8X Discoverer (1 Viewer)

I was looking at Bushnell's website today and I noticed that in the Discoverer line, the 7x model has been discontinued and has been replaced by an 8x model. (I guess the 7x models just didn't sell well enough... :king: ) I have said numerous times that I think the Discoverer line is one of the absolute best values on the market.

What is interesting about this is that the published 8x specs claim a field of view of 420 ft @ 1000 yds. This corresponds exactly with the FOV of the old 7x model so, I thought it was just a simple mistake. I called Bushnell's customer service to find out what the real FOV would be and they assured me that the 420 feet figure is correct. They said that "advances in technology" allowed them to retain this very wide FOV while increasing the magnification.

I remain skeptical (at best) but, if they hold true to their word, then this would I believe, be the widest 8x binocular on the market. I don't know if that would be enough to get me to go back to using an 8x binocular but, who knows...

The Zeiss Victory and Swaro EL have 420' also. Nikon LXL and Swaro 8 x 30 have 408'. Leica has 405'. Discontinued Nikon 8 x 30 EII had 462'!! Swift Audubon 8.5 x 44 has 430'. A few cheap 8 x porro's also have 420 or so.
Bob

Personally I would take most things on Bushnells site with a large pinch of salt.

The Trophys I reported on in another thread are shown to have a close focus of about 12ft on the website, but in reality (and the seller in ebay tested a large sample of her stock) it is closer to 35-40 ft !

lucznik said:

I called Bushnell's customer service to find out what the real FOV would be and they assured me that the 420 feet figure is correct. They said that "advances in technology" allowed them to retain this very wide FOV while increasing the magnification.

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The "advances in technology" here would most likely consist of employing a shorter focal length eyepiece, while leaving the diameter of the eyepiece field stop unchanged. What will they think of next?! ;-))

I'm reminded of my time in the U.S. Army in the late 1960s. We had manuals that gave the effective ranges of various weapons in meters. But I happened to see an older manual for one of these same weapons, and the effective range was stated in yards with the exact same numbers. WRT the binoculars in question, it might be interesting to know if the FOV is really the same or if they were just too @#$%^&* lazy to rewrite the books and brochures.

ceasar said:

The Zeiss Victory and Swaro EL have 420' also. Nikon LXL and Swaro 8 x 30 have 408'. Leica has 405'. Discontinued Nikon 8 x 30 EII had 462'!! Swift Audubon 8.5 x 44 has 430'. A few cheap 8 x porro's also have 420 or so.
Bob

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Although these figures are correct, I must point out that you are looking at 32mm models, which more often than not have wider fields of view but, usuallyat the expense of eye relief, resolution, and brightness. The Discoverer is a full size 42mm binocular. Thus the proper comparison is between the 40+ mm models of the binoculars you mention. This would give us:

Zeiss Victory - 405
Swarovski EL - 390
Nikon LXL - 366
Leica Ultravid - 388
Leica Trinovid - 390

The Swift represents a fair comparison and I would like to try one of those sometime too.


I suppose my real question revolves around not just the physical dimensions of the field of view but more importantly, how much of this field has sufficient clarity to be useful. I've seen some of the cheap 8x porros with super wide fields that you mention but, in all of them the outer 2/3 + of these fields were so distorted as to be completely unusable. I therefore, generally discount them completely. The 7x Discoverer had a wonderfully clear field all the way out close to the very edges. I didn't buy one because I don't think 7x is enough magnification. 8x is a bare minimum for me and if they have been able to retain the edge to edge clarity of the 7x in this new model, I might be more interested in giving it a closer look. (Though to be honest, I would still probably choose the 10x model as I have lately become an unrepentant magnification junkie.)

henry link said:

The "advances in technology" here would most likely consist of employing a shorter focal length eyepiece, while leaving the diameter of the eyepiece field stop unchanged. What will they think of next?! ;-))

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Henry,

Assuming you are correct here, what would be the expected tradeoffs? In other words, if this can be done without any (or even many) negatives, why hasn't it been done before?

lucznik said:

Henry,

Assuming you are correct here, what would be the expected tradeoffs? In other words, if this can be done without any (or even many) negatives, why hasn't it been done before?

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Well, this has been done many times before, going back to the very earliest binoculars. It's the easiest and cheapest way to increase the magnification of a binocular while maintaining the same real field, since it uses the same objective, prism and much of the same eyepiece housing in both the 7X and 8X binoculars. As to tradeoffs, there will always be an increase in apparent field in the 8X (in this case from 56* to 64*) and, depending on what eyepiece design is used, there will probably be a decrease in eye relief and somewhat increased astigmatism and/or field curvature at the edge of the wider apparent field of the eyepiece of the 8X.

lucznik said:

The 7x Discoverer had a wonderfully clear field all the way out close to the very edges. I didn't buy one because I don't think 7x is enough magnification. 8x is a bare minimum for me and if they have been able to retain the edge to edge clarity of the 7x in this new model, I might be more interested in giving it a closer look. (Though to be honest, I would still probably choose the 10x model as I have lately become an unrepentant magnification junkie.)

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I have the 7x42 B&L Discoverers with silver mirror and phase coating. It's a very good bin and most of its virtues stem from the 7x design. Have you tried the 10x Discovers? I have. They are unremarkable & do not stand out compared to other 10x bins as the 7x do.
7x is so forgiving. It allows all of these virtues: brightness, clarity, deep focal planes, wide field of view, long eye relief. Bring the bin up to 8x and it loses or compromises some of these things. The 10x Discovers have none of the above listed virtues. Lucznik, I think you will find the 7x42 made such an impression on you because of qualities linked to them being 7x. When compared with an 8x, a 7x will give you more of everything except magnification.

My other primary bin is the Swift Audubon Porro 8.5x44. It has better clarity, perhaps due to the prism, than the Discoverers, but is very slightly less bright. It has terrible compromised short eye-relief to gain that impressive 430' field of view. But, I think it is the better bin for someone who does not wear eye glasses, or who can manage with only about 14mm of eye relief (not the 17mm advertised).
I prefer the Audubon in general for its clarity. I would not consider going over 8.5x in magnification. The compromises of image quality, etc are too much. I prefer brightness, clarity & field of view for birding. I identify more birds with them than with additional magnification of 10x.
Also, I think edge to edge sharpness is overrated. It is often achieved at the expense of a wider field of view. That's one of the optical trade offs. I prefer the wider field of view for tracking flying birds, scanning beaches & tree lines, etc. Once I get on a bird, I'll keep it in the clear center of view. But out of focus edges are natural to the human eye and useful peripheral vision.
Regards,
Marc

jedku said:

Have you tried the 10x Discovers?

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Yes I have though, only in the porro prism model which has since been discontinued. Actually, I bought this particular porro binocular and am very happy with it. For a 10x, it has a very wide FOV of 341 ft. This is a bright, clear, and very satisfying binocular. It is noticably brighter and exhibits better resolution than either my 8x or 10x Pentax DCF WP. Its only real fault (which is, of course standard for any porro model) is that it is a bit bulky. I don't know whether the roof prism Discoverer can favorably compare with this porro prism version but, I'd be willing to give it a try.

jedku said:

Lucznik, I think you will find the 7x42 made such an impression on you because of qualities linked to them being 7x.

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I suppose this is very possible and certainly there are too many proponents of lower magnification binoculars around (with good, reasoned arguments supporting their preferences) to simply ignore. The problem is that 7x just is too little magnification for me. Almost all of my glassing is done in Utah and Wyoming, which are both in the heart of the wide open American west. I am commonly glassing wildlife at distances more easily measured in miles than yards. I tried using my dad's 7x porro prism Brunton Eterna a few times but, it just never got me close enough to be acceptable.