What is a spotting scope?

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David Frydman
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What is a spotting scope?

Post by David Frydman »

Although I have good stereo vision and can do the puzzles Mike mentioned, I do have problems reading in that my eyes don't come together. My optician several years ago realised this and my reading glasses have the full prism correction of 1.5 dioptres in each lens. Perhaps this prism correction could help others.
With two eyes I see better than with one as the imperfectios of each are mainly corrected. My left eye also now gets tired quite quickly. I am quite long sighted and need distance glasses to see well. These don't have prism correction.
At best I can separate Mizar at 14 arcseconds with 10x30 IS binoculars or selected 12x45 Russian. However I need variablt thin cloud to act as a neutral density filter so that the optimum brightness is achieved to get the best resolution. When young I could separate Epsilon Lyrae with unaided eye from London and regularly saw 11 Pleiads. From Helsinki by the sea 13 and from La Palma in about 1988 I saw 15 or sixteen with unaided eyes. My eyes are not so good nowadays.
regards, David
brian livesey
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Post by brian livesey »

Despite having double-vision without specs, I find, as with Mike, some of my binoculars don't need the specs lenses modification that I've done on the 10X50's and 20X60's.
I put this down to the fact that the bins that don't need modifying are probably out of collimation to the point of being compatible with my double-vision.
brian
David Frydman
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Post by David Frydman »

Dear Brian,
Although I don't use glasses when using binoculars I do have slight astigmatism in each eye. When testing binoculars I try to choose ones which don't have astigmatism in either barrel. However, sometimes I have come across binoculars where the astigmatism in the binoculars perfectly compensates for my astigmatism. These give good views.
I have found lately that my eyes get tired quickly, particularly my left eye. This is when reading or watching T.V. I don,t do any testing in this condition and wait till I am fully rested.
Regards, David.
andrew robertson
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Spotting Scopes

Post by andrew robertson »

Talking of spotting scopes, have a look at Cliff Meredith's observation of Jupiter using a £25 one from Aldi which I've just posted on the SPA web site:
http://popastro.com/planet/category/observations/

Andrew Robertson
Planetary Section Director
David Frydman
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Post by David Frydman »

Dear Andrew,
That is a good observation by Cliff. The Aldi scope seems to be similar to the Clifford James, Daily Mail scope. The price varies depending on special offers or not.
On 2010 August 12 at 22.24 UT I had a broadly similar view of Jupiter with the Pentax 500mm f/8 mirror lens, 45degree prism adaptor and 6mm Ortho eyepiece just dropped in but not secured. This was through double glazing at nominally 83x(85x is what I put). Mirror lenses change focal length as you focus and change the separation of mirror and secondary.
Callisto was also initially not seen, but then rather easily seen as a tiny star near Jupiter's limb.
In fact last year I noted with 18x50 IS binoculars that only one main belt was visible. I confirmed this by handholding 3x opera glasses behind the binoculars, also handheld but touching the window. A lot of false colour as lining things up perfectly holding two binoculars is impossible. But the single belt was clearly seen. It was at last apparition, I can't remember if it was 2009 or 2010.
Best regards, David.
Davej
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Post by Davej »

Hi,
Managed a rare view of Jupiter last night (Tues. 22.35 BST).
Although still low I could easily pick out the NEB with my Celestron C70 (25x75 zoom) Mak. Ganymede, to the left and Europa and Callisto, to the right of the planet were sharp pinpoints of light. Was hoping to catch Io as it re-appeared from behind Jupiter but once again the clouds spoilt it.
Managed to get a view of the Moon earlier (around 8.5 days old, one of the best times for observing I think). On full zoom I found it a bit tricky to focus (x75) but otherwise was well pleased. No CA on the Moon views but there was a bit on Jupiter when zooming in. Wont be expecting much from DSO's but M31 showed up well and the 'Coathanger' was nice and sharp (bit tricky finding things with no viewfinder but 'star-hopping is made easier due to the 'right-way-up' image).
Will have a reall good go with my own eyepieces the next chance I get :roll:
All the best.
Dave
Meade LX 200 (7"). Odyssey 8" Dob.
11X80 10x50 15x70 bins
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Cliff
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Post by Cliff »

Dear David et al
Thanks for the comprehensive commets about spotting scopes and indeed about small optics in general.
You did well getting the Questar at such a good price.
I was so pleased with my small 60mm Aldi x20 - x60 that I got one for my brother in law who enjoys bird watching - apparently some of his bird watching acquaintances were amazed when he told them the Aldi scope was only £24-99 including table top tripod and shoulder bag.
Early this summer my wife and I visited Bempton Sea Cliffs which is a well known bird watching location, south of Scarbough. There is a visitor centre there with a shop selling Scwarovsky scopes - the prices being a bit dearer than Aldi needless to say. Incidentally is the scope Scwarovski the same company who sell jewellery -they are pricey as well ?
Best wishes from Cliff
David Frydman
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What is a spotting scope?

Post by David Frydman »

Dear cliff,
Yes, Swarovski binoculars and scopes are made by the same people as the Crystals, although different divisions of the overall company that also makes other things. They are Austrian. I have never actually tested or even seen any of their optics.
At present it doesn't seem as if the Daily Mail sell the 20x to 60x 60 scope. They have a 20x to 54x 60 at a higher price. Their 8 to 24x 50 binoculars varied from £14.99 to £29.99 with other folks selling them at about £60. They are not very good, I gave mine away as presents but they seem to like them for horse racing.
Aldi and Lidl do have bargain scopes, binoculars, even DSLRs at silly prices on the principle when they are gone they are gone.
Sorry Cliff I still am not good at typing.
Regards, David.
andrew robertson
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Post by andrew robertson »

Interesting technique.

Regards, Andrew
David Frydman wrote:Dear Andrew,

In fact last year I noted with 18x50 IS binoculars that only one main belt was visible. I confirmed this by handholding 3x opera glasses behind the binoculars, also handheld but touching the window. A lot of false colour as lining things up perfectly holding two binoculars is impossible. But the single belt was clearly seen. It was at last apparition, I can't remember if it was 2009 or 2010.
Best regards, David.
David Frydman
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Post by David Frydman »

Dear Andrew,
If using the two binocular method one may need to adjust the focus of both. Once in Helsinki I was looking at a building about 12 miles away, but couldn't identify it. With the binoculars on a telephone catalogue on the window cill, I added some 7x50s behind giving 140x approx. The hotel sign was not only seen but read. The main binoculars were Celestron 20x80. Most good binoculars are capable of high magnification.
Swarovski, Zeiss and Opticron provide monoculars of 2x, 2.5x and 3x that screw into the rear of one eyepiece to make a spotting scope. This may also apply to their normal spotting scopes.
I take no responsibility if anyone drops their binoculars by trying to handhold two at one time. It is not something I recommend, but I work with whatever is to hand. It is much better to use a dedicated scope.
Regards, David.
mike a feist
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Post by mike a feist »

And there is yet another alternative use of binoculars/monoculars, although not astronomical. If you are out and about with your binocular/monocular and come across some interesting tiny natural object or even very small print you cannot read, and do not have your reading glasses, turn the optics upsidedown, put you dominent eye to one OG and bring the tiny object up towards the eyepiece....you then have a great magnifier too! maf
David Frydman
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Post by David Frydman »

As mentioned earlier various makers have magnification BOOSTERS.
The Opticron Universal Tele Adapter is particularly useful as it fits many Opticron binoculars, monoculars and spotting scopes using various coupling rings. It boosts the magnification by 2.5x.
I don't have this item but do have various old opera glasses of 2x, 2.5x, 3x, 3.5x and 4x. These are available for a few pounds from charity shops.
The very small ancient 2x is most useful for spotting scopes where the normal zoom eyepiece doesn't fully exploit the potential of the scope.
Opera glasses have many other uses in astronomy. Some of them are actually of very high optical quality although usually they are just average.
You must choose glass lenses, Plastic toy glasses should be discarded.
David.
mike a feist
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Post by mike a feist »

Hello David etc
I bought one of these x2.5 to increase the power of my 8 x 42 quite expensive Opticron monocular but really was not that impressed with it, although at the time did not have the facility to mount the mono on a tripod (it needs a special ring adaptor which I have since acquired). Venus for example had a marvellous ghost "satellite" and reminded me of the very early drawing (by Fontana, I think) showing Venus and it Moon! Perhaps I should have persevered in light of your comment!
Unfortunately, as you said different size, push-fit adapters are needed,and of course if you use with binoculars rather than monos it is a one-eye job or very expensive!
My previous request for information as to whether camera screw-in front filter will fit a spotting scope the anwer would seem to be in the negative. Discounting scopes with rubber armour which gets in the way and this may even be the case some with extending light shields, I looked at a std 52mm front camera filter and although initially it seemed "almost right" for a 50mm spotter, but the thread on the filter was not really long enough and the pitch of thread was different. maf

regards maf
Cliff
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Post by Cliff »

Dear David
That "double" binocular technique is certainly interesting. Unfortunately I don't think my hands are steady enough for me to do it, though I might consider trying it with tripod mounted bins sometime.
I was middle aged when I got into "serious" observing myself and generally feel more comfortable using higher magnifications to say observe planets - although I am quite happy observing the Sun at x32 with my Coronado PST (generally better for me than using higher powers).
When I was a youngster (and assume my eyes were best) I had a 30mm "classic" brass draw tube refractor providing x20 magnification. I saw Jupiter's Galilean moons with it, and Venus's crescent but I never saw any of Jupiter's belts, nor Sturn's rings properly (though it might have appeared a funny shape-ish). However, I never had any sort of mount for that refractor I only used it hand held.
Best wishes from Cliff
Cliff
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Post by Cliff »

Dear Mike
I don't know of any screw in filters suited for spotting scopes
However, my old 20 x 60 Russian binoculars came with "yellowish" push on filters that can be fitted over the binocular eyepieces - I never bothered with them though.
Two possiblities occur to me though.
15-ish years ago I got a swottch of sample Lee theatrical lighting filters (then provided free. There are\were about 100 different filters in a swotch though only say 25% suitable for astronomy, but several varying density of filters for the main clours. Furthermore every filter had a lihgt curve diagram with it. I still sometimes use the filters handheld between a telescope eyepiece and my eye. Of course it would be trickier to use the technique with a handheld spotting scope and more so binoculars.
However, hand held filters using a mounted telescope can be handy. Very easy to swop from one filter to another. So useful even if only to assess which type of filter to use without the chore of needing to mess about putting eyepieces in and out and screwing filters in and out, which can be a chore reducing precious observing time.
Another possibilty might be to make simple small rolled card tubes to enable ordinary screw in 1.25 eyepiece filters to be used push fit on spotting scopes or even binoculars - though good screw in filters are not dirt cheap.
Best of luck from Cliff
PS I originally read about the possibility of using Lee filters in Sky and Telescope (about 15 years ago). Luckily Lee then had an outlet near here.
I got two free samples but when my local astro society then made more requests understandably Lee got a bit cheesed off giving them away.
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