Night bins/owling bins - what do I need? (1 Viewer)

jjg213 · Mar 14, 2011

Hi Ronald, It is dark outside now so I took my 8x56 BGA's and my 10x40 BGAT*'s outside in the garden and looked at several 'dim' targets. The 8x56's were significantly brighter in my brief, and not very scientific, tests, and to my eyes.
I really think you should perform the photo experiment, it really is not much different than having your picture taken, and the results are so much more definitive!
Regards, John

ronh · Mar 14, 2011

Ronald,
4mm maximum is unusual enough that, like John, I wouldn't accept that result quite yet. Higher power alone will show more. Brightness differences are difficult to judge, in the presence of magnification differences.

If you still have the 8x56 available to test, here is a simple although nerdy test you might want to try. Cut out a couple of paper rings that you can lightly fix over the objectives, with holes in them that are 8x4mm=32mm in diameter. Try the 8x56 in low light with and without these aperture reducers. If you can't see any difference, then I'd agree, for all practical purposes you eyes open up to about 4mm max.

I went after owls tonight with an 8x30. Didn't see any. Duh.
Ron

KorHaan · Mar 14, 2011

ronh said:
Ronald,
4mm maximum is unusual enough that, like John, I wouldn't accept that result quite yet. Higher power alone will show more. Brightness differences are difficult to judge, in the presence of magnification differences.

If you still have the 8x56 available to test, here is a simple although nerdy test you might want to try. Cut out a couple of paper rings that you can lightly fix over the objectives, with holes in them that are 8x4mm=32mm in diameter. Try the 8x56 in low light with and without these aperture reducers. If you can't see any difference, then I'd agree, for all practical purposes you eyes open up to about 4mm max.

I went after owls tonight with an 8x30. Didn't see any. Duh.
Ron

Hi Ron,

I still have the 8x56 available, I'll try the test you're describing.
You're quite right that the magnification factor plays a role, I should have known that of course.
I'll get back on this, thanks for your excellent suggestion!

Best regards,

Ronald

KorHaan · Mar 14, 2011

jjg213 said:
Hi Ronald, It is dark outside now so I took my 8x56 BGA's and my 10x40 BGAT*'s outside in the garden and looked at several 'dim' targets. The 8x56's were significantly brighter in my brief, and not very scientific, tests, and to my eyes.
I really think you should perform the photo experiment, it really is not much different than having your picture taken, and the results are so much more definitive!
Regards, John

Hi John,

Lucky you, to have both! I love my slim, leather jacket 10x40BT*'s.
Thanks for taking the effort to compare them in the dark, with big eye holes the brightness of the 7 mm pupil bin should indeed be significantly better.

If Ron's testing method, which I will carry out, reveals a difference in brightness, I'll reconsider the picture experiment.

Best regards,

Ronald

hinnark · Mar 14, 2011

We need to know the pupil's size

Hi Ronald,

two things are quite important for those who want to help you with your search of binoculars for owling.
1. We (and you) really need to know your maximal pupil size with dark adapted eyes. For that purpose I put an attachment here. It shows a pattern of pupil sizes from 1,5 to 8 mm in 0,5 mm steps. I hope that your printer prints the pattern in the correct size. If not, you have to change the scaling of the printing properties (e.g. at 50%) in a way that the size of the dots are correct.
How does the pupil size pattern work? I suggest you'll go out in the dark with a partner. Why not going direct to the place you would for owling? Now your partner should hold the pattern next to one of your eyes and identify the dot with the size that comes closest to the size of the eye's pupil. That works surprisingly easy as only residual amount of light is needed here. If it's really too dark one could use a red flashlight but without shining directly into the eyes.

The 2nd question is: Do you want to search and find the owls or do you already know where they are and you just want to see the most details of these?

Kind regards, Steve

ronh · Mar 14, 2011

Ronald,
I hope you have been going owl hunting already, even with a non ideal binocular, just to get a feel for what it's like. I really enjoy the optics and vision aspects of the discussions here, and I think it is useful to know what one's eyes will do if planning to observe in low light and darkness. But in the field, I have found that other factors are at least as important as these.

When twilight starts getting deep, naked eye isn't worth much at all, and you will have to depend on the binocular. Then, a wide field to cover more territory and up your chances of seeing movement, and light weight and comfort, for holding and viewing steadily for something like 15 min. at a time without a rest, are important. Another thing is control of scattered light, since you will probably be looking into shadows with somewhat bright sunset sky all around.

My eyes open a tad over 6mm, and I have a Fujinon 7x50, which is wide fielded, highly transmissive, fits my eyes, and controls scattered light better than anything else I've seen. Optically it is ideal. But for all that, I'd still pick a handy 8x42 over it for ease of use.

Of course, this depends on the your manner of use. I know about where the owls are, stand 200yds away starting at sunset, and just wait and watch and hope they come out, and watch them as long as I can. It's a favorite after dinner activity for my wife and I, in the summer when the evenings are long.
Ron

hinnark · Mar 14, 2011

ronh said:
My eyes open a tad over 6mm, and I have a Fujinon 7x50, which is wide fielded, highly transmissive, fits my eyes, and controls scattered light better than anything else I've seen. Optically it is ideal. But for all that, I'd still pick a handy 8x42 over it for ease of use.

Hi Ron,

at the end it´s all a matter of personal taste, of course. The eyes (or in other words the visual system) seem to have something I would call a 'memory of the best view'. My eyes open at 7mm and they know what they do like most. They feel most comfortable in the dark with optics with exit pupils of 7mm. IMO a good 7x50 without CF like your Fujinon is one of the best solutions when price does matter. Focussing in the dark is most of the time pretty tricky so best is to focus at infinity at the beginning of the owlwatch session. Than you have a sharp image from 20m to infinity and I doubt that any owl would let any observer closer than 20m.

Steve

Jonathan B. · Mar 16, 2011

Owling at dusk is one thing, but after dark, even under a full moon, no binocular will provide a good view of an owl even as close as 20 feet. If you can pull an owl in with recordings, you are likely to get your best views at close range with a great flashlight and the naked eye. If the owl is more distant, you will need somebody else to hold a light on it while you study it with binoculars.

I do a lot of owling, and I use a 7x42 binocular, which provides a better view under flashlight than a smaller bin. In my experience a bin bigger than 7x42 is unsteady, heavy, and provides no advantage. My most important tools for owling are not my binocular, but my iPod, speakers, and Maglite flashlight with a Maglite Xenon bulb, which provides brilliant illumination for about 100 feet that won't blind an owl. If you owl at dusk, a binocular with a huge exit pupil may help, but it will be usable for less than an hour, it will provide a decent image for about five minutes more than a 7x42, and it won't help much anyway, because many owl species are inactive until well after dark.

KorHaan · Mar 17, 2011

After several misattempts with paper and scissors I've decided I don't give a toss about my eye pupil size, certainly so after reading Jonathan's post.
Using a flashlight may not be always possible under restrictive law in nature reserves here, but plenty of other places it would greatly help.
I don't see a thing in the dark of night anyway, no matter what binoculars I use.
A big scope, maybe, but only on stationary targets, like the Barn Owl breeding place in the vicinity of my home.
For other owls, like Tawny and Long-Eared, the sound approach is most satisfying when it's completely dark. Little Owl I can find at dusk with my 10x40BT*'s, or even easier in daylight when I know its haunts. Short-Eared are bound to show up in my vacation on Texel in broad daylight, when I'll have my 18x50 Canon IS's ready.

I think I can live with that.

Thank you all for the suggestions I've received through time on this topic, as far as I'm concerned we can close the thread.

Best regards,

Ronald

Jonathan B. · Mar 17, 2011

KorHaan said:
After several misattempts with paper and scissors I've decided I don't give a toss about my eye pupil size, certainly so after reading Jonathan's post.
Using a flashlight may not be always possible under restrictive law in nature reserves here, but plenty of other places it would greatly help.
I don't see a thing in the dark of night anyway, no matter what binoculars I use.
A big scope, maybe, but only on stationary targets, like the Barn Owl breeding place in the vicinity of my home.
For other owls, like Tawny and Long-Eared, the sound approach is most satisfying when it's completely dark. Little Owl I can find at dusk with my 10x40BT*'s, or even easier in daylight when I know its haunts. Short-Eared are bound to show up in my vacation on Texel in broad daylight, when I'll have my 18x50 Canon IS's ready.

I think I can live with that.

Thank you all for the suggestions I've received through time on this topic, as far as I'm concerned we can close the thread.

Best regards,

Ronald

Ronald,

Owls are magical, and I appreciate your quest. Where I live, Boreal Owl (known to you as Tengmalm's Owl) is very rare and is at its absolute southern limit in North America. I have hiked hundreds of miles locally seeking it without success, but I have seen amazing things in the process. We have Barn Owl, Short-eared Owl, and Long-eared Owl in common. The one bird you would envy, which can be found only a few hours from where I live, is Elf Owl, which is only slightly larger than a finch. It has to be seen to be believed.

Jonathan

hinnark · Mar 17, 2011

Ronald,

I'm not sure for what purpose you used scissors here. For my simple 'pupil size caliber' no scissors are needed. You just print it and hold it in the dark beside the eyes. With this it's possible to measure roughly pupil size within a second or two.

#Jonathan: I did try several binocular sizes and even night vision devices for watching at owls, nightjars and other nocturnal species. I've found that my eyes do benefit by big pupil sizes provided by types of binoculares like 8x56 or 7x50 the whole night through if the moon is big enough. Maybe the light pollution in large areas of Europe does play a role here. I know places where I can find Barn Owl, Tawny Owl, Tengmalm's Owl, Pygmy Owl, Eagle Owl, Longeared Owl and also Nightjar and Woodcock which all I watched with 7x50 binculars. While I'm really fascinated by owls by myself I think it's a good idea to take some care of the 'birdwatcher's code' (e.g. http://www.bto.org/sites/default/files/u10/downloads/taking-part/health/bwc.pdf) Using a flashlight is a bit too invasive to nature for my taste. IMO using birdsounds to attrack birds should be done very carefully and not just for personal purposes.

Steve

Chosun Juan · Mar 17, 2011

Jonathan B. said:
If you can pull an owl in with recordings, you are likely to get your best views at close range

hinnark said:
Ronald, #Jonathan:....While I'm really fascinated by owls by myself I think it's a good idea to take some care of the 'birdwatcher's code' (e.g. http://www.bto.org/sites/default/files/u10/downloads/taking-part/health/bwc.pdf) Using a flashlight is a bit too invasive to nature for my taste. IMO using birdsounds to attrack birds should be done very carefully and not just for personal purposes.

Steve

I'm no owl expert, but I'm known around these parts to the great mirth of all of those at the local bowlo as 'whoo whoo' among others |

| due to my penchant for elaborate owl hollow constructions, falling out of trees, and warning of the foolhardiness of immitating ( B

) certain owl calls!

Apart from disturbing the poor birdies hunting, mating, territory, security etc, calling out anything more than a casual 'mo-poke' round here, will see not only a curious inspection, but likely great strips torn out of your hide, and may even result in the loss of your eyeballs........its happened before :-C

Of the many large and fearsome owls around here (Barking, Masked, Sooty), they seem like sparrows when compared to the Powerful Owl - see attached (2ft+ tall, 4&1/2ft+ wingspan, 4lbs+, and talons the size of a man's hand :eek!: )..........you definitely don't want to make one angry, and you definitely don't want to see him "at close range"........Indeed!

I've read this thread with interest, hoping to unlock the secret code to the perfect owling binoculars - but the bottom line is that you're going to need a set of eyes to see through any binoculars (perfect or not). Take only care, and give only thanks :t:

Chosun
_________________________________________________________________

For long, long time.............. the earth - she cry....
now, the children - they cry too....
All terribly, terribly sad...

Jonathan B. · Mar 17, 2011

hinnark said:
Ronald,

I'm not sure for what purpose you used scissors here. For my simple 'pupil size caliber' no scissors are needed. You just print it and hold it in the dark beside the eyes. With this it's possible to measure roughly pupil size within a second or two.

#Jonathan: I did try several binocular sizes and even night vision devices for watching at owls, nightjars and other nocturnal species. I've found that my eyes do benefit by big pupil sizes provided by types of binoculares like 8x56 or 7x50 the whole night through if the moon is big enough. Maybe the light pollution in large areas of Europe does play a role here. I know places where I can find Barn Owl, Tawny Owl, Tengmalm's Owl, Pygmy Owl, Eagle Owl, Longeared Owl and also Nightjar and Woodcock which all I watched with 7x50 binculars. While I'm really fascinated by owls by myself I think it's a good idea to take some care of the 'birdwatcher's code' (e.g. http://www.bto.org/sites/default/files/u10/downloads/taking-part/health/bwc.pdf) Using a flashlight is a bit too invasive to nature for my taste. IMO using birdsounds to attrack birds should be done very carefully and not just for personal purposes.

Steve

Hi Steve,

I am always cautious in dealing with owls and do most owling at dusk or just before dawn. Around here some species, especially Flammulated Owl, do not vocalize until well after dark. This is a migratory, insectivorous species, and it can be found readily in May simply by listening for it in appropriate habitat. A small flashlight is harmless for brief viewing of an owl. However I have seen people use a 50,000 candlepower light for owls, which is absurd. Keep in mind that photo flashes are momentarily blinding--including the one used to photograph the Barn Owl on the "birdwatchers' code" webpage. Some photographers attach elaborate rigs to trees to invade nesting owls' space and document them for weeks on end for the purpose of profit, which I consider highly unethical. Recordings used in fall and winter are harmless; their use can be potentially disturbing in the breeding season.

After reading Chosun Juan's post I will be very careful if I ever go to Australia.

ronh · Mar 17, 2011

Last year we watched a pair of Great Horned Owls fledge, on consecutive days. They came out of their nest hole in a cliff, which is right above a road. The first young owl drifted down and landed right in the middle of the road. I hopped in the car, and zoomed down there, parked, and went to shoo him out of the road, before he got run over. Naturally, he came after me, hissing, clicking, and swelling his wings up. Oh well, chasing me worked OK.

His sibling must have learned from the incident, and the next day mananged to get well across the road.
Ron

hinnark · Mar 17, 2011

I know there are much more owl species in North America than in Europe. Some of them do look really awesome, e.g. the mentioned Elf Owl.

One last comment to the optics. When the position of an owl is known, e.g. the nest of an eagle owl, a spotting scope is best suited to watch at. Again, with no matter of the twilight factor, because of the better contrast I prefer the big exit pupil, which means a low magnification at the scope.

Steve

KorHaan · Mar 17, 2011

Jonathan B. said:
Ronald,

Owls are magical, and I appreciate your quest. Where I live, Boreal Owl (known to you as Tengmalm's Owl) is very rare and is at its absolute southern limit in North America. I have hiked hundreds of miles locally seeking it without success, but I have seen amazing things in the process. We have Barn Owl, Short-eared Owl, and Long-eared Owl in common. The one bird you would envy, which can be found only a few hours from where I live, is Elf Owl, which is only slightly larger than a finch. It has to be seen to be believed.

Jonathan

Hi Jonathan,

Tengmalms Owl is extremely rare here but nevertheless shows up of and off in one particular area in the north-east of the Netherlands; its exclusively nocturnal habits make it a challenge to find one, and so far I haven't made the effort to tick it. Matters are further complicated as it seems to favour non-excessible estates, so an organized excursion is the only way to get it on the list.

Elf Owl I don't know, the smallest owl I've encountered here is Scops Owl, a good tick last spring with not only calls but seen flying too, the size of a Starling. Pigmy Owl is the smallest and rarest one, size of a finch, one bird showing well and causing ecstasy among twitchers. I'm not a twitcher, so I haven't got it on my list. I like to seek owls locally, or whenever I'm on vacation.

I finally ticked an Eagle Owl this winter, a breeding pair of which has found solid ground in a quarry for years now, in the most southern parts of the Netherlands.
I was looking for Wall Creeper, but only got Eagle Owl. Not impressive, a long distance off, but a lifer for me anyway.

Best regards,

Ronald

KorHaan · Mar 17, 2011

hinnark said:
Ronald,

I'm not sure for what purpose you used scissors here. For my simple 'pupil size caliber' no scissors are needed. You just print it and hold it in the dark beside the eyes. With this it's possible to measure roughly pupil size within a second or two.

#Jonathan: I did try several binocular sizes and even night vision devices for watching at owls, nightjars and other nocturnal species. I've found that my eyes do benefit by big pupil sizes provided by types of binoculares like 8x56 or 7x50 the whole night through if the moon is big enough. Maybe the light pollution in large areas of Europe does play a role here. I know places where I can find Barn Owl, Tawny Owl, Tengmalm's Owl, Pygmy Owl, Eagle Owl, Longeared Owl and also Nightjar and Woodcock which all I watched with 7x50 binculars. While I'm really fascinated by owls by myself I think it's a good idea to take some care of the 'birdwatcher's code' (e.g. http://www.bto.org/sites/default/files/u10/downloads/taking-part/health/bwc.pdf) Using a flashlight is a bit too invasive to nature for my taste. IMO using birdsounds to attrack birds should be done very carefully and not just for personal purposes.

Steve

Hi Steve,

I was referring to Ronh's method earlier.

I've made three attempts to print your thumbnail dots, carefully calibrating the right size, but got three prints of the same size, meaning 8 mm was in fact 20 mm. So I gave up, tried Ron's method first, and after fiddling with scissors and sheets of paper I just lost the will to live. :king:

It all seemed a bit pointless, as I just watched the Japanese disaster aftermath on CNN, so I'm probably somewhat biased thinking a major catastrophy is more important to be concerned about than a nerdy experiment to be tried in the constrictions of my safe home environment at the moment.

I may try it later. :t:

Best regards, slightly disturbed,

Ronald

Robert Wallace · Mar 22, 2011

John Dracon said:
Ronald - Obviously the large exit pupil of a 7x50 at night will help with alignment, but what your own pupil expansion is at your age is another matter. It is very difficult to measure the diameters of your own pupils. Your maximum exit pupil with ambient light may be only 5mm. That big exit pupil of the Zeiss 8x56 - 7 mm - may not be used in its entirety.

I had a real jolt with my last eye examination - annually with eye drops. My pupils expanded beyond 7 mm, and that evening I could see well with a 7x50. But by the next evening, I was back to 4mm at most and seeing very little.

Perhaps a good 10x50 would be helpful since magnification does help with items viewed at night. Or the Nikon 12x50 SE may be useful, although it is hardly inexpensive. Good luck with your search.

John

Ronald I totally agree with John. Pupil dilation reduces with age so is there any point in using binoculars with a larger exit pupil than your maximum pupil dilation? My optician informed me at my last eye test that my pupil dilation was just less than 4mm. I still use my Zeiss 7x42 because they are easy to look through but they no longer give me a brighter image than with my 8x32 binoculars.
I would consult with an optomertrist before making a choice.

Kevin Purcell · Mar 23, 2011

Robert Wallace said:
Ronald I totally agree with John. Pupil dilation reduces with age so is there any point in using binoculars with a larger exit pupil than your maximum pupil dilation? My optician informed me at my last eye test that my pupil dilation was just less than 4mm. I still use my Zeiss 7x42 because they are easy to look through but they no longer give me a brighter image than with my 8x32 binoculars.
I would consult with an optomertrist before making a choice.

Remember that "Pupil dilation reduces with age" is an average over a population. It does more for some than others. So measuring is always good. A dark room; a digital camera (with red eye turned off) and a ruler held to the forehead will help you get an accurate measurement. It's also helpful to get a bright day measurement and a dusk measurement.

The other reason for using a large exit pupil (other than just an "easy view") is any edge of field glare will be well outside your full dilated pupil. That can help too.

KorHaan · Mar 23, 2011

Hi Robert,

Yes, perhaps I should consult an optometrist.

I returned the Zeiss 8x56 Classics today to the friend I had loaned them from. He's 10 years older than I am, and he has the same issue with the 8x56's that I had; brightness loss due to old age. We talked about using the 8x56's three decades ago, and wallowed a while in the good old days and how wonderful the big Zeiss was, then.
He owns and uses Swarovski EL 8.5x42's now, and he's happy with them.

I for one, am happy with my second-hand Zeiss 10x40 BT*'s, which hold up well into dusk. They have an ease of handling that I've grown fond of, now that I've owned them for 6 months. Weight is nice , too, quite a difference compared to the Zeiss 8x56's.
They handle much better too than the long 8x56 Classics, a thing I have to admit since in the old days I quite liked the long housing, but no more now.

Best regards,

Ronald

Night bins/owling bins - what do I need? (1 Viewer)

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