Magnitude

[Redscouse]

Evening all.  

Is there a scale somewhere I can use for magnitude v telescope (or size of)

IE:

6" Newt = mag 5
10" Frac = mag 8
etc. 

or can anyone put a quick guestimate together for me pls?
Reason for asking is Stellarium. I'd like to hide the things that I can't (nor will ever) see through my current scope and then change accordingly as/when I upgrade.

Thanks.
Pete.

[MarsG76]

have a look here 

http://www.twcac.org/Tutorials/limiting_magnitude_table.htm

 

and 

 

http://www.nature1st.net/bogan/astro/optics/maglimit.html

 

[Redscouse]

Thanks Mars.  

[laowhoo]

 

Probably my favorite online calculator

http://www.stargazing.net/naa/scopemath.htm

gives you lotsa good things, including theoretical limiting magnitude for stellar objects, brightness factor for extended objects, theoretical resolving power of seconds of arc, and more (theoretical size of moon features, etc.). Just plug in your aperture, focal ratio and EP.