Rating matrix needed for binoculars

For a long time, I have wondered if anyone would ever come up with a rating matrix for binoculars.  Different situations call for different performance specifications.  For some situations, razor sharp resolution with vibrant color transmission is critical, in others, size and weight may be the deciding factor, still in others, extreme low light performance is of utmost importance.  It would be nice to know for example that model X had 94% light transmission, while model Y had only 85%.  Many of us don't have the ability to try out a number of units, so we depend on people who have significant knowledge of a particular model to give recommendations.  We often times spend 100's of dollars based on these recommendations.  Without specific knowledge we often make decisions based on brand recognition.  I did this a number of years ago when I bought several Leupold Vari-X-III scopes thinking that they were probably one of the best low light scopes available.  Boy, was I wrong.  They are certainly well made scopes, but near dark they just don't do the deed.  Little did I know that they were doing good to get 90% light transmission and that there were better models out there for that application.  Some were even priced significantly less.  It would sure be nice if anyone with enough knowledge would be willing to give a try to developing a rating matrix for binoculars.

There are lots of them around.  I see them turn up fairly often on birdwatching sites. I can't remember what site it was (birdwatching.com? Optics4Birding.com?) that has a buying guide built into the site. 

 

The problem you will run into is that all such rating matrices, buying guides, etc. are built along the biases of the people who develop them.  They cannot properly rate things like weight, handling, touch, sufficiency of eye relief, color bias, eyecup comfort, etc. as these are all subjective issues.  There also is no standardized and reliable way to measure the degree and effect of optical abberations, nor to measure resolution, contrast, etc.  

 

Although you can measure the average light transmission, you cannot measure how well the binocular is using that light.  95% transmission of light is great unless the optics are too poor to allow for good resolution.  In such a case a binocular only allowing 85% light, but whose lenses are ground to perfection so that detail can be seen would really be preferable. After all, no matter how bright it is, an unresolved blob is just an unresolved blob.

 

I actually made up a rating matrix of my own once figuring that, since this matrix would be based on my own personal biases, it would at least be useful for me to use in rating different binoculars. The problem was, once it was finished, I found myself constantly arguing with it over how some optics I like got poor scores and how others that I don't much like kept scoring too high.      So, I got rid of it.

 

 

Edited by lucznik

I have pretty staight criteria. I need a cerain apparent FOV. With this I have three pair, one reverse porro 9x, one fairly cheap 8x32 and one cheap 10x28 roof. All have the same apparent FOV. Clarity is needed, at least in the sweet spot, which must not be ridiculously small. Brightness as much as possible. I sold a nice 10x25 that had just barely the OK FOV, btu was dim.

Roof prisms preferred over porro, if the FOV is not close to 400. I can point roofs faster. The 9x25 reverse porros are the exception. They are compact so they go with me often.

Tero,

 

I believe you just nailed some of my basic criteria without my really giving much thought to them. I do prefer a relatively large apparent field with a fairly large sweet spot. I prefer those two characteristics so much that I would be willing to sacrifice a bit of perceived center field sharpness for a wider sweet spot. It just gives me a more relaxed and comfortable image.

Frank,

Bigger lenses have a larger central area (sweet spot) of resolution than smaller lenses.

For an "old codger" like myself, that is part of the reason I really enjoy the larger objective aperatures.

I'm not a hunter, so weight is not a major concern.

Edited by Bird Watcher

Tero,

What do you consider to be "ridiculously small"?

You seem to be a person who is into "compact" binoculars! (under 30mm)

Bird Watcher wrote: Frank, Bigger lenses have a larger central area (sweet spot) of resolution than smaller lenses.

 

True, but I did see an interesting discussion recently on how exit pupil size affects the perceived size of the sweet spot for any given binocular. The comparison in question was between a 7x42 and 8x32 Leica model. Good reading.

http://www.birds.cornell.edu/Publications/LivingBird/winter2 005/Age_Binos.html

 

Try this link.  I've been doing some research on binoculars, and I found this very interesting.

 

http://www.binoculars.org/

 

This link was also interesting.

 

Hope this helps.

 

Steve

I'll propose that astronomy places the most stringent demands on binoculars and scopes as point souces are often used to test optics, and the night sky is full of them :^)  Aside from optical quality one needs consider price, weight, eye relief, etc., and what I call 'individual compensation', which I'll babble about later. For astronomy porro prisms seem to be most common as roof prism models need to work hard to be almost as good so they typically cost more for a given quality level, but they're still used as they're popular for birding and such. For optical quality the size of the sweet spot is the primary criteria, and the best models are well corrected to the edge of the field. On good models even 7x need to be on tripod in order to realize all the resolution available. Wide field models tend to have more problems at the edges. 'Color' seems to be essentially a product of overall light transmisson, where the best models seem to set the industry standards. Another factor is how one's eye's interact with an optical system as designers make assumptions about curvature of field and such, so regardless of how well regarded a model is its' best to look thru it before dropping lots of money on it. Along with curvature of field aberrations in a specific model may also be 'compensated' by aberrations in one's eyes, as the aberrations may cancel each other to some degree. 

 

Anyway, after looking thru lots of different models, including lots of fancy German stuff, I ended up choosing between the Nikon 7x50 Prostar and the 7x50 Fujinon FMT-SX. It was to be a lifetime buy, primarily for astronomy but also for general use. Build quality ws the same for both, the Nikons were sharper to the edge but I liked the color better in the Fujinons, the Fujinons had a tripod mount, and since the Fujinons were less than half the price at the time price I ended up with them. Years later I'm still amazed at good they are, esspecially when glassing while they're on a tripod, which is what is needed for maximum resolution. People complain about the weight (about 48oz or 4 cans of soda), but other smaller models are available.

 

Anyway, look at some astronomy sites too for comparisons.  

I'll take a stab

10: Swarovski EL & SLCneu, Zeiss FL, Leica Ultravid, NIKON LX
9: Leica Trinovid, Swaro SLC old, Zeiss Victory, Leupold GOlden RIng HD
8: Vortex Razor, Pentax DCF ED, Minox HG, Kahles, Bushnell ELite
7: Pentax DCF SP
6: Nikon Monarch


you guys finish it

SAKO75 wrote: I'll take a stab 10: Swarovski EL & SLCneu, Zeiss FL, Leica Ultravid, NIKON LX 9: Leica Trinovid, Swaro SLC old, Zeiss Victory, Leupold GOlden RIng HD 8: Vortex Razor, Pentax DCF ED, Minox HG, Kahles, Bushnell ELite 7: Pentax DCF SP 6: Nikon Monarch you guys finish it

couldnt the same be said about scopes? eye relief, FOV, 1/4, 1/3, or 1/2 MOA, turrets or no turrets, AO, etc.?? its just a starting point, a ball park generalization?

I dont think a monarch is a zeiss no matter what the FOV is, for instance....

Interestingly enough, the latest reveiw from Birdwatcher's digest and the review from Cornell both rated the Nikon Monarchs higher than the Pentax DCF SP. I have a pair of the Pentax in 8x42 and like them but I would like to put them up against the Monarchs and if there really is a noticeable difference.

SAKO75 wrote: I'll take a stab 7: Pentax DCF SP 6: Nikon Monarch