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Rolling Ball: what do I do?! (1 Viewer)
- Thread starter emmalibertine
- Start date
Hi Steve! For the record...I wasn´t referring to anyone as a fool, I was just fooling around myself. We´re all just having fun here talking nonsense about our favourite obsession!First I quoted here three responses but deleting as that makes this post quite a bit longer.
Holger, David, Ed, thanks. Ed, please excuse my ignorance and/or lapses of reasoning, but could you kindly explain the foll. point if not too much trouble, or direct me where that'll be done. Went through the article a couple of times but need to clarify this before I can try to proceed to understand it well enough. (Do feel I may be missing something obvious.)
"This equation provides additional support for the statement that there is a useful upper limit for the magnification of a hand-held binocular, and that this upper limit is about 10." Cannot quite work that out, from what either precedes or follows it. Thanks! (Other facts familiar to those who know the subject I had to work out from scratch, e.g. "A night glass does not increase the apparent brightness of an extended object, but acts to increase the apparent size of the object.")
In the meantime been away on a waterbird survey. The other two in the team used a new Opticron scope. I prefer a high-x bin to a scope. Used a Nikon EX 16x occasionally and in comparison it was certainly useful for many seconds at a time. Am now thinking/dreaming of a Fujinon 14x40 stabilised! After denouncing CJ have realised I have myself been a "pure optics" chauvinist.
I totally forgot to look for "RB" in our bins! None of the three mid-power models we used (8x and 10x) are known for it. When we did pan at those beautiful wide landscapes (acc. to need) it was slow and only through a small angle at a time.
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Chosun Juan
Given to Fly
Brock !! :storm: again with "deniers" BS :-@. & with a large dose of self-aggrandizement :loveme:+ chunder inducing faux "humble" pie thrown in!
As a self proclaimed "has-been, drip under pressure", IF you could be bothered to actually read (& comprehend?!:h?
every post in this thread -you'd see that there is Not ONE single "denial" :smoke:
You are living in the past; Times have moved on; Things have changed (yup! even dennis' mind! - well at least where his favourite bin is concerned!) ..... Won't you too ? :scribe:
You're going the wrong way down a slippery slope; "boxing at shadows"; "walking down the street muttering to yourself"; lost down a deep dark hole .... :stuck: When offered an olive branch from the tree of knowledge, you've bitten the hand that would feed you .....
A man that's painted himself into a corner, and dug a hole so deep, that the light is just a long forgotten memory, needs a ladder .... not a shovel |^|
And yet when presented with the ladder of learning - you've reached (again) for the shovel of BS - with all the restraint of a kitten chasing a ball of string :cat:
Yes, - but will you be there with a bucket? for all the readers who are completely and utterly sick of this BS tripe!
Chosun :gh:
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Sancho,
that's exactly the way I've understood it, nothing personally. You've just hit the nail on the head. It did remind me what's, after all, is my passion (not obsession) is all about: birdwatching but not optics as an end in themselves or on the internet.
Steve
Pomp,
I'm no mathematician, but I suspect the model used in that Vukobratovich paper is too simplistic. It presumes the tremor frequency is constant irrespective of weight etc. but takes no account of the amplitude of the shake. It seems very obvious to me that my heavy 10x is steadier than my lighter 10x. For me at least the tremors have two components. The one in my arms supporting the binoculars, and a second one in my hands from holding the binos at the required angle. This is particularly noticeable if the binocular is nose heavy. That heavy 12x50 porro of mine is perfectly balance in my hands and I don't need to grip it at all, so I only have the weight damped tremor from my arms. The view is steadier for me than many 8x pairs. I've not tried a higher power but I strongly suspect I could with a well balanced pair. Models like the Swaro ELSV 12x50 were not balanced in my hands. I need to hold them one hand forward and the other back to get some kind of balance, but that is not nearly so steady for me. I've sure there is a practical weight limit as well. I find the 1.2kg porro OK for reasonable periods, but I'm not sure I'd want to go much higher.
David
David, thanks for complicating that further. But seriously, you've shown another factor, and explained it really well; thanks.
My problem is: where does one see a stated value, or formula, or graph... which shows or implies a max. or min. at or near 10x? Again sorry if I'm missing something obvious or embarrassingly basic.
My problem is: where does one see a stated value, or formula, or graph... which shows or implies a max. or min. at or near 10x? Again sorry if I'm missing something obvious or embarrassingly basic.
Holger Merlitz
Well-known member
There exists no such formula - if you plot the result reported by Vukobratovic, you just obtain a curve (resolution via power) that increases with the power. They have tested that up to a magnification of 18x. But even at 6x a mounted binocular is performing better than a hand held binocular, and the same happens at 18x. Hand-held performance is not increasing linearly with the power, of course, its growth is becoming increasingly slow.
I believe these tests are of limited use - the perception of hand held performance is more than just the maximum achievable resolution on test charts. It is also about convenience, ease of view, depth of field, exit pupil size, weight and such things, which are not easily quantified in a single formula, and here a natural limit appears to be reached somewhere near 12x ...
Cheers,
Holger
Holger, thanks. Could you, further, kindly explain, if it's not too much bother: "This equation provides additional support for the statement that there is a useful upper limit for the magnification of a hand-held binocular, and that this upper limit is about 10."
Russ, bad news: http://www.youtube.com/watch?v=F7dsQ9sb_9A. Entering "rolling ball" in the YouTube search strip brings up several such devices. Most are in the USA but one other "playing near you", with French text, engages a viewer more (i.e. disengages him less). The chief use of all these is to train one to endure this thread. (I do hope that early on the Original Poster was sufficiently well answered.)
Russ, bad news: http://www.youtube.com/watch?v=F7dsQ9sb_9A. Entering "rolling ball" in the YouTube search strip brings up several such devices. Most are in the USA but one other "playing near you", with French text, engages a viewer more (i.e. disengages him less). The chief use of all these is to train one to endure this thread. (I do hope that early on the Original Poster was sufficiently well answered.)
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Mike Penfold
Well-known member
While I've adapted to rolling ball with the 8.5x42 SVs, there are small, central, fleeting blackouts when trying to get on a raptor, or following something like a warbler or redpoll.
I've tried another sample of the 8.5x42, with the same experience. This happens with or without progressive lens eyeglasses, with close attention to the IPD setting, and with methodical, minute adjustments to the eye relief. BTW, neither my second generation 8x42 Bausch and Lomb Elites, my wife's 10x42 EL WBs, nor my 10x32 EL WBs have shown these centre field blackouts.
The static view is superb -- spot a bird, raise the binoculars, just a great view.
Clay Taylor of Swarovski suggested eyeglasses with a prescription for distance viewing, or switching to 10x42 SVs.
There are other perhaps relevant topics such as spherical aberration of the exit pupil; twitchy eye placement; saccadic eye movements; the complexity of the SV eyepiece and its possible redesign in current production -- but I'm not qualified to comment on any of these.
As a last step, I sent them in to SONA, with a detailed email comment. They were inspected and returned as is, still showing the same performance. Swarovski paid the shipping both ways. Swarovski repairs again suggested 10x42 SVs; however, my 10x32 EL WBs fill this niche more effectively.
After a year and a half or so, it's time to move on. No one else appears to be having this issue; so another birder will probably appreciate them more.
My shortlist includes 8x42 Swarovski SLC HDs (also suggested by Swarovski repairs), and Zeiss HTs.
Mike
I've tried another sample of the 8.5x42, with the same experience. This happens with or without progressive lens eyeglasses, with close attention to the IPD setting, and with methodical, minute adjustments to the eye relief. BTW, neither my second generation 8x42 Bausch and Lomb Elites, my wife's 10x42 EL WBs, nor my 10x32 EL WBs have shown these centre field blackouts.
The static view is superb -- spot a bird, raise the binoculars, just a great view.
Clay Taylor of Swarovski suggested eyeglasses with a prescription for distance viewing, or switching to 10x42 SVs.
There are other perhaps relevant topics such as spherical aberration of the exit pupil; twitchy eye placement; saccadic eye movements; the complexity of the SV eyepiece and its possible redesign in current production -- but I'm not qualified to comment on any of these.
As a last step, I sent them in to SONA, with a detailed email comment. They were inspected and returned as is, still showing the same performance. Swarovski paid the shipping both ways. Swarovski repairs again suggested 10x42 SVs; however, my 10x32 EL WBs fill this niche more effectively.
After a year and a half or so, it's time to move on. No one else appears to be having this issue; so another birder will probably appreciate them more.
My shortlist includes 8x42 Swarovski SLC HDs (also suggested by Swarovski repairs), and Zeiss HTs.
Mike
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Hi Mike
Unless SONA were desperately thrashing around for any old solution, suggesting alternative models should indicate they know what is happening with your 8.5, if they truly think the same won't happen with the 10x models. Perhaps a good idea to ask them why these alternatives are a good idea.....?
Lee
brocknroller
porromaniac
Lee,
I wondered the same thing after I read Mike's post. I experienced "image blackouts" with the 8x30 SLCneu and to a lesser degree with the 8x32 EL WB, and both only have 15mm of ER, so I doubt if "long ER" can be the reason in those cases. I don't remember whether or not I also experienced this with the 8.5x EL.
The fact that Clay recommended switching to the 10x42 version could mean that this has been a commonly reported issue with the 8.5x SV EL. OTOH, there are probably a lot more people who buy the 8.5x model than the 10x42, so it could be Swaro has gotten less reports of this with the 10x model simply because less people own them so there's a smaller pool of those who might be susceptible to "Image blackouts" with that model.
The question is if Mike could hold 10x steady enough to make it worthwhile swamping his 8.5x. He's also going to lose FOV and depth of field.
I think a better idea would be to try the 8x32 SV EL. It has the same ER as the 8.5x model, so it's still good for eyeglass wearers, but if the issue is due to EP design, it might not cause him image blackouts. And instead of losing FOV, he gains FOV with the 8x32 model. In theory, the DOF should be the same.
<B>
NDhunter
Experienced observer
Mike:
I do have to ask if you have tried both of the eyecups that Swaro. has had
for the SV. They brought out a revised eyecup with slightly different detents
for the 4 positions, and I have tried both. They are sent out complimentary
if you have a need.
I don't wear eyeglasses, and I find the SV, 8.5x42, to be a bit finicky with
eyerelief. They do take a bit of work finding just the right position, just like
a lot of binoculars do.
There are plenty of posts concerning this issue, if you look back
here on the site.
Jerry
Holger Merlitz
Well-known member
Sorry, but I don't see how his formula (12) would support such a statement. His table is not understandable to me anyway: In the second column, it contains M*T^0.25, M being the power and T the transmission, but for M=18 the value is 12.10, which would imply a transmission of 20%, quite weird indeed. Perhaps he made a mistake and typed M*T instead (67% transmission would be realistic for single coating), but then all his calculated numbers in column 4 were wrong ...
I cannot help here, you would have to contact the author of the paper for clarification ...
Cheers,
Holger
Holger, thanks! Wouldn't have expected such things in this paper, published in that journal, and suggested by Ed. The other flaw, which you point out, I had missed - didn't go that far without trying to clear up more basic problems. All the more reason for my next question (/demand!) - where's your book? Cheers!
Holger Merlitz
Well-known member
Oh well, there are more errors in scientific publications of this planet than you think ;-)
My book is done, and in a couple of days I will hand over the manuscript to my publisher (Harri Deutsch). Sorry, all in German so far. Whether, or when an English translation would come out, I cannot tell at this point. If anybody here is in contact with a publisher who might possibly be interested in preparing an English translation, he may let me know ...
Cheers,
Holger
Brock
Good practical advice.
I had an EL way back in 2003 and didn't have this issue but that was a previous model and doubtless several unannounced updates ago. It would be nice if SONA would explain what it is about the 10x bins that would alleviate this issue. But brands don't like admitting anything so I guess its not likely to happen soon.
I absolutely agree with the implication in your post ie that recommending someone with an issue with an 8/8.5x to swap to a 10x is missing the point.
Lee
