Should I buy a light pollution filter?

[Hefty_Texas]

I live on the wirral in the UK, and despite my part of it being semi rural I'm probably about 10 miles from the city of Liverpool, as you can tell my night sky is not exactly dark. Don't get me wrong I do quite alright for myself. I have seen many a faint object using my 8 inch reflector but as I was not using it as regularly as I should I buy a small 3 inch one.

I do have a 5 inch that I want to add a view finder too (the celestron astromaster has the worst red dot in history) so for now it's the 3inch

I was wondering if it would be worth buying a light pollution filter for general viewing. I have read that these do not completely block out bad lights, but would they help? I have read all over the internet and got some really conflicting information.

I do want to look at fainter objects but would a filter help with just looking at stars and planets? 

Cheers guys 

[RT65CB-SWL]

Hi Hefty_Texas and welcome to SGL. 

With regard to light pollution filters, they are only efficient with the 'old'/sodium streetlights as the 'new' LED streetlights have very little or no effect. You could consider the Baader neodymium filter. I call mine the 'Swiss Army knife filter'. You could consider a Baader contrast filter too! 

Link here ---> https://www.firstlightoptics.com/light-pollution-reduction/baader-neodymium-filter.html

...and here ---> https://www.firstlightoptics.com/achromat-semi-apo-filters/baader-contrast-booster-filter.html

 

[Ben the Ignorant]

Hello.

Yes, they work. They are obviously not perfect because nothing is, but they help a lot. I'll let you in a little secret: some binoculars are threaded for filters, and those filters being sold in pairs, they cost less per unit. Best of all, their threads are the same as telescope eyepiece threads, so you and maybe a friend can try these:

http://shop.tecnosky.it/Articolo.asp?SessionID=CCA0EFBF-F704-429E-8C06-00D17F59ADD9&GetInfo=RPOo3&AddScore=RPOo3&Score=1

http://shop.tecnosky.it/Articolo.asp?SessionID=EA70EE7A-BCA4-4510-A1BD-B8591191075E&GetInfo=RPOuhc&AddScore=RPOuhc&Score=1

35€ for each light pollution filter is a bargain if you accept buying them in pairs, I believe they cost at least 50€ each anywhere else (Tecnosky has an english version).

 

 

[Ricochet]

I've got a neodymium filter and while it can be used to increase contrast on the moon and Jupiter I see no use for it at all as a light pollution filter under any sort of lighting. I've also got an Astronomik CLS which on certain targets under certain conditions can be useful but is not a magic bullet that can be left in the focuser at all times and will not replicate getting away from the lights. If the objects you are looking at are open/globular clusters then the best filter (aside from a tank of petrol) is probably just more magnification. So long as you keep the exit pupil over 1mm in order to limit diffraction and maintain the brightness of each individual star, more magnification will darken the background sky and increase contrast. UHC and OIII filters are the best to get for nebulae and will be useful useful from both light polluted and dark sites.

[Hefty_Texas]

Thanks for the advice guys. I'm pretty sure the lighting round mine is the old type as all street lights have that orange glow to them. I understand that using a filter will not whisk me a hundred miles from civilization but I think I'll still get one especially as it's Christmas coming up and my girlfriend is undecided on what she will get me ?

[Dave In Vermont]

If you only want a filter to block the 'orange sodium-lights,' I'd suggest an Orion Skyglow Filter, assuming you're in the US:

https://www.telescope.com/Orion/Accessories/Telescope-Eyepiece-Filters/Orion-SkyGlow-Broadband-Light-Pollution-Filters/rc/2160/pc/-1/c/3/sc/48/e/3.uts

But filters are good for much more than partially blocking troubling outside lighting. If you tell us about what variety of telescope you have, we can help you more as this will give a better idea of which filters are best for your size of instrument. Try a walk through this article at your leisure:

Filter Performance Comparisons For Some Common Nebulae - by Dave Knisely.pdf

Enjoy -

Dave

 

ps - Oops! I missed you're in the UK <face palm>, anyways, the Skyglow is a good type of filter for annoying sodium-vapor lighting.

[Hefty_Texas]

I own a skywatcher explorer 200p goto

Great scope but a bit of a pain to set up as it's rare I have the time to get it out

Celestron astromaster 130mm I'm replacing the awful red dot with a better spotter so can't really use it until I've done the work on it

Meade Polaris 76mm. Despite being bought from pc world and being a lot smaller then my skywatcher. I've really been enjoying using it especially as I can have it set up in 10 mins

I have replaced all bar the 26mm eyepiece. I do have:

8mm BST Explorer starguider ED

6.3mm possl

celestron x-cel lx barlow X2

I want to get a 32mm to replace the stock 26mm 

[willinliv]

Did you end up getting a filter?

[laowhoo]

On 10/18/2017 at 04:26, Dave In Vermont said:

If you only want a filter to block the 'orange sodium-lights,' I'd suggest an Orion Skyglow Filter, assuming you're in the US:

https://www.telescope.com/Orion/Accessories/Telescope-Eyepiece-Filters/Orion-SkyGlow-Broadband-Light-Pollution-Filters/rc/2160/pc/-1/c/3/sc/48/e/3.uts

But filters are good for much more than partially blocking troubling outside lighting. If you tell us about what variety of telescope you have, we can help you more as this will give a better idea of which filters are best for your size of instrument. Try a walk through this article at your leisure:

Filter Performance Comparisons For Some Common Nebulae - by Dave Knisely.pdf

Enjoy -

Dave

 

ps - Oops! I missed you're in the UK <face palm>, anyways, the Skyglow is a good type of filter for annoying sodium-vapor lighting.

Definitely helps for us, and I've since switched to these for lunar over our moon filters.