Which telescope is best to observe yachting from land?

[Schooner Chandlery]

That's an interesting one. I would think the motion issues would be more significant than normal use of a telescope would require. The optics and stabilizing electronics would seem to be much more costly, yes. I'm following the thread to see what you come up with.

Thanks for a question to noodle
Brenda

[cristee]

Originally Posted by UNCIVILIZED

Steady, & guys, sorry, but 20x is woefully underpowered for those kinds of distances. Especially for literally reading something at that distance.

Regarding telescopes, I know of several which get great reviews (none under $1k by themselves). But one big issue which you're going to run into is that to get the magnification needed to see sail numbers at that distance, is that Any, repeat, Any; haze, moisture, mirage, dust, etc. in the air, is going to make using that much magnification impossible. And such is all but ever present around the sea.

The stuff in the air (denoted above) essentially, well, literally, scatters the light reflected by the target, which you're trying to see. Thus distorting it to the degree that resolving said images is probably just not possible.

Plus, you're trying to resolve a moving target, & one which, at that, doesn't move in a manner which the eye's not used to tracking. Meaning it's moving in a quasi random manner. Not lineally or in an arc. Like your eye's used to. Making it that much tougher to focus on & resolve.
Especially as boats are continually jerked around moving through waves, & sails flap & flutter with the breeze. Plus they're attached to the mast, which is a magnifier of any motion that the boat goes through.

It might be possible using a computer hooked up to a telescope, which has software with algorithms that'll render "it's best guess" as to what it "sees". And then it'll put up (a composite of) said image on your screen.
Oh, & you'll likely also need a motorized drive on the optic to track the target. And track it in a way which the computer's software moving the optic, can predict.
That's how big time celestial is done, & has been for decades. High end amateur, & Professional. Ditto on look down satellites.

Somewhere over land, on a perfectly clear day, with zero mirage it might be possible to get & use that kind of magnification/resolution, but otherwise, you can likely forget it.
I mean you probably can't read sail numbers with the naked eye @ 100yds. And 4 miles = 8,000yds, so....
Though I may be wrong. Then again, this ain't an optics forum. And unless you know guys who build things like the Hubble...

Do some reading on the usual high end models. One other option might be a surveyor's scope, the big ones. Plus astronomical telescopes, as mentioned.
But the thing is, getting into that kind of glass, plus a good tripod, as well as a good tripod head, will likely set you back a good bit more than $1k (several times that is likely).

And you need all 3, as without a steady base, & a smooth way to pan your optic, you're sunk at the starting gate. Especially as with the kind of magnification you're talking about, your field of view at such powers, will be tiny, so following motion via hand operated gear will be a "challenge" to say the least.

Plus, without the premium vibration dampening built into what's holding up & panning the optic, you're sunk again. As the motion of everything which touches the optic is magnified by 80x, or whatever. Such as one's heartbeat & breathing. I mean that's discernable with plain old 7x binoculars.

Maybe using a digi-scoping kit would work. Which is where you have a digital camera bolted onto the same plate as the telescope. Mounted on top of the head on top of the tripod.
Then, as you snapped off pics (using remote shutter activation so as not to disturb your optics), & pulled them out of the camera via your computer, you could magnify them sufficiently (& or with the right software) so that you could read sail numbers. Maybe. Though again, such is a several $K setup.
Ditto on possibly using a high end camera, with image stabilization, & lens the size of a bazooka, on a tripod. Again with a remote shutter, & image downloading to a computer.

A place to start might be www.OpticsPlanet.com But my friend's the astronomer, not me. Neat stuff those astronomers have though. Albeit Really pricey.

I hate to sound defeatist, however, based on what I know, it is what it is.
Though I would be curious to find out if you come up with something which works. So good luck.

I agree that haze might muck up any view but we have many very clear bright days and it rarely rains on Saturdays.
Boat movements may not be an issue at a distance. Yachts tend to hold steady courses and speeds whilst pitching is relatively small in proportion to boat size.
Thanks for your helpful comments.
Chris

[UNCIVILIZED]

Yeah, I am kind of fence sitting in terms of how much of the motion of the boats would be at those kinds of distances. And figure that to some extent, it would depend on ocean & wind conditions that day, plus the stability of the boats involved. The faster, planing, or foiling ones being more stable.

[mstrebe]

You want what is referred to as a spotting scope. For example:

Celestron Ultima 100 4"/100mm Spotting Scope 52252 B&H

That's a 66X tripod mounted scope with an interchangeable zoom eyepiece (meaning it is also a telescope and can be mounted with standard telescope prime focus eyepieces).

They make the same scope with higher quality "ED" lenses for about $600. ED lenses have more transmittance and less reflectance.

It's exactly what you're looking for. I use mine to spot from my roof deck over the Pacific ocean in Cardiff, CA. I also have two other telescopes (a 16" Newtonian reflector and an 11.25 Schmidt Cassegrain)

You need a refractor because astronomical telescopes that use mirrors invert the image. While it's possible to rig them with errecting prisms, you'll be out many thousands of dollars before you're done with that route.

A 100mm (4") lens is as big as you can get within your $1000 price point limit. Firstly a good tripod is going to cost $200 so you need to leave room for that. 6" refractors are in the $3000+ price range.

At 66X, a refractor is very near its diffraction limit, which means you can't get much higher before you start to lose resolving power anyway.

As for quality, you can pay more than Celestron to Nikon or Swarovski, but you're not going to get a better scope. These are actually made in Russia by Lomo, a century old optics house that used to do all the high-end optics for the soviet military. Bullet proof scopes.

You can easily mount a DSLR camera to these and use them as an extremely long-range telephoto lens equivalent to a 600mm telephoto lens. I've used mine (along with a solar filter) to take pictures of venus transiting the sun, for birding, and to take pictures of sailboats going by the house. It works very well but it lacks autofocus so you need some time to compose your shot if you want to use it as a camera lens.

Now if you want something made of brass that looks like it's out of a victorian sea-widow's watchtower, then you're not going to get a serious instrument that can actually resolve with the magnification you'd need for this purpose within $1000.

I have a pair of Canon 18x50 image stabilized binoculars. They're very nice, but expensive and they don't have the magnification you'll need to really see boats at sea with the resolving power you're looking for.

With a tripod, you do not need image stabilization. That's what the tripod is for. Just get a nice tripod. There are astro-tripods made that have rotating knobs to move the telescope precisely in azimuth so you can track a moving ship very precisely with no shake, which can be had for under $200. For example:

http://www.bhphotovideo.com/bnh/cont...=REG&A=details

I have one of these mounts, and it handles the celestron spotting scope quite well. It's no great looker with its cheap aluminum legs, but the gear drive is quite nice. I think you could replace the legs with varnished would and end up with something really nice that functions very well.

You could also use a heavy-duty camera tripod like a Manfrotto but they lack the precise gear drive and have a lot of features you won't need but will pay for.

[StuM]

Originally Posted by cristee

I am drawn to video as it allows viewing on a TV.
The equipment would be behind the windows.
Maybe too much technology for me.
But who would I ask?
Chris

Maybe out of your price range, but check out Sony digital binoculars:

https://www.youtube.com/watch?v=nPcbCzXbD_8

[cristee]

Originally Posted by mstrebe

You want what is referred to as a spotting scope. For example:

Celestron Ultima 100 4"/100mm Spotting Scope 52252 B&H

That's a 66X tripod mounted scope with an interchangeable zoom eyepiece (meaning it is also a telescope and can be mounted with standard telescope prime focus eyepieces).

They make the same scope with higher quality "ED" lenses for about $600. ED lenses have more transmittance and less reflectance.

It's exactly what you're looking for. I use mine to spot from my roof deck over the Pacific ocean in Cardiff, CA. I also have two other telescopes (a 16" Newtonian reflector and an 11.25 Schmidt Cassegrain)

.

Eureka??

Can you read sail numbers at 4 miles?
Have you considered auto tracking?
Can you project onto a TV?
This is wishful think but I might as well ask.
Chris

[UNCIVILIZED]

It appears that you may have struck ("Red") gold. As most of the other scopes which fall into that class, with that kind of clarity, cost big.
Some of them which he names.

As to the camera question. The answer's most likely yes, as the majority of cameras can be hooked up to a TV, especially SLR's or one's akin to them. Plus, as long as the focal length is right, you could likely just use a video camera to look through things with. And they're definitely TV compatible.

Though what you can see will still be air quality limited. And as to seeing that kind of detail @ 4 miles. Well, I'll be curious to hear how it works out.
Should be an interesting project.

Also I'd imagine that with a VHF & or a scanner set on the right frequency(s) you could monitor the unofficial chatter of the race committee & specatator boats.
The trick being finding the frequency, as it wouldn't be something that they'd advertise, as the chatter might give one competitor or another an edge.

I'm sure that there are some on here who are savvy enough to steer you to the gear which would let you figure such information out very quickly.

[mstrebe]

There are a number of simple ways to put a video camera on this or any other telescope. Any existing video camera that accepts threaded filters can be adapted to a telescope. There are also a number of telescope specific cameras but they're generally expensive.


You won't be able to make out sail numbers at 4 miles with this scope or any other. Atmospheric disturbances alone will make that impossible for any scope. One thing to understand about terrestrial telescopy is that heat rising from the earth or ocean creates refractive disturbances that accumulate into a limit of maximum resolving power. My best scope couldn't do this at 16".

Autotracking is built into most telescopes these days, but they're designed specifically to eliminate the effects of the earth's rotation. There are trackers that can lock onto stars, but nothing exists which will lock onto an arbitrary daytime object for tracking. You can buy mounts (tripods) with manual tracking controls and put a wireless interface that will allow you to use an iPhone app to control the scope position from anywhere in the world, and cameras that will send you back the video through the eyepiece.

But not for $1000. On second thought, maybe.

Boat movement is not a significant issue at this distance. You can easily and slowly move the scope to keep a boat in frame. If you think about the distance and speed, a boat moving 8 knots four miles away moves across 45 degrees in 30m, or 1.5 degrees degrees per minute. Your angle of view will be something like 1.5 degrees, so a boat will be in view for about one minute as it moves across the fixed of view. Not a huge tracking problem.

I haven't done any compatability analysis so don't go buying stuff willy nilly but here's a computer controlled mount that will handle the scope:

http://www.telescopes.com/products/sky-watcher-allview-mount

And here's a wireless controller that puts it on an iPhone app:

http://www.telescope.com/Orion-StarS...B/p/101905.uts

[missourisailor]

mstrebe,
The Celestron Ultima 100 Spotting Scope that you referred to, on the B&H site has quite a few reviews that state that it doesn't focus very good above 22x.

I assume that it is because the main optic is not ground to a high precision.
Is this to be expected in all sub $500 scopes?

[mstrebe]

Hmm, that is troubling. Focus problems could be poor grind, cheap glass, or imprecise alignment during construction.

I own the more expensive "Regal 100ED" version which focuses very precisely but costs more than 2X as much:

http://www.bhphotovideo.com/c/search...Fc9gfgod4TYFVA

As you can see that version has mostly five star reviews, so I'll limit my recommendation to it.


Sent from my iPad using Cruisers Sailing Forum

[tomfl]

You may want to start off here

beginners forum at cloudynights

I would suggest a good pair of binos, here is the forum link.

Make sure you have a good understanding of eye relief what ever kind of optics you get.

[S/V Alchemy]

Binoculars on a tripod does the trick. The boats are moving and you want a wide field of vision.

[canyonbat]

We have pretty much quit using our expensive binoculars both on shore and on the boat. Instead we use our 50 X Image stabilized Canon Power Shot camera. Zoom in and take the picture then zoom in again when viewing and you can read signs and stuff from a long ways off.

[reed1v]

Telescopes are so last century. Get a GoPro cam attached to a drone and just fly it out there. Well within your budget and you can watch via your laptop or smart phone in real time or later.

[mstrebe]

LoL. Well, I have a drone with a gopro, and binos, and a telescope, and I'm here to tell you that I don't use any them for any overlapping purposes. And in this case, you can't really line up any shots, you just have to fly around and hope the footage you get is worth anything. Drones aren't the end-all, be-all of photography and they certainly don't replace a scope for most of its uses.

Using a drone takes quite a bit of setup. Far more than taking the cover off of a outdoor proof spotting scope on the deck and having a look at the boats. They have about 30 minutes of runtime and take longer to recharge than they run. So hopefully you get your entire event in that time.

If you want video of boats to watch later, then a drone with a GoPro is probably the way to go, and they can certainly get a lot of interesting shots that there's no other good way to get.

But this comparison is like stating that RIBs have made sailboats obsolete.