"Florian" wrote in message ...

The one object i find that really benefits from a UHC
filter is M76, the Little Dumbbell in Perseus. M76 is almost invisible
through my home skies without the filter but with the UHC the nebula
becomes quite easy. Almost bright! ;-)

I think that depends on the size of your scope. In my 70mm scope, M76
is a pretty faint object even under dark skies, and bright skies make
it marginal indeed. So M76 is definitely easier to find from the city
in my 70mm scope when I'm using a filter. On the other hand, filter or
no, the 70mm scope isn't *quite* big enough to show interesting detail
in this object -- it looks elongated, but that's that.

The story is completely different in my 7-inch Dob -- which *is* big
enough to give a very interesting view of M76, city or country, filter
or no filter. Due to its extremely high surface brightness, M76 jumps
right out in that scope even when I'm viewing from the city, even
at very low power. Under dark skies, the filter gives a *different*
view of M76, but I wouldn't necessarily say a better view. Parts of
M76 that show well without a filter become fairly obscure with one,
and vice versa.

So I would say that this is a case, as with other small bright
planetaries, where a filter makes the object easier to find but
not necessarily better to view. And in a scope big enough to do
the object justice, it's pretty easy to find even without the
filter.

- Tony Flanders