Questions regarding ATM

Hi!

I hope you don’t mind me asking two questions, regarding amateur
telescope making:



1. How... Ineffective or less “good” is a 6 incher from an 8 inch mirror?

[6 Inch with a F/8 ratio, or 8 inch with a F/6 ratio, hence focal length
isn’t significant].

I am aware that there will be an “effective magnification”

drop from 400x to 300x, but I am unsure as to how that may affect
planetary observing? [I know that aperture is more important, but is say,

240x with some knocked off cos of seeing enough?]

I know that brightness and light gathering will be less for DSO and
planets, but how significant is this? [I.e. 6 inch vs. 8 inch, how much
would I lose? Cos I was gonna make a 8'' but the cost seemed too high for

me, so how sufficient is a 6''? ]



I am also aware that light-gathering and brightness would be reduced in
the 6 inch, but for a first telescope making attempt, is a 6 inch, f/8
too small or insignificant for observing of the cosmos? [Would one be
able to see clouds on Jupiter [small, of course, not like Voyager! ] and

Saturn’s ring(s)]? N.B. I am aware that DSO won’t be in colour or like
pics in books etc. cos of the human retina etc., just wondering how a
planet would look like through a 6 incher].



2. Secondly, I have heard folks comment [and the FAQ!] that making one's
own mirror for cost isn't a good reason for small uns.

Well, I did some comparisons, and found a 6 incher mirror would
cost about £150 to buy, whilst to make it would cost:

£~75 [incl. p+p], including £23 for aluminising + p/p,

£23 for a mirror "kit" [pitch, grit etc.], and £33 for blank incl. p+p+,
roughly]



Well, putting aside labour costs, it seems there is a significant saving?

[If I made an 8 inch one, it would be £40 more tho.]

Have I missed something out significant here in the mirror making
stuff? I know that I'm missing the Tool, but would one be able to make
one cheaply at home?


Any advice would be much appreciated.



Thanks in advance.

#MK.