james holdsworth
Consulting Biologist
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Swaro names (1 Viewer)
- Thread starter njlarsen
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birdrousta
Well-known member
are you measuring diopters of focus past infinity? that is a make or break spec for me, and one I've seen variation in. however, I know that after time in use some of the focusers need to be readjusted - the pair I particularly noticed this in was not brand new, but I have read others suggest testing several pair if that is a significant parameter for a user.
Gijs van Ginkel
Well-known member
James, post 21,
Thank you James, you made my day.
Birdrousta, post 22.
As yet I did not observe that with the ones we have investigated and with the ones I have used through the years, so of course it can happen if users report it, but I have not found it yet, but I keep good hope.
Gijs van Ginkel
Thank you James, you made my day.
Birdrousta, post 22.
As yet I did not observe that with the ones we have investigated and with the ones I have used through the years, so of course it can happen if users report it, but I have not found it yet, but I keep good hope.
Gijs van Ginkel
I have the Habicht 8X30....nice binocular. I wish the ER were more. All but useless while wearing glasses. For the most part it stays by the back door for quick use without glasses..
Agree about the glasses. Fortunately, I don't wear them.
Gijs van Ginkel
Well-known member
Birdrousta, post 19,
Today we found out that you were right, the SLC we tested did not comply with the given specifications: the WEB-site writes a 3,2 m close focus value and we measured with a calibrated electronic ruler 2,8 m. You were right.
Gijs van Ginkel
Today we found out that you were right, the SLC we tested did not comply with the given specifications: the WEB-site writes a 3,2 m close focus value and we measured with a calibrated electronic ruler 2,8 m. You were right.
Gijs van Ginkel
birdrousta
Well-known member
Thank you very much for checking. I'm curious - how much focus travel past infinity did this pair of SLCs have? the ELs which caught my attention as having relatively less focus travel past infinity than the spec (the spec is 5 diopters) seemed to have very close close focus, but I was not in a position to measure it.
I have long had a sneaking suspicion that the extremely close focus specification which many reviews and specifications cite has a tradeoff in the longer focus. It is essentially no longer possible for me to purchase binoculars with any sense of sureness that I will be able to use them unless I am able to handle the particular pair of interest ahead of time.
It's frustrating; it's effectively limited me to a single vendor for binoculars if I want them to work on arrival.
Gijs van Ginkel
Well-known member
Birdrousta, post 28,
Infinity is far away, but to speak in mathematical terms: if I try very long distances no problem, the images stay sharp and the focuswheels stopped at that point. Closest to infinity is the star illuminated sky and that also did work well with the instruments I have investigated as yet.
Gijs van Ginkel
Infinity is far away, but to speak in mathematical terms: if I try very long distances no problem, the images stay sharp and the focuswheels stopped at that point. Closest to infinity is the star illuminated sky and that also did work well with the instruments I have investigated as yet.
Gijs van Ginkel
birdrousta
Well-known member
hi gijs --
for me, focus past infinity i can check approximately with my eyes and eyeglasses. with glasses, there should be substantial focus travel left in the focuser if I am looking at, say, the Orion nebula. if the focuser stops just where my corrected vision can bring it to focus, I know there is very little focus past infinity and I cannot use the binoculars.
if there is some travel, then I take off my glasses and try again. if the focuser stops before both eyes are able to get to focus, it usually means there is about 3-4 diopter of overfocus, which for me is not sufficient.
I picked up a pair of +5 reading glasses recently, thinking that by putting them between my eyeglasses and oculars, I should be able to reduce overtricks by 5 diopters. it sort of works as a crude test, but the eye relief required for it is very high.
I was hoping there was a way to quantitatively measure it, and perhaps see if a binocular that could focus closer than spec was compensating for that by losing some of the overfocus in its spec.
kimmo in another thread made an excellent point about focusing past a relatively nearby pinpoint light source and seeing how many diffraction rings are formed as a way to compare available overfocus between binoculars. I don't know if there is a way to make that a quantitative measure as one can with near focus, though.
so for now I'm working with maven. they are willing, for an additional fee, to assemble binoculars that have overfocus beyond their normal range.
for me, focus past infinity i can check approximately with my eyes and eyeglasses. with glasses, there should be substantial focus travel left in the focuser if I am looking at, say, the Orion nebula. if the focuser stops just where my corrected vision can bring it to focus, I know there is very little focus past infinity and I cannot use the binoculars.
if there is some travel, then I take off my glasses and try again. if the focuser stops before both eyes are able to get to focus, it usually means there is about 3-4 diopter of overfocus, which for me is not sufficient.
I picked up a pair of +5 reading glasses recently, thinking that by putting them between my eyeglasses and oculars, I should be able to reduce overtricks by 5 diopters. it sort of works as a crude test, but the eye relief required for it is very high.
I was hoping there was a way to quantitatively measure it, and perhaps see if a binocular that could focus closer than spec was compensating for that by losing some of the overfocus in its spec.
kimmo in another thread made an excellent point about focusing past a relatively nearby pinpoint light source and seeing how many diffraction rings are formed as a way to compare available overfocus between binoculars. I don't know if there is a way to make that a quantitative measure as one can with near focus, though.
so for now I'm working with maven. they are willing, for an additional fee, to assemble binoculars that have overfocus beyond their normal range.
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jan van daalen
Well-known member
Doesn't this imply that the close focus will go up with a few meters?
birdrousta
Well-known member
I think feet at most. I've measured my b3, which have 8 d overfocus, and they can focus as close as 7 feet or so.
I honestly don't understand the importance of focusing within about 3 meters in any event, for most binocular uses.
I think it is popular with manufacturers because close focus is an easy spec to describe, verify, and put in a "compared to our competition" grid. for many people over focus isn't interesting as they leave their glasses on.
I drove microscopes professionally for a few years, and in that group of folks the first thing you do when getting ready to look is remove your eyeglasses. that is consistent with how the field biology folk I've worked with operate as well, the preference is to view without eyeglasses when possible.
so in any setting where I can, I take my glasses off. I have a wire tether so I don't lose them. it has the added benefit of keeping them on my head at times when they would otherwise fall, and is great if I'm out at night with bins or a telescope.
Hi BR
If you don't use your bins for close focus distances you are missing out on some wonderful opportunities.
As well as more obvious creatures such as butterflies and dragonflies, there are things such as fungi, lichens and flowers. Yes all of these can be observed by going up close and using the naked eye, and yes it seems counter-intuitive to think that using bins could be better, but believe me it is.
And then there is stuff under water. Using close-focusing bins you can get breathtaking views of fish and aquatic insects and by the sea many other creatures such as sea-anemones, starfish, sea-slugs and fish.
You spent all of that money on optics: why not see if you can get even more pleasure from them?
Lee
Thank you to everyone who have answered in this thread. I just noticed one more thing: eye relief seems a bit shorter on the 10x42 SLC than on the 10x42 EL model? is that corresponding to the experience you all have had? The specs for the SLC looked like the eye relief was the same as on Leica's 10x42 HDplus.
thanks
Niels
thanks
Niels
Wish I had a current 10X42 SLC to compare.. I wear glasses and have no issues with eye relief of 8X32, 10X32, 8.5X42 and 10X42 EL Swarovision binoculars. I DO have a Leica Ultravid HD Plus 8X42. No eye relief issues with it either although I do feel it's eye relief IS about the least I can tolerate.
Once more, thank you to everyone who participated in this thread. I am now the happy owner of a 10x42 EL. If I am looking for it, I can see the rolling effect, but in real life use, it has not been a problem. The last bird I have seen with with this new pair of bins was the Bahama Mockingbird that is visiting S Florida, and finding this involved plenty of scanning around.
Niels
Niels
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