I need a new pair of binoculars.

There is no substitute for picking up a pair and handling them, in my opinion. I am one of those who think the Canon IS ones are brilliant, but others are less convinced. Mine are 15 yrs old and are as good as new, but I don't bring them out when it is wet. They are not perfect for bird-watching as their field of view is less than the recommended ones, but they are still damned good.

Tip for the day - use Lithium batteries. They last longer and weigh much less.
 
Barnac1e said:
Whilst the idea of a compass bearing within the binocular field of view seems appealing at first, I'm wondering what use I would make of it.
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I don't so much use the compass to take bearings on things, but to find things on a known bearing. So for example on my first visit to the Channel Islands last year, as we arrived off the top of the Little Russell and I was trying to identify what was what among all the rocks and beacons, it was useful to get from the chart that a particular mark was at, say, 173º, and then look down that bearing through the binos to find it.

When crossing the shipping lanes, I also like to compare the visual bearing of a ship with the AIS bearing, when it first becomes visible (I have my AIS set to give magnetic bearings for that reason). That ensures that the ship I'm looking at on the AIS is the same one I'm looking at on the horizon. In fact on one occasion it wasn't, proving the value of this check - a car transporter was steaming up the Channel without AIS, and another vessel not yet visible through a slight haze was beyond it in roughly the same direction. With just an eyeball check on the direction, I'd have assumed that the single ship on the AIS and the single ship I could see were one and the same. The AIS was giving a comfortable CPA, so I might have got really quite close to the non-AIS ship before realising that something wasn't right and we were actually on a collision course (which we were, or nearly so, as I discovered when I started taking bearings the old-fashioned way). Because I compared the AIS bearing with a visual bearing through the binos, and repeatedly couldn't quite get the two to match up to my satisfaction, I realised a lot earlier.

Like you, I haven't plotted a formal 3-point fix for years, but I do quite often take a single bearing on a landmark and check that it's within a couple of degrees of what the GPS says (a Yeoman plotter makes it a trivial operation to find the GPS version). This might not be rationally necessary - what are the odds of the GPS being wrong to a subtle, believable degree, rather than "no fix" or "you're in Birmingham"? - but it makes my inner navigator happier. Same reason I sometimes put the radar on in chart overlay mode and check that the purple echoes are lining up with the yellow charted land - somewhere at an early age it got drilled into me that A Single Source Of Information Is Bad. You don't have to get out your RYA pencil-case and start drawing multi-headed arrows all over the chart to do a casual cross-check, and compass binos are part of that for me.

That's what I use mine for, anyway, and why I'll be sticking with non-stabilised binos until they bring out a compass version.

Pete
 
Thanks for your extensive and persuasive explanation Pete. I agree single, unsupported assumptions are bad form and visual bearings as confirmation can only be A Good Thing.

In fact, as soon as I had posted it occurred to me how many ships I meet contravening SOLAS requirements by not transmitting an AIS signal and that there may well be times I should be checking their bearing. To date, none were threats, and if they were then out would come the hand-held fluxgate compass. However, I can see that the binoculars would be more quick and accurate. Like you, I'll wait for both IS and compass integrated.

I'm just back from Düsseldorf Boot .... pity I hadn't read this before going to be able to check the compass versions. Ah well, perhaps by next year.
 
Nikon hg brilliant for size but if you want to see than I have never regretted the cannon is18x50 swmbo bought me. Pricey but I have had admirals and thls inspectors look through them and they have been converted in seconds. Visual navigation is about planning and they let you plan for a lot longer.
 
Somebody here wrote on a recent thread that the 7X50 the 50 part relates to the pupil size of your eye. He also mentionned that with age this size reduces so that 7 X42 would be quite adequate for most adults as well as being more compact. He seemed to know what he was talking about.
 
Sybarite said:
Somebody here wrote on a recent thread that the 7X50 the 50 part relates to the pupil size of your eye. He also mentionned that with age this size reduces so that 7 X42 would be quite adequate for most adults as well as being more compact. He seemed to know what he was talking about.
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dancrane said:
Please, Mr Sybarite, I'm feeling sadly slow today. Would you kindly confirm that you're being funny?
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hahahhahahah The x50 part is the size of the objective lens diameter (big lense ) ;) I would indeed say he is joking lol :cool::encouragement:
 
dancrane said:
Please, Mr Sybarite, I'm feeling sadly slow today. Would you kindly confirm that you're being funny?
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Here is what "Relax" wrote on 8/12/12 :

I have quite a few binoculars - Canon, Bushnell (x2), Opticron, Boots(!) and Swarovski SLC. I usually have two on board - the Bushnell 7x50 and the Opticron 7x42. I use these for both sailing and stalking deer.

It's not totally true to say that the bigger the objective lens the more (useable) light you have admitted. The important number is the product of the objective lens diameter divided by the power - this gives you the exit pupil diameter in mm. e.g. 7x50 = exit pupil diamter of 7.1mm. Smaller objective lens smaller exit pupil and vice versa. BUT the human eye only opens to about 7mm - and only then between the ages of about 15 and 30. Older than that astigmatism reduces the pupil diameter slowly so that age 70 it will only open to about 4mm. So for many of us (most ??) the extra 10mm is totally wasted.

One result of this is that the great majority of deer stalkers (particularly professionals) who use bins almost continuously will go for 7x42. My Opticron and Swarovski are both 7x42. Another point is that, since I assume its difficult for manufacturers to sell less power and smaller lenses, 7x42's are only made by (as far as I know - may be others) Opticron, Ziess, Swarovski and Lieca - expensive, professional quality kit for professional use. 7x42 are about half the weight and bulk of 7x50.

Quality makes as big, if not bigger difference, to objective lens diameter.

If you can get second hand ones they can often be good value - have a look at R McLeod in Tain - they often have second hand optics - but I'm sure there are manu others.

In truth though on a boat you usually do not need the 'see in the dark' quality of optics you need in a dark wood at last light. Will I be taking my brand new Swarovski SLC's sailing - no way!!

I did say "relates to". I did not say it was equal to.
 
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Sybarite; ignore the mocking smart-alec responses.

I take issue with the final paragraph of your quoted post: "In truth though on a boat you usually do not need the 'see in the dark' quality of optics you need in a dark wood at last light." As I posted earlier in this thread, such conditions are exactly when I most value my 7x50 binoculars, When I am approaching my area of Italian lagoons at dusk with their myriad of channels marked by marker posts that can be quite invisible to the naked eye in low light, but with those binoculars I can clearly see them. No doubt my ageing exit pupil diameter cannot match the available 7mm worth of light supplied but it sure works for me.
 
Sybarite said:
It's not totally true to say that the bigger the objective lens the more (useable) light you have admitted. The important number is the product of the objective lens diameter divided by the power - this gives you the exit pupil diameter in mm. e.g. 7x50 = exit pupil diamter of 7.1mm. Smaller objective lens smaller exit pupil and vice versa. BUT the human eye only opens to about 7mm - and only then between the ages of about 15 and 30. Older than that astigmatism reduces the pupil diameter slowly so that age 70 it will only open to about 4mm. So for many of us (most ??) the extra 10mm is totally wasted.
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Using the word "product" started my confusion; should have been "result". The calculation is really 50/7=7.1.

Then the misuse of "astigmatism"; from wikipedia:
Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina.
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So nothing to do with pupil diameter. So what do we believe?

Mike.
 
I measured my aging pupil a year or two back when the subject arose here and got a figure of over 6mm, so I too will keep my 7x50s, which last saved my bacon when we entered the only partly lit Dovetief at the end of dusk. On the other hand, the 7x50s will never compete with my Canons in daylight, and there are times when I don't want to cart them around ashore and only my good quality 8x25s will do. I can't see how any sailor can manage with fewer than three pairs on board.
 
Little Grebe said:
I haven't had a pair of binoculars on board for several years now and do not appear to have come to any obvious harm
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Are you aware of the trail of destruction you have left behind you from all those ships that you failed to spot in time and who had to swerve away causing utter carnage on the high seas?
 
johnalison said:
Are you aware of the trail of destruction you have left behind you from all those ships that you failed to spot in time and who had to swerve away causing utter carnage on the high seas?
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:D

That said I will probably be getting a new pair later in the year.

The hand bearing compass spends most of its time sitting unloved in the chart table, maybe I am doing something wrong.
 
roblpm said:
I am too poor to join in the £400 bino conversation. Anyone tried these gael force ones for 89?
http://www.gaelforcemarine.co.uk/Mobile/MobileModels.aspx?ModelID=511
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Yes, just got a pair. Not used in anger yet but look to be identical to previous pair which sell for £140 or so with a different brand logo. Previous pair were great - and withstood much abuse, but not being dropped six foot onto deck then stood upon. VisuAls were fine but compass card shifted. Gael Force seemed too good a bargain to miss rather than paying for repair
 
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