Color filters on deep-sky (was Re: (IAAC) Obj: M42)

>The Red filter (orion #25 red) pretty much hid everything from view.
>It is a deep red filter and I am still not sure what I am supposed
>to use it on since it seems to be too dark to actually see anything
>once the filter is added.

This has also generally been my experience, Mark, when using the commonly
available color filters: These are generally designed for observing very
bright objects like planets, so they have considerably low transmittance.

However, I have seen and heard hint of some very interesting observations
done with higher transmittance (and much rarer, and more expensive) color
filters. Our own Yann Pothier (if I recall correctly?) has tried various
unusual filters on the Planetary Nebulae he observes.

And if memory serves (and I might be confused as to identity) one Brian
Skiff has even tried using high transmittance color filters to observe a
Low Surface Brightness galaxy or two! Does anyone have access to logs of
such interesting observations, they'd be willing to share with us?

Take care,
Lew Gramer

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