Low Light Binoculars (1 Viewer)

[Chosun Juan]

Is there an echo in here ??! 3 :t:

 

[MPeoples]

Hi,
Low light Binoculars, look at 50, 56, 60, 70 and 80mm objectives. But be warned 70 and the 80mm get very large and heavy. Companies are Celestron, Fujinon, Nikon, Zeiss, Leica, Swarovski, Pentax and Barska.

Best
Mike

 

[ceasar]

Is there an echo in here ??! 3 :t:

No.

It is in response to Steve's statement wondering how Allbinos came up with that figure? I wonder why there is no graph shown to back it up.

I will let others speculate on that.

 

[Chosun Juan]

..... It would've helped if they had shown the 10x42 SE's actual transmission graph .... the 10x scores 4.1/5.0 .....

Anyone who can't find the Allbino's test of the Nikon 10x42 SE now, after 3 lynx :cat: - probably needs a labrador! 3 :t:


Chosun :gh:

 

[ceasar]

Anyone who can't find the Allbino's test of the Nikon 10x42 SE now, after 3 lynx :cat: - probably needs a labrador! 3 :t:


Chosun :gh:

Anybody can find the test! Nobody can find Allbinos graph of it's light transmission to prove that it has 96% light transmission. It's not in the "lynx" you supplied either.

 

[hinnark]

While it would be certainly nice to see a graph of both SEs here, we still have the two numbers of 89.1% for the 8x32 and 96% for the 10x42. I don't think that does go well together.

@Chosun: I didn't realized that in these cases the exit pupil assessments do differ as well that much. However, while I think you are right in respect of filtering and common sense we should also take into account that some people being newbies in optics could take those informations for genuine truth.

Steve

 

[Equipment]

Quipo,


It will help you sort through to ask yourself a series of questions .....
1. Usage - will it be general all-around conditions? (~5mmEP - 8x42-44 would suit, maybe even 10x50), mainly dawn /dusk? (~5.6mm - 7x42, or 8x44, or 8x50, or 10x56), or night-time? (by moonlight, etc ~7mm - 8x56). The answers to this will determine what objective size /exit pupil combo you want.

It will be in all conditions, daylight, low light and moon light.

2. Age - what is your maximum dark adapted pupil size? Can you use a full 7mm EP? (8x56), or only 6mm? (7x42, or 8x50), or only 5.6mm? (8x44, or 10x56), or only 5mm? (8x42, or 10x50). Will you even be out in the dark long enough for it to be a consideration?

I don't know my adapted pupil sight? Is there a way for my to find out by myself? I wear specs.

3. What magnification do you really want? Higher mags (and objective sizes) will give higher Twilight Factors (TWF =sqrt[mag x obj]), but will also trade FOV to give a more restricted true field (7x ~140-150m, 8x ~112-136m, 10x ~100-120m) - is that important to you? This choice needs to be married up to the EP you can use to give the objective size class you'll look at. You should note too, what sort of low light view do you prefer - maximal brightness? (8x56) or maximal detail? (8x50, 8x56, or 10x56)

I would think 8x would be sufficient and cos I would be sometimes using it in low light, it would be good to have maximal brightness, hence I think 8x56 would seem to be what I am seeking?

4. Weight /size - how much are you really prepared to carry? x42-44 class bins will be up to ~850g and can be worn by most around the neck with a good padded strap, whereas x56 class bins are a different animal again at 1100g+ probably requiring a sling, or harness for extended use, for all but the most hairy-chested!

As light as possible!I don't mind wearing a harness, I have to i guess for those occaisions where I would be moving fast paced with it..etc...I understand as you've pointed out that with 8x56 I can't escape 1kg, which I guess, if I end up going for an 8x56 then I would have to accept that and make that compromise..this is the reason I rejected the Doctor Nobilem because of its size and higher weight in comparison to the other 8x56...

5. What quality ($$) of view are you really after? The best of the best? (Zeiss victory HT, or Swarovski SLC-HD in 8x42, or an 'alpha' 7x42), or something half that price? (Steiner's 8x44, 10x50, 10x56, or 8x56, similar brands etc). Only you can decide what's important to you - Those very few last percent of sharpness, light transmission, contrast, detail, and glare performance? Or, something 90-95% as good (for half the price) with larger objectives? (x44, x50, or x56 which will equalise the brightness /light gathering of the top alpha's if not perhaps the ultimate detail seen, unless under darkness). To put things in perspective, in terms of the amount of light each format offers - 95%tr@42mm = 87%tr@44mm = 67%tr@50mm = 53%tr@56mm, or put another way (relative to the amount of light of a 42mm), 90%tr@44mm = 98%tr@42mm, and 90%tr@50mm = 127%tr@42mm, and 90%tr@56mm = 160%tr@42mm. So bigger objectives well and truly trump even the brightest 42mm's. They also add much more weight, and less FOV. The choice is yours. The 8x56's will certainly tick your brightness box, but only you can decide if they are versatile enough that they "can do a bit of everything" ......

Well, at first I thought If I go for a low light binocular that is rugged, it would suffice me for all other uses..as opposed to if I went for a general purpose or hunting specific binoculars then it wouldn't do well in low light - for those occaisions where I would want it to work well in low light.

Perhaps that was the wrong thinking...I would be happy with around 90 to 95% light transmission, I read that any half decent 8x56 binoculars performs well in low light? Such that anything less than 56 isn't really considered in line up for low light binoculars, that I noticed from the reviews that Kestral1 posted in post no.5 all the binoculars in the review for low light performance were 8x56...

You seem to be really, really attracted to Steiner bins. Any particular reason?

Lee

There is no particular reason other than I do like the look of them, especially the new Ranger Extreme that Kestral1 posted about in post 33, looks real cool..But more importantly, I understand that Steiners are more rugged and an can take a lot of rough and tumble...A a lot of people in the US army use Steiners? Though I would take care of the binoculars, as I will be paying for them but alot of others in my family and friends will use them and they won't be as merciful with it as me....

Thanks for that Chosun and to everyone who has responded, look forward to further input from you all.

 

[kestrel1]

Steve, yes the SE's are another puzzling one, hence why I only said "seem reasonably consistent". I think there are some questions over the level of accuracy, and there certainly are some clangers in there, however most seem in the ball park. It would've helped if they had shown the 10x42 SE's actual transmission graph. The one for the 8x32 SE shows the value @550Nm to be ~89.1% as they have recorded. They seem to test many different ages of individual bins (Zen ED2 comes to mind, even though superceded by the ED3 which has been around for years), and maybe some of the differences in the 8x and 10x SE's is down to vastly different coatings on each unit, from widely spaced production years - although ~7% does seem excessive (and implausable).

It's also interesting to look at the photos of the exit pupils in both the 8x and 10x SE. The 8x scores 2.9/5.0=58% and internal reflections are described as "A bit of flares in the area nearest to prisms". Whereas the 10x scores 4.1/5.0=82% and internal reflections are described as "Slight". Well I'm sorry, but looking at the photos I'm stuffed if I can see that the 10x is ~40% better than the 8x.

I think what both of these things say is that Allbino's is a little bit airy-fairy sometimes, and you need to filter some of their stuff through common sense. Kudos to them though for having a go.


Chosun :gh:

Yes it seems that the allbinos does not apply in transmission percentage value
some mid value counted by integral formula of transmission divided by width of spectrum,
and only write the value of transmission for
green color where the eye is most sensitive at day.
That is maybe reason why many binoculars with coatings
tuned to peak transmission in 550nm, has extreme values,
while in blue or red part of spectrum transmission is lower,
and true transmission is lower.
But value of 96% transmission is I think claimed in
Habicht porro from Swarovski.
I dont know how the ISO or DIN specify measuring of transmission,
but seems that allbinos is using simpler method.

Best regards Kestrel

 

[Pileatus]

SE transmission rates are not that high...
http://www.birdforum.net/showthread.php?t=180743

 

[Binastro]

. To get really dark adapted you need about 20 to 30 minutes in total darkness.
but as you will not be observing probably in total darkness may be 10 to 20 minutes might suffice.
This also depends on the person's age and general health and is variable.
If one has been in bright sunshine during the previous 24 hours this affects the level of the dark adaption that one can achieve.

However, the iris dilates quite rapidly.
To measure your dilated pupils get somebody to measure your pupil sizes with a ruler in as dim lighting as is possible to read the ruler markings.
Then add a bit maybe 10 to 15% depending on the individual.

Another way is to construct different aperture holes say 5 mm 5.5 mm, 6 mm, 6.5 mm and 7 mm.
If your eyes don't focus at Infinity without your glasses look at a distant streetlight perhaps half a mile away then carefully examine the out of focus streetlight through the different holes.
If the diameter of the out of focus streetlight is not affected when the hole is absolutely central to your iris then use a smaller hole until it is affected.
Your pupil size will then be somewhere between these two hole diameters.

Of course with different levels of outside lighting your pupils will vary.
They also very slightly anyway.
You should measure both pupils as they may not be the same.

There are also several other ways of measuring pupil size.

I use photographic methods but one must take great care when trying to do this and generally it is not safe with a normal camera. in fact some camera instruction books specifically say you should not do this.

 

[brocknroller]

Kestrel,

as far as I can see Allbinos didn't test the Navidoc but the 7x50 Nobilem. These two are different binoculars. Also the Steiner's construction is just as simple than the Nobilem's (cemented doublet objective, AFAIK).

I'm afraid Allbinos transmission tests couldn't be always considered as a reliable source because some of their results are much too high as are their noted tolerances (e.g. Docter Nobilem 8x56 98 %, Nikon 10x42 SE 96%). A tolerance of 3% (how does this value come from and how is it calculated?) is certainly not state of the art. I wonder which kind of device and procedure they use.

Steve

Steve,

Arek tested the 7x50 Noiblem model. Check out the introduction and photos:

Docter 7x50 Nobilem review

I wish the transmission in the 7x50 Nobilem were as high and as flat as the 8x56 model, since I would prefer the 7x50 over the 8x56, but according to Arek, the 7x50 Nobilem and 8x56 Nobilem have different coatings, with the 7x50 being lower in transmission in the blue and purple than the 8x56 model.

I guess it was just easier to use the same lenses for both 7x50 models rather than create a new set of optics for the Nobilem version. In addition, the prism coatings are different on the 7x50s vs 8x56.

Here's what Arek said about the 7x50 Nobilem coatings in this allbinos' article (he was comparing the to the 7x50 Jenoptem:

Colour_rendering_in_binoculars_and_lenses.html

"As the time passed also the Docter binoculars have been changed in a more noticeable manner – the optics became a bit more complex and the devices got a solid, rubberized casing. Their construction, though, remained very similar so it’s easy to compare it with that of the Jenoptem 7×50. An immediate comparison is possible when you look at the graph below which presents the transmission of the currently produced Docter Nobilem 7×50 B/GA.

Here the situation is much better. The transmission of yellow and green light reaches a very high level of 94%. A distinctly purple hue of the Nobliem’s 7×50 coatings indicates that for these wavelengths the transmission level will be the lowest and it is indeed– for the blue light it gets to 80% and for purple light – about 70%. What’s interesting a definitely better result in this category we got for the Nobilem 8x56 so a bigger brother of the described model. The Docter 7×50 had a noticeably shiny coating on the prisms, indicating that here something must have gone wrong to some extend. As the 8x56 model didn’t feature such a flaw, its transmission was even higher."

As to his methods of testing, they are found HERE.

<B>

 

[hinnark]

Steve,

Arek tested the 7x50 Noiblem model. Check out the introduction and photos:
<B>

Brock,

that was just what I did try to explain to Kestrel who seemed to think they tested the Navidoc.

Thanks for the links. So Allbinos did use different methods of transmission testing. That might explain the odd results I found mainly in some of the older tests. Regarding the mentioned quotation I don't think that it is possible to assess the transmission characteristics of binoculars just by the apparent color of the coatings.

Be this as it may, I will have to try the two Docters at next occasion by myself.

Steve

 

[plyscope]

Allbinos rate the Nobilem 10x50 coatings as 5/5, however do not show a tramsmission graph for it. I would presume the 10x50 and 7x50 are the same except for the eyepieces but maybe the coatings are model specific.