Buying first new binoculars in 30 years (1 Viewer)

[elkcub]

This theory sounds interesting but I don't understand it yet. Wouldn't a defocus gradient due to the eye's own curvature of field still apply when gazing straight ahead through binoculars? (And wouldn't it then be curved-field models that exaggerate that gradient in a potentially odd way?) Or am I falling into the old camera-analogy trap, whereas field curvature here is a property of the whole eye-binocular system, so FFs correct for both?

Hi tenex,

My reference to a "cue conflict situation" is based in part on the following understanding of how the eye takes advantage of field curvature.

"Field curvature is a measure of defocus for off-axis objects and implies that the best image is formed not on the paraxial image plane but on a parabolic surface called the Petzval image surface (Smith & Atchison 1997). In real eyes, the retina, which may be approximated as a sphere with a radius between 11 and 13 mm, constitutes a curved image plane that in most cases compensates for field curvature." (from: Image Formation in the Living Human Eye," by Pablo Artal, 2015)

To answer your question, I don't know whether field-flattener design includes corrections for the eye's cornea and lens curvatures, or where the resulting "flat image" is formed relative to the eye's Petzval surface. It would seem that they project an extended paraxial image tangent to the curved retinal surface, which would then produce cue conflicts that somehow result in the spatial perceptions I mentioned. I could be completely wrong. It's just a conjecture.

Ed

 

[tenex]

Thanks, got it! I wasn't considering the role of a curved retina. The other thing I wonder about is that with optical illusions etc, everyone seems to be affected, whereas some seem troubled by flat-field bins while others don't. I don't seem to mind it myself -- but then I haven't bought one yet either. (I don't suppose I could just be a creature of habit?)

 

[Maljunulo]

I’m not overly fond of rolling ball, which some describe as a consequence of field-flattening optics.

 

[Binocollector]

I’m not overly fond of rolling ball, which some describe as a consequence of field-flattening optics.

Strictly speaking those don't have to be related. Flat field doesn't mean "no pincushion distortion". A manufacturer can introduce both in the optics of a bino. Flat field and a slight pincushion distortion -- which AFAIK is exactly what Swarowski did with the NL Pure.
You could theoretically even have a curved field with no pincushion distortion -- which would mean that lines are straight but out of focus at the edge. That could still lead to a rolling ball effect. Most vintage binos after about 1950 have field curvature and pincushion distortion but some are rather sharp even at the edge but still retain the pincushion distortion and have no rolling ball effect. Others, like the Komz 7x30 have a flat field and no pincushion distortion and therefore a rolling ball effect.
Most flat-field binos I own have a rather narrow field of view where rolling ball is not much of an issue, like: Canon 8x32 WP -- 7.5°, DDoptics Lux HR 10x42 -- 6.2°, Komz 7x30, 8.5°; Canon 18x50 -- 3.7°.

 

[elkcub]

Thanks, got it! I wasn't considering the role of a curved retina. The other thing I wonder about is that with optical illusions etc, everyone seems to be affected, whereas some seem troubled by flat-field bins while others don't. I don't seem to mind it myself -- but then I haven't bought one yet either. (I don't suppose I could just be a creature of habit?)

Apparently the perception is similar to CA (chromatic aberration), which many people are oblivious to until someone points out where to see it. At that point many can't not see it.

I'd suggest comparing your 10x42 SLC-HD with the EL. The difference was quite apparent to me when I made the comparison years ago. If not, count your blessings.

Ed

 

[Rg548]

Thanks, got it!

Glad YOU did🤣🥴

 

[jring]

Hi Andrew,

first of all, a warm welcome to birdforum!

Whether you prefer binoculars with field flateners is hard to predict - some love it, some not so much. For birding binoculars it's not such a big deal as one still can see movement in a blurry edge of field and quickly point the bins to the new object of interest. For astro it's sth different - if the object you are observing fills the whole field and the edges are blurry - too bad.

I would recommend a pair of used alphas with your budget (and having been spoiled by an alpha before ;-)
In focus has a pair of Zeiss SF 8x42 just inside your budget in their Hertfortshire shop (or via mail orders) - that would be a worthy flat field successor to the 7x42 T*P.
Other things to look for would be Nikon EDG 8x32, 8x42 or 7x42 - also with very good field flatening, Swaro EL 8x42, also with field flateners (I would not take the 8x32 there due to their flare/glare problems) or Leica Noctivid.
Traditional alphas without field flateners would be Leicas Ultravid, Zeiss HT or FL series or the already mentioned almost alpha Kowa Genesis series.

Joachim

 

[tenex]

I'd suggest comparing your 10x42 SLC-HD with the EL. The difference was quite apparent to me when I made the comparison years ago. If not, count your blessings.

I have tried several flat-field bins, especially lately SF and NL, without experiencing anything odd. What I haven't done is an A-B comparison with a conventional glass, and now I'm curious to.

 

[exup]

One thing I recommend before you splash big cash on new (Alpha grade) binoculars, is to try Canon IS first.

I have recently bought 18x50s and 12x36s and nothing comes close to these.
Alpha bins might have marginally brighter and sharper optics, but unless you mount them on a tripod, the 'glass benefits', don't makeup for the addition of IS.

The x12 will give you a more steady view than a non-IS x8.

I might buy a 10x42L IS, which is the premium model in the Canon lineup, but still significantly cheaper than a top line 'Alpha'.

 

[Paultricounty]

One thing I recommend before you splash big cash on new (Alpha grade) binoculars, is to try Canon IS first.

I have recently bought 18x50s and 12x36s and nothing comes close to these.
Alpha bins might have marginally brighter and sharper optics, but unless you mount them on a tripod, the 'glass benefits', don't makeup for the addition of IS.

The x12 will give you a more steady view than a non-IS x8.

I might buy a 10x42L IS, which is the premium model in the Canon lineup, but still significantly cheaper than a top line 'Alpha'.

Here we go again with those subjective terms like marginally. One persons marginally is another persons freight train of difference 🤔😜✌🏼.

 

[exup]

subjective terms like marginally.

Yes, that's why I prefixed it with "might have".

I live in the science and complex engineering world and there is little objective assessments in forums.

However, subjective opinions still have value.

Recommendations to try particular binoculars are very much based on subjective opinions. It is up to the receiver of the recommendation to act on it or not.

 

[etudiant]

Here we go again with those subjective terms like marginally. One persons marginally is another persons freight train of difference 🤔😜✌🏼.

No argument, but the old 7x42 T*P* Zeiss is still a worthy alpha glass, very much in the same league as modern optics.
IS however is a qualitative shift in the binocular experience.
Imho, Exup is correct that AndrewC1's search for a modern glass needs to include IS binoculars, they represent the major innovation in the field.

​

 

[Paultricounty]

Yes, that's why I prefixed it with "might have".

I live in the science and complex engineering world and there is little objective assessments in forums.

However, subjective opinions still have value.

Recommendations to try particular binoculars are very much based on subjective opinions. It is up to the receiver of the recommendation to act on it or not.

I live in sales in the complex world of peoples emotions, it’s part of the reason we have E&O insurance 😉

Others could say , may be exceptionally brighter and sharper. ✌🏼

 

[Paultricounty]

No argument, but the old 7x42 T*P* Zeiss is still a worthy alpha glass, very much in the same league as modern optics.
IS however is a qualitative shift in the binocular experience.
Imho, Exup is correct that AndrewC1's search for a modern glass needs to include IS binoculars, they represent the major innovation in the field.

​

I agree, I think it should be considered in every bodies search for modern glass. They do represent innovation that has been making incremental improvements for close to 30 years now. Yeah it seems that serious observers, birders etc. etc. have consistently passed on these IS binos. I think they shine more for astronomy or boating IMHO.

 

[exup]

world of peoples emotions,

I read daily on forums the emotional comments about binoculars ...... Nothing wrong with that ....it is a hobby and gives people joy.

I am probably more like Captain Spock, who ..... Binoculars are tools to present an image to the brain. IS bins are the best handheld tools to do this, irrespective if Alphas are brighter and sharper.

I accept, of course, that weight, ergonomics and other factors contribute to the experience.

I don't accept badge 'pride'.

 

[Paultricounty]

I read daily on forums the emotional comments about binoculars ...... Nothing wrong with that ....it is a hobby and gives people joy.

I am probably more like Captain Spock, who ..... Binoculars are tools to present an image to the brain. IS bins are the best handheld tools to do this, irrespective if Alphas are brighter and sharper.

I accept, of course, that weight, ergonomics and other factors contribute to the experience.

I don't accept badge 'pride'.

I agree it’s definitely an emotional thing. And some people do like the pride of ownership of having the best of the best. Do you like Timex or Rolex😆

And by the way, it was first officer Spock 😀

 

[exup]

Do you like Timex or Rolex😆

And by the way, it was first officer Spock 😀

Ha .... You have made me laugh .....

Garmin Fenix ...... which I expect you could have guessed by now ......

And, yes, you are correct not Captain ...... It was Captain Kirk who was the emotional one too! 👍

 

[Paultricounty]

Ha .... You have made me laugh .....

Garmin Fenix ...... which I expect you could have guessed by now ......

And, yes, you are correct not Captain ...... It was Captain Kirk who was the emotional one too! 👍

Lol 😄, I was trying..

Its all good, we all have a good time here going back and forth with banter.

Kirk also got all the babes.

Paul