Hi,
[warning, screwy questions below
]
I have been following the thread "
??????Increasing ED80 magnification????????", http://www.iceinspace.com.au/forum/s...ad.php?t=28833 ,
with interest.
If I had a choice between:
- skywatcher ED80, f/7.5
- orion ED102 f/7
- skywatcher ED100 f/9
What difference would the 900mm versus 700mm versus 600mm focal lengths have on the image, i.e. what difference in magnification would i see on the image? I would be using a DSLR at prime focus.
Should I be worried about the extra exposure time required for the skywatcher ED100 f/9 in light-polluted Melbourne skies?
Given the extra exposure time required for the f/9 ED100 over the f/7 ED102 telescopes, what effect would the skyglow, being an extended object, have on the final image? I am sure there would be differences between faint objects and stars. Also, LPS filters must make a difference. If I did not care about magnification of the image should I be worried about exposure time?
Would I gain much benefit in Melbourne (or in dark skies) by getting the Orion ED102 over the ED80? The magnification would be similar (700mm fl versus 600mm fl). In this case, will skyglow obscure the objects to be photographed given the ED102 has about 1.6 times the light-gathering power?
this would seem more coherent if I was speaking with someone...
this forum is great but sometimes voice communication would be easier. especially if the questions are screwy!
cheers,
DJDD