spotting scope advice (1 Viewer)

Hi, i'm asking this on behalf of a freind who isn't on the internet, he is looking to get a spotting scope for observing wildlife in general and basicaly wants to know how much detail he will be able to see at long range say approximatly between 1.5-3 kilometers (1 to 2 miles), if he sees a golden eagle feeding or a mountain hare will he clearly see the details, he knows he will need a top end scope, could anyone put up photos that show what detail to expect with which scope, magnification and distance, thank you

Hi ivanpaul, welcome.

I would probably go for an astro refractor, although not waterproof, for that distance.
Perhaps an 80mm or 100mm ED, say a Skywatcher. See OVL website.
But a top spotting scope would work although much more expensive.

The detail visible is almost all down to atmospheric conditions.

Early morning, late afternoon in spring or autumn are best.
In temperate climates we do better than places with extremes of temperature.

Ideally,the land, sea and air should all be about 15C or 16C.

A Kowa 884 would do it with the 1.6 doubler but adding the scope eyepiece and doubler your about 3500 bucks. I would try the astro first.
Steve

One way to predict what will be visible through a scope like the 88mm Kowa 883/4 is to work out the resolving power of a perfect 88mm scope (1.32 arc seconds) and multiply that by the maximum magnification available (96x with the 1.6x extender). That's 126 arc seconds or about what can be resolved by a person with 20/20 or visus 1.0 eyesight acuity. Add perfectly still and transparent air to perfect optics and an object at 3 km, viewed at 96x, would have the same detail as if it were viewed without a scope at about 31 meters by someone with 20/20 acuity.

In the real world the optics of even a cherry sample of an 883/4 will probably not be quite that good and the air will never be perfectly transparent at long distances, so a more reasonable expectation for an object at 3 km viewed at 96x under ideal real world conditions might be more like the same object viewed without the scope at maybe 40 meters. Of course, under mediocre or worse conditions you won't even at be able to tell whether you're looking at an eagle or a hare at 3km through any scope.

Hi,

as has been said - the distances asked call for higher magnifications than typical spotters can deliver (some exceptions with extenders exist though) and air turbulence will be the factor governing image quality even with top level optics.

Cheapest way to do this would be indeed an astro refractor like a SW 80 ED or 100 ED but they're huge, heavy and not very rugged compared to spotting scopes. Plus you want a serious tripod and mount for their weight and lever.

A spotter with an extender or two can be used too and will come in a small and light package - but will be quite expensive.

Here's an example of what to expect from a good example of Kowa 883 with one or two extenders. The distance is only 250m though, so atmospheric conditions are less important.

http://www.kowaproducts.com/DigiscopeBlog/steve-blain-reviews-the-kowa-tsn-ex16-1-6x-extender/

Also the image with two extenders at 150x will be quite dark, so visual observation even in bright sunlight will be borderline. The camera sensor is not bothered by this - just crank up the time or iso...

Joachim

thanks for your replies, my friend is quite willing to pay out for a top end scope but being uncertain if it will give the performance he hopes for would rather wait and get all the advice he can, it will be used outdoors and being in ireland that means damp or wet conditions, he was looking at the top swarovski but has been a bit ut off when he was told it only has a 10 year warranty, he is now looking at ziess, leica, vortex and pentax though is open to suggestions, initaily it will be used just to observe though later he might start taking photos through it, hes very practical person but not as technical with electonics, again thank you everyone

ivonpaul, post 6,
The 19 year waaranty, as I am well informed an European rule, all large companies have it, but Swarovski is famous for its level of service also after the 10 year warranty period and that is not certain for the other companies mentioned in your post 6.
Gijs van Ginkel

I have successfully used my 150mm f/10 Maksutov at 95x at distances of 5 miles but in locations with superb Seeing or air stability, and very clean transparent air.

The 120mm f/8.3 doublet high quality refractors were used at 250x and resolved one inch black marks on a lit clock face at 4.7 miles but at 3 a.m. on many nights. But one must choose the time and place. During the day the conditions can be hopeless.

Astronomers learn to read the sky and the weather. If conditions are poor then they don't even bother to open the observatory.

A 135mm f/16 observatory refractor showed great detail at long distances during the daytime.
My 100mm Pentax f/12 refractor was very good, but the observatory 135mm f/16 was better.

The 317mm thin edge mirror Dall Kirkham with full size optical window was exceptionally good during the day with stable temperatures, but is not a normal telescope for birdwatchers.

A 12 inch long focus refractor mounted on a truck in New York was also exceptional.

What I haven't seen discussed here, although maybe I didn't see it discussed, is how different scopes deal with temperature variations due to the scope itself.

In my experience short focus scopes, even refractors, perform worse than long focus refractors.
Maksutovs and Schmidt Cassegrains are worse than refractors.

What one really needs is an observatory class 6 inch or even larger long focus refractor, even a high class doublet, but a triplet or true Apo may be better.

I would think that a Swarovski 95mm or Kowa 88mm with extenders is the most practical choice, but a 150mm or 180mm Maksutov could be good if either left outside to ambient temperatures or viewed through a high quality window at right angles to the glass or 2 degrees off centre to prevent ghosts. Astro scopes are not usually waterproof, so viewing through high quality glass windows is a good way to go. The observing room must be unheated with no radiators turned on.
A 120mm ED or 150mm ED refractor would also be good.

Additionally one must not view over asphalt or concrete but over grass or vegetation and no roofs or heat sources between the observer and object viewed.

3 km is not in the range of any spotting scope to see a hare,I would say..1 km was my range to test my optics in my old location , and with good specimens in good air ,I could push the image well past the 96x mark that is been pointed here..at that power and aiming to less than a mile,I could try to work some fine detail,with time and concentration..My tests were really subjective,but reading a ten digit phone number on a 50cm sign ,at about 800 m was my main achievement..sometimes more power helped,sometimes didnt matter.....really,even with all favorable conditions and top equipment ,the eye has to do some work and the brain needs to be receptive

mayoayo, you are probably correct.

But I think that an eagle may be able to spot a hare at 3km without a telescope.

The military use adaptive optics, as do astronomers.
Some units were available also to amateur astronomers.

Also golf balls were easily picked out on the green on film from 80,000 ft altitude even with longer oblique range, with the aircraft flying at 2,000m.p.h.

http://www.birdforum.net/showpost.php?p=1637047&postcount=6

Here is a picture I took from my place using Celestron 80ED prime focus and a not super clear day, this overlook is about 2.8 miles from my place. I hope this helps a little. I have a picture with the Orion 100ED that is better.

Hi Ivonpaul. If your friend is based in Roscommon, tell him to check out Conn's Cameras in Dublin or Birdwatch Ireland's website. Black and Lizar's in Belfast might also be worth a try. For general wildlife and birding here, I think the max he should be considering is an 80/82/85mm objective spotting scope. There as a lovely Zeiss Victory Diascope currently on the 'bay from England at an excellent 'buy it now' price. Your friend could also attend a Birdwatch Ireland field outing (see website), where I'm sure all participants would be more than happy to let him have a try of their scopes, to give a better idea of what's required. Alternatively, if in the Bray area, I can show him my Meopta S2Hd82mm scope with 30-60 zoom. Calvin Jones of Ireland's Wildlife website has a review of this, IMHO the best scope I've owned (and I've owned far too many!)