LP filter for imaging?

[ianpwilliams]

Would it be worth me buying this light pollution filter for imaging with the 130PDS and Canon 1100D:

http://www.firstlightoptics.com/light-pollution-reduction-imaging/baader-neodymium-filter.html

I know that there are more expensive LP filters on FLO, but I would be reluctant to spend hundreds of pounds on something when I don't know if it would help or not (and this one is £80 for the 2" as it is).

[jambouk]

I've found for shorter exposures (60 seconds) it works well, but I've always been a mile or two outside of the city centre. In the actual dome or looking into the LP dome, and for longer exposures, it might not be as effective. I think they are pretty easy to sell if you find it doesn't do what you want it to do.

Good luck

James

[ronin]

It is very difficult to give a specific answer to LP filters.

When the LP was a nice yellow/orange glow it was much simpler - get a simple filter that blocked the sodium yellow lines, and to an extent blocking those was easy.

We now have lights emitting a whole range of wavelengths and that means each one has to be blocked and that is not possible - unless you leave the front cap on.

The one given blocks at 5700 to 6000 A, and also at 5200 to 5400A (not fully blocked here), the other big block is up at 7400 to 7500A but this is IR

Here is a link to the filter transmission curvers the Baader is down at the bottom, the "link" internally seems to go one past the transmission curve so read the title: FilterCurves

If you are a member of a club then ask people there, they will suffer from the same LP as you do, but different people will have differing opinions also. Asking here is somewhat haphazard, I still have lots of the old sodium lights around, you may not. In effect diffiernt locations have different forms, or balances, of LP.

[Uranium235]

Id describe the Neo filter as "alright", perpaps even useful as a combined LP/UV/IR blocker.

However, spending a bit more will give you something with much better rejection properties. The standout two are the Astronomik CCD CLS, or the Hutech IDAS.

[ianpwilliams]

Yes it's tricky. I'm 2 miles East of Edinburgh city centre, so there's an orange glow to the West. There's a small stadium to the East with white floodlights which are sometimes on. And there are various buildings more locally which have various lights on in their windows. So there's a lot going on, so I'm not convinced that a filter would help. Having said that, on a clear night I can see a lot of stars, so I am hopeful that I might be able to take some decent images with post processing, especially having seen some of the before and after light polluted images on these forums.

So I'm thinking maybe I'll give an LP filter a miss for now.

[wxsatuser]

I'm using both the Hutech P2 and the Astronomik cls clip both do a good job here on LP.

I have orange glow nearly all round, Gatwick/Horsham north east, Brighton and Worthing SE to SW.

We have just had our streetlights changed to compact flourescent, I can see more Milky Way now

but the overall sky is orange, so the LP filters stay on.

I also have football field floodlights that are just about 100yards away, lucky they are not on all the time.

This is the LP here with a 15sec exposure no filter,  the orange is slightly enhanced here by some thin cloud.

[lensman57]

Would it be worth me buying this light pollution filter for imaging with the 130PDS and Canon 1100D:

http://www.firstlightoptics.com/light-pollution-reduction-imaging/baader-neodymium-filter.html

I know that there are more expensive LP filters on FLO, but I would be reluctant to spend hundreds of pounds on something when I don't know if it would help or not (and this one is £80 for the 2" as it is).

I have this filter as well as Idas D1 and P2 and also a couple of UHC-s filters. If your LP is low to moderate and of the old yellow orange variety then the Neodyminum filter will work. I live and image from an extremely heavy LP zone and the Idas filters do better but by no means they can filter out the new LED lights that are proving a menace. In general the Idas filters are more useful but also a lot more expensive. I also use my UHC-s filter on most of the emission nebulae, this one can work as well as the Idas or even better with the caveat that your exposure times are much longer and the filter is of no use with planetary imaging.

A.G

[DaveS]

I've got orange streetlights around me, but there are hp sodium and I think bb lights as well. Between IDAS P2 and Astronomik CLS I think the latter does a better job, but that's been mainly looking at the orange cloud through them. Looking at one of the local lp sodium lights, the CLS knocks it out completely whereas the IDAS still shows some orange colour.

[jambouk]

Here is a 10 minute sub i took the other night with the baader filter on the 6D at iso 800, the first time i'd guided, and clearly i need to try the CLS filter clip next time.

James

[ianpwilliams]

Ave you tried processing that image James? I don't know how to do it myself, but I've seen some amazing before and after light pollution shots.

[DaveS]

How many subs did you take? Stacking and processing could make a big difference.

But, yes a CLS filter can work wonders.

[lensman57]

I've got orange streetlights around me, but there are hp sodium and I think bb lights as well. Between IDAS P2 and Astronomik CLS I think the latter does a better job, but that's been mainly looking at the orange cloud through them. Looking at one of the local lp sodium lights, the CLS knocks it out completely whereas the IDAS still shows some orange colour.

The transmission curve of the Astronomik CLS CCD is very close if not identical to a Baader UHC-S L booster. Infact the CLS is a nebula filter the CLS CCD is also IR blocked. I think that the Baader is the cheaper option.https://www.google.co.uk/search?q=astronomik+cls+clip+filter+transmission+curve&biw=1366&bih=641&tbm=isch&imgil=Q10lbF0Jc6hJkM%253A%253BNn-kqDm1BvusmM%253Bhttp%25253A%25252F%25252Fwww.astronomik.com%25252Fen%25252Fphotographic-filters%25252Fcls-ccd-filter.html&source=iu&pf=m&fir=Q10lbF0Jc6hJkM%253A%252CNn-kqDm1BvusmM%252C_&usg=__j7aLFlTEgg5qiTen_x9eGPpjszY%3D&ved=0CEMQyjc&ei=9xBNVMyNLMHW7AbJ74D4BQ#facrc=_&imgdii=_&imgrc=Q10lbF0Jc6hJkM%253A%3BNn-kqDm1BvusmM%3Bhttp%253A%252F%252Fwww.astronomik.com%252Fmedia%252Fproduktabbildungen%252Fastronomik%252Ftransmission%252Ffull%252Fastronomik_cls-ccd_trans.png%3Bhttp%253A%252F%252Fwww.astronomik.com%252Fen%252Fphotographic-filters%252Fcls-ccd-filter.html%3B800%3B618

A.G

[toxic]

i have the baader UHC L booster filter with the eos 1100D not modded and it will cut out the lp of hp sodium and lp sodium and to some degree mercury but wont touch l.e.d lights i am so lucky that i have all the above lights around our street.as lensman57 has mentioned you will need to up your exposure time with the baader uhc l but i have found that the red and blue colors are enhanced but not the green when used with the 1100D. i have the skywatcher lp filter as well but it works only on the orange lp.never had the other lp filters so i cannot coment on them.it a shame you cannot borrow 1 to try out.

[DaveS]

From what I recall, the Astronomik CLS has a wider bandwidth than the UHC which is tailored more to [OIII] and Ha. Both will block sodium light but the CLS lets more useful light through.