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New Sub Forum needed - Astro scopes for Visual (1 Viewer)

goldenarrow

Well-known member
I have an idea that seems to be missing here. The Digiscoping forum includes telescopes for photography but what about a sub forum here to use astronomy scopes as visual field work devices? I don't always want to use a camera for circumstance when out in the field. Sometimes, I just want to watch the birds do their thing! I want to know things like, which scope has the best sharpness and contrast for visual use. Which astro eyepieces work best with which scopes. Which accessories will work with my scope vs. someone else's type of scope. Can binoviewers help in ID work, especially reading tags on a birds' legs. ETC......

For instance, I have come into ownership of a Questar Birder. I am finding interesting things about its operation in the field. Would like to share such stories and progress over time along with other people's experiences with telescopes as spotting scopes. Like, did you know that if you find a way to add a 45 degree angle amici-prism to the axial (backside) port of a Questar, that the image is right-side up and correct left and right? I didn't until I tried it myself on a whim.

I would think with a number of people using telescopes for photography, there must be some interest in using them as visual spotting scopes too???

Is there a way to add a Sub-Forum to this Equipment forum and how is that done???

B :)
 
Well....I've certainly stumbled into that category myself. The distance of the eagles makes that
practical and economical. It was a bit of a surprise how well they worked. Long astronomicals
would be there, but most nature-watchers in the high-f category use folded reflectors
(CATs, MAKs) ....around f/12, for looong range. Maybe not exactly astro, but long focal length.
So many MAKs seem to end up digiscoping terrestrial things miles away.

You could also call it the long-barrel forum, (or slow barrel?) seeing as that encompasses the promises
(high power, easy on the oculars) and the perils (narrow field width, longer or heavier) of the breed.

The ED/APOs (f/6.5 - f/8) do seem to compete for both the high-power and the big-fov spaces.
You can sort of have your cake and eat it to, but not your money..
one big difference between those and a C90 or C8 an astro telescope is cost.
(but you pay weight for the MAK and length for the astro).

One topic becomes crucial at 100x and up: the tripod.
One great thing about the high f-ratio has been how the eyepieces perform.
It's like a new life for them at the field edges.
Most eyepieces have eye relief equal to some fraction of their f.l. ..
if their focal length can be longer, the eye relief is longer.
 
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Well....I've certainly stumbled into that category myself. The distance of the eagles makes that
practical and economical. It was a bit of a surprise how well they worked. Long astronomicals
would be there, but most nature-watchers in the high-f category use folded reflectors
(CATs, MAKs) ....around f/12, for looong range. Maybe not exactly astro, but long focal length.
So many MAKs seem to end up digiscoping terrestrial things miles away.

Any of the Cassegrain variants are well known for being "planet hunters". The long focal length and lack of distortion from aberrations make them ideal for looking at Jupiter, Saturn and their moons. But my thing is the weight. I just cannot carry a heavy refractor and tripod into the field. And I don't want to spend on high end spotting scopes (maybe one day, but not able to now). So, a high quality mirror telescope with a high contrast eyepiece becomes a very nice view at 50x or 60x power. If the light is good, up to 100x seems usable to me. And the targets do not always have to be birds....

And to add more reasoning to use telescopes for visual work, a review posted on Cornell's web site has favorable mentions of TeleVue refractors and the Questar. Others would work also, they just did not review any others like the people like Paul here are using for photography, like the many Chinese made 80mm/500 focal length telescopes. And I recently shared how I took that 500mm refractor apart and made it portable and only 3.5 lbs, good for field photography. But I still wanted a spotting scope! Then comes along this very generous person with a Questar.....

:t:
 
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There is a saving grace for the astro refractor: daylight.
I can be very happy at 80x with 70-80mm. The scope is very light
(maybe lighter than the spotter, with the precision-milled body and extra glass
and armor). High contrast helps make up for missing light..

I carried my 70mm up a hill with one hand. Now....the tripod needs
improvement. That would add maybe 5 lbs (like the Vixen mounts).
A hollow refractor is light...its tripod can be heavier.
I'm pondering some kind of wire+sorbothane scheme to damp vibrations.
That would save weight, but I don't understand the vibration modes yet.
I think my main devil is azimuthal, and from the legs 'rolling' together.
 
There is a saving grace for the astro refractor: daylight.
I can be very happy at 80x with 70-80mm. The scope is very light
(maybe lighter than the spotter, with the precision-milled body and extra glass
and armor). High contrast helps make up for missing light..

I carried my 70mm up a hill with one hand. Now....the tripod needs
improvement. That would add maybe 5 lbs (like the Vixen mounts).
A hollow refractor is light...its tripod can be heavier.
I'm pondering some kind of wire+sorbothane scheme to damp vibrations.
That would save weight, but I don't understand the vibration modes yet.
I think my main devil is azimuthal, and from the legs 'rolling' together.

How about using carbon fiber legs and a medium duty ball head - tilt the head sideways and use it as a poor man's alt-az ?? The only thing I don't like is that the quick release plate is always getting loose!!! A dealbreaker unless I actually used gorilla glue to attach it to the bottom of the scope!!!
 
The ball is interesting, esp. for moving targets. Carbon fiber legs are usually quite expensive.
Ah...plate rattle. I was thinking a ball might be fitted to the scope somehow.
Like...wrap the scope in polyethylene and have a cured foam grip it. The problem is always
how to make it. Builders are using polyurethane foam more and more to stick things together.
Messy stuff, though. Everything has to be thought out and the cure cannot be deep.

What I'm pondering would sort of make a tripod look like an oil drilling derrick...triangles
going up the uprights, stretchers across. Sway-bracing between legs. Most members
would be wire, which you could wind on on site and either re-use or toss out. The legs are
very strong along the axis but the joinery at the top has play to it. My heavy-duty
Bogen pod would work but it's much heavier...cast iron at the top.
 
How about a "Long Distance" forum, 300 yards to 5 miles (and beyond, you C8 crazies ;-) )?
That would cover long-FL scopes and also bring in EDs and APOS, when they can go past 100x.
 
I add a signature for the new "astro scopes and eyepieces" sub-forum addition...Its a useful one with all the different makers ,models and accessories...good idea
 
The TV 76 is pretty spectacular. All at f/6.3 to boot. Thorough enough to have a nice shade.
They cooked up the idea of stuffing the barrel with emery cloth. No holds barred.
And.... $1700! Comes with 20mm Plossl....I'd be trading that in for a harder drug pretty soon. Heh.
Add a few $200 eyepieces and a $350 tripod, maybe.
 
And don't forget the small Takahashi and Borg refractors being used for birding.

The aim would be to see what considerations make it different for visual usage. I like the idea of comparing eyepieces with different telescopes since the characteristics are slightly different with different combinations of equipment. The pleasure and satisfaction of seeing the living bird as if it were right next to you!
 
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good title

I add a signature for the new "astro scopes and eyepieces" sub-forum addition...Its a useful one with all the different makers ,models and accessories...good idea

I like the title. I might prefer "Visual Astro scopes and equipment". I get into so many problems with choosing accessories and measuring for adapters and like, how to figure how much extension tubing to buy. Like, I just ordered a custom made adapter to convert the port in the back of the scope to SCT threads so I can use other astro accessories. Problem is, I don't know if the extension tube attachment will fit quite right to the custom made adapter. We shall see...... But that is the stuff that one gets into when having to use an Astro scope. Lots of choices for adapters, but will any of them work? Sometimes not. So, having a space where we can compare notes as birders, not astronomers, and not photographers, seems necessary. Just my humble opinion expressed in the deepest gratitude for all here!

B :)
 
setup pics

For anyone who needs to see what a telescope could look like as a spotting scope:
1. 89mm Maksutov-Cassegrain on Manfrotto 410 geared head. ~8 lbs.
2. Everything on top of a carbon fiber tripod. ~11 lbs total.
3. Optical train: axial port -- chinese step rings -- PreciseParts SCT adapter -- Reducer -- SCT 2" holder -- 1.25" (gray) twist lock -- 1.25" Amici erect image diagonal -- 18mm orthoscopic eyepiece.

I could do without the reducer if I wanted to buy a couple of longer focal length eyepieces. This works for now. Also, I don't have a video fluid head, the geared head is an experiment. Works best with ducks and shorebirds where I am mostly panning left and right.

Not in the pics - straps dangling from the tripod (a gun strap + an old photo bag strap). I am able to carry it almost hands-free if worn diagonally across my shoulders. Let's me use my binoculars as needed.

One caveat, the focal reducer takes up a lot of extra infocus travel, so that setup is limited to 627 feet to get focus (according to Google Earth measurement). I will need to do without it if I want to look farther than that. That also means 2 inch eyepieces and diagonals may have a similar limitation.
;)
 

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That's an effective-looking rig. I need to peek at some carbon fiber tripods..

There is an astros-for-digicam subforum. I'm finding many issues in common with them,
like 'flocking' (tube lining) and eyepieces.
 
I come from astronomy and use an Orion ST80 achro, a Celestron 102mm Maksutov and a William Optics 66ED for terrestrial also. Mounted on a Manfrotto tripod with Novoflex MagicBall or a Vixen Porta Mount. Baader Hyperion Zoom is nice for terrestrial but other eyepieces such as Nagler T4, Delos, Radian, Explore Scientifics etc are effective.
The f/5 achro has noticable color error unless used at moderate powers, 13-40x. The f/13 Mak is colorfree but very powerful, 55x with 24mm eyepiece. I can use the 0.63x reducer though. The f/6 Petzval is perfect. Not a real APO but very nice from 13x-66x, a nice range for terrestrial. It also has an SCT visual back and T2 adaptor, so it is very flexible. I take it everywhere as widefield second to the dobsonians or catadioptrics. It could be used in the field although it's more delicate than a real spotting scope.
 
A 70mm-f/10 achro with blackened barrel/tube and a Super-Plossl EP from binoculars is amazing at 40x,
very fine at 70x, sharp but dimming at 120x. It's long, of course, but quite light.
The tripod could stand upgrading.

I did the same treatment to a 60mm-f12, including a Bushnell Custom 7x26 bino eyepiece (Plossl. ~15mm).
Clear and no fringing at 50x! Very big apparent field. The tripod was useless. It was great on the old
Bogen mount. The 60mm starts fuzzing at 100x, but no detectable chromatics.

If you wanted the best at all powers for the cheapest, you could have 6x30 binocs, then a plain 25x50
spotter, then an astro at 70x70. You need the 25x50mm to fill in the field width up to
a few hundred feet. What costs is having it all at once.

You're getting a lot of light With that Mak. I'm obsessed with contrast. A folded refractor would be nice,
but All I've seen is the pricey Leupold.
 
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subforum

That's an effective-looking rig. I need to peek at some carbon fiber tripods..

There is an astros-for-digicam subforum. I'm finding many issues in common with them,
like 'flocking' (tube lining) and eyepieces.

Thanks, it is a used Benro gotten from KEH for $139 in "EX" condition. Joke, it had pebbles and wet sand inside all three legs. Almost sent it back but decided to take the whole thing apart and disinfect it. River pebbles and sand all over the place but got it cleaned and it only mildly smells of mildew now. Works well too, even with the tacky rubber furniture feet that does not mark up wooden floors.

Also, your link for digicam did not show. Maybe if you could try posting it again, thanks.
:t:
 
portable scopes

I come from astronomy and use an Orion ST80 achro, a Celestron 102mm Maksutov and a William Optics 66ED for terrestrial also. Mounted on a Manfrotto tripod with Novoflex MagicBall or a Vixen Porta Mount. Baader Hyperion Zoom is nice for terrestrial but other eyepieces such as Nagler T4, Delos, Radian, Explore Scientifics etc are effective.
The f/5 achro has noticable color error unless used at moderate powers, 13-40x. The f/13 Mak is colorfree but very powerful, 55x with 24mm eyepiece. I can use the 0.63x reducer though. The f/6 Petzval is perfect. Not a real APO but very nice from 13x-66x, a nice range for terrestrial. It also has an SCT visual back and T2 adaptor, so it is very flexible. I take it everywhere as widefield second to the dobsonians or catadioptrics. It could be used in the field although it's more delicate than a real spotting scope.

I think portable telescopes are still underrated since most are about the same size and weight of an expensive spotting scope. No weather proofing yet though. I like the power of the Maksutov, differentiates it from the other usual spotters. Someone mentioned a hawk on a distant power tower, put in my orthoscopic eyepiece without the focal reducer (about 83x power) and he was impressed how detailed it was. I have a Pentax spotting scope eyepiece that lets me get 112x power. Dim but very pleasant view.

By the way, I use an f/6.25 Celestron refractor as a portable telephoto lens when photographing birds. Sounds like you have a nice choice of gear to choose from!

Question - do you think the MagicBall is more useful that a regular ball head? I was thinking of just using a panorama head/base under the gear head but not sure.

B :)
 
achros

A 70mm-f/10 achro with blackened barrel/tube and a Super-Plossl EP from binoculars is amazing at 40x,
very fine at 70x, sharp but dimming at 120x. It's long, of course, but quite light..
.
.
If you wanted the best at all powers for the cheapest, you could have 6x30 binocs, then a plain 25x50 spotter, then an astro at 70x70. You need the 25x50mm to fill in the field width up to a few hundred feet. What costs is having it all at once.

Never tried an achro, I like not having to see false color. But yeah, the mirrored type scopes do lack contrast. Anyway, the detail is still there and the portability cannot be beat. I am getting too old to carry large refractors. Someone needs to invent a refractor telescope that wraps around my body with flip up goggles for an eyepiece (stereo). Oh well.....

Never tried astro binoculars. Something else to experiment with!
B :)
 
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