Big fan of Porro prism . (2 Viewers)

[typo]

Herman,

I really have no idea about how specification standards may have changed in different companies over the years but I suspect ISO 14133-2 from 2006 may have been very influential. I don't know who was on the standards committee but I believe the leading manufacturers were represented. Ron (Surveyor) posted a copy here:
http://www.birdforum.net/showpost.php?p=3539092&postcount=84

If you note on the second sheet there are two specifications for resolution. A 10x42 binocular with a exit pupil of 4.2mm will fall into the first category and require the instrument resolution be better than 5.71 arcseconds. An 8x42nwith a 5.2mm EP would need to be better than 7.5". I don't know how they arrived at those numbers but for a user with 6/3 (20/10) eyesight their magnified acuity would be 6" and 7.5" respectively. That is, the standard limit was roughly matched to 'perfect' eyesight. For reasons I've already explained in this thread that was an incredible dumb thing to do, but I understand even the names big names adopted it. Zeiss bragged they exceeded this standard using 5.2" as a cut-off, but that still allowed the critical measurement, the effective resolution to be significantly worse than the acuity limit of those with better eyesight.

I challenge Zeiss to measure both the instrument resolution and effective resolution for the HT 8x54. I guessed the latter figure at 8.5-9" and, having studdied their MTFs, they didn't disagree, and assured me they would be revising their QC procedures. That was about three years ago, I hope things have changed. The ISO committee has met again and only made a trivial ammendment, but I suspect in the meantime Zeiss and others may have improved their internal QC standards.

David

 

[typo]

Binastro,

I know you have often claimed the best astronomers are bless with supernatural powers, but let me assure you they are still bound by the laws of physics.

David

 

[Binastro]

When have I ever claimed that the best astronomers have supernatural powers?

I answered you in full, but have decided not to put this reply in the public domain, as I do not want to cause hurt to anyone.

I will also not send this reply as a PM.
It is unnecessary.
Basically, we disagree.

So I have deleted my full reply, and wish you well.

What I will say is that you are acknowledged binocular expert, and rightly so.

 

[typo]

Binastro,

I too had composed quite a long reply to your post 78 rebutting your statement but decided against posting it. Please go back and reread our PM exchanges where I explained constant radiance amd the diffraction limit of the eye amongst other things.

David

 

[adhoc]

Here is a fascinating thread active (to date) between 12 and 5 years ago.

 

[Binastro]

David.
It is most unlikely we will ever agree on this topic, so it is fruitless to discuss it.

As I have said to you personally. I don't need to prove anything to you. I just state my experience over 60 years of observing and also reviewing many other observers results.

To suggest that astronomers don't know what they are doing and have not for hundreds of years is something I don't accept.
One only has to go back through about 70 years of journals of the Association of Lunar and Planetary observers or 200 years of the Royal Astronomical Society to find numerous planetary observations where powers of up to 70x per inch are routinely used. These include Rev Dawes observations.
With difficult double stars somewhat higher magnifications have sometimes been used to good effect.

Book learning, or internet learning is one thing. But one actually has to do years of actual observations at the telescope to make judgements.

In my opinion you would have been an excellent observer of planets and double stars, especially with your good eyesight. But it was not your calling. One needs a good telescope, good skies, years of being up at all sort of hours, in the cold sometimes, and usually with not very good conditions.
But to give catagorical opinions, without having done this, and on your own interpretation of optics or Physics, where your opinions differ to how it actually is, I for one do not do not agree with you.

 

[typo]

Binastro,

I have never doubted the centuries of atronomical achievement. To explain it in a manor that breaks the laws of physics endows it does it a great disservice in my opinion. Don't take my word for it, go and read up about constant radiance/luminance and the physiology and optical properties of the eye.

David

 

[Surveyor]

superbrick

I love it. Should be the official name of the 12x50 BN.

A very good optical device, a better than average defensive bludgeoning device and with a little longer strap, suitable for beating bushes down for trail breaking.

 

[Sollas]

Should I buy the Habicht 10x40GA then for use with raptors and general shoreline identification of waders. Would this be a reasonable consideration against the Zeiss Victory FL 10x32?

Your surgical dissection of technology is immensely interesting if not somewhat over whelming. Does the Habicht suffer from the same issues as the 8x30W?

I'm don't really want to burn unnecessary cash on top end roofs. I generally don't need the last 20 mins of daylight and most of my birding is done around the coast and the Scottish islands, where we occasionally glimpse cetaceans offshore.... thus 10x mag required

Your advice and opinions are welcome.

 

[Troubador]

Should I buy the Habicht 10x40GA then for use with raptors and general shoreline identification of waders. Would this be a reasonable consideration against the Zeiss Victory FL 10x32?

Your surgical dissection of technology is immensely interesting if not somewhat over whelming. Does the Habicht suffer from the same issues as the 8x30W?

I'm don't really want to burn unnecessary cash on top end roofs. I generally don't need the last 20 mins of daylight and most of my birding is done around the coast and the Scottish islands, where we occasionally glimpse cetaceans offshore.... thus 10x mag required

Your advice and opinions are welcome.

Hi

Does your raptor watching include searching for circling Golden and Sea Eagles, or trying to catch sight of a Peregrine that has stooped on a flock of waders but you have lost sight of, and do you scan from side to side to try and find that Hen Harrier that was gliding just above the heather and then slipped over the other side of a rise and you are hoping will climb back into view?

If the answer is yes to these and perhaps many other similar questions then perhaps you might agree that a really wide field of view is useful to have. In that case consider that the FL 10x32 has 120m wide FOV at 1,000 metres while the Habicht only has 108m. Now, remember that these figures are really the diameter of the circle of view that you get through your binos and that it is the area of this circle that is interesting when wondering how much sky or hill or mud flat or estuary or open sea you capture through your bins. The FL captures 23.5% more than the Habicht (11,310 m sq vs 9,161 m sq).

The Habicht has eye relief of only 13mm whereas the FL has 15.2mm, the Habicht is considered shower proof (which I wouldn't want to rely on when on the Inner Hebs or Western Isles or Ardnamurchan for that matter) and, although this might not matter to you now, its close focus is only 4 metres so if you get an interest in butterflies or dragonflies or similar you might be better off in the long term with the FL's 2.0 metres.

The Habicht is a beautiful instrument and I never fail to pick up the 7x version at Bird Fair, but as an every day instrument, no matter what turns up and no matter what the weather, for me, it fails compared with the FL.

Lee

 

[Sollas]

Hi Lee,

Many thanks for your reply. Your assessment sounds like you've been watching me! ;-)

Much of my birding and wildlife watching is indeed done in the highlands and western isles which is mainly what I have in mind here. Short eared owls and harriers are always on the horizon, forgive the pun. However, my great passion is waders on the shoreline and around the coast, you never quite know what might turn up.

I'm beginning to think that the 10x40 Habicht is maybe more of a traditional desire as opposed to a functional state of the art, modern roof such as the 10x32FL. I thing FOV is probably more important and given the how and when I birdwatch I doubt brightness is really an issue. Plus my go to Nikon 8x32SE have me used to a very nice FOV and brightness.

I do have the "paralysis by analysis" disease at times, but I guess when its not see easy to see all these binoculars in the flesh you can only go with what BirdForum experts advise and think.

 

[etudiant]

Hi Lee,

Many thanks for your reply. Your assessment sounds like you've been watching me! ;-)

Much of my birding and wildlife watching is indeed done in the highlands and western isles which is mainly what I have in mind here. Short eared owls and harriers are always on the horizon, forgive the pun. However, my great passion is waders on the shoreline and around the coast, you never quite know what might turn up.

I'm beginning to think that the 10x40 Habicht is maybe more of a traditional desire as opposed to a functional state of the art, modern roof such as the 10x32FL. I thing FOV is probably more important and given the how and when I birdwatch I doubt brightness is really an issue. Plus my go to Nikon 8x32SE have me used to a very nice FOV and brightness.

I do have the "paralysis by analysis" disease at times, but I guess when its not see easy to see all these binoculars in the flesh you can only go with what BirdForum experts advise and think.

You seem like an ideal candidate for a Canon 10x42, good FoV, superb glare resistance, fully waterproof, bright and true color image. All that at half the price of other alphas, with the IS feature thrown in.
I think once you try the IS on a bird in flight, you'll never look back. However, if you hate electronics, just omit the batteries, you'll still have the best modern porro available.

 

[Sollas]

In truth I don't know what anything about canon binoculars even though I've used their slr's for years.

I assume they're providing some optical niche which I've yet to understand. I don't really relate understand their true application......and they look a bit weird. I can only assume they are not a replacement for a traditional bin?

 

[Binastro]

They are a class above traditional binoculars when used handheld with IS on.

But they are heavy and bulky.
One needs to try them to see if they are suitable or not.
For prolonged use some use a Finnstick.

I have used several models for almost 20 years.

 

[Hermann]

The Habicht has eye relief of only 13mm whereas the FL has 15.2mm, the Habicht is considered shower proof (which I wouldn't want to rely on when on the Inner Hebs or Western Isles or Ardnamurchan for that matter)
...

The Habicht is WATERPROOF. Period.

Hermann

 

[Sollas]

Hermann,

Please remember we're talking Scottish rain here...which is much wetter than any normal rain ...... thus Habicht's would possibly meet their maker!

Shower proof? surely not.....don't see that in the spec's?

 

[Troubador]

I have never owned a Habicht so I have no personal experience of its waterproofness or otherwise. I am, however, skeptical of its ability to keep out Scottish (or British Isles) rain given that it has moving eyepieces and a sealing area open to the elements. It must be hard to get a seal tight enough to keep water out (and maintain that for many many years) but not so tight as to unduly impede the focussing action. I accept that some people may have experience with their own Habicht that fills them with absolute confidence but I would be nervous at the chances of all Habichts being the same. This doesn't mean I am right, but this is how I feel about porros in general. Perhaps I am unduly influenced by the number of times water got into my Swift Audubons and my wife's Swift Saratogas.

Allbinos review contains this sentence: The binoculars can work in the – 25 to +55 degrees C temperature range and be stored without any damage from –30 to +70 decrees C. They are splash-proof.

The storage info comes straight out of Swarovski's specifications so I would be surprised if the comment about being splash-proof was made up by Allbinos despite the specs saying they are safe to immerse to 13ft.

Lee

 

[Gijs van Ginkel]

Lee,
I have immersed quite a few binoculars in a bucket filled with water, some of them I left even for a week in their bath. Among them also porro's like ones for example made during WW-2 (Bausch and Lomb types) and with the exception of a few (among them top brands roofs) they all stayed perfectly dry inside. I gave one of the WW-2 porros to a student for use during his stay in the tropics for half a year, it came back in very good condition and no water or fungi anywhere. So do not worry to much and give it a try.
Gijs van Ginkel

 

[PeterPS]

with the exception of a few (among them top brands roofs) they all stayed perfectly dry inside

Gijs: Can you please mention the exceptions? Allbinos found some of Leica binos to be rather poor in this respect, so I would expect them to be on your list.///Peter

 

[Troubador]

Lee,
I have immersed quite a few binoculars in a bucket filled with water, some of them I left even for a week in their bath. Among them also porro's like ones for example made during WW-2 (Bausch and Lomb types) and with the exception of a few (among them top brands roofs) they all stayed perfectly dry inside. I gave one of the WW-2 porros to a student for use during his stay in the tropics for half a year, it came back in very good condition and no water or fungi anywhere. So do not worry to much and give it a try.
Gijs van Ginkel

Thank you for your post Gijs and your tests sound interesting. Please note it is not me considering buying a Habicht. And I feel compelled to point out that binoculars sitting quietly in a bucket of water is one thing, but it is entirely another if the binocular is being focused continually with the eyepieces moving in and out like those on a Habicht do.

As I said earlier, my only experience of porros has been two Swifts in the 1970s which both let in water every holiday. Of course just because a Swift behaved like this it doesn't prove a Habicht would.

Lee