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Tele Vue Pronto Review

Tele Vue’s Ranger and Pronto were the little scopes that got the Renaissance (sorry) in small refractors going twenty years ago.

Small and beautifully handmade in the USA, both had 70mm aperture semi-apo objectives and were made for Tele Vue’s simple push-pull mounts: Ideal if you just wanted to plonk them outside and take a quick look – at the Moon, an open cluster or two, even Jupiter.

The Pronto was my first experience of that new wave of grab-n-go refractors. Up until then, I had always owned large telescopes and the Pronto was a revelation. I loved its high quality, keep it simple design. I loved, frankly, its chic looks with those ‘mag wheels’ for focuser knobs. I was prepared to look past the fact that for a not-very-apo it was expensive, even used.

In the end, the Pronto was replaced by the TV-76 (both in the Tele Vue brochure and in my study) - a proper apochromat with a larger lens and faster f-ratio that looked outwardly very similar. No one will ever build anything like the Pronto ever again, because cheap Chinese APOs mean a hand-built-in-the-USA semi-apo would never sell for what it costs to make.

So if you can find a nice one, does the Pronto make a good buy as a potential classic, or is it hopelessly outclassed by that newfangled Sky-Williams GoldCat 71ED?

At A Glance

Telescope

Tele Vue Pronto

Aperture

70mm

Focal Length

480mm

Focal Ratio

F6.8

Length

~14” (36cm)

Weight

~2.7 Kg

 Data from Tele Vue.

Design and Build

The TeleVue Pronto looks much like the TV-76 which replaced it and the triplet Oracle that came before it. Unlike those two scopes, though, the Pronto shared its optics with another Tele Vue - the Ranger, which was a 1.25”-only helical focused lightweight that catered to a wider use case (and weighed about half as much).

Optics

This is where the Pronto is very different from the TV-76. The TV-76 has a 76mm (!) FPL-53 F6.3 doublet that is a full-on (more or less) apochromat and so good for imaging and high powers as well as low-power deep sky.

In contrast, the Pronto has a 70mm F6.8 doublet which uses cheap E.D. glass that doesn’t (according to someone who should know) do that much to cure false colour (chromatic aberration). Consequently, the Pronto is very much at the achromatic end of semi-apos, though optical quality is high and the objective is properly multi-coated.

Like almost all Tele Vues, the objective is held in a slim, non-adjustable cell, nudged into alignment on an optical bench and then fixed in place with blind rivets (or perhaps filled screws). If this sounds crude, believe me it makes the scope robust – I once dropped mine from about a metre onto tarmac and it suffered no ill effects at all (really!)

Pronto shared its 70mm F6.8 optics with the Ranger.

Tube

It is a very well made, compact, but quite heavy OTA finished in cream pebble powder coat, or a mossy metallic green, the latter perhaps a concession to birders who apparently favoured the Pronto’s tack-sharp images. Inside, the tube has no baffles; instead it is lined with the TV-standard flocking paper that looks a lot like black-painted sandpaper.

The lens is protected by a sliding black anodised dew-shield: beautifully machined, it slides with just the right friction. Like most modern TVs, the objective is protected by a weighty thread-on cap that squeaks rather too much in the small hours.

Personally, I think the Pronto and early TV-76, with gloss anodising and chrome focuser tube, look better than the more recent ones with their heavy-duty focusers and satin powder coat. The Pronto has a kind of artisanal look to it that is virtually gone from astronomy these days.

A weight of 2.7 Kg doesn’t sound much, but the compact OTA feels very hefty and solid. By comparison, a modern Borg 71FL would weigh maybe half as much (depending on configuration). At just 15” long, it’s a slim and compact telescope though.

The Pronto has all the period Tele Vue styling features, like gloss anodising and that screechy thread-on lens cap.

Focuser

The Pronto has Tele Vue’s original single speed 2” rack-n-pinion focuser with its characteristic cast body, serial number plate and ‘mag’ wheels. This focuser was once fitted to almost their entire line-up (apart from the Ranger). The focuser tube is thickly-chromed brass; nice.

This is how a simple focuser should be. When new and unmolested (lots of people tried to retro-fit the dual speed pinion assembly, whereupon the shims fell out ruining the action), it was super-smooth and free of image shift, with ample travel and properly designed with no vignetting.

Mounting

The Pronto comes with a clamshell ring that has a pair of outer ¼-20 threads to fit Tele Vue’s own ‘Panoramic’ and ‘TelePod’ mounts using Tele Vue’s lozenge-shaped Bakelite fasteners, along with a central ¼-20 thread if you can find a photo head strong enough to take it.

The clamshell has an Allen bolt on one side and a thumb-screw on the other. Adjusting tension with the thumbscrew is easy, but removing the ring requires an Allen key. The Allen bolt and thumbscrew were ferrous on the Pronto and so corrode; later ones were stainless and make a cheap upgrade.

Tele Vue make a Vixen-compatible dovetail that attaches to those outer holes and allows the Pronto to fit most Vixen and Skywatcher mounts (an EQ5 or similar is more than stable enough).

Clamshell has three ¼-20 threads.

Vixen-compatible dovetail.

Identical-looking early TV-76 on Panoramic mount.

Accessories

The Pronto came with a nice soft case (usefully cabin carry-on sized), a 2” mirror diagonal (not dielectric), a 1.25” adapter and a 20mm Plossl eyepiece. Accessories to buy included the Starbeam red-dot finder.

Numerous eyepiece options were possible (of course), but the older 4.8mm Nagler was a favourite for higher powers.

Pronto and Naglers just go together.

Pronto and case.

In Use – Daytime

There’s some false colour on high-contrast subjects like birds in high branches, but the view is super-sharp and contrasty at moderate powers – better than the majority of prismatic scopes, even HD ones.

The Pronto can serve as a good casual telephoto lens, but false colour spoils high-contrast areas, see example below.

This Pronto telephoto snap looks good, until you zoom in to see the false colour.

In Use – Astrophotography

The Pronto gave very reasonable starter images of the deep sky, but with too much blue-violet bloating for ‘serious’ imaging.

Likewise, decent snaps of the Moon at prime focus are easy and that false colour doesn’t show up nearly as much.

Pronto snap of M42 with slight tracking error.

In Use – The Night Sky

General Observing Notes

Star images are pin-point and given the conservative f-ratio, the field is quite flat for visual use. It’s generally a great view, even if Pronto is ‘only’ a semi-apo. The flocking works well to eliminate internal reflections and give good contrast.

The super-smooth and precise focuser is a pleasure to use and doesn’t run out of travel for 2” eyepieces. Maximum field of view for a 55mm Plossl is a generous 5.5° - well into binocular territory, so you don’t really need a finder for bright stuff.

Overall, the Pronto continues to give excellent views. I recall that when I first upgraded to the TV-76 I had them out side-by-side comparing. The difference wasn’t nearly as great as their cost difference might suggest.

Note: I owned the Pronto ages ago, so I’ve cribbed the viewing notes for the Ranger (it’s optically identical), which I tested recently alongside two Takahashi 60s.

Cool Down

Cool down is quite fast, but this is a heavy OTA with lots of metal, so it’s typically a bit slower than something like an ST80.

Star Test

Lens quality is very good, easily diffraction limited and with smooth polish, so the star test is good.

The Moon

Just after full, with Mare Criseum highlit by terminator shadows, the Moon through the Pronto surprised me. A cold hard ball full of detail was much as I expected at 32x. At 96x with a 5mm Nagler it was still a great view, albeit with a purple fringe off the limb.

Increasing the mag’ to 137x with a 3.5mm Nagler, the view was still good. Yes, the purple was now bright and obvious, but it wasn’t washing out the detail and everything stayed sharp and contrasty. Short focus achromats don’t do that, Tele Vue’s own Renaissance included, washing a lot more violet across the Moon’s craters at powers over 100x.

Back at the Moon, I enjoyed the embayments and cliffs and craterlets around Mare Criseum, bright Proclus with its odd shape. Nearer the limb, I could make out Hummocks on the floor of Gauss, the central peak in Hahn. I found the Messier twins and their bright rays. Next night, the strange straight rille like a clock hand in Petavius was easily resolved in poor seeing.

One frosty November Monday morning of excellent (8-9) seeing, I got up early and looked out on a last quarter Moon, high in the sky just off the meridian, with Albategnius on the terminator. With a 3.5mm Nagler giving 137x, I could make out the craterlets like a string of beads along Rima Hyginus and Rima Ariadaeus disappearing into the lunar night.

The view was sharp and full of detail: running down the terminator, I enjoyed Mons Piton shining alone in Mare Imbrium near the ‘ring wall’ of Archimedes, the sharp peaks of the Apennines, the slumped walls of Tycho in detail. Clavius and its arc of craters.

Upping magnification to a maximum 192x with a 2.5mm Nagler, the view stayed surprisingly sharp with no softening. But now a wash of pale lilac started just back from the dark limb, spoiling the view and reducing contrast a little. In this respect, the Pronto outperformed the TV Genesis, but the Takahashi fluorite doublets alongside could take higher powers in the excellent seeing.

Overall, and despite the purple rinse, the Pronto gave a very satisfying view of the Moon.

Mars

I caught Mars low in the dawn sky at the beginning of an opposition year when it was quite bright but just 3.8” in size. The Pronto showed a nice little orange disc with just a trace of false colour at 96x with a 5mm Nagler.

Deep Sky

Early before dawn one frosty November morning, Gemini, Orion, Leo and Auriga hung in front of my balcony twinkling coldly. I set the Pronto out and went deep sky observing – honestly more fun than I’ve had with a scope since I can remember.

Just three (of TV’s own) eyepieces were all I needed – a 32mm Plossl (my most used eyepiece for 20 years), a period 15mm Panoptic and a 5mm Nagler T6 - giving 15x, 32x and 96x respectively. But even just the standard 20mm Plossl, included with the Pronto new, would give great deep sky views at 24x.

The Pronto’s optics give a very flat field with the perfect lens squashing all the light into the tiniest stars across the field to give strong star colours. For deep sky, false colour just doesn’t intrude visually, even on brighter O-A stars.

I flitted between Orion’s sword, the diamond Pleiades, brilliant but faintly misty, Auriga’s clusters, the Double Cluster in Perseus. I split Castor and enjoyed some simply beautiful star fields. Everything looked gorgeous, more so than in a 60mm because the Pronto is grabbing 36% more starlight.

On another night, I just about split the Double Double in terrible seeing and moved on to a good view of the nearby Ring Nebula, it’s shape easy to pick out with averted vision through a Nagler 7mm at 69x – much better than the FC-60, with a third less light gathering aperture and that uncoated fluorite element. Similarly, globular cluster M15 was easier to pick out from Moonlight through the Pronto’s 70mm ED lens than the FC-60’s 60mm fluorite one.

The Pronto is a very nice deep sky tool.

Summary

The Pronto looks lovely, is built to last forever and is very robust. The focuser is wonderful if undisturbed.

It may be an ED-glass semi-apo in theory, but it’s closer to being an achromat in practice. That means a dark purple rim around the Moon at high powers (only noticeable over 100x) and too much blue-violet bloat for serious imaging.

But the Pronto still delivers a fabulous view, especially for deep sky, but of the Moon and most terrestrial subjects at spotting-scope powers too. You won’t be disappointed by the view, even today.

The Pronto remains a great scope and something of an heirloom-quality classic.

Recommended as a classy grab-and-go, but don’t be tempted to pay TV-76 money for one.