Review of the Tele Vue 76 or What are the benefits of a small, portable Refractor?

As I have indicated recently I have very much enjoyed my views through the Tele Vue 76 and it’s capacity as a birding/nature photography scope (and air shows!) but more importantly, it’s go-anywhere size makes it the ideal buddy to take out on a moment notice. This logic doesn't just apply to the TV76, it applies to any and all small, quality refractors. Built like a tank. How many times have you heard that phrase about this class of telescope? It harkens from the Tele Vue Pronto days that has been the hallmark of the small Tele Vue refractor lineup. Heavy duty in a small package. Structurally these scopes are truly overbuilt with buttery smooth focusers, sliding dew shield, accessory clamshell and a powder coated white tube. I did not opt for a green tube.

Optics, build and accessories

My ’76 is actually a used one, not new and is slightly older than the current crop with a different eyepiece holder and it doesn’t have the satin body, it has the older machined shiny body. If anything, I would like to swap out the eyepiece holder as the newer version is an upgrade with dual screws, not one. But the one I have is still sufficient as it too is a compression ring style. It’s tank-like build is sometimes criticized as it’s Achilles heel because it is generally heavier than it’s birding counterparts, but when compared to larger telescopes, it really isn’t that much of a pain. Still birders will prefer rubber bodied, waterproof, gas charged spotting scope in exchange for the views because, you guessed it, the ’76 is not a waterproof scope and as a conventional refractor in terms of structure, focusers are classic rack and pinion with a 2” eyepiece capability that results in mirror reverse images. Birders may prefer the more traditional upright, left to right view. I however, am not one of them. I prefer to keep the image as pure as possible. To keep the tube relatively thin, the scope is not baffled, it is flocked.

Optically this scope is great. But so what. Let’s qualify that statement. Obviously it’s light years ahead of its older sibling, but never mind that. Pronto vs TV76 is a fruitless discussion because they are completely different refractors. Structurally similar, but that’s it. Nothing to talk about there and it has been done to death on Cloudy Nights. However, for buyers looking at used Pronto’s, don’t worry, it’s still a great achromat and worth the investment. Just be careful not to overpay on one because, put simply, you can get great optics from other ED Refractors that are much more modern even though you might sacrifice the build. My 76 exhibits what is typical in an SD doublet (it is assumed that it is in fact FPL-53 but I don’t think it has ever been directly stated) where you will find the in-focus image to exhibit next to little false colour on bright objects. Out of focus images do produce some false colour as expected. Concentric rings are nicely visible and the out of focus image does not indicate any correction issues, astigmatism, collimation problems or rough images. A nicely made lens. If anything, it has been on more than one occasions, been the “gold standard” to judge by in it’s class and only in it’s class not beyond it. The lens is held in collimation with no user adjustment. If it goes out of collimation, it has to go back to the factory. A Starbeam Reflex site as well as a Vixen/Synta finder scope base was added to enhance it’s capabilities with an 8X50 finder scope, although one can argue you might not truly need a finder. The clamshell has been adapted to the ADM 7” Vixen Universal Plate so it is compatible with all Vixen and Synta style saddle plates. It will ride on a variety of mounts like the AZ-4, EQ5 and EQ6.

Working with the Tele Vue 76

Vega Test: Well, I didn’t do one and I don’t really want to do one.

Venus Test: I haven’t done that either. I might one day…

Planets: I have truly enjoyed this scope on Jupiter and Saturn despite the smaller aperture. I have at least detected the Great Red Spot Hollow on more than one occasion, enjoyed tracking transits of the Jovian moons and it is no problem spotting the C Ring and Cassini’s Division. Don’t think I have ever spotted the Encke Gap, but I don’t think I went looking for it in the first place. I’ll have to check next year. I have not seriously looked at Mars though with the ’76 and a review of it pointing out that any f/6 ED doublet APO might not be the ideal “Mars Scope” can be found here at Scopereviews in the UK.

Deep Sky: With just an aperture of three inches, this is going to be relegated to the brighter deep sky objects but there have been plenty of nice views to be had here. None of them are surprising. What I won’t do is compare this to say, a large Dobsonian. This is nonsensical because they aren’t in the same class of instrument. Besides, to state that “a dob blew away the ’76 on faint object X” is more than enough of a statement of “Captain Obvious”. The grandest thing is the wide field. M31 has that galactic feel to it in a dark sky. With a five degree field at maximum, it has been the preferred view at StarFest over much larger instruments with a narrower field. Open clusters like the Beehive, Coat Hanger and Pleiades look like open clusters that you could only fathom in your 8X50 finder scope on larger instruments. The Double Cluster is bordering on glorious in a five degree field. Truly an experience to behold. There is something to be said while taking the whole view in of Orion’s Sword region where M42 reigns supreme. It’s something you have to experience. Reading about it doesn’t do justice. Any quality f/6 doublet ED/APO can do this.

This is not a “Herschel Hunter” nor should it be considered as such. It’s a different approach to the traditional deep sky observing. I would treat the ’76 as a nice supplement to your larger telescope.

Double Stars: This is not my primary telescope for double stars, that is reserved for my larger refractors but views have been rather pleasant in the ’76 especially colour contrasting doubles where the APO optics do help. The focal length of course is short at 480mm so “barlowing up” is required or get some of those high quality, low focal length eyepieces. The scope is capable of operating very well up to 200X. Some of the finer splits have been Porrima, Castor, Rasalgethi (Alpha Herculis) and Rigel (split surprisingly well).

Crossing over to the other side

Crossing over as a multi-function scope is where I think this scope really shines. I actually purchased it for the ability to photograph birds and wildlife on top of the astronomical capabilities already stated. It extended my options to 480mm (760mm crop factor) with the camera and I have been more than satisfied with the results and if you saw my post from Rattray Marsh, you’ll see why. However, one must remember that dealing with a conventional refractor focus is much trickier than the instant auto-focus mode of my 70-200 L. When you do get the focus right, and it takes work, it’s a nice image as seen from my Rattray Marsh post. I have not used the ’76 as much as I would like visually in this capacity, but what I can say it is breathtakingly bright, crisp and virtually false colour free as expected and keeps up with the big kids on the birding scope scene like Swarovski, Leica, etc.

I have been working with the ’76 for some concepts as a terrestrial or landscape imaging telephoto. This is really out of the norm for an astronomical telescope as I have not seen many people attempt it. My 70-200 L is truly my go-to landscape lens but I decided to see what the ’76 could muster. It’s a strange, unique world indeed as these photos indicate. As mentioned in my Rattray post, the Orion Field Flattener is a BIG help here to keep images sharp across the focal plane. It may not be the most efficient scope for this purpose, but it’s fun to tinker and go outside normal boundaries. Canon does make 500mm and 600mm lenses…have you seen the prices? Have a look at some of these concepts.

We established the TV76 as a capable Air Show supplement to existing lenses here

Can you hike it? The simple answer is yes with conditions. The weather has to be fairly nice. The ’76 is a fair weather friend. Weighing in at five pounds, it's bulk in contrast to lighter, rubber-armoured spotting scopes could be an issue but short hikes are reasonable. One must keep in mind that the supporting cast is larger than most spotting scopes depending on what it’s intended for. One must take a robust tripod capable of supporting it well, eyepieces, barlows and a diagonal, camera adapters, field flattener( again I find it useful), and camera bodies. Given that list, it’s clear one must be dedicated to this kind of activity. If doing an overnight backpacking trip is in order, chances are, the ’76 is not your scope. Short hikes, possibly day hikes can be done with the above conditions IF you want to do it.

Some other thoughts

Despite all that has been written, what place does this little refractor have in the era of the (modestly) inexpensive ED/APO doublets from Asia? Well, given it’s price new, the TV76 is a big investment. But what you do get is a capable telescope/terrestrial scope that’s built to last forever, assuming you treat it right. Now, I do have many friends who have invested in small ED/APO doublets imported through SkyWatcher, Explore Scientific, Astro-Tech, etc, and I can say these scopes can deliver as good as or very close to the TV76, optically. They may have not subjected their refractors to the rigors that I have as stated above but I cannot say anything negative about them only positive things which might lead some to wonder why I even bothered to post this at all. My attempt here was to lay out what you can do with a small refractor in this class. There are many debates about the merits of this or that refractor and it’s been done to death. Some say Tele Vue’s quality will last forever. That may be true, but if you treat your telescope well, chances are it will last just as long. Treat it badly and well, you know what happens. There is no real need to debate this anymore except where quality control may be a factor. Tele Vue’s reputation as a fine optical maker cannot be disputed and every unit that leaves the factory is essentially guaranteed to deliver as promised. That reputation in and of itself might sway owners to it.

As a result of the influx of imported doublets, the used value of the ’76 is taking a beating. Units can be purchased for under a thousand USD which was unheard of a few years ago. So it’s a buyers’ market in the used department.

Bottom line is this. The concept of a small, quality ED/APO doublet is indispensable as indicated above as they can go anywhere at a moments notice. Portable and hike-able with some restrictions. If you choose a TV76, the quality, build and endless possibilities...you will be more than happy.

Here is the scope in it's various configurations.

An Air Show of Tele Vues (and other stuff)

The CIAS or Canadian International Air Show hosted at the Canadian National Exhibition (CNE) has been a yearly pilgrimage for K and I for the last couple of years on Labour Day Monday. Last year we tried a new spot a little closer to the show at the West Arm of Humber Bay Park. The East Arm would be preferred IF we didn't take quite the production with us. But because we have the means to actually photograph the show closer up, we don't have to go near the crazy-crowds at the CNE or pay a mint for parking as is always the case, never mind actually trying to find a parking spot. Our yearly pilgrimage starts fairly early in the morning as we want to get the best possible view from our location...typically we arrive around 9:30am for a 12:30pm start time...that might sound crazy, but it isn't given that you don't know how the crowds will be, even that far away. Not only that, the weather was gloomy for most of the morning leaving us wondering if the show was actually going to be given the green light.

To say we bring a "production" is an understatement. We don't pack light.

Pictured above from right to left, the Tele Vue Pronto and the Tele Vue 76, two Canon 30D's, an older Canon Rebel, two tripods, binculars and lenses, never mind what is not shown, the chairs, a table, food/cooler and the Alinco scanner for listening in.

We did manage to shoot through the Pronto but we mainly kept that as our visual scope and given it's age and era it was made, it is still delivering a wonderful image. Granted it was harder to track some of the aircraft at higher speed, but the view was crisp and bright, as expected. False colour? Yeah, but who cares.

Of course false colour can be a biggy when you photograph so the '76 was called in. Of course that's where the insanity begins.

Think about it. A 480mm Refractor telescope, with a crop conversion to 768mm with a manual focus trying to capture a fast moving object. Crazy. But it can be done with a lot of practice and patience. Don't expect a high success rate either. I would predict that one out of every two photographs will be a flop. One thing that helped was the Orion Field Flattener to help sharpen the image. For whatever reason, I seem to have an easier time focussing the '76 with it. Perhaps it's my eyes going. I don't know. Of course it will help with the edges, that is for sure. Also it's important to keep the shutter speed up as the '76 is working at f/6.3 and given the weather and haze was having an effect, I will find out how many shots suffered from too slow a shutter, if any actually did. Overall I found it fun to work with if not quite challenging. A challenge because not only are you trying to do so much at one time including trying to frame it too look nice, the target is moving and at times moving FAST. As aircraft approached our site, I would switch to my 30D and the 70-200 f/2.8 with the 1.4X telenegative to get a different perspective. Both combinations seem to have worked.

I have a boat load of images to process but check out this first image and I have found what appears to be a smudge on the sensor of my Canon Rebel. Ugh. Anyway, check out this cropped pic, desaturated and a little bit of sepia added of the planes approaching the CN Tower in the background. This was taken with the '76...

Early results look good.

I think it is fair to say that both K and I are fortunate indeed with two very good, reasonably portable, multi-functional refractors that again are proving their worth in some very unique circumstances.

Addendum: The photos are up and are a mixed bag of images where the Canon 70-200mm f/2.8 and 1.4X Telenegative and the Tele Vue 76 were employed. Enjoy! M:)

A case for the quick set up...in Winter (or why astronomers should never HIBERNATE!.

Just to summarize:

I have been looking at double stars...like I normally do. Eta Orionis is fab! Go look at it! Mars has been great. This has been a good opposition. Go look at it! Saturn is back, it's great! Go look at it!

So anyway...

But what I want to do is talk about the quick set up. I honestly feel today's amateur short changes himself/herself by imposing a moratorium on winter observing because of the usual excuses...it's too cold, the set up takes too long, it's too cold...blah, blah, blah. The question of portability has more involved in it than "can I lift it"...just like picking the right clothing, picking the right telescope is very important.

Okay so it might sound more like a "Pronto Brag" (thanks SUG!). But whatever you have, the case for the "quick set up" is this. If it takes too long to set up, takes too long to cool down and quite frankly, is too cold to touch in the dead of winter, chances are you have the wrong "winter scope". This assumes you live in a snowy country (what snow? Toronto has had so little this year). If you are observing in Florida, you might want to skip this blog entry.

Any small Refractor, SCT/CAT, 6"-8" Dob or Reflector that can be mounted to a sturdy, portable AZ mount (or EQ if not too big) is desirable. In my case, the Tele Vue Pronto which can be converted to so many different types of observing, it's been a great scope in the quicky set up (assuming I remember to convert it to the right dovetail--side note to that is I merged the universal dovetail to the TV balance plate--that worked!).

How fast is the Pronto up? Well, under 10 minutes. I would hazard a guess that I could set up the Pronto in five minutes with heaters and e/p's ready to go. Simple AZ mounting, no motors, no polar alignment, no elaborate GO-TO alignment. Set up fast, to be taken down fast. Oh and the big thing. Short cool down time. Less than 30 minutes on average. You don't know how important that is till you drag out the monster aperture and it cools down after you want to go home.

So whatever you do, the quick set up adds to your winter enjoyment. While you don't have the aperture to work with, or perhaps the elaborate, imaging set up, the old argument, "the best telescope is the one you use most often", comes into play. It's far more important that the astronomer is "out looking through equipment" rather than "looking at equipment"....

No, I am not going back to astrophotography...much

I took a few images last night just to fool around and give people the perception of what it was to actually look through what used to be known as a "rich field refractor". I hooked up the 30D to the Pronto just to goof around a bit. The moon image is alright, but deep sky imaging in Mississauga is a chore with all the light pollution.

I am not really that interested right now in astro-imaging. Too many other things going on to take it seriously, so for now, I am just meddling with the Pronto a bit but my focus is visual observing.

M:)

November Moon and Pleiades

What a view tonight! Just went out tonight to see if a binoviewer would work with the Pronto and couldn't spot the Pleiades at all visually without the telescope. The Moon was overwhelming. Spotted both in the Pronto at very low power and it was quite pleasing but still overwhelmingly bright.

Orion is rising slowly in the southeast, but it's cold tonight.

Oh and the binoviewer? Well it worked, but I had to try several combinations before it focused. Found out it works well with the Tele Vue 2X barlow combination. Otherwise I couldn't wrack in the focuser far enough.

Rare treat to have a clear night in Mississauga in November. It's hard to get them and being on standard time again, no more easy daylight set ups. Still, it's kind of surreal to be out in the cold when everyone else is hiding inside.

M:)

SP Mount to make a comeback?

Well that was a short retirement...

I said earlier that the Super Polaris mount was to retire gracefully which really meant to be used only as a back up. Well maybe retire was not the right word. Given the convoluted mess that the two mounts, the CG-5 and the SP mount create because they use two different saddle plates, it became necessary to standardized the saddles just in case both the C102 and Pronto go out without having to take two different plates out. The SP saddle was upgraded with an ADM Super Polaris Saddle. I outfitted the Pronto with a simple Vixen style universal dovetail which nicely fits into the ADM SP Saddle. The C102 has been given a standard Synta eight inch dovetail which is also the Vixen standard. My original dovetail for the Pronto did not work right. Two screws got in the way of the ADM adapter and it had to be simplified. Just two screws and two washers now. It looks much better.

The combination works and is now seamless without accidentally forgeting a plate or forgeting the tools to switch things around.