Quote:
Originally Posted by AstralTraveller
Robert,
I think calling the difference between an 8" and a 10" 'a relatively modest increase in telescope aperture' is quite misleading. We both know that a 10" collects 1.56x more light than an 8" and I wouldn't call that a modest increase - it's over half a magnitude. I accept your point about weight and volume but I also understand that often the limiting factor is width of the back seat or length of the tray in a crew-cab ute.
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Sorry, AstralTraveller, I actually
didn't mean in my post that the difference in light gathering power between an 8 inch and a 10 inch is modest. I had both an 8 inch and a 10 inch for years, and I well know that the jump between 8 and 10 is significant for deep sky viewing. In fact, I wouldn't recommend anything under 10 inches for viewing galaxies, as galaxies have "a certain sameness" when viewed in an 8 inch.
There are people I know who do find the 8 inch Dobs a lot more "luggable" than the 10 inch Dobs, so I guess it all depends on the person and their requirements......
for instance, now that I am an older bloke and "my back goes out more than I do", my perspective on what is a moveable telescope has changed somewhat!!
There seems to be a split between those experienced amateurs who recommend an 8 inch Dob for a beginner and those who recommend a 10 inch Dob. This indicates to me that there are arguments for both of these options.
But I don't think any of us would think much of apertures under 6 inches for general Deep Sky and Planetary viewing by beginners, except for those extremist "refractor fanatics" who regularly crop up in these forums and who insist that their 4 inch Apo Refractor is all that they need.....but then this is hardly a mainstream view!
Best Regards,
Robert
In the 1980s, I used to have a 10 inch F6 Newt in a
heavy iron tube, on a beautifully machined and
very heavy german equatorial mount. I cut it down to F4, so that the tube could fit on the back seat of a small car!