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8X32 FL vs 8X42 FL (1 Viewer)

henry link

Well-known member
I had the opportunity yesterday to briefly compare a new Zeiss 8X32 FL to my 8X42 FL. My time at the store was limited so I confined the comparision to the two areas of optical performance that interested me the most between these two binoculars. I felt I could make reasonably accurate judgements about relative light transmission and off-axis sharpness in the 20 minutes I had available. Most of the observations were made in bright sunlight, a few in subdued light inside the store.

Since Zeiss claims that there is less than a 2% difference in light transmission between these two binoculars even though the 32mm uses a Schmidt-Pechan prism and the 42mm an Abbe-Koenig, I was curious to see if I could detect any difference in image brightness in sunlight, where the difference in exit pupil sizes would not be a factor. I know from comparing eyepieces with measured transmission figures that my threshhold for being able to detect any difference at all in light transmission is about 3%. The binoculars were extremely close, but the 8X42 was consistently slightly brighter in sunlight. In a low light area of the store it was substantially brighter. Color transmission appeared to be identical between the two. Contrast in the 32mm was extremely good, roughly equal to the 42mm in sunlight.

From looking at internal views of the FLs' optics on Zeiss websites I suspected that the objective focal ratio of the 32mm might be higher than the 42mm. I wondered whether this could produce better off-axis behaviour in the 32mm. Sure enough, I did observe an improvement in sharpness at the edge of the field in the 32mm (even though it's apparent field is actually a little wider than the 42mm), and more importantly for actual use in the field (provided this aspect of performance matters to you at all) there is clearly some improvement in the area about 10-15 degrees of AFOV away from the center. I would say the off-axis loss of sharpness in the 32mm closely resembles the behavior of the Swarovski 8.5X42 EL, not in the same class as binoculars with field flatteners, but quite good.

The store had a Nikon 8X32 SE and a Swarovski 8X32 EL in stock so I very briefly compared the 8X32 FL to those. The FL was obviously brighter and had better off-axis sharpness than the EL. It appeared about equal to the SE in brightness, but as usual the SE field flattener produced superior off-axis sharpness. I didn't have time or the resolution chart, magnification booster and tripod I would have needed to judge center of the field sharpness, but hand held the 32 FL appeared to have no obvious problems even compared to the 42mm FL.

One curious observation; I noticed that magnification in the 32mm FL appeared a little higher at close distances compared to the 42mm FL. I remembered that AK prisms have a slight off-set like porros, only much less. When I compared the objective spacing of the two I could see that the centers of the 32mm objectives were around 5-10mm closer together than 42mm's at the same IPD setting. A good indication of just how sensitive the eye/brain is to this particular illusion.
 
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I'm really pleased that someone has got around to comparing these two models. The other day I compared the Zeiss 10x32FL, 8x42FL and Leica 8x32 Ultravid. Unfortunately, there were no Zeiss 8x32 in stock.

I'm unable to see CA, so can't comment on that. I looked for the reported lack of off-axis sharpness in the 8x42, but couldn't see that either. In fact to my eyes they all looked superb, and at that price they should be!

What I can comment on is how they felt in the hands.

The 10x32FL was extremely comfortable to hold, a pleasure to use. Almost as comfortable as the suprememely comfortable Swaro 8x32EL.

The 8x42FL, I thought was comfortable, well-balanced, but very bulky - they dwarfed my Leica 10x42BAs.

As for the 8x32 Ultravids, they look the business, feel superbly engineered (better than the Zeiss), but in my hands they are far too small. I found them uncomfortable - no space to put the thumbs. Even my wife, with her relatively small hands, came to the same conclusion. No doubt they are optically superior to the model they replace, but ergonomically they are a backward step.

Incidentally, they all worked well with my glasses, but I had to twist up the eyecups a notch on the Zeiss 8x42 to avoid getting black-outs when panning.

Rich
(still can't make up my mind what to buy)
 
Richard Scott said:
(still can't make up my mind what to buy)

Rich, same with me, I am still undecided. I did not have the x32 Ultravids to compare, but other than that, I fully agree with your findings. I also felt the x42 FLs were rather bulky. But what bothered me most were the ribs. They are not as bad as on the (Leica) Trinovids, but definitely irritating as long as one does not wear gloves.

I did have the x32FLs to compare, however. They a rather smallish, too. But I gave little attention to them as I don't have a need in that size now. They were a bit brighter than the x32 ELs, but the ELs had a more comfortable feel in the hand. (Unlike the x42 ELs which are too large for my hands.)
 
Swissboy: Some users in the (in)famous Living Bird article agree with you -- they don't like the "ribs." For me, the FL is very comfortable. I have small hands.
 
Curtis Croulet said:
Swissboy: Some users in the (in)famous Living Bird article agree with you -- they don't like the "ribs." For me, the FL is very comfortable. I have small hands.

Thanks Curtis, I think I could get used to the ribs; it's just not optimal for me. But definitely better than on the Trinovids. There, I had tried to file off the ribs to some extent. With unsatisfactory results I should add, as they now have a rough texture. So I actually made things worse in a way.

But the ribs on the FLs do increase the circumference to some extent.
 
My Eagle Optics bin has a smooth exterior, like the Ultravid, so I immediately liked the Ultravid (that aspect of it, anyway) when I picked it up. It's all a matter of individual preference. One man's, "It should have ribs, to make it easier to hold when I'm wearing heavy gloves in Antarctica" becomes another man's, "Why the @#$% did they put those ribs on there -- it's so uncomfortable to hold!"
 
I have owned a pair of 8x42fl for about 6 months and like them very much. I bought my wife a pair of 8x32 fl so I have had an opportunity to look through both extensively.

The biggest difference is that the 8x42fl appears brighter. Because they appear brighter, the resolution appears to me to be slightly better in the 8x42fl. I am not sure that if someone did a scientific test, I would be right. But this is what I see.

The "ribs" do not bother me. I frankly find the 8x42 easier to hold steady than the 8x32-maybe balance or mass of the 8x42. I am not sure Both are comfortable.

Mike
 
Although I hate to admit it, I feel myself being drawn into looking into a new pair of bins & I'm particularly taken with the FLs - although I've not had the opportunity to extensively look at them.

My only chance, in fact, was at the Rutland Water Birdfair 2004 - hardly ideal testing conditions I know. My impression was that theses - both 8x32 & 8x42 were the first Zeiss bins in a long while that I'd looked through & thought - wow these really do deliver "the business". Previous views with the Victories were lacklustre, with massive CA being visible to me - this seemed to have been banished with the FLs and resolution & brightness seemed to have been upped a notch to boot.

My dilema therefore is, should I consider upgrading my Leica 8x42 BNs.

I find them comfortable and they provide fantastic, relaxing images. However, I guess I just have that nagging feeling that there's something better out there. Can I justify this feeling???!!! Can anyone help sway me one way or the other.

Recent binocular coverage is also hinting at the pros of 7x magnifications bins - this appeals too. Shame nobody's thought of a hi-spec 7x32 bin as I'm sure this would have great potential.
 
Eric F said:
Although I hate to admit it, I feel myself being drawn into looking into a new pair of bins & I'm particularly taken with the FLs - although I've not had the opportunity to extensively look at them.

My only chance, in fact, was at the Rutland Water Birdfair 2004 - hardly ideal testing conditions I know. My impression was that theses - both 8x32 & 8x42 were the first Zeiss bins in a long while that I'd looked through & thought - wow these really do deliver "the business". Previous views with the Victories were lacklustre, with massive CA being visible to me - this seemed to have been banished with the FLs and resolution & brightness seemed to have been upped a notch to boot.

My dilema therefore is, should I consider upgrading my Leica 8x42 BNs.

I find them comfortable and they provide fantastic, relaxing images. However, I guess I just have that nagging feeling that there's something better out there. Can I justify this feeling???!!! Can anyone help sway me one way or the other.

Recent binocular coverage is also hinting at the pros of 7x magnifications bins - this appeals too. Shame nobody's thought of a hi-spec 7x32 bin as I'm sure this would have great potential.

Eric,

Since you already own a nice bin, my suggestion would be to comparison shop. Always use your BN for direct comparison and, if you find something more appealing, buy it. If you compare across magnifications, you will be surprised to find that 7X42's are very comfortable on the eyes and that, in some instances, you might actually see more due to increased stability. The truth is, however, that during the initial moments of an observation an 8X, IMO, always shows more detail than a 7X due to the increased magnification. The same is true for 10X versus 8X/7X. As soon as handshake kicks in, and it always does, lower powers become VERY appealing.

I strongly urge anyone who owns a nice bin to make direct comparisons under different lighting conditions. It's amazing how similar the best of the best are.

John
 
Eric F said:
Recent binocular coverage is also hinting at the pros of 7x magnifications bins - this appeals too. Shame nobody's thought of a hi-spec 7x32 bin as I'm sure this would have great potential.

Swarovski had a 7x30 and discontinued it, so I assume it did not sell very well. The 7x30 SLC is a fine binocular whose exterior is identical to the 8x30. The FOV is slightly disappointing at 378' and the image has a subtle but noticeable amber cast. Nevertheless the image has great depth of focus and has a wonderful, natural feel, in addition to being very sharp.
 
Eric F said:
Although I hate to admit it, I feel myself being drawn into looking into a new pair of bins & I'm particularly taken with the FLs - although I've not had the opportunity to extensively look at them.

My only chance, in fact, was at the Rutland Water Birdfair 2004 - hardly ideal testing conditions I know. My impression was that theses - both 8x32 & 8x42 were the first Zeiss bins in a long while that I'd looked through & thought - wow these really do deliver "the business". Previous views with the Victories were lacklustre, with massive CA being visible to me - this seemed to have been banished with the FLs and resolution & brightness seemed to have been upped a notch to boot.

My dilema therefore is, should I consider upgrading my Leica 8x42 BNs.

I find them comfortable and they provide fantastic, relaxing images. However, I guess I just have that nagging feeling that there's something better out there. Can I justify this feeling???!!! Can anyone help sway me one way or the other.

Recent binocular coverage is also hinting at the pros of 7x magnifications bins - this appeals too. Shame nobody's thought of a hi-spec 7x32 bin as I'm sure this would have great potential.

Hi Eric,

The Leica 8x42BN is a great binocular. I love mine. I plan to keep it even if I add a Zeiss 8x32FL. I have a Zeiss 10x42FL and love it. It may be very rugged but it doesn't look as rugged as the Leica BN.

My Swarovski 8.5x42 EL I like a little better than my Leica 8x42BN.

Rich
 
Field Flatteners

henry link said:
I would say the off-axis loss of sharpness in the 32mm closely resembles the behavior of the Swarovski 8.5X42 EL, not in the same class as binoculars with field flatteners, but quite good.

Henry,

With respect to your comment about field flatteners, what are the tradeoffs that preclude designers from incorporating field flatteners in all binoculars?

Thanks very much for your insights,

Tony
 
tlb said:
Henry,

With respect to your comment about field flatteners, what are the tradeoffs that preclude designers from incorporating field flatteners in all binoculars?

Thanks very much for your insights,

Tony

I'm sure Henry can give you a better answer, but I would guess that the reason is simply cost. Manufacturers decide what features they think are most important and which can fit into the design budget. A field flattener as used in the 8x32 HG makes the eyepieces more expensive. Zeiss do not use field flatteners in the 8x32 FL, but unlike Nikon, they use use dielectric coatings on the prisms rather than silver. These are more expensive but give improved transmission and contrast. Zeiss also use flouride glass in the objectives, increasing the cost still further. I can only guess that Zeiss thought that improved coatings and improved objectives were more important than using field flatteners. Whether that is a correct call will no doubt be decided by sales. I happen to think that in 10 years time we will have binoculars with all the advantages of the FL series plus better edge to edge sharpness as per the Nikon HG and SE series. They will be more expensive, but the last few decades show that we all willing to pay ever more for better quality.

Leif
 
Hi guys,

Thanks for all your messages - I'm surprised that at current top-end binocular prices the big names feel they have to compromise somewhere - i.e. field-flatteners or coating - I guess profit creeps in to the Q as well.

I'm off to Portugal next week and will be taking my trusted BNs. I may be tempted to have a closer look at the 7x42FLs - trouble is in an ideal world I'd also like a decent camera adapter, a new lightweight large scope and a carbon fibre tripod!

I think I might have to compromise on the bins & scope as I already have decent kit & look at a set-up for my digi-scoping. :)
 
tlb said:
Henry,

With respect to your comment about field flatteners, what are the tradeoffs that preclude designers from incorporating field flatteners in all binoculars?

Thanks very much for your insights,

Tony

Tony,

Sorry for the late reply. I just saw your question, to which I don't really have much of an answer. I don't see any apparent optical tradeoff that I can attribute to field flatteners in the binoculars I own that use them. There has to be a very small light loss from the extra glass to air surfaces and it has been suggested here that the central sharpness may suffer, but I haven't been able to measure or see that. However, as usual with binoculars there is no way to know how a completely identical instrument except without a field flattener would compare.

I'm sure Leif is right about cost being a factor in low to medium priced binoculars, but some field flatteners like the ones in the Fujinon FMT-SX and the Nikon HG/LX are just simple singlet eyepiece elements. I would think the cost of manufacturing them must be less than $10 each, probably less than $5.

Henry
 
May I suggest that effective field flatteners preclude a wide field of view and that they may have an adverse affect on edge distortions. Then again field flatteners may be used with narrow fields of view to prevent edge distortions.

Happy bird watching,
Arthur Pinewood
 
henry link said:
I'm sure Leif is right about cost being a factor in low to medium priced binoculars, but some field flatteners like the ones in the Fujinon FMT-SX and the Nikon HG/LX are just simple singlet eyepiece elements. I would think the cost of manufacturing them must be less than $10 each, probably less than $5.

Henry

Henry: Although there is only one extra element, I suspect that other elements in the eyepiece also have to change, leading to a greater increase in cost than might otherwise be expected. To my eyes the issue with the Zeiss FL (and Swarovski 8.5x42 EL) is not primarily field curvature, though there is some, but off axis softness. In other words, simply flattening the field would provide minimal benefit though it might still be worthwhile. To get a signficant improvement the entire eyepiece design would have to change.

I suspect the field flattener element is just the one component of the design that the marketing wonks have focussed on (no pun intended) as it sounds good ("we've got something Leica haven't got [from Nikon HQ comes the sound of a raspberry being blown]") and highlights the fact that there is an almost flat field and almost perfect edge to edge sharpness.

Perhaps there are also patent issues? I wonder if companies such as TMB and Televue patent eyepiece designs such as the Naglers ...

Leif
 
Leif said:
Perhaps there are also patent issues? I wonder if companies such as TMB and Televue patent eyepiece designs such as the Naglers ...

The Nagler eyepiece design is patented: U.S. Patent #4,286,844, issued Sep 1, 1981.
 
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