Multi use filters

[Moonshane]

I thought I'd start this thread to encourage people to experiment with filters and report back their findings.

My own experiences have indicated the following:

Baader Neodymium - many people think of this as a light pollution filter but although I live in an area which is bad for LP, I don't use it for this. I do use it for lunar observing when 50% or more of the surface is illuminated and find it provides lovely contrasty visual images. I find it reduces the scatter of light around the moon too, enabling some objects to be detected and enjoyed even when quite close to the lunar glare.

I also use it for Jupiter where it is quite effective in increasing contrast between the different cloud bands and Mars where I consider it essential to increase surface contrast and detail.

Oiii

As an experiment I thought that an Oiii filter being a very narrowband filter like my Baader Solar Contiuum filter, might provide the same sort of result. I was quite happy that it did seem to increase contrast of solar features and also reduce the glare which is present even with the required solar film filter - I Use Baader Solar film. So whilst the Baader SC filter does provide slightly better detail, if you don't have one (but have an Oiii) and want similar results then try your Oiii.

UHC

Similar to the Oiii for solar use but possibly slightly better detail and actually eaier to use than either the BSC or the Oiii as there seem less issues with eye placement.

Baader Solar Continuum

Certainly me best secondary filter for solar use but not by much, I suspect this will provide a steadying effect on the moon and provide good detail but not tried it yet.

Share your own experiences and recommendations!

[Naemeth]

Hm... any experience with the Variable Polarising filter on a Solar Film filtered scope, it may help reduce the glare and perhaps provide better contrast.

There is also this.

[Steve Ward]

I use an OIII filter with Baader ND3.8 film for my Solar photography.

I find it gives a little more detail on the surface ,

It's main benefit is that it seems to even out the overall brightness of the disc , reducing the overdark lower edge I get sometimes if I have to get creative with settings due to the cloud etc.

A purely accidental discovery on my part caused by forgetting to remove at the end of a night session.

[GlassWalker]

Astronomik IR742 (742nm longpass) - I originally got this for terrestrial use, but Astronomik sell it as aiding imaging as IR wavelengths are supposed to be less affected by seeing. I haven't tested their claims yet.

Unbranded 850nm IR longpass from ebay - I got this for astro use, although haven't significantly tested it out yet either. The idea of this one was as an alternative to regular light pollution filters. Low pressure Sodium has a significant spike in the IR region at 818nm, so by using a 850nm longpass we avoid that. Of course it also depends on what wavelengths the subject gives out... haven't figured out what to use it on yet, but looking at star fields in IR makes them quite different in relative brightness compared to visible.

Baader CaK - originally sold for solar imaging. For terrestrial imaging use, I find it can be used to get the insect's view UV effect on flowers. That's where you get a dark core and light outside yet with human visible light you don't get that.