Light Pollution Filters

[Robny]

I've done a bit of research ahead of writing this, but just wanting to know peoples thoughts directly before make a purchase.

I'll be using a cooled 183c OSC camera in bortle 8 skies, predominantly with LED street lighting, I'm looking for good light pollution filters and have narrowed it down to these two on FLO's website (most likely buying both):

IDAD D2 : Optolong L-enhance

I would use the IDAS for reflection nebula and galaxies, the L-enhance I would use for my NB nebula targets etc, maybe can even combine them in post not stack both filters  

Does this seem reasonable or am I leaving something on the table.  Anyone used or have experience of these with a similar setup and conditions.  Should I be worried about reflections with either of these, bloated stars, bad colour etc.  I'm ready to buy just want to make sure I'm not missing something.

Thanks as always

Rob

[Phillyo]

Any particular reason you're going with the L-enhance over the L-extreme, especially for Bortle 8 skies? No judgement, just curious.  

[Nigella Bryant]

I use the IDAS D2 excellent with the local LED lights, but I'm bortle 3/4 so not as much light pollution. 

[Robny]

14 minutes ago, Phillyo said:

Any particular reason you're going with the L-enhance over the L-extreme, especially for Bortle 8 skies? No judgement, just curious.  

Purely based on cost, I know if I only had one filter I could most likely get it but I want the option to shoot both bands.

[Robny]

5 minutes ago, Nigella Bryant said:

I use the IDAS D2 excellent with the local LED lights, but I'm bortle 3/4 so not as much light pollution. 

I know, im going to be battling what ever I buy, but just want something that will give me a fighting chance...lol

[nfotis]

My understanding is that a combination of monochrome sensor and narrowband filters is the easiest way under bortle 8 skies (and the more costly, unfortunately).

These dual and tri-band filters are a different approach. Best of luck, anyway.

N.F.

 

[Seelive]

I image from a Bortle 5/6 sky.  All local street lighting is LED, but unfortunately due south of me is the local town and a very large industrial estate (and I've no idea what lighting they use!).  Here's a couple of unprocessed single frame images of Orion taken a few days apart back in February this year when it was approximately due south.

This was taken without any filters (60 sec with a 50 mm lens at F2.8):

 

And this was taken using an IDAS D2 filter:

The most obvious difference is the colour shift (which can be corrected in post processing) and I suspect that the local LED light pollution has been mostly removed by the filter leaving the more distant light pollution from the unknown sources.  However. I don't think that the filter is particularly suited to be used at such wide apertures as reflections appeared on stretched images, so in the end I used the unfiltered images. This is the 75 x 60 sec unfiltered images with my unmodified Canon 200D at ISO1600.

[Robny]

26 minutes ago, nfotis said:

My understanding is that a combination of monochrome sensor and narrowband filters is the easiest way under bortle 8 skies (and the more costly, unfortunately).

These dual and tri-band filters are a different approach. Best of luck, anyway.

N.F.

 

Your understanding is correct and I'm changing from mono to OSC, due to time restraints, family, work and weather.....for the time being.

Just sold all my mono stuff and going back to OSC

[Robny]

9 minutes ago, Seelive said:

I image from a Bortle 5/6 sky.  All local street lighting is LED, but unfortunately due south of me is the local town and a very large industrial estate (and I've no idea what lighting they use!).  Here's a couple of unprocessed single frame images of Orion taken a few days apart back in February this year when it was approximately due south.

This was taken without any filters (60 sec with a 50 mm lens at F2.8):

 

And this was taken using an IDAS D2 filter:

The most obvious difference is the colour shift (which can be corrected in post processing) and I suspect that the local LED light pollution has been mostly removed by the filter leaving the more distant light pollution from the unknown sources.  However. I don't think that the filter is particularly suited to be used at such wide apertures as reflections appeared on stretched images, so in the end I used the unfiltered images. This is the 75 x 60 sec unfiltered images with my unmodified Canon 200D at ISO1600.

Interesting....thanks for that, my scope is GT71 at 4.9 so hopefully that won't be an issue 

[Seelive]

I suppose your choice of filter will ultimately depend upon if you're looking to get 'tri-colour' (RGB) images or just 'bi-colour' (Ha + O3) images.

[rnobleeddy]

I asked a similar question and came to the conclusion that

 

- the IDAS is probably the best general purpose light pollution filter. I have a CLS CCD which works fine but doesn't have the LED street light blocking

 

- the dual or triband narrowband filters should probably be considered as a little more than simply light pollution filters as they're a more fundamental change in what you're doing. They do work well in light polluted skies however. I didn't see anyone suggest the additional pass band in the tri/quad filters added significant signal so I'd go for the dual band if you can afford it. The dual band filter should get you some way towards what you'd see with mono + single band filters but no one is going to claim that OSC + dual/Tri band filter is better!