Which monocular as a substitute for binoculars...? (3 Viewers)

[Bentley03]

I'm blind in my left eye but still prefer to use binoculars as I can hold them better than a monocular.

I'd agree, binoculars definitely have the edge, in terms of stability, due to them having two points of contact.

That said, I'm amazed how 'easy' I'm finding the view through my monocular, I've genuinely surprised myself, in terms of stability after a period of learning.

 

[wm.wragg]

The Opticron DBA VHD+ monoculars retail in the region of £300.

But, my reason for purchasing was to experience a type of optic I've not owned/used before, because I only have one eye in working order (just for the time being, hopefully!). I'm simply using my temporary disability as an opportunity.

Make no mistake, I would not recommend a monocular as an alternative to a binocular. A monocular is a compromise. Apart from being half the size and weight of an equivalent binocular, making it lighter and more portable, the view is not as relaxed or enjoyable as the view through an equivalent binocular (there's a reason why monoculars are not so abundant on the market, they're a compromise and quite niche).

And, take my experience of the three monoculars I've tried and tested with a pinch of salt. The one I'm keeping is the only one of the three which fitted me straight out of the box. The other two didn't, although with a little time (and o-rings) the 8x42 DBA VHD+ would have been just as comfortable and as much of a joy to use as the 10x42, for sure. The problem was me, not the monocular. The experiences of others with the same three monoculars will be individual to them, and inevitably different to my own, unless by coincidence.

There are other monoculars out there, different designs and with different types/location of focus wheel. I auditioned just three, based purely on my uneducated perception of what I was looking for, what I thought I might prefer, and recommendations from other forum members.

The most important rule to follow (if you can) when purchasing optics, is try before you buy, spend as much time as you can testing the instrument in as diverse conditions/situations as possible, and compare them side by side with other brands/models. Use spec sheets and opinions of others as a guide, but make the final decision based on your own hands on experience.

James

I decided to try out a DBA VHD+ 10x42 monocular, and compare it with my DBA VHD+ 8x42 monocular, as I always thought the lower mag. was preferable due to shaking (though I can now hold a monocular as steady as a binocular, perhaps even more steady). The main difference I noticed is that the focusing is super smooth on the 10x42, and not stiff at all like my 8x42 is. This makes focusing much easier, as the monocular tends to wobble when focusing. The other difference I noticed, is that the extra magnification seems to offset the loss of detail due to only using one eye, it feels, detail wise, like an 8x42 binocular.

I'm going to try to carry the DBA VHD+ 10x42 monocular as a companion to my Kowa YFII 6x30, as the two would seem to complement each other rather well. The steadiness of the Kowa YFII 6x30 allows it to use it's high detail optics to their fullest (I can see as much in these as I can in a high quality 8x32) and has a very deep depth of field, while the DBA VHD+ 10x42 monocular would give that extra reach when required, but keep the extra optics small and light.

 

[Ignatius]

I decided to try out a DBA VHD+ 10x42 monocular, and compare it with my DBA VHD+ 8x42 monocular, as I always thought the lower mag. was preferable due to shaking (though I can now hold a monocular as steady as a binocular, perhaps even more steady). The main difference I noticed is that the focusing is super smooth on the 10x42, and not stiff at all like my 8x42 is. This makes focusing much easier, as the monocular tends to wobble when focusing. The other difference I noticed, is that the extra magnification seems to offset the loss of detail due to only using one eye, it feels, detail wise, like an 8x42 binocular.

I'm going to try to carry the DBA VHD+ 10x42 monocular as a companion to my Kowa YFII 6x30, as the two would seem to complement each other rather well. The steadiness of the Kowa YFII 6x30 allows it to use it's high detail optics to their fullest (I can see as much in these as I can in a high quality 8x32) and has a very deep depth of field, while the DBA VHD+ 10x42 monocular would give that extra reach when required, but keep the extra optics small and light.

When I first read that, it stumped me. More magnification and a smaller exit pupil, all hand-held in one hand. I thought that would compound problems.
I am not as good with one eye as with two. Astigmatism and an evident laziness of my brain to compose a satisfactory image of the world with unilateral visual input. It is why I've got a BTX rather than something cheaper. And also why I do not have a monocular (except that blasted Tur[d]mon that won't focus to infinity).
Spurned on by your comment I did a self-test of sorts. The left barrel of a SFL 8x30 and a Habicht 10x40 alternately held to my right eye. Right handed, so easy focussing with a finger on the right. The 8x30 was ohhkaayyy (why I've always avoided spending money on monos). The 10x40 was a marked improvement to the image. Much better details and not nearly as wobbly as I had anticipated. If need be it can of course be steadied with the other hand.

I think there is something to your observation, even though I cannot think of any good reason why that should be so, except that a larger objective lens should give higher resolution and higher magnification gives you a bigger picture with less content, ie. more detail.
I guess I will now look into the availability of a good 10x42 monocular.

 

[albie...]

Hello all,

In the space of the past 5 days I have suffered a tear in the retina of my left eye, laser surgery to close the tear, then a second tear adjacent to the original tear and some retinal detachment. Yesterday I underwent (rather unpleasant) surgery to fix the tear and reattach the retina. My eye is (hopefully) now fixed, but my vision in the left eye is definitely not and won't be for some time.

So, whilst I'm recuperating, rather than simply accepting a degraded view through my binoculars, I fancy adding a full size monocular to my 'wardrobe'. I think I've probably settled on an Opticron DBA VHD+, although I'm very open to recommendations of other monoculars, but what I'm really puzzling over is whether to purchase the 8x42 or 10x42.

James

I have the Opticron DBA VHD+ 10x42 , very nice optic and probably the best in it's size . I use it on a monopod because it's too hard for me to hand hold it steady . It works very well on the monopod for day and night viewing . There is enough eye relief for me to see the entire fov comfortably with my glasses on .

 

[wm.wragg]

When I first read that, it stumped me. More magnification and a smaller exit pupil, all hand-held in one hand. I thought that would compound problems.
I am not as good with one eye as with two. Astigmatism and an evident laziness of my brain to compose a satisfactory image of the world with unilateral visual input. It is why I've got a BTX rather than something cheaper. And also why I do not have a monocular (except that blasted Tur[d]mon that won't focus to infinity).
Spurned on by your comment I did a self-test of sorts. The left barrel of a SFL 8x30 and a Habicht 10x40 alternately held to my right eye. Right handed, so easy focussing with a finger on the right. The 8x30 was ohhkaayyy (why I've always avoided spending money on monos). The 10x40 was a marked improvement to the image. Much better details and not nearly as wobbly as I had anticipated. If need be it can of course be steadied with the other hand.

I think there is something to your observation, even though I cannot think of any good reason why that should be so, except that a larger objective lens should give higher resolution and higher magnification gives you a bigger picture with less content, ie. more detail.
I guess I will now look into the availability of a good 10x42 monocular.

I think it has to do with how the brain processes binocular vision. On the Cloudy Nights binocular forum, there are a few articles where the advantage of binocular vision is estimated to be about 1.42 times that of a telescope, i.e. a binocular behaves like a telescope with an aperture 1.42 times that of the binocular. This is related to light gathering and ability to see faint details. So bearing that in mind, a 42mm monocular should behave like a 30mm binocular, but I tried an 8x42 monocular, and it wasn't as good at seeing details as a 30mm binocular, while the extra magnification of the 10x42 seemed to add what was needed to make them behave similarly. My guess is that the 1.42 factor is mostly around light gathering, and not related directly to detail. A single eye gathers less information than two eyes, so the brain can use the binocular vision's additional information to attain more detail from the view. This is why I think the increased magnification is needed, to aid the single eye in seeing the same level of detail as with binocular vision. The added aperture of the 42mm binocular keeps the exit pupil, and brightness roughly the same as the 30mm binocular. It would be interesting to see if a 10x30 monocular had a similar result, but I wanted the 4mm exit pupil, so went with the 10x42 monocular.