Observing Log for 2005-07-09
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2005-07-09


Location: Billingborough (South Lincolnshire, UK)
From: 2005-07-09 20:45 UT
To: 2005-07-09 21:14 UT
Equipment: Cheap Telescope
Notes:

Test of a very cheap "spotting scope" type telescope against Jupiter. As with other recent observations of Jupiter this was done when the sky was still light due to the fact that Jupiter disappears from view quite early for me now.

There was quite a lot of high-level cloud kicking about so this session didn't last very long. I did want to get the 130M out as it got darker but it wasn't worth it as the cloud cover kept increasing.

Note that this isn't a "serious" observing session — it's more of a quick and dirty equipment test.

Test of telescope against Jupiter

From: 2005-07-09 20:45 UT
To: 2005-07-09 21:14 UT

First some notes about the telescope itself. I purchased it on a whim a couple of weeks earlier (in Woolworths of all places) when I noticed that they were trying to get rid of them for £10.00. They'd been selling them (or trying to sell them) since around Christmas 2004 (they were generally stocked in the "gifts for blokes when you don't know what to get the bloke" section; alarm bells should be ringing right now).

Normally I wouldn't have given such a thing a second glance but I wanted to get a toy telescope for my son and this, at £10.00, seemed as good a thing as any.

It claims a diameter of 50mm and a focal length of 350mm. It comes with a 45° diagonal, three eyepeices (17.5mm, 12mm and 9mm), a 3x barlow and a very small tripod.

With the 'scope mounted on a photographic tripod I had a look at Jupiter first with the 17.5mm eyepeice, then the 12mm and the 9mm. In each case it was obvious that Jupiter was a disc but no hint of any sort of detail, and none of the moons, was visible. To be fair failure to see any moons probably came down to the fact that the sky was still very light.

Next, using the 3x barlow, I went back through the eyepeices. The image was terrible. Very dark and almost impossible to focus. I'd say that the barlow is next to useless (I didn't expect anything else).

What really horrifies me about this is that it is sold as an "Astronomical Telescope" (it even says so on the 'scope itself). Something like this, especially when sold at £25.00, could put someone off the hobby for life. I suspect that it might be ok for some daytime work and will probably be ok for some simple views of the Moon but it isn't much use for anything else.

Still, that's what I purchased it for: a toy 'scope for a child who can use it to look at the Moon now and again.


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Dave Pearson <davep@davep.org>
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