Re: (IAAC) Obj: IC 1296 - Inst: 200mm Newt F5

In a message dated 8/29/01 3:49:47 PM Eastern Daylight Time, 
graywwoolf@msn.com writes:

<< Since our eyes are more blue/green sensitive to the light output of most 
nebulous objects, OIII lines of emission, we can see about 1.5 to 2 
magnitudes brighter than the published photographic magnitues. >>


I assume what you mean is that most nebulous objects will appear to our eye 
to be 1.5 to 2 magnitudes brighter than their photographic magnitudes would 
indicate. And I tend to agree with you. I find that many nebulae - especially 
planetaries - with only a photographic mag. published are far easier to see 
than one would expect. Adding the appropriate filter (normally an OIII) 
usually helps, but not always. Many high contrast nebula like M57, for 
instance, look best with no filtering, whereas more diffuse objects like M27 
or even M76 look much better through the OIII.

Doug Stewart
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