Televue astro scopes for birding (1 Viewer)

[Hugh Clayton]

I've just bought a Televue TV76 apo for astronomy and birding and wonder if anyone else has done the same with a TV76 or the similar but discontinued Pronto ED model. Its performance leaves my Bushnell Spacemaster ED miles and miles behind, as it should. It's one of the few astro scopes that is realistically promoted as a "crossover" instrument suitable for birding as well. I'd be interested to know if anyone has compared Televue performance with that of 80mm apo birding scopes.

 

[Glen Tepke]

Here are a few reviews that give high marks for Televue's optical performance for birding:

http://betterviewdesired.com/march02/index.html#TV75

http://betterviewdesired.com/BVD701/tv85.html

http://birds.cornell.edu/programs/AllAboutBirds/GearGuide/Scopes/ScopeReview2002.html

Glen

 

[galt_57]

I've just bought a Televue TV76 apo for astronomy and birding and wonder if anyone else has done the same with a TV76 or the similar but discontinued Pronto ED model. Its performance leaves my Bushnell Spacemaster ED miles and miles behind, as it should...

If I remember correctly the only downsides are that it's heavier, isn't waterproof, and won't focus as close as most popular birding scopes.

But it is designed and calibrated more precisely to support much higher magnifications.

Dave

 

[Hugh Clayton]

Many thanks for the review addresses. So far I've taken the TV76 up to 190X on some young thrushes about 40 yards down the garden in bright sunlight. The image is darker than at lower powers, but there's very little loss of clarity and contrast and the depth of field is surprisingly good. I think the image quality is helped by the use of a wide mirror diagonal instead of the narrow prism set-up built into birding scopes. I suspect, too, that a lot of birding eyepieces are of much lower quality than astro ones.

Here are a few reviews that give high marks for Televue's optical performance for birding:

http://betterviewdesired.com/march02/index.html#TV75

http://betterviewdesired.com/BVD701/tv85.html

http://birds.cornell.edu/programs/AllAboutBirds/GearGuide/Scopes/ScopeReview2002.html

Glen

 

[henry link]

I think the image quality is helped by the use of a wide mirror diagonal instead of the narrow prism set-up built into birding scopes. I suspect, too, that a lot of birding eyepieces are of much lower quality than astro ones.

Hugh,

A subject dear to my heart. I have used small APO astro refractors for birding for the last 20 years because of their optical superiority to birding scopes. Of course there was a much bigger difference in the 80's than now.

A Pentax 80mm EDscope I recently tested did have a significant problem with vignette coming from the porro prism housing. In this scope one part of the prism housing moves to change focus. At close distances starting at about 25m the prism housing begins to vignette the objective until only about 68mm of the objective is actually in use at closest focus.

Some of the eyepieces made for birding scopes are actually just as good as the best astro eyepieces. The wide field Swarovski and Nikon eyepieces are some of my favorites, and the Zeiss and Swarovski zooms are far better than the zoom TeleVue markets. Any of these can be adapted for use in your scope. The Zeiss zoom would produce 19-57X and the Swarovski 21-63X. Zeiss makes very expensive adapters and less expensive ones for Zeiss, Leica and Nikon eyepieces are available from APM Telescopes in Germany (their Zeiss 2" adapter can be used for the Swaro zoom by substituting longer hex screws).

The main problems I have using this type of scope for birding are weight, the need to be careful that the diagonal and eyepieces don't loosen and fall off when I'm moving around and the lack of waterproofing. But, you can expect queues to form behind your scope at good scoping places as word spreads that "the bird really looks good in that big odd scope over there".

Henry

 

[Hugh Clayton]

Henry,

Many thanks for your helpful message. At last, somebody who uses astro scopes for birding - whenever I've come across crowds of birders looking out for some rarirty in England, I've never yet seen an astro scope among the lines of Kowas, Opticrons etc. I'm grateful for your comments about zooms - I've always been wary of birdscope eyepieces because of the adaptor problem and because the makers never reveal anything about their configuration. I've seen some dire birding eyepieces over the years, including the useless 40X one that goes with my Spacemaster. I wonder if anyone will ever make a true crossover instrument with astro power and optical versatility combined with birding lightness and toughness. I think Televue has probably got as close as anybody.

Many thanks again - Hugh

Hugh,

A subject dear to my heart. I have used small APO astro refractors for birding for the last 20 years because of their optical superiority to birding scopes. Of course there was a much bigger difference in the 80's than now.

A Pentax 80mm EDscope I recently tested did have a significant problem with vignette coming from the porro prism housing. In this scope one part of the prism housing moves to change focus. At close distances starting at about 25m the prism housing begins to vignette the objective until only about 68mm of the objective is actually in use at closest focus.

Some of the eyepieces made for birding scopes are actually just as good as the best astro eyepieces. The wide field Swarovski and Nikon eyepieces are some of my favorites, and the Zeiss and Swarovski zooms are far better than the zoom TeleVue markets. Any of these can be adapted for use in your scope. The Zeiss zoom would produce 19-57X and the Swarovski 21-63X. Zeiss makes very expensive adapters and less expensive ones for Zeiss, Leica and Nikon eyepieces are available from APM Telescopes in Germany (their Zeiss 2" adapter can be used for the Swaro zoom by substituting longer hex screws).

The main problems I have using this type of scope for birding are weight, the need to be careful that the diagonal and eyepieces don't loosen and fall off when I'm moving around and the lack of waterproofing. But, you can expect queues to form behind your scope at good scoping places as word spreads that "the bird really looks good in that big odd scope over there".

Henry

 

[Ryder]

Hi:
What tripods and mounts are folks using with the Tele Vue 76 and 85 scopes for good stability and portability?

Cheers,
Craig Ryder

 

[Eric F]

Anyone got any digi pics they've taken with an astro scope? Sounds ideal for high shutter speed, crisp photo's

 

[Hugh Clayton]

The TV76 is just light enough for a Benbo Trekker using the adjustment plate that comes with the telescope. The ring in which the telescope tube slides is threaded for camera tripods and the adjustment plate allows it to sit slightly forward to make use of heavy eyepieces and diagonals. I'm pretty sure the TV85 would be too heavy for this tripod - Hugh Clayton

Hi:
What tripods and mounts are folks using with the Tele Vue 76 and 85 scopes for good stability and portability?

Cheers,
Craig Ryder

 

[Jay Turberville]

I'm grateful for your comments about zooms - I've always been wary of birdscope eyepieces because of the adaptor problem and because the makers never reveal anything about their configuration. I've seen some dire birding eyepieces over the years, including the useless 40X one that goes with my Spacemaster. I wonder if anyone will ever make a true crossover instrument with astro power and optical versatility combined with birding lightness and toughness.

When you consider that Pentax eyepieces are highly prized as astro eyepieces, it should be little surprise that the best efforts from the best birding scope makers hold up very well. I think Leica also has an excellent rep with the astro crowd.

One of the fundamental differences between a birding scope and an astro scope is that birding scopes assume the need for an upright and correctly oriented image. This means the use of a prism and usually an integrated one due to another major requirement - waterproofing.

I think any true crossover scope would require a waterproof system where finders and eyepieces could be changed while maintaining nitrogen filled environments for each. Sounds difficult and heavy to me.

Its a tough bill to fill. The uses are different enough that the intstument is almost assured to fall clearly in one camp or the other. At least until some very clever person comes up with a new solution.

 

[henry link]

One of the fundamental differences between a birding scope and an astro scope is that birding scopes assume the need for an upright and correctly oriented image.

Jay,

I got used to mirror imaged birds a long time ago. Up side down is where I draw the line.

Henry

 

[Vectis Birder]

Jay,

I got used to mirror imaged birds a long time ago. Up side down is where I draw the line.

Henry

On a Televue astro scope, you can buy an erecting prism to get an upright image. The only reason astro scopes have an upside down image is when doing astronomy you do not need a right way up image. Therefore the erecting prism is left off, so more light (essential in observational astronomy) can reach the eyepiece.

 

[normjackson]

Who's taken amici?

Jay,

I got used to mirror imaged birds a long time ago. Up side down is where I draw the line.

Henry

Henry, perhaps you're not so "batty" after all 3

 

[Jay Turberville]

On a Televue astro scope, you can buy an erecting prism to get an upright image. The only reason astro scopes have an upside down image is when doing astronomy you do not need a right way up image. Therefore the erecting prism is left off, so more light (essential in observational astronomy) can reach the eyepiece.

The erecting prism is also left off because the additional optical surfaces and refraction of light that they introduce further degrades the image. This degradation is fairly minor from a birder's perspective but certainly not worth tolerating from an astronomer's point of view. Especially, as you point out, since astronomer's usually don't care much about image orientation.

On the surface, this seems to be a farily minor thing, but such fine things are part of what separates a mediocre astro scope from a fine one. The "true crossover" scope will be difficult to make. One use or the other is bound to suffer compromises in features that many users in the respective groups would consider essential. Such is the case with the TeleVues.

They are optically excellent, but they are not waterproof. I suspect they lose some of their optical edge if you add even a very good prism (Televue reccomends their use only at moderate magnifications). And I don't think they are champs in the areas of ergonomics and weight. As Hugh pointed out, Televue is probably about as close to achieving this "true crossover" ideal as anybody, and their scopes are clearly more oriented to astronomy.

 

[Ryder]

Right side up?

On a Televue astro scope, you can buy an erecting prism to get an upright image. The only reason astro scopes have an upside down image is when doing astronomy you do not need a right way up image. Therefore the erecting prism is left off, so more light (essential in observational astronomy) can reach the eyepiece.

Hi:

I'm no optics expert but a few days ago I bought a Tele Vue 85 for birding and star gazing and, at least in mine, the image does not need erecting. The image is reversed left to right but it is right side up.

It's a very nice piece of equipment too.

Cheers
Craig Ryder

 

[Jay Turberville]

I'm no optics expert but a few days ago I bought a Tele Vue 85 for birding and star gazing and, at least in mine, the image does not need erecting. The image is reversed left to right but it is right side up.

Right. I is probably using the standard in astronomical scopes - a mirror finder. This will erect the image, but leave it reversed left and right.

 

[Bob D]

I've used a TeleVue 85 for birding, albeit rarely and when I did close to the car. Have used with it with Leica's zoom with an adapter and also with Nikons' fieldscope wide angle eyepieces and their 20x60 zoom with a commercial adapter. There is no doubt that these are excellent eyepieces.

Used a TeleVue Ranger more frequently for birding with the Nikon Eyepieces. Carried it in the field when my wife was using our Nikon Fieldscope III ED. I recently purchased a Swarovski 80 ATS HD and as a result the Ranger has not seen any birding use recently.

Although the Ranger has not the quality of the TV 76/85 etc. and has some (rarely noticable) chromatic abberation it offered excellent images when matched with Nikons wide angle 24X and 40X eyepieces (magnification slightly higher on the Ranger because focal length is longer than on my Fieldscope III ED 60 mm.) Used Rangers in excellent shape without an eyepiece go for about $425. A lot of optical quality for the dollar. And the Ranger is a fairly light scope.

I've attached a picture of a Ruby-throated Hummingbird taken via the Ranger and a Nikon 15X non-wide angle eyepiece.

Bob

 

[Art Thorn]

I'm now using a Televue 85 with a series of non-zoom eyepieces, from a 5mm Radian (120x) to a 24 mm Panoptic (27x). My favourite eyepiece is my 9 mm Nagler, which produces an incredible 67x, wide field view, and with excellent eye relief. The field of view (82 degrees apparent FOV) with the Televue and a Nagler eyepiece far exceeds anything available in a dedicated birding scope, and brightness (85mm objective, no prisms) and lack of chromatic aberration (true APO) overshadow the problems of weight and waterproofness, for ME. I emphasize that, because I don't bird in the rain (drizzle OK) and I don't cart the setup for miles or hours. I park the car close by, and use the scope mostly at the shore. In the woods I use binoculars. I love the view, and would not go back (I did have a Swaro 80), but my needs are different than those of some others. I did have both the Televue zoom and the Swaro zoom, and did not enjoy the very small field of view to which I am now accustomed. You have to try it!!!!!