• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

The 10X42 HT compared to the SF and SV (1 Viewer)

Well, would RGB colours really do the trick? Relative to what, and within which colour space?

Given controlled lighting, wouldn't an absolute colour space like L-a-b be better than any of the common RGB colour spaces (sRGB, Adobe RGB, ProPhoto RGB and similar)? Or, perhaps, we should go with comparisons of views of printed Pantone(TM) colours that can be approximated via CMYK printing or its variants, under varied colour temperatures and lighting conditions (direct, indirect, at various angles left, right, above, below...)? And that's just a brief summary of where things can go if you want them to...

Personally (and many thoughts may vary here) I'm @ Birdforum and the binocular bits to avoid these kinds of discussions - which happen all too often on photography forums - but more power to your left elbow if you wish to persist. My guess: this kind of thing never ends, so certainly can't end well...

...Mike
8-P

Didn't really wan't to get started on this one. I knew I was drowning.

David
 
Colour temperature is not the same as white balance correction by the way.

We were talking colour temperature. If, and it's a big if, the illuminating light has a locus on the colour temperature scale then using it to correct colour balance would work. If it isn't a locus it cannot work for colour correction and another method needs to be employed. If we assume Tobias's light source was such a locus, putting a colour filter in between it and the camera that doesn't produce a pricise locus shift, like a binocular, makes a correct colour temperature calculation impossible. A green or yellow bias simply cannot exist as a colour temperature. The software will still produce a number, just a meaningless one. Reapplying meaningless numbers to another image is then pointless of course. If Tobias had actually put up the Raw RGB values we might have had an idea what the colour bias was like.

Did you try those programs?

David

Hm, ok, this is my theory..
I suppose you could say that a binocular will act as a filter and the effect of that filter can be registered with a digital camera. The WB thing is just a way of estimating the residual proportions of red, green and blue light.
I don't think it's more complicated than that.
And so it seems that the amount of the WB applied correlates to if a binocular have a more warm or cold look. As well as a warm or cold view seem to correlate to the characteristics of the transmission curve.
So, no, I don't find it pointless.
It might even be replicable.
But it's not like measuring the speed of light with 14 decimals in vacuum. I'm the first to admit that.

Tints and casts, and if they exist and why, well, that is another story I suppose. I leave them to you for explaining...;)

BTW, I hope I didn't write that WB correction is the same as color temperature. That would be strange...
But in some image processing software the WB adjustment is called "Color - Temperature" and in others "White balance - Temperature".
 
Last edited:
Vespobuteo,

Apologies if I didn't explain things clearly. The colour temperature calculation cannot quantitate or correct the colour changes caused by these binoculars. Any image manipulated using CT values cannot represent the colour change caused by the binoculars.

I can see colour differences between various models. The transmission profiles clearly show there are differences. What's the problem?

David
 
Vespobuteo,

Apologies if I didn't explain things clearly. The colour temperature calculation cannot quantitate or correct the colour changes caused by these binoculars. Any image manipulated using CT values cannot represent the colour change caused by the binoculars.

I can see colour differences between various models. The transmission profiles clearly show there are differences. What's the problem?

David

I don't say it's a perfect method but photos are not bad for comparisons. Digital WB and color correction by temperature also includes a tint dimension. But the values were quite similar between the bins except the old Swaro habicht so I didn't include them. In general I would say that WB and digital color correction does work. Otherwise "digital images" would look like shit.

Transmission graphs are nice but they are a bit like looking at the RGB exposure histogram for a photo. It might be hard to translate to the real picture for most people.

I still haven't got any correct answers on the color temp quiz so I guess it wasn't as easy as ranking bins...
;)
 
Last edited:
One thing that surprised me was the easy view of the 10X42 HT, It's very comparable to the 10X50 SV. It obviously doesn't have the edge sharpness or lack of visible distortion the SV has, but eye relief is beyond adequate for eyeglasses, and there is no messing around to get the full view, just pop it up to your eyes and bang, a full locked in view. It's very impressive considering the 4.2mm exit pupil.
 
One thing that surprised me was the easy view of the 10X42 HT, It's very comparable to the 10X50 SV. It obviously doesn't have the edge sharpness or lack of visible distortion the SV has, but eye relief is beyond adequate for eyeglasses, and there is no messing around to get the full view, just pop it up to your eyes and bang, a full locked in view. It's very impressive considering the 4.2mm exit pupil.

I've only seen the Zeiss HT in 8x42 format, and compared side by side with the Swarovski 10x50 SV, both with circa 5mm EP's, and that was pretty much my impression too. I had the eye cups just opened an identical smidgen on both of them with my eyeglasses on.

Both have really WOW views - the Swaro with its 'crystalline' view which makes the (to my eyes) well balanced colours 'pop' and 'sparkle', and the Zeiss with its outstanding 'clarity' also seems to have a well balanced colour pallete, though without the 'sparkle'. The Blues and Reds seem quite well balanced, though I think the tr% peak in the Green adds to the impression of brightness without unduly tinting the view greenish-yellow (to my eyes). That was in 2014, so I do hope that Zeiss hasn't mucked around with the 'White Balance' along the lines that David mentioned ..... :cat:

Any 'washed out' of colours that people refer to, I'd suggest has everything to do with glare control, or lack of, and nothing to do with brightness. Can't have too much brightness in my opinion ! :brains:

Chosun :gh:
 
For those who are not familir with this stuff I thought I'd had a go at illustrating what just changing the spectum in the blue will do for colour.

In the attached photo you should be able to make out the transmission profile for that filter. There is something like a 30% reduction in transmission between 450 and 500nm. That would be about 3 times more than we've seen posted for the FL and four times for the HT.

Against a northern sky early this morning the colour shift is quite dramatic. I can assure you that it also considerably lightens the darker greens and dulls the blues and purples in my flower beds. We probably haven't seen models with that kind of shift for a long time. The question is how many could see the difference at a quarter that strength?

Of course that filter doesn't characterise the whole profile of the HT or FL. The reduction in the red as well will push the balance closer to the green and mute different colours a bit as well. I personally think these shifts are quite noticable. Others may well disagree. Whether it's a good or bad thing is a totally different issue.

David
 

Attachments

  • 20160715_054447.jpg
    20160715_054447.jpg
    151.4 KB · Views: 74
I had a brief look tonight at the moon (through a little haze), stars and planets ( not sure which ones), and a few night lights of various intensities and distances with the HT. The high transmission, low CA, and excellent rendering of whites made for a beautiful image of the moon. Low intensity night lights, stars, and planets looked fairly clean and pinpoint, handheld is obviously not the best way to check this. Higher intensity light sources did show a few fairly faint spikes, not anything nearly as visible or pronounced as my Minox BD BP Porro though. The cause with the Minox is prism intrusion into the optical pathway. To the best of my memory the SE and SV were pretty much free of any spikes, others who use theirs on the night sky feel free to correct me if I'm remembering incorrectly.
 
For those who are not familir with this stuff I thought I'd had a go at illustrating what just changing the spectum in the blue will do for colour.

In the attached photo you should be able to make out the transmission profile for that filter. There is something like a 30% reduction in transmission between 450 and 500nm. That would be about 3 times more than we've seen posted for the FL and four times for the HT.

Against a northern sky early this morning the colour shift is quite dramatic. I can assure you that it also considerably lightens the darker greens and dulls the blues and purples in my flower beds. We probably haven't seen models with that kind of shift for a long time. The question is how many could see the difference at a quarter that strength?

Of course that filter doesn't characterise the whole profile of the HT or FL. The reduction in the red as well will push the balance closer to the green and mute different colours a bit as well. I personally think these shifts are quite noticable. Others may well disagree. Whether it's a good or bad thing is a totally different issue.

David

Comparing the transmission graphs side by side I suspect that
the HT will look a bit less tinted than your filter does.
I hope we can agree on that at least.
Over and out for me in this subject for the moment.
Thanks for an interesting discussion.
:t:
 

Attachments

  • filter-ht-comp.png
    filter-ht-comp.png
    129.6 KB · Views: 64
Last edited:
Fine with me, but please correct your overlay image first. This is from the contemporary specification sheet, and is the same as in my photo.

David
 

Attachments

  • 007 filter.jpg
    007 filter.jpg
    11.1 KB · Views: 52
I repete. Please correct your image. It's grossly misleading.

David

Ok, Guess I'm lucky it's not a court room..
"grossly misleading", sounds like death penalty to me...??
or maybe 10 years without any access to digital filters..
.:-O

I thought it was obvious that it's not the EXACTLY same filter
but it's definitely A LEE filter, pale yellow 007,
so the blue cutoff is about the same.

http://www.leefilters.com/lighting/colour-details.html#007&filter=cf

The main point is that I don't think it's close to the HT-look since there is no red cutoff. A slightly green filter would be a better match IMO, perhaps a
278 Eighth Plus Green, seems a bit wavy though..but overall behaviour looks not too far from it, mind the bump in extreme red, but can't find any that seem to fit much better.

http://www.leefilters.com/lighting/colour-details.html#278&filter=cf&sort=number

Added an overlay diagram of the green filter + HT. Note that I ONLY matched the slope for easier comparison, not 0 and 100%.
 

Attachments

  • green-filter-vs-zeiss-ht.jpg
    green-filter-vs-zeiss-ht.jpg
    40.5 KB · Views: 27
Last edited:
Had you not corrected this misinformation, I was thinking of trying to contact the proper authorities in order to have you disciplined by an international optics tribunal. ;):-O


Ok, Guess I'm lucky it's not a court room..
"grossly misleading", sounds like death penalty to me...??
or maybe 10 years without any access to digital filters..
.:-O

I thought it was obvious that it's not the EXACTLY same filter
but it's definitely A LEE filter, pale yellow 007,
so the blue cutoff is about the same.

http://www.leefilters.com/lighting/colour-details.html#007&filter=cf

The main point is that I don't think it's close to the HT-look since there is no red cutoff. A slightly green filter would be a better match IMO, perhaps a
278 Eighth Plus Green, seems a bit wavy though..but overall behaviour looks not too far from it, mind the bump in extreme red, but can't find any that seem to fit much better.

http://www.leefilters.com/lighting/colour-details.html#278&filter=cf&sort=number

Added an overlay diagram of the green filter + HT. Note that I ONLY matched the slope for easier comparison, not 0 and 100%.
 
Vespobuteo,

Thank you acknowledging you used an incorrect profile.

The starting point for me in all this is Tobias's original images.
http://www.birdforum.net/showpost.php?p=3320307&postcount=34

If you concentrate on the middle panel of square boxes you can see differences between the different models. Even between the SF and HT. The relative difference between those two from my analysis is 0.2% in the red and 0.9% in the blue by my software if anyone 's interested. The problem is that the difference between the two Zeiss and the EDG and Leicas looks nothing like the what I see in the flesh. I thought it odd at the time but didn't persue it. I now realise it's because the difference in the red is negligable in those images whereas, in the flesh or in the transmission spectra, the red difference looks significant.

Tobias said he would be away most of this year so I can't check with him what he did. I'm just wondering if his method of white balance correction he used might have been the cause. For instance, below 6500k a red value cannot be less than the green or blue value on the black body curve. It just looks odd to me, but the process might be fine for all I know.

We then have your colour temperature results. It cannot be used for this purpose as I said, but having done it, 100k is under 2% difference in the blue if I understand it correctly and doesn't reflect the blue range in original images either. As I said I don't understand the CT algorithm and what it's done here, but again the results look wrong.

Your photo collage varies by about 5% in the blue it appears, but scarcely visible in a photo with lowish blue content. But I don't believe that has much relevance to how the colour of the HT or the others look in real life.

I used that 007 filter as a clean blue cut which seemed to be closer to yours and Tobias's images, but would agree that 278 Eighth Plus Green looks closer to what I remember. However there was no transmission curve provided at the time I got these samples but I'd agree the current profile looks a reasonable approximation.

David
 

Attachments

  • 20160716_162113.jpg
    20160716_162113.jpg
    151 KB · Views: 30
I don't know whether the image below will help or hurt the color bias discussion here. It comes from the tests I've been doing for a review of the Swarovski 8x30 Habicht and is an effort to demonstrate the color filter effect of four binoculars (clockwise from the upper left: 8x30 Habicht, 8x30 Nikon EII, 8x56 Zeiss FL and 8x32 Nikon SE).

It was assembled in Powerpoint the usual way I do it. A white background is photographed in sunlight with the camera set for manual exposure for deliberate underexposure and the white balance manually set for "direct sunlight". Then the same background is photographed through the objective lenses of the four binoculars with the same camera settings. In this case I've lightened crops from the binocular photos to try to approximately equalize their brightness with the background so that the main visible difference among them will be color bias. Sorry for the blotchy quality of the color in the crops. Not sure whether that is related to the small sample size or the transfer to Powerpoint. I don't see it in the original photos and I think the overall color bias of each crop still comes across well enough.

I hope the exemplary color neutrality of the Habicht is visible on other computer screens. In the image on my computer it looks a tiny bit blue to my eyes, but in the real world I can detect no bias at all, which is what you might hope for in a binocular with the most linear light transmission shown in any of Gijs' transmission measurements. The biases of the other three, even the relatively mild green bias of the Zeiss, are evident to me in the real world by just putting the binoculars to my eyes and comparing what I see to the same scene without binoculars. In normal use the EII has a stronger red bias than the SE to my eyes, perhaps because its image also appears to be darker than the SE, so maybe the same red bias looks more saturated.

Henry
 

Attachments

  • Slide3.jpg
    Slide3.jpg
    42.5 KB · Views: 68
Last edited:
David:
It's reassuring to hear that you agree on that the 278 Eighth Plus Green filter
is quite close for visualizing the slight HT color bias.

I guess it would even be possible to use a correction filter for the HT if wanting a
completely neutral view in daylight when transmission is not an issue.

279 Eighth Minus green looks like a candidate:

"Provides very slight correction. Used on lighting to eliminate unwanted green cast /../."

http://www.leefilters.com/lighting/colour-details.html#279&filter=tf

Tobias method might have faults as you point out.
(Artificial) daylight would be better to use as the light source.
Digital cameras are not spectrometers obviously. And WB can be off,
a "gray card" would be preferable to use for calibration.
But it should work ok if done carefully and systematic.
(Henry just did).

Nevertheless, comparing filters with characteristics similar to the bins, is practical, easy to relate to
and might be valuable in communication. You could also inspect real scenes with them to see how colors are affected.
 
Last edited:
Henry: That is a nice comparison photo.
The SE and EII look very much like the 279 Eighth Minus green filter to me!
Slightly pink. And the transmission curves on allbinos also seem to predict that result.

http://www.leefilters.com/lighting/colour-details.html#279&filter=tf

When looking at Zeiss camera lenses they have always been famous for their "strong reds".
This transmission graph look quite different from the bins (HT, FL):

http://www.lenstip.com/179.9-Lens_r..._ZS_ZE_Ghosting__flares_and_transmission.html

Different T* coatings or just priorities in the camera lenses compared to the bins perhaps?
 
Last edited:
Warning! This thread is more than 8 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top