bands (2) and so removing these 2 sections of the spectrum was releatively easy. If however you have pollution that  is more relevant to the "white" light then you cannot remove that as the light you want is part of the spectrum, so you remove the light from the object.

About 2 years back there was a lot of talk of the lower pollutions caused by the new LED street lights, they were going to be "the solution", however they are in effect "white" and light from them cannot be removed and are now "the problem".

I do not know about the advantage of a nebula filter, but cannot see them doing a great deal. it really does matter what wavelengths are the cause of the pollution. Also it removes wavelengths meaning the exposure  length or number has to increase, which effectively means you collect more light pollution.

I would have thought the idea of a nebula filter was the pass the major nebula wavelength and block the others that occur just outside of these, so boosting the apparent contrast, I say apparent as if you block 20% of the nebula light and 50% of the other then the contrast should go up. None of this says light pollution wavelengths.

A simple question: Are nebula filters intended for visual or imaging? As the eye and the camera work differently, they may be useful for visual but by the time everything is summed in a camera no advantage may occur.

One post I recall from the US asto forum was that it was said the only filter that seemed to be of some use and so worth considering was an O III.

Now all this is based on very little direct experience as I do not bother with filters (at least so far) and I do not do any imaging.

[wuthton]

My experience of light pollution filters with photography has been quite poor. All colours washed out to shades of blue.

Shorter exposure times and address the light pollution in post processing is the best way to go in my opinion.

[michaelmorris]

I've been using a Hutech IDAS LP2 filter on my Canon 1100D for over a year and cannot speak highly enough of it. I can now take 10 minutes subs of the Veil Nebula from my light polluted back garden in Worcester. The subs require very little colour balancing. The only downside is the £200 price tag (but well worth it in my opinion).

Sent from my Nexus 7 using Tapatalk

[lensman57]

Ive got a 70mm refractor with a short focal length. im an astrophotographer. most of my images aquired get washed out in light pollution when i stack them. ive been looking for the best filter to help me with this problem. the baader Uhc-s nebula filter looks nice. all i need are some nice opinions on this topic. thanks!

Hi,

As Ronin has already mentioned, unless your LP is of the good old fashion yellow sodium light variety then you are out of luck, LP filters do not work if you have white light pollution. You may wish to give Baader UHC-s L Booster a try and see if it makes a difference. It works for me as a nebula filter as well as a narrow band LP filter but your mileage may vary, if it doesn't work you can always sell it on as these are popular. In the end there is no substitude for real dark skies.

A.G

[ronin]

No idea how good or bad this is, and I suppose it could be another filter under a different name, but there is a "CLS" filter around.

CLS = City Light Suppression.

Optcorp seem to be the only US supplier I can see, whereas there are several over this side.

[SkyGibbon]

Astrnomik cls filter, or go narrowband.