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Old Monday 22nd September 2014, 02:12   #101
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I know there is a difference between the "relative brightness" of binoculars with the same exit pupil and the "twilight factor" which comes into play when binoculars have different size objectives and I agree that a 10x42 and a 10x40 will be brighter in those conditions than an 8x32. This is something hunters should consider at that time of day. I don't know how much difference it makes under normal daylight conditions.
Oh yes, I agree. I was just making the pedantic point that the difference in light-gathering power between the 2 specifications was appreciably greater than the tiny difference in diameter might suggest.
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Old Monday 22nd September 2014, 03:24   #102
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Here are transmission charts for the Swift HHS, left and right. Not too impressive, actually. It peaks about 73% (at roughly 630 nm), but the ""day" and "night" values are lower.

Ed
Thanks Ed,

That's a bit less than Brock noted.

I've often wondered how important "dimness" is as a factor of a binoculars usefulness. Allbinos gives the Porro prism Swift 820 8.5x44 a transmission value of 85% which is more than 10% over the 828 but ranks it below the 828 in it's ratings. And the 820 ED which has 90% transmission isn't ranked much higher than the 828 is.

http://www.allbinos.com/allbinos_ran...ng-8.5x45.html

I recall an older couple, perhaps in their mid 60s, on the Deck at Cape May Lighthouse this past spring being guided by a lady who was using a large Swarovski CL. They were both using Swift 828s. And to tell the truth I was surprised to see two of these binoculars being used at the same time! It was a lightly overcast day but I don't think they were at any disadvantage by using them.

Bob
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Old Monday 22nd September 2014, 03:35   #103
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Originally Posted by ceasar View Post
Thanks Ed,

That's a bit less than Brock noted.

I've often wondered how important "dimness" is as a factor of a binoculars usefulness. Allbinos gives the Porro prism Swift 820 8.5x44 a transmission value of 85% which is more than 10% over the 828 but ranks it below the 828 in it's ratings. And the 820 ED which has 90% transmission isn't ranked much higher than the 828 is.

http://www.allbinos.com/allbinos_ran...ng-8.5x45.html

I recall an older couple, perhaps in their mid 60s, on the Deck at Cape May Lighthouse this past spring being guided by a lady who was using a large Swarovski CL. They were both using Swift 828s. And to tell the truth I was surprised to see two of these binoculars being used at the same time! It was a lightly overcast day but I don't think they were at any disadvantage by using them.

Bob
Bob:

Which Swaro. CL was the guide using ? The largest CL is the 10x30.
That would not be a very bright binocular.

I have the 8x30 CL, and it is very bright for an 8x30, and could suffice as the main binocular for many users. Great ergos, and I like and recommend
it.

I have not used any of the Swifts mentioned, and as this is a Leica thread,
seems a bit off topic.

Jerry

Last edited by NDhunter : Monday 22nd September 2014 at 03:46.
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Old Monday 22nd September 2014, 04:15   #104
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Bob:

Which Swaro. CL was the guide using ? The largest CL is the 10x30.
That would not be a very bright binocular.

I have the 8x30 CL, and it is very bright for an 8x30, and could suffice as the main binocular for many users. Great ergos, and I like and recommend
it.

I have not used any of the Swifts mentioned, and as this is a Leica thread,
seems a bit off topic.

Jerry
You're right. I meant the SLC. It might have been a 12x50.

As for being off topic: It will happen often when another binocular is introduced into a thread for use as an horrible example.

Bob
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Old Monday 22nd September 2014, 04:23   #105
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You're right. I meant the SLC. It might have been a 12x50.

As for being off topic: It will happen often when another binocular is introduced into a thread for use as an horrible example.

Bob
Bob:

That's what I thought, and if it was the larger SLC, it may have been
the 10x50 SLC. They did not make a 12x50.

I have a 10x50 SLC Neu, and it is a very nice binocular, and the view
is addicting, very big and bright. These big ones put the smaller objectives
to shame in many ways, and the only drawback is weight.

Jerry
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Old Monday 22nd September 2014, 04:31   #106
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Here are transmission charts for the Swift HHS, left and right. Not too impressive, actually. It peaks about 73% (at roughly 630 nm), but the ""day" and "night" values are lower.

Ed
Totally Fuggly! Swift's 962 Ultralite Porro has an overall transmission of 91%! That's a whopping 16% more light transmission than the 828.

Swift_Optics_962_Ultra_Lite_10x42l

I think something must have been lost in translation when Arek wrote "average transmission" in the Cons list at the end of his Swift 828 review. That probably should have read "below average," considering what he wrote below that:

"The transmission was the thing that disappointed me the most. A weak result in this category was obvious as soon as I looked through the binoculars – you could immediately notice this device gave the darkest image of all group of binoculars, tested at the same time."

Maybe "average" for a bin made in the late 1980s/early 1990s before the changeover to FMCs by optics companies, but not average for a bin made today.

Brock

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Old Monday 22nd September 2014, 05:01   #107
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As to the comment about relevance by Jerry, who joined us late, I think discussing other bins' light transmission is relevant since the OP spawned a discussion about how much light transmission boost is significant?

My point in drawing Bob into this was to show that if some people can't see a difference in 13% more light transmission, I wonder how many or if any will see the 2-3% difference between the UV HD and UV Plus? Arek already has the 10x42 UV HD @ 89%.

Three percent is supposed to be the minimum threshold at which people can see a difference in brightness, but not everybody will even see that difference. So is the difference in brightness between the UV HD/UV Plus touted by Leica more marketing than performance?

I think Omid's terse post sums it up quite nicely:

Omid's post

Brock

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Old Monday 22nd September 2014, 06:12   #108
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Bob,

My own experience regarding your question goes back to the first good birding binocular in my house, a late model non-SV Swaro EL. I was humping my individual focus 7x50 around at the time, and oh man the Swaro was so nice in comparison that being a tad less bright than my allegedly 95% transmitting Fujinon FMT was scarcely noticed.

Enough I said, I gotta get me one of these things, and bought myself an 8x42 Trinovid BA. It was a great birding tool, but when compared to my wife's EL it was disappointingly dull. The best I can determine as far as transmissions go is that the BA was mid 80%s, while that EL was about 90%. That looked like a big difference to me.

Almost solely because of this shortcoming in the BA, I replaced it with a Zeiss FL, which usually measures about 93% in the tests I've seen. The FL controlled color better than the EL, although it was not as sharp off axis. But the difference between 90% and 93% was, if noticeable at all, certainly not an issue. Mainly the image difference was off axis, also the FL felt nice and light in comparison.

More recently, when the original EL was stolen and insurance came through handsomely, we replaced it with a Swarovision, about 93% transmitting like the FL. I do like the SV better than the original EL, but its main advance is in its color correction, about as good as the FL. Its very slightly improved weight and physical form, and its even better edge correction don't especially impress me. It wasn't at all like, at last a Swaro that's as bright as an FL, that was not an issue at all.

So FWIW, my complaints about a binocular being dim cease at 90%, and that is with my luxury of comparison to brighter binoculars and a passion for the best. Physical usability and other image qualities dominate the comparison if binoculars are at least that bright. But if you never looked through anything brighter, I think a dimmer binocular that was well suited for birding in every other way, like the BA or even the Swift 828, would serve well. How low you could go I cannot say, but many a person has been happy with an uncoated Porro, about 65% transmitting. I think it's only when you look through something better that you start to worry.

Ron

Last edited by ronh : Monday 22nd September 2014 at 14:44. Reason: typos
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Old Monday 22nd September 2014, 10:20   #109
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Lee,

If you will go back to post #87 you will see that I responded to Sako's "complaint" (if you will) that he could see "no tangible difference" in light gathering going from an HT 10x42 and a SV 8x32. I surmised that it might be because of the closeness of their exit pupils. I will admit that I could have been wrong.

Humor aside, what do YOU think the reason was that Sako could not see the difference?

Bob
Hi Bob

Its an interesting question. I will make one suggestion as to why Sako might not see a difference but first, some background.

I know that my HT 8x42 transmits better than my old FL for one good reason. I used to do surveys for the presence of Water Voles (a threatened UK species) and very regularly walked along certain stretches of local streams and rivers. One of these in particular has many undercut banks with hollows behind tree roots where the Voles or their droppings might be, and I scanned these with my FLs more times than I can count and some of them never, ever have light falling into them and they became known to me as black holes.

Along came my HTs and now I can make out vague shapes of things inside those black holes that were previously impenetrable. I don't say I could make out a stationary Vole but if one moved I am sure I would be able to see it. Some of these shapes I can just about tell are more tree roots and rocks but mostly theyare just shapes where there were no shapes visible through the FLs.

OK, what is the relevance of this to your question? Because when I am in other habitats with the HTs and just lift them up to my eyes without the FL there to compare, I couldn't tell you whether the HTs are brighter or not. However, given dark enough conditions, there are times when I am confident I can just make out stuff, at the limits of perception, that my FL wouldn't have shown. I am sure I am able to do this only because of my eyes and brain having been trained by the experience of doing the surveying time after time.

So, I would think for Sako to detect a difference (this is assuming an awful lot of 'all other things being equal' about his eyes etc) I would say he needs dark enough conditions with both bins together at the same time or in a habitat that he knows better than the back of his hand in a dark room. From my experience I don't think one should expect just to pick up a pair of bins at any time of day and perceive a brightness difference.

But the killer question here is how Sako's eyes and brain react to differences in light levels and that is something we don't know.

Lee
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Old Monday 22nd September 2014, 12:58   #110
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this " improvement " of the leica HD ultravids is small, very small......
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Old Monday 22nd September 2014, 13:23   #111
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That's very interesting Lee and I think you've hit the nail on the head. The more someone uses something then the more likely that they'll see what it is capable of.

The subtle variations in late evening light and the particular landscape being observed, with all of its hues and contrasts, makes me now question my earlier post. In other words, in certain situations it is entirely possible that I could see a difference in light gathering between my 8x32 SV and my 10x42 HT. I need to spend more time peering through these masterpieces of optical design side by side.

Of course I'm no spring chicken and my pupils may only dilate to 4mm for all I know.
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Old Monday 22nd September 2014, 14:15   #112
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Leica in Mayfair confirmed the price of the Plus as 1600 for 7x, 1650 for 8x and 1700 for 10x. Availabilty should be in October.

Cheers Tim
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Old Monday 22nd September 2014, 14:37   #113
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I think it's worth noting, to the best of my knowledge, almost no women join these binocular minutia discussions on this forum... I suspect they are out birding instead.

:
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Old Monday 22nd September 2014, 15:16   #114
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Of course I'm no spring chicken and my pupils may only dilate to 4mm for all I know.

I'd say most of this thread boils down to this.
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Old Monday 22nd September 2014, 16:30   #115
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I think it's worth noting, to the best of my knowledge, almost no women join these binocular minutia discussions on this forum... I suspect they are out birding instead.

:
Well Mac although you say almost no women join these discussions I can't let you get away without reminding you of the inimitable Chosun Juan and of the calm and measured views of Annabeth2, who enliven and grace these pages regularly.

Lee
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Old Monday 22nd September 2014, 16:55   #116
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Bob:

That's what I thought, and if it was the larger SLC, it may have been
the 10x50 SLC. They did not make a 12x50.

I have a 10x50 SLC Neu, and it is a very nice binocular, and the view
is addicting, very big and bright. These big ones put the smaller objectives
to shame in many ways, and the only drawback is weight.

Jerry
Swarovski has a 12x50 now but it could have been a 10x50.

http://www.eagleoptics.com/binocular...2x50-binocular

They both cost a ton of money and they are on sale till the end of the month so act now! As you can see Eagle Optics will also take a trade of your old Swarovski. You will want to get that last little bit of extra transmission to increase your satisfaction and pleasure while you are using your new, up to date binocular!

Bob

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Old Monday 22nd September 2014, 17:19   #117
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As to the comment about relevance by Jerry, who joined us late, I think discussing other bins' light transmission is relevant since the OP spawned a discussion about how much light transmission boost is significant?

My point in drawing Bob into this was to show that if some people can't see a difference in 13% more light transmission, I wonder how many or if any will see the 2-3% difference between the UV HD and UV Plus? Arek already has the 10x42 UV HD @ 89%.

Three percent is supposed to be the minimum threshold at which people can see a difference in brightness, but not everybody will even see that difference. So is the difference in brightness between the UV HD/UV Plus touted by Leica more marketing than performance?

I think Omid's terse post sums it up quite nicely:

Omid's post

Brock
Right Brock,

Maybe I should have advised that couple I saw on the deck who were using those 828s while taking a Birding tour at the Cape May lighthouse last spring that they might not be getting near enough pleasure from their experience because of the dimness of the binoculars they were using? As I recall the day was lightly overcast and somewhat windy.

After all, they probably could have afforded much better. I think they drove up in a late model Acura.

Bob
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Old Monday 22nd September 2014, 18:31   #118
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How much do the eye pupils dilate in a overcast day? I guess they are still rather small and far from maximum dilation. As long as eye pupils are smaller than the exit pupil of the binocular, it is difficult to compare brightness as the eye can simply compensate dimness by dilating the pupil a bit and let in more light. How much the eye really compensates, who knows? But surely transmission differences can only really be compared in twilight conditions, once the eye pupil is larger than the exit pupil and any compensation effect of the eye can be excluded.
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Old Monday 22nd September 2014, 19:37   #119
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How much do the eye pupils dilate in a overcast day? I guess they are still rather small and far from maximum dilation. As long as eye pupils are smaller than the exit pupil of the binocular, it is difficult to compare brightness as the eye can simply compensate dimness by dilating the pupil a bit and let in more light. How much the eye really compensates, who knows? But surely transmission differences can only really be compared in twilight conditions, once the eye pupil is larger than the exit pupil and any compensation effect of the eye can be excluded.
You would think so Florian but there are questions would could ask.

For example does the eye react instantaneously to 0.5% more photons or 1% and close down a bit or what? Or does it work like a thermostat that doesn't turn off or turn on until several degrees warmer or cooler than the set temperature? In otherwords is there a threshold of more photons that has to be reached before the eye closes and similarly a threshold below which the photon count has to drop before the pupil dilates?

If it works via thresholds (and so avoids incessant and flickering opening and closing of the pupil) then there could be a certain increase of light input that is tolerated and utilised for vision but which does not prompt a closing of the pupil.

Lee
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Old Monday 22nd September 2014, 20:02   #120
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Lee, post 119,
That is an interesting topic: how many photons are necessary for the eye to generate a signal for the optical nerve. I touched that topic in my review paper on "Color vision etc. and from what I remember from the literature two photons are necessary for the optical system of the eye to generate an observation signal. It was already established in 1946 if my memory is still correct by investigations of Dr. Maarten Bouwman, who died recently. If you are really interestd I can probably find the data.
Gijs
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Old Tuesday 23rd September 2014, 04:12   #121
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Right Brock,

Maybe I should have advised that couple I saw on the deck who were using those 828s while taking a Birding tour at the Cape May lighthouse last spring that they might not be getting near enough pleasure from their experience because of the dimness of the binoculars they were using? As I recall the day was lightly overcast and somewhat windy.

After all, they probably could have afforded much better. I think they drove up in a late model Acura.

Bob
Pretzel logic, Bobby boy! The fact that he owed modestly priced 828s with "average light transmission" (still think that was a translation glitch) and an above average priced car does not in any way reflect on the value of the binoculars.

It reminds me of the rich couple who threw me out of their luxury home (literally threw my vacuum cleaner demo boxes out into their driveway) and nearly slammed the door on my butt, after I failed to deliver a steak knife set that the telemarketer promised them who set up my home demonstration of a $1,500 Filter Queen HEPA filter vacuum cleaner (I arrived with a 24-pack case of Pepsi, because the office ran out of steak knives). As I picked up my gear, I stared at their shiny, late model Mercedes.

After months of "sticking my foot in the door" of strangers' homes to sell them an overpriced vacuum cleaner that could beat the pants off their Kirby, my dealer and our crew realized that it was useless trying to sell a high value vacuum cleaner to the rich, because they couldn't put it on display, but had to stick it in the closet where nobody could appreciate its beauty or luxury. Whereas the Merc, well, it shone proudly in the half circle driveway and wherever they drove it.

I think that's probably the explanation behind why they had $300 Swift 828s for bins but a $48,000 Acura RLX for a car.

Also, they probably have maximum entrance pupils of 3mm, so better low light performance wouldn't mean that much to them.

Anyway, I can see that you're never going to admit defeat and will continue to champion a "disappointing light performance" roof, so let's go with your explanation. Now let's see if Swift and Acura are interested in using that couple for a cross-promotion TV commercial.

Brock

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Old Tuesday 23rd September 2014, 06:48   #122
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Pretzel logic, Bobby boy! The fact that he owed modestly priced 828s with "average light transmission" (still think that was a translation glitch) and an above average priced car does not in any way reflect on the value of the binoculars.

It reminds me of the rich couple who threw me out of their luxury home (literally threw my vacuum cleaner demo boxes out into their driveway) and nearly slammed the door on my butt, after I failed to deliver a steak knife set that the telemarketer promised them who set up my home demonstration of a $1,500 Filter Queen HEPA filter vacuum cleaner (I arrived with a 24-pack case of Pepsi, because the office ran out of steak knives). As I picked up my gear, I stared at their shiny, late model Mercedes.

After months of "sticking my foot in the door" of strangers' homes to sell them an overpriced vacuum cleaner that could beat the pants off their Kirby, my dealer and our crew realized that it was useless trying to sell a high value vacuum cleaner to the rich, because they couldn't put it on display, but had to stick it in the closet where nobody could appreciate its beauty or luxury. Whereas the Merc, well, it shone proudly in the half circle driveway and wherever they drove it.

I think that's probably the explanation behind why they had $300 Swift 828s for bins but a $48,000 Acura RLX for a car.

Also, they probably have maximum entrance pupils of 3mm, so better low light performance wouldn't mean that much to them.

Anyway, I can see that you're never going to admit defeat and will continue to champion a "disappointing light performance" roof, so let's go with your explanation. Now let's see if Swift and Acura are interested in using that couple for a cross-promotion TV commercial.

Brock
I'm not "championing" the 828 Brock. It is a perfectly useful binocular for its price. Why don't you reach into your pigs knuckle jar and buy a couple of inexpensive binoculars to keep and use for a while before you pass judgement on them? I do that and Frank does that.

You won't go broke.

Maybe then you could explain why Allbinos rates the Swift 828 right between the two Swift 820s despite the fact that they have transmission ratings 10 to 15 points more than the 828 does? Which is 85% and 90% for the 820s and 75% for the 828. This is clear evidence that you overrate the usefulness of brightness when you evaluate a binocular. You should spend more time using binoculars before you pass judgement on them.

http://www.allbinos.com/allbinos_ran...ng-8.5x45.html

I posted this link in my response to Elk Cubs transmission charts in my post #102 which also has the comments about the couple using the 828s at Cape May and which is the one you take issue with here. In that post I commented on their respective transmission ratings. I don't know why you ignored it but then I'm not a journalist.

That's all I will say except I wish you the best of luck in winning a binocular in the Zen Ray raffles. I hope you keep it long enough and use it long enough to learn something about it.

Cordially,

Bob
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Old Tuesday 23rd September 2014, 09:37   #123
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Lee, post 119,
That is an interesting topic: how many photons are necessary for the eye to generate a signal for the optical nerve. I touched that topic in my review paper on "Color vision etc. and from what I remember from the literature two photons are necessary for the optical system of the eye to generate an observation signal. It was already established in 1946 if my memory is still correct by investigations of Dr. Maarten Bouwman, who died recently. If you are really interestd I can probably find the data.
Gijs
Thanks for this Gijs

Could they really count individual photons in 1946?

And while only 2 extra photons may be registered via the optical nerve does this mean an instantaneous adjustment of the pupil is called for or does the 'system' tolerate this extra light to avoid constant adjustment of the pupil?

Lee
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Old Tuesday 23rd September 2014, 11:33   #124
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Post #121

In a recent survey (forget what university over here actually did it) it was found that the rich are more likely to:
Steal money from the church plate (if they go to church).
Give the lowest tips.
Give the least amount to charity.
Complain the most about service.
Complain the most about prices when shopping.
Complain the most about just about everything.

I personally know a 70 something husband and wife who are multi millionaires and they buy most of their clothes from the local Salvation Army Op shop. They're always whining about something or another. If they knew what my binoculars cost I'd certainly get a lecture along the lines of a fool and his money are soon parted.

I guess once they drop off the hook they're going to leave their millions and all their property for their two offspring to squabble over.
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Old Tuesday 23rd September 2014, 11:59   #125
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Lee, post 123,
We are talking here about Utrecht University where Bouwman worked, the absolute top of the scientific world, but I do not have to tell you that, since you are of course aware of this Scientific Paradise.
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