I have to say wow to the quality of my Alpen 853 scope. It is a clear day here in Nampa idaho and I can see just over 20 miles away bogus basin ski resort and I can make out people skiing on the mountain. I can't tell who they are or anything like that but I can see them moving across the snow. I was amazed I could see people that far way. I was about 7 or so miles from the mountain and could see them fairly well but was shocked to still see them from my home over 20 away. This alpen rainer 853 is really top notch. The views even at 60x are clear. Just wanted to share my excitement with all of you. 20 miles away that is impressive. :0)
-
Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.
Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
I can see people 20+ miles away :) (1 Viewer)
- Thread starter tazzilla
- Start date
mooreorless
Well-known member
I guess this sort of answers your other question. Don't you just love being able to see that far! From my back porch I can only see 5 miles and an overlook at 2.8 miles. Picture of the power line at 5 miles.
Do you think you could read license plates at 5 miles? 2 miles?
I am glad you got a good scope!
Do you think you could read license plates at 5 miles? 2 miles?
I am glad you got a good scope!
Attachments
FrankD
Well-known member
Hmm, I never thought of trying for distance with my scopes. It isn't how I typically use them. However, this sounds like fine. I will see what I can do in terms of pics with the scopes that I have on hand. Maybe the 75x wide angle on the Theron will produce some interesting results.
If this were hawkwatching season then the view from up on the mountain would be perfect. I believe one of the locations that one is able to see on a clear day is about 17 miles. Will see what I can come up with when time allows.
If this were hawkwatching season then the view from up on the mountain would be perfect. I believe one of the locations that one is able to see on a clear day is about 17 miles. Will see what I can come up with when time allows.
Wildmoreway
Well-known member
Back in 2004 I have a Fuji S20 pro compact digicam with a 6x zoom and 3MP resolution, I took a few shots on the Dover Cliffs over the channel towards France. in one shot there was a cottage with what appeared to be someone standing outside it (no more than a few pixels), that with equivelent focal length of about 210mm, the distance there would be about 22 miles. With decent glass, good magnification and clear air it wouldn't surprise me that you would see people at 20 miles plus and have an idea of what they might be doing.
No this is with my Canon SX40 at 160X zoom.
henry link
Well-known member
I'm not questioning the quality of this scope, which may be excellent, but neither the photos nor the visual report of "people" visible at 20 miles tells us anything much about its resolving power.
The photos tell us nothing because we don't know the true angular size of the objects in them. A distant skier on snow is the equivalent of a single black dot on a white background. That can be detected at a much smaller angular size than the resolving power of the scope, just as the eye can detect stars that are vastly smaller than the eye can resolve. A person at 20 miles is not really that small compared to the resolution of an 80mm scope. An average sized skier at 20 miles would be a dark object about 2 arcsends wide and 5 arcseconds tall. An 80mm diffraction limited scope has LP/mm resolving power of about 1.5 arcseconds, but that same scope allows the eye to detect a single black dot on a white background much smaller than 1 arcsecond. If the air is steady enough, the individual skiers should be easy to see.
The photos tell us nothing because we don't know the true angular size of the objects in them. A distant skier on snow is the equivalent of a single black dot on a white background. That can be detected at a much smaller angular size than the resolving power of the scope, just as the eye can detect stars that are vastly smaller than the eye can resolve. A person at 20 miles is not really that small compared to the resolution of an 80mm scope. An average sized skier at 20 miles would be a dark object about 2 arcsends wide and 5 arcseconds tall. An 80mm diffraction limited scope has LP/mm resolving power of about 1.5 arcseconds, but that same scope allows the eye to detect a single black dot on a white background much smaller than 1 arcsecond. If the air is steady enough, the individual skiers should be easy to see.
Last edited:
It is a awasome camera Frank. That was taken with out a tripod hand held. It records great video. Check out my utube vids I posted you will be impressed. USATAZZILLA is what to search under. I sold my HD video recorder after gettijng the canon and the new digic 5 processor is really that good :t:
henry link
Well-known member
Frank,
These camera lens numbers should not be confused with telescope magnification. It's true that the SX40 had a 35x zoom lens, but that refers to the focal length range of 4.3mm to 150.5mm. The 4x digital enlargement on top of that adds no detail, so the highest "magnification" is only equal to a mild telephoto lens.
The HP PW55o has a 5mm to 25mm zoom range. At 3x zoom its focal length is only 15mm. Combine that with a 20x telescope and you have the equivalent of a 300mm telephoto lens.
Henry
henry link
Well-known member
Those focal lengths are not real. They're the so-called "35mm equivalent" focal lengths. The size of an object focused at the sensor is the same for any 150mm lens, no matter what the sensor size is.
For digiscoping I often use a 50mm lens combined with a 30x scope. That makes the size of an object focused at the sensor equivalent to a 1500mm telephoto.
For digiscoping I often use a 50mm lens combined with a 30x scope. That makes the size of an object focused at the sensor equivalent to a 1500mm telephoto.
Hey Henry sould like you are well intune to this so I have to ask. What camera and scope are you using. I am just a newbi at the whole digiscope aspect as well as spotting scopes in a whole. I just purchased the alpen 706 camera adaptor and a Alpen 810 22x fixed zens both for $100 shipped from Tim the owner at Alpen optics. He really cut me a great deal and I can't wait to try them out. I am trying to get the Alpen 815 30x fixed eyepiece but they are no longer making them at this time and all on line prices are about $170 so I will wait on that one. Tim at Alpen Optics has treated me with great customer care. I am just one person who had some questions and felt like I was being treated like one of his biggest accounts. They really have great customer skills there. I have become a big fan of their products and hope some of you here give them a try I sure you will find them to be as good as I do. I may have only owned a few pair of optics over my time but I have a very sharp eye and can tell good bad and ok apart and the Alpen 853 is really great. Thanks Taz
henry link
Well-known member
Well, I'm really mostly a visual user of scopes. My digiscoping is of the crude handheld variety, done only for bird ID purposes. The scopes I use for birding are small astronomical refractors made by Takahashi and Astro-Physics, but I have the wrong kind of camera for digiscoping, a Nikon D40 with pixels too large to take full advantage of the optics of the scopes. There are others here and on the digiscoping forum who can tell you much more about that subject than I can.
mayoayo
Well-known member
Yes,...I think You should ask your buddy Tim to send Him a copy of that wonderful scope for him to review...a good score in that arena and You are in the hall of fame of ED optics!..at least in this forum..
But if You guys are afraid,and prefer to rely in opinion and good words...thats ok
