• BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

    Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

I do not like green cast and ham - 10x alpha redux (1 Viewer)

Troubador

Moderator
Staff member
Supporter
Lee,
Thanks for the essential Sun warning.

The Sun is actually white not yellow.

Yes B, but the joke was, if I want to see a yellow sun I look through the SFs.

Which is a double joke as I don't see the tint anyway, any more than I see Rolling Balls through Swaros or Zeisses.

Meanwhile Dennis is right......

Don't get started again Lee
 

elkcub

Silicon Valley, California
United States
Which is hardly the basis for any serious colour calibration of a monitor.

I'd have no "objective rationale" either, if I didn't employ a rather expensive colourimeter to objectively assess all the stages of my colour-managed photographic workflow.

Hey, you spend the money on binoculars (and there's nothing wrong with that; and I've spent a few bucks myself). For me, binoculars are both a sideline and a means to an end (one of the ends being finding birds to photograph). Some might not spend $thousands on colour-constant monitors and colourimeters which can assess cameras and monitors, and also profile paper/printer/ink combinations in order to manage colours well. That's not a cost-free exercise in terms of either equipment or skull-sweat.

It is refreshing, though, to be told[*] that counts for nothing in terms of objective assessment (which is precisely what it's designed to do) after I've already acknowleded that subjective assessment is a different thing entirely. I guess objectivity isn't what it used to be.

...Mike

[*]not by Ed, who I'm quoting above; I'm thinking more the generality of the whole thread, in which it seems a great many people think their assessment of colour on an uncalibrated monitor decices whether a colour-cast exists, or doesn't, based on their own subjective assessment of "how it looks" on whatever screen they happen to be looking at

I'm with you, Mike. If you look through my past writings it will become evident that I often harken back to the need for laboratory controls. No one ever commented on this, in over a decade, so I'm pretty sure that very few understand what I'm saying. You're gonna have to be stoic about this and don't take it personally... and I'm not being sarcastic.

Ed
 

[email protected]

Well-known member
Supporter
Well, i was determined not to get involved with this, but just had an idea...
if you look up to the sky (white cloud, or grey cloud) with the right eye piece just off your left eye, and keep your right eye open (a trick in itself!) any colour tint becomes bleedin' obvious immediately.
Doing the same the other way round (assuming the bins have the same optics in both barrels!) will either give the same result, or show any differences in your eyes.
Sorry if you've already tried this or discussed it before. I haven't read all the posts, and this might be a tried and tested technique.
Just tried it with the FL8x32, and there is a touch of 'whatever that colour is that people call green/grey/blue - but it doesn't worry me much. Put both barrels to your eyes as normal, and it's not noticeable.
This cuts out cameras, and filters, and monitors and just concentrates on what you see through binoculars, which is all that matters.
Ok. Paddy7 I tried your "One-eye Jack" test on my three Swaro's this afternoon on some fluffy white clouds that were drifting by on the Colorado horizon and let me describe these. The clouds were white, white. Almost an alabaster, pure white or should I say bleached, chalky white. These dxxm clouds were whiter than Snow White's hair. In other words they were pretty white. Well, I looked through the binoculars with one eye and with my other eye I looked at the same cloud. With all three Swaro's I could see no hint of any "Green Monster's" or any other added color tint. The clouds color looked the same through the binocular as they did with my naked eye. These were the Swarovision SV 8x32, Swarovision SV 10x50 and the Habicht 8x30W that I tested.
 
Last edited:

Gijs van Ginkel

Well-known member
Binastro, post 135,
Yes the Zeiss porro 10x50 has T-coating, so single coating. I will collect the data to answer your other questions, that will take a little time.
Lee, post 136,
Which model SF did you buy.the Super Fuzzy, the Smart Fantasy or the one with incorporated illumination?
Dennis, post 143
These results were to be expected from the transmission spectra of the three binoculars you investigated.
Gijs van Ginkel
 

elkcub

Silicon Valley, California
United States
I hope this doesn't add to the confusion, but from the perspective of experimental psychology much of the discussion has strong Perceptual Learning implications. For those interested, the Wiki article is a good read, and color vision is embedded in it. Even today the subject is by no means settled, or easy to understand. But that's not a good reason to ignore it either.

Ed
 
Last edited:

perterra

Well-known member
I hope this doesn't add to the confusion, but from the perspective of experimental psychology much of the discussion has strong Perceptual Learning implications. For those interested, the Wiki article is a good read, and color vision is embedded in it. An important reference article by Burns & Sheep (1988) concerning Hue, Saturation, and Brightness is attached below. Note that their experiments typically involved 30 or more human subjects, and correlations generally involved subsets around N= 10. [Square the correlation values to estimate predictive effectiveness.]

Ed

Okay Ed, I can appreciate an attempt to educate, though in my case, this is way over my head. But it sure seems easier to just look thru the binoculars, and if you like them you are good to go, if not, then keep looking for another pair.

That another person may see something, really means nothing to me if I dont see it. I dont have an overwhelming desire to know it's there if I cant see it.
 

elkcub

Silicon Valley, California
United States
By golly that's what I've been trying to say. My "attempt to educate" is only to point out that the methods being used to characterize binoculars are so contaminated by variations in perception that the enterprise serves little purpose.

Based on your reaction I've deleted the Burns & Sheep study, which is a bit over the top.

Thanks,
Ed
 
Last edited:

cycleguy

Well-known member
Thanks everybody for all the interesting posts, especially Alexis, Vespobuteo, Joachim, Ed, David and Gijs for sharing your expertise. I think this thread has turned into a good lesson about what sort of photographic information can be successfully shared through our computers.

I guess I haven’t quite learned my lesson yet, so here are some more images.

In the one on the left I took the liberty of downloading Vespobuteo’s color charts and cropped out the same gray square from each (bottom row, second from the right). The crops are presented the same way I’ve been showing crops from my photos. One half of the gray bar is greener than the other half. I’ll leave it to you to decide whether it’s the left or the right half.

In the other image I’ve modified the crops from my photo that V used to make his charts. As closely as iPhoto allowed I brightened the crop from the binocular optics to match the brightness level of the background crop in order to remove transmission loss as a visual cue.

On my computer screen both crops from my photo look greener than the color chart crops and the color difference between the halves seems a little easier to discern, perhaps because the brightness has not been fully equalized.

Certainly the color bias of the FL is slight (something I said in my first post) and yet strangely I have no difficulty noticing it if I choose to pay attention when I first lift the binoculars to my eyes. It’s obviously far from a deal breaker since I’ve happily used the 8x56 FL as my primary birding binocular for about nine years. I have some other old binoculars with such strong color biases that they are deal breakers (one about as yellow as the old Russian binoculars Joachim mentioned). It’s cloudy here now, but when the sun returns I’ll photograph a few of those and we’ll see how they come across on other computer screens.

Henry

I can easily see the difference between the right half and the left half in each....

CG
 

OPTIC_NUT

Well-known member
I think it's interesting that there are discussions of nearby color swatches,
when Zeiss has been designing for the pursuit of natural animals and objects
under conditions where the atmosphere can haze the image and 'blue-shift' it strongly,
and specular glare from items can cause a local brownout around the edges in the eye.

In a nutshell, I think they know what they are doing....under actual real conditions.
They have to get a little head-start on the violet/UV attenuation, and the red nudge
is to compensate for that. Just as they have done for hunters and birders for over
40 years, in all seasons.
 
Last edited:

[email protected]

Well-known member
Supporter
I think it's interesting that there are discussions of nearby color swatches,
when Zeiss has been designing for the pursuit of natural animals and objects
under conditions where the atmosphere can haze the image and 'blue-shift' it strongly,
and specular glare from items can cause a local brownout around the edges in the eye.

In a nutshell, I think they know what they are doing....under actual real conditions.
But the point is some people don't like it.
 

perterra

Well-known member
By golly that's what I've been trying to say. My "attempt to educate" is only to point out that the methods being used to characterize binoculars are so contaminated by variations in perception that the enterprise serves little purpose.

Based on your reaction I've deleted the Burns & Sheep study, which is a bit over the top.

Thanks,
Ed

3:)

As seen in the Boat House Bar in Terlingua
 

Attachments

  • BrilliantMindsboathouse_zps75f4a043.jpg
    BrilliantMindsboathouse_zps75f4a043.jpg
    88 KB · Views: 61

etudiant

Registered User
Supporter
I can easily see the difference between the right half and the left half in each....

CG

When using one eye at a time, I find a substantial shift between my left and right eye in the perceived color. So individual variation is actually even greater than generally understood. This makes it challenging to arrive at satisfactory glass formulations for general use.
 

OPTIC_NUT

Well-known member
It aint so damn hard, look through it, if you dont like it, dont buy it.

There ya go. Maybe some variation though...
They need to make a special model that works perfectly on color swatches
at 30 feet. And keep the other one for hunters, guides, explorers, rangers,
tourists, and people where the weather can get messy.

I could save a lot on birdseed if I looked at color swatches,
but I would feel lonely. Nothing more wonderful than following a deer
or a turkey through deep woods 100 yds away. No worse tool than
flat optics...the critters wash out in the blue-grey glow.
 
Last edited:

perterra

Well-known member
There ya go. Maybe some variation though...
They need to make a special model that works perfectly on color swatches
at 30 feet. And keep the other one for hunters, guides, explorers, rangers,
tourists, and people where the weather can get messy.

I could save a lot on birdseed if I looked at color swatches,
but I would feel lonely. Nothing more wonderful than following a deer
or a turkey through deep woods 100 yds away. No worse tool than
flat optics...the critters wash out in the blue-grey glow.


Yeah yeah, maybe they could make a special model depending on the bird you wanted to watch.
 

ceasar

Well-known member
When using one eye at a time, I find a substantial shift between my left and right eye in the perceived color. So individual variation is actually even greater than generally understood. This makes it challenging to arrive at satisfactory glass formulations for general use.

The same with me. I notice it particularly in autumn when the leaves are changing color.

Bob
 

[email protected]

Well-known member
Supporter
It aint so damn hard, look through it, if you dont like it, dont buy it.
Exactly, I agree. It sure is helpful when you get such good reviews on Bird Forum from members like Cyclist that help you make decisions on purchases. Sometimes in the store you don't see everything right away and it is hard to fully judge a binocular until you have tried it out in the field for awhile. Everybody has to make their own final decision on a purchase but the more you learn the better qualified you are to make a wise decision. You really benefit from other peoples experiences. Thanks Cyclist for the excellent review.
 
Last edited:

Holger Merlitz

Well-known member
Dear all,
In the attachment a transmission spectrum of a bright yeloow-green color definition in the Aus Jena 7x40 BGA.
Really special to look through and looks very bright.
Gijs van Ginkel



Dear Gijs,

Thanks a lot for that transmission spectrum of the 7x40 (EDF). I took the liberty to extract some of the transmission data, to weight them with the standard V-Lambda curves (luminosity efficiency curves) of human daylight- and night vision. The resulting visual transmission then was 82.4% (day) and 81.6% (night).

In fact, the dramatic loss of transmission of the EDF in the short-wavelength regime has hardly any impact on its effective (perceived) brightness, because the blue and violet parts of the spectrum have such a low weight. It is fascinating that, despite of the tiny contribution of the violet to the brightness, its absence causes a very visible color shift of the image. As a result, the image looks yellow, yet bright.

The yellow color tint of the EDF is a result of the addition of cerium oxide to the optical flint glass (SF3R) that is used for one optical element of the objective and the eyepiece, too. The additives made the glass resistant against nuclear radiation.

Another point I found on https://en.wikipedia.org/wiki/Luminosity_function:

For older people with normal color vision, the crystalline lens may become slightly yellow due to cataracts, which moves the maximum of sensitivity to the red part of the spectrum and narrows the range of perceived wavelengths.


That might imply that to some elder folks with yellowish lens the color rendition of binoculars may shift. If these cataracts exist in a single eye only, then the color renditions of both eyes of one observer may differ. Now we have to figure out: Do, in average, the young people see the green tint of the Zeiss SF, and the old guys not, or vice versa?

Cheers,
Holger
 

Attachments

  • edf_transmission.pdf
    7.6 KB · Views: 36

jring

Well-known member
What would the transmission be for an uncoated roof prism binocular with 3 and 5 element eyepieces?

Hi,

the roof design makes that a bit tricky to calculate as we get a lot more effects on performance than just lens coatings (or the lack of). Also there are a few kinds of roof prisms with different effects.

Specifically in the optical worst case scenario of Schmidt-Pechan prisms we have the question of what material is used for mirroring the one prism face which cannot use total reflection and phase coating to fight interference between the two half-beams with different polarisation due to being reflected on different sides of the roof edge.

Also two surfaces of the Schmidt-Pechan prisms are both reflecting and transmitting the light so optimising one is making the other worse. Some guy at Zeiss found out that single coating these two surfaces is the lesser evil even if multicoatings are available.

So if we assume an uncoated pair of bins with a cemented doublet objective (2 surfaces), Schmidt-Pechan prisms (4 surfaces, one mirrored surface plus destructive interference from lack of phase coating), external focussing Dialyth style and a 2 to 4 element EP (the number of groups is relevant and we have 2 groups or 4 surfaces for any from Huygens over Abbe to Ploessl), we get 10 uncoated surfaces for 40% light loss plus the mirror (probably silver here due to easy chemical deposition) for up to 20% light loss in the violet/blue part of the spectrum plus reduced contrast due to no phase coatings.
A 5 element EP (assuming erfle with 3 groups) will just add 2 more surfaces or 8% loss to this "design"

I'd say thanks but no thanks to these pairs of bins - I'm not a collector...

Joachim
 
Last edited:

Users who are viewing this thread

Top