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

[Troubador]

If the Zeiss T* is resulting in a slight emphasis on the green is this likely to be the result of a deficit in the red transmission? And is it possible that those who notice this have a slight deficit in their red sensitivity that increases the green to a level they can perceive? The corollary would be that those who do not see it may have a slightly better red sensitivity.

Lee

 

[perterra]

Originally Posted by [email protected] View Post


RGB values mean nothing. What the eye sees is what matters. You are using you eyes when you use your binoculars.

Dear Dennis
RGBs mean nothing?
The pictures that Henry took were captured by the camera as a set of RGB values, stored by his computer in a similar way, interpreted by your computer as a set of RGB values that your monitor did its best to display. Only then your eyes and brain did their thing.

Lee

Lee, since Dencos original post seems to have vanished, I'll reply using yours if that's okay. Was going to reply last night but was beat, got up this morn, post is gone daddy gone.

I think I agree completely with Dennis, your eyes are important, not the specs of the binocular, I think I have said that for years. I dont see a color shift with the Z, so for my reality, no green cast, no problem, it doesnt exist.

Goes back to the point of why I can get by just fine with a less expensive optic

 

[David in NC]

Why am I reminded of this:

What color is the dress?

Its OBVIOUSLY gold and white. o

 

[henry link]

OK, here's another image. This time I went back to some photos I made while vacationing on the NC Outer Banks in September. Same camera, same sun, same 8x56 FL, but the other binocular is a Zeiss 8x42 HT and the background is a white plastic cutting board from the kitchen of the cottage we rented. The photo was not as underexposed as the recent ones I posted, so I used the exposure control in iPhoto to darken it. The crops show unaltered background in the middle, 8x56 FL on the left and 8x42 HT on the right. I have no way to analyze the RGB channels, but eyeballing suggests there may be higher blue transmission in this particular HT (early production) compared to the FL but perhaps not much more red.

Please note this is not a test of the neutrality or accuracy of the background color. It's about how well the colors within the circles of the binocular optics match the background color, however you may see them. Imagine you need to repair some paint on a wall and are trying to match the original color by placing paint swatches next to each other and against the wall.

However, I'll have to bow to Alexis' much greater experience with the color inaccuracies of computer monitors as well as the possibility of genetic differences or compromised color perception and concede that some people may just not see what I'm seeing.

Henry

 

[perterra]

I see nothing at all on the left photo, and the right side looks a different shade but no real color difference. I think you are beating your head against the wall on this one Henry. Chances are we would not see it regardless of the monitor

 

[jremmons]

Some people see the difference and some don't. To me the greenish hue is readily apparent; to others it is not. I think this exists both in the real world and through computer screens. No reason to tell others what they should see - if they don't, they don't; that is why there are 4+ brands that are able to sell binoculars >$2000 in price despite, relatively, minor differences.

 

[typo]

If the Zeiss T* is resulting in a slight emphasis on the green is this likely to be the result of a deficit in the red transmission? And is it possible that those who notice this have a slight deficit in their red sensitivity that increases the green to a level they can perceive? The corollary would be that those who do not see it may have a slightly better red sensitivity.

Lee

Lee, it's a subject I've tried to look into but haven't made a lot of headway.

A reduced transmission in the red alone is sufficient to change a grey to bluey green. Reduce the blue as well and the green looks greener. The FL and probably the HT and SF have a higher transmission in the green/yellow than and in the blue and red so will have a green or yellow bias. What appears to be clear from these comments is that individuals differ in their ability to discern this and/or recognise small blue/green differences in photos. Colour blindness might do this of course but less than 10% of males are are affected so would not account for the roughly even numbers reporting blue or green. The mutation I mentioned alters the peak sensitivity of the long wavelength receptor by a few nanometers but not the red sensitivity as I recall. What difference it might make in this context I'm not sure but I wondered if there might be a clue in gender reporting. Much better understood is the yellowing of components of the eye as we get older. This reduces blue transmission and might make a differences to colour discrimination as well.

The real difference in reporting could all be in the brain. What we think we see is nothing like the image projected on our retina. 'Seeing' is a learned activity and subject to all kinds of experienced based modulation. Like other skills, maybe colour discrimination is the product of regular training. At least some of those who were reporting 'green' were professionals who use colour as part of their professional life. Artists, photographers, scientists etc.. It could be just a coincidence of course. It's interesting, but I don't know the answers.

David

 

[Binastro]

Thanks Alexis for post 75.

I suppose I should be green with envy at all the top binoculars being used.

I don't see green in any of the photos here, but the computer is old as am I.

I tend to look for different characteristics in binoculars to birdwatchers. Some binoculars extolled here I find very poor. Others shunned here I find to be great.

I changed the old thicker 6ft fluorescent tube in the kitchen for a new slim one and my salad looks quite different. The carrots, which I consume a lot, look decidedly unreal in the new light. It really is a big difference, but they taste the same. The whole mixed salad looks unreal.

By the way LED lamps, which are mainly blue, are really being seen to be bad for health. I certainly won't use them.

 

[Troubador]

Thanks Alexis for post 75.

I suppose I should be green with envy at all the top binoculars being used.

I don't see green in any of the photos here, but the computer is old as am I.

I tend to look for different characteristics in binoculars to birdwatchers. Some binoculars extolled here I find very poor. Others shunned here I find to be great.

I changed the old thicker 6ft fluorescent tube in the kitchen for a new slim one and my salad looks quite different. The carrots, which I consume a lot, look decidedly unreal in the new light. It really is a big difference, but they taste the same. The whole mixed salad looks unreal.

By the way LED lamps, which are mainly blue, are really being seen to be bad for health. I certainly won't use them.

I really shouldn't ask you this B but what light do you have in the bathroom?
Have you changed this recently and are the results encouraging?

Lee

 

[Troubador]

Lee, since Dencos original post seems to have vanished, I'll reply using yours if that's okay. Was going to reply last night but was beat, got up this morn, post is gone daddy gone.

I think I agree completely with Dennis, your eyes are important, not the specs of the binocular, I think I have said that for years. I dont see a color shift with the Z, so for my reality, no green cast, no problem, it doesnt exist.

Goes back to the point of why I can get by just fine with a less expensive optic

PT couldn't agree more.
I was poking Dennis in the ribs in other posts because he was condemning RGBs one moment but relying on them the next to reach a conclusion.

It surely wouldn't be surprising if all bins had a colour bias of some nature and some degree, even those that we individually, or even severally, think are neutral. As long as my swans and shell-sand beached look OK thats fine by me.

Lee

 

[Troubador]

The real difference in reporting could all be in the brain. What we think we see is nothing like the image projected on our retina. 'Seeing' is a learned activity and subject to all kinds of experienced based modulation. Like other skills, maybe colour discrimination is the product of regular training. At least some of those who were reporting 'green' were professionals who use colour as part of their professional life. Artists, photographers, scientists etc.. It could be just a coincidence of course. It's interesting, but I don't know the answers.

David

David
I suspect that your paragraph above explains a lot of what we have been talking about, in both those that see a colour cast and those that don't.

Last year I read an article about a few folks who had vision impairment leaving 'holes' in their perceived fields of view. Their brains copied images out of their memories and pasted them over the gaps in their vision. So they saw objects floating in the air in quite inappropriate settings and contexts. They were a type of optical illusion caused by the brain's unwillingness to accept a lacuna within the field of vision.

Amazing.

Lee

 

[jring]

OK, one last effort; same piece of white paper, same camera, same binoculars, but this time in direct sunlight.

Hi,

I did some more number crunching - same as with my last post - that is I took RGB values of 10 random points in left and right half of Henry's crop shots from post 60 and 66.

Post 60:
Left R62G65B70 Right R64G66B64
white balance still off toward blue, also red and green transmissions are over 100% here but well inside error margins...

Post 66:
Left R48G48B47 Right R46G47B42
Now this one is good - white balance is almost bang on target if a bit dark and through the bins blue channel is a bit lower which explains a very slight yellow/green tint.

So I guess there might be a very small tint but nothing your brain will not compensate for after a few seconds. In direct comparison like in Henry's shots it can be seen by some.
If you want to see a real tint, get some old soviet bins ;-)

Regarding the white balance problems I've got a suspicion - did you use white paper as a background, Henry? If yes, this is probably the reason - I remember to have read on some photo site that it often contains optical whitening agents that will make it reflect more blue and thus mess up camera white balance... so one should use a neutral grey card to avoid this effect...

Regards,

Joachim

 

[[email protected]]

So don't you trust your own eyes now Dennis? You tried them out and looked for the green ghost and couldn't find it. Gijs can't find it in his measurements either. Also, see Elkclub's post 22 for cautions about comparisons.

Do some people see green? Yes. Do they vary in their descriptions? Yes. Do other people not see green? Yes. Did you see green? No.

Lee

No, I didn't see any green when I tried the Zeiss 10x42 SF's. But I just tested them inside the Cabella's store for a short time so I don't know if you could trust my results. Cyclist used them for three weeks under different conditions so I would tend to trust his results more than mine. The green cast is mild so I think it would take awhile to notice it. I definitely see it in Henry's pictures though and so does my wife so for me it exists.

 

[[email protected]]

OK, here's another image. This time I went back to some photos I made while vacationing on the NC Outer Banks in September. Same camera, same sun, same 8x56 FL, but the other binocular is a Zeiss 8x42 HT and the background is a white plastic cutting board from the kitchen of the cottage we rented. The photo was not as underexposed as the recent ones I posted, so I used the exposure control in iPhoto to darken it. The crops show unaltered background in the middle, 8x56 FL on the left and 8x42 HT on the right. I have no way to analyze the RGB channels, but eyeballing suggests there may be higher blue transmission in this particular HT (early production) compared to the FL but perhaps not much more red.

Please note this is not a test of the neutrality or accuracy of the background color. It's about how well the colors within the circles of the binocular optics match the background color, however you may see them. Imagine you need to repair some paint on a wall and are trying to match the original color by placing paint swatches next to each other and against the wall.

However, I'll have to bow to Alexis' much greater experience with the color inaccuracies of computer monitors as well as the possibility of genetic differences or compromised color perception and concede that some people may just not see what I'm seeing.

Henry

I see a green cast through both binoculars in the left photo with the FL being more green and the HT more blue-green. In the right photo the left picture which is the FL is greener and the right picture which is the HT is more blue-green.

 

[Troubador]

I see a green cast through both binoculars in the left photo with the FL being more green and the HT more blue-green. In the right photo the left picture which is the FL is greener and the right picture which is the HT is more blue-green.

Its a minefield Dennis, trying to control and separate out all the things that can affect these images. I am not trying to say there isn't a colour bias in the bins. Its most unlikely in my humble opinion that there are any bins that are 100% accurate with regard to colour. Have you read some of the tech comments from other contributors? Its enough to make your hair curl.

By the way have you ever had a look through Meopta bins? I am testing a pair of Meostar 8x32s right now and they are really neat.

Lee

 

[Binastro]

Lee,
I have fluorescent lighting in the bathroom, and things are looking up.

However, ten days ago the neighbours above caused torrents, almost, of water to pour through my bathroom ceiling. It is the shower. I had to go upstairs at midnight to complain.
So I have had the extractor fan and light on for ten days non stop to reduce the awful smell of stagnant water.
I hope they repair things soon.
And of course the ceiling needs repainting. It did look white under fluorescent, now it looks a a sickly colour.
Must try to view with the Russian bino.

 

[Troubador]

Lee,
I have fluorescent lighting in the bathroom, and things are looking up.

However, ten days ago the neighbours above caused torrents, almost, of water to pour through my bathroom ceiling. It is the shower. I had to go upstairs at midnight to complain.
So I have had the extractor fan and light on for ten days non stop to reduce the awful smell of stagnant water.
I hope they repair things soon.
And of course the ceiling needs repainting. It did look white under fluorescent, now it looks a a sickly colour.
Must try to view with the Russian bino.

I must try fluorescent lighting myself.

Perhaps you should ask your neighbours above to use fresh rather than stagnant water when they shower. I've never been attracted to a pair of Russians myself, but I could be wrong about this like so many things. On average I fancy that Dutch girls are the prettiest in Europe, although the Italians can't be beaten for style nor the French for allure. Next year when we visit the Languedoc I must ask the ladies there what they think about fluorescent lighting.

Lee

 

[henry link]

Its a minefield Dennis, trying to control and separate out all the things that can affect these images.

Lee

Lee,

I'm not sure there are very many mines in this minefield. I've used the technique for years and so far the color bias in the photos has always conformed to what I see under the test conditions: binoculars that look red bias in front of the white background photograph red biased, ones that look yellow biased photograph yellow biased, etc. I've never run into a case where a binocular changed its basic color bias in different tests over time.

But, don't take my word for it. Anyone with a camera, a white piece of paper and a sunny day can make the same kinds of photos. So far Tobias and I seem to be the only ones pursuing it.

Henry

 

[Alexis Powell]

Thanks Alexis, I found that very helpful. I'd had a quick look for suitable tools to analyse the colours but found nothing much that did what I wanted... for free.

If I understood it correctly we are arguing over a 6 or 7 point hue shift in the cyan. I'm just curious what a similar shift might look like around 530nm. Is it psssible to generate that?

The other interesting little detail I noted was the RGB numbers suggest the biggest difference between the areas is in the red, which might tie in with the trasmission spectrum. It's in the warm light of sunset where I'd noted that the FL appears most different from the more obvious alternatives.

David

Glad you found it useful.

My goal (already ostensibly accomplished by jring's report of RGB numbers), going back to the original dispute (e.g. post#2), which was over whether or not the Zeiss bins have perfect color fidelity (i.e. no transmission bias), was to point out that the bins definitely have a transmission bias (or else the RGB values relative to one another would not differ between sky and bin). The effect of that transmission bias on human color perception (The only case of which that has practical significance being that when a user is looking through the bins) is a much more complicated topic, affected by both the lighting conditions and observer characteristics. I thought I could at least demonstrate that given the RGB numbers, the properly rendered image from post#14 seen against a computer monitor with some semblance of a standard white surrounding (as images are displayed here on the Birdforum website), would appear blue-cyan, and that the bin patch would be tilted closer to green than is the sky [The color shifting dress of internet fame shows that the assumption of a white surround can be important].

To indirectly answer your questions, a digital camera is not a spectrometer. There is not a 1:1 correspondence between spectra and RGB values. Also, recorded RGB values (and differences in magnitudes of shifts in R vs G vs B) are not absolutes because the camera adjusts them (overall level, gamma, white balance...) to attempt to mimic the brightness, contrast, and color as a seen by a person. To extract data from digital images to make absolute comparisons about the light-reflecting or light-transmitting properties of photographed objects, it is necessary to include a set of color standards in the image (a card with color swatches), render the data according to a standardized illuminant, and also linearize the rendering. Also, keep in mind that there is not a 1:1 relationship between RGB and H values. The color ("hue in the rainbow") seen has to do with the R vs G vs B levels relative to one another.

--AP

 

[Kammerdiner]

For what it's worth, I can see the shift in Henry's photos pretty clearly, even on my cheapo $400 laptop.

And I can see the same thing if I take my 8x32 FL and 8x32 SV out and compare them against a white cloudy sky. I just did that--again--and saw the same thing I always see. The FL is a little yellow-green in comparison. Nothing major, but it's there.

I haven't seen the HT or SF so I can't comment. But I wouldn't be surprised if some viewers saw the same thing through those. Henry's and Tobias' photos certainly reveal some differences that many viewers can see.

Mark