DSO Imaging and filters

[Rossco72]

Apologies if this has been asked hundreds of times already but is a filter essential for good DSO imaging and if so does anyone have any views on the best one(s) for nebulas?

I see broadband filters, narrowband filters OIII filters, UHC etc.

All thoughts appreciated, all knowledge is useful.

Cheers

[Psychobilly]

Hi Rossco,

What camera are you planning on using?

Peter...

[brianb]

is a filter essential for good DSO imaging and if so does anyone have any views on the best one(s) for nebulas?

Essential, no, but if you have significant light pollution, very helpful.

The "best" filter depends hugely on the individual nebula being imaged. For galaxies, IMO the best filter is a broadband deep red used with a camera with extended red sensitivity. For planetary nebulae, narrowband OIII usually works well. For hydrogen emission nebulae, narrowband hydrogen alpha (for a camera with extended red sensitivity) or hydrogen beta (for those that don't).

All the above assumes monochrome imaging. If you want to make "single shot" colour images, try the ordinary CLS, which will knock back the light pollution with minimal colour shift. It helps to some extent, but not as much as narrowband filtering. The B+W 491 "Redhancer" is also useful for camera lenses when you can't find a CLS to fit, assuming your camera won't take a "throat" filter.

[Rossco72]

Thanks, I have to admit, most of that went way over my head!!

At the moment I have a Canon 5D DSLR and a basic Neximage webcam. I may fork out eventually for some dedicated CCD Astro kit but right now I am still recovering from the open wallet surgery of buying my scope and mount

Anyway for the time being if a reasonably inexpensive filter would help my fledgling attempts then I might give it a go before moving up a level next year probably (Assuming no lottery win!!)

Regards

[Psychobilly]

Ok so its the Canon 5D connected to the FLT with a t ring - 2" nosepiece adaptor?

Whats the LP like at your site...?

[Rossco72]

I have a T-Ring for the 5D and both 1.25 and 2" adapters. I also have a 32mm Eyepiece which can be screwed into the T-Ring and I have used that on occassion to get some "zoom".

I travel to a generally dark site in the local hills. I use a slight valley at the top which protects me from direct light pollution but there is a faint glow to the south from the city and at my northerly latitude there is a permanent glow to the north from the sun during summer.