Scope recommendations for beginner owl stalker? (1 Viewer)

[CriesofCarrots]

I've been stalking some Great Horned Owls around my town with binoculars, and I'd like to up my game with a spotting scope. Can anyone recommend a good intro scope that would perform well in low light?
Options for attaching a phone mount to take mediocre photos would be a plus.
I do foresee future, more intensive, birding. But I'm not really sure what my needs will be.

 

[Tringa45]

Hi, and welcome to birdforum.
For owling in low light most would consider binoculars with exit pupils of 6 mm or 7 mm (e.g. 7x42, 8x50 or 8x56).
The premium birding scopes such as the Swarovski ATX 85/95 or Kowa 883 only have exit pupils around 3-3,5 mm at their minimum magnifications, so are going to be handicapped in low lighting. Apart from that the higher magnification of a scope would only be required at long distances for such large birds.
If you are currently using compact binoculars, one of the above binocular formats would be better suited to the purpose.

John

 

[mayoayo]

I mean ..I havent chased them at night,so besides a couple of fortuite encounters and one resident that lived in my in-law's property in Colorado, all the Great Horned Owls I have seen(many many more than Eagle owls here in Spain) have been daily sights..I had a local resident located in a riparian forest in Portand and saw it either roosting or quietly flying between the trees ,pretty much everytime i went looking..
Scopes dont get a lot more than 4mm exit pupil except if you adapt some specialty eyepiece like a 42mm ,but the gain in brighness would be at the cost of magnification,thus defeating the scope primary purpose..getting bigger detail.
Then again 4mm can be bright enough for night observation ,depending where..If you have been locating the Owls already and saw them with binos at night..then you will see them with the scope as well..So one thing that you might wanna consider is ..How do you move around town..?..Do you walk,..bike, drive?..This can determine if you will be be better off with a large,medium or even a compact scope..

 

[Binastro]

11x80 Binocular, usually 4.5 degree field.
Exit pupil 7mm.

15x80 binocular.
Exit pupil 5.3mm.

Both of these are used by astronomers for low light use.

There are 14x80 binoculars, but maybe heavier and longer.

Not sure about 12x80.

However the 80mm f/5 Skywatcher or Celestron doublet refractor performs well with a 32mm Erfle eyepiece in 2 inch fit.
12.5x
4.8 degree field.
Exit pupil 6.4mm.
Any CA problems not a problem in low light.

Regards,
B.

 

[Binastro]

I cannot remember if the 80mm f/5 refractors have a 2 inch drawtube.
I think that the 100mm f/5 does.

If only a 1.25 inch drawtube then a 32mm eyepiece will have a smaller field.

I have a Steiner 15x80 binocular, actually 15x77, which is quite good and a lower weight than most 80mm binoculars.

Regards,
B.

 

[jring]

Hi,

first of all, it would be interesting to know your age (or even better, your fully dark accommodated pupil size) so we can decide what exit pupil to aim for...

But as others have pointed out, chances are that your fully dark accommodated pupil size is larger than what the usual suspects in spotting scopes offer. If I knew a place to look for owls that could be reached w/o a lot of hiking, I would take an small or medium size astro ED refractor and the lowest mag EP that gives an exit pupil close to what my eye's pupils are at night. So either my ED 80 f7.5 with a 40mm EP resulting in 5.3mm exit pupil (exit pupil diameter = EP focal length / objective f focal ratio) resulting in a 15x magnification or the ED 120 f7.5 with the same 40mm EP and consequently the same 5.3mm exit pupil at 22.5x.

The ED 80 with rings and rail, a 2" diagonal and the quite heavy ES 40mm 68 deg EP will be about 5kg, the ED120 with the same diagonal and EP will be close to 10kg and has a length of more than 1m. Tripod and mount excluded - expect at least the weight of the optics for a suitable one.

An f6 scope would give 6.7mm exit pupil with the 40mm EP (which happens to have the largest field stop diameter possible with a 2" focus drive and thus the largest possible true field).

Also as Binastro has pointed out, these low magnifications will also be handled nicely by a good achromatic doublet objective - so if you want it just for owling, an f6 achro with the 40mm EP will be fine if you're still young or an f5 achro with a 30mm EP if 6mm exit pupil is all you need.

And no, spotting scopes rarely offer larger exit pupils than 3 or 4mm, the only exception that comes to mind would be the Celestron Hummingbird ED 9-27x56 with 6.2mm at the low mag end... but at that magnification you are probably getting better views with a pair of night bins (7x50, 8x56 or 10x60 - as the brain adds the images of both eyes you can actually see fainter objects in binoculars than in a monocular telescope of the same aperture).

Also I really wanted to go back to my scope and stuff and get my 5mm Nagler for some higher magnification views before I tested the Hummingbird at some telescope meeting, but after trying it with the stock zoom at 27x, I reconsidered - not worth the trouble as the image was not great beyond 20x or so. It might have been a dud, of course... or just physics telling the designer that an f3.5 ED doublet is not a good idea...

Joachim

 

[tenex]

Hi and welcome Carrots... you didn't mention which binos you have and want to improve upon, but unless they're full-sized already, I agree that larger ones would serve this purpose better than a scope, for reasons given above. (Note that the 80mm astro models suggested lack central focusing.) I had my 10x56 SLC out just last night, looking for a horned owl up the hill from my house which was too far away to locate, but have done better. One evening last year I followed a pair of screech owls, and got a nice view of one perched on a branch clutching the mouse it had just caught.

 

[Binastro]

The 11x80 binoculars were generally centre focus.
They were vignetted a bit internally but still had 6.6mm exit pupils.

I prefer the 20x80 centre focus and had no problem hand holding it.

I think the 15x80s were also centre focus

However, there are probably many independent eyepiece focus 80mm binoculars.

There are also 10x70s but I don't know if any are centre focus.
They may be heavy.

Regards,
B.

 

[tenex]

Sorry, didn't realize there were x80s with central focus. The astro bins I've seen have been IF.

 

[Mr_K]

Hello,

I have used owl calls from Cornell and Audubon web sites.

I have to wait an hour or two after dusk, but then the Eastern Screech and Great Horned sometimes will come to a branch about 30 feet away in my backyard here in Austin TX. Then I just use my Nikon Monarch 10 x 42, 5°5 binoculars to watch. They only stay a minute or 2 but it is a nice view.

Thanks.

 

[GeorgeL]

My old Vixen 15x80 bins are CF.

 

[Tired]

Not a scope recommendation, but: to see owls during the day, try listening for mobbing. If you hear multiple species worth of alarm calls coming from one place, particularly if blue jays are involved, go and check it out. Owls that are spotted during the day are often mobbed, as all the little local birds try to annoy the predator out of town. I've found multiple owls, several hawks, and a large rat snake by following angry jays. The main difficulty is figuring out if any given jay can actually see the predator, or if it's just calling because it hears another jay calling a block over.

 

[JerryLogan]

A quick answer!

Pentax 65mm scope $400 (wait for sales or used).
TeleVue 32mm Plossl eyepiece $100 (same as above).

12x magnification, 5.5 exit pupil. Light, easy to set up. Will not crumble the first time you stumble in the dark woods. Add other eyepieces for different magnifications or to make fully water proof.

Or, you could buy a cracking good used Pentax 65 right now for $345 total from Gwen Cole on the BirdForum classified (well know and respected here). But the eyepiece is fixed instead of interchangeable and you’d be permanently around 20x with 3+ exit pupil.

 

[PhilR.]

If I were wanting a scope for lower light levels, I would go with a Pentax 80mm scope and a fixed-focal length eyepiece from their XW line, or something like the Televue mentioned above. I use our PF-65ed Pentax scope for bright days, and our PF-80ed when light levels are low, such as the situation you described. Be aware that Pentax makes two lines of eyepieces. You want the XW's. Also be aware that you will need a reasonably substantial tripod too, which will limit your mobility. That is the main reason why I don't use our three spotting scopes all that often.