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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

ScopeViews reviews the 10x42 Noctivids (1 Viewer)

Just talking apparent edge sharpness here - not anything else. Compare the two and let me know. I'm not pretending to know the answer here and I'm happy to be educated - is there any reason why the review picture of the NV seems to show such poor edge sharpness? I can take a similar photo with any number of my bins that do not show such degradation - and posted one as illustration.

I'd like to know too. Digiscoping can't capture the magic of a binocular, but it should give us at the very least a rough idea of how how wide the sweetspot is in one tube.
 
With regards to flare, I saw no peripheral "crescent" flares which would indicate the sun coming close to the FOV. But paradoxically quite a lot of veiling glare when viewing against the sun. Probably less than in Swarovision but more than in EDG. With the Ultravid it was sometimes almost vice versa, despite strong crescent flares image center was sometimes cleaner than in the Noctivid. This is the one big caveat with the Noctivid for me.

Your second remark is very much appreciated and casts light on modern trends - why flat field binoculars need wider FOVs...?!

Still I don´t quite get it.

- What does AMD mean?

- Compression of objects towards field edge... ??? Of course that would explain the impression of wider FOV and more dimensionality. But:

Normal distortion type is pincushion, that should magnify/widen objects towards the edges of the field, not compress them. Could that be counterbalanced by field curvature?? Where does the compression come from, from which aberrations?

Zeiss SF if I remember correctly has mustache distortion which would explain good dimensionality despite flat field. Barrel distortion would bulge out objects in the center and draw them away from the background. Pincushion should push objects in the middle further away from the foreground.

I started to hate the Canon 16-35/4, an almost perfect wide-angle zoom. It´s images look just way too flat. In binocular world, flat images, IMO that would be Swarovision and maybe Nikon EDG, but not the Noctivid, neither the SF.

Hi Tobias,

I'm not Kimmo, but I'd like to also respond to the questions you posed to him.

The old post below is on the subjects of distortions, including the effects of AMD (Angular Magnification Distortion) and glare.

http://www.birdforum.net/showpost.php?p=3251084&postcount=

Notice that mustache distortion in binoculars like the SV and SF is the opposite of what you describe for camera lenses: pincushion increases normally in the inner part of the field, then reverses in the outer part.

It would be interesting to see photos of the Noctivid interior like the ones in my post taken under the conditions that cause the veiling glare you described. There must be some visible cause near or within the exit pupil.

Henry
 
Hi Tobias,

I'm not Kimmo, but I'd like to also respond to the questions you posed to him.

The old post below is on the subjects of distortions, including the effects of AMD (Angular Magnification Distortion) and glare.

http://www.birdforum.net/showpost.php?p=3251084&postcount=

Notice that mustache distortion in binoculars like the SV and SF is the opposite of what you describe for camera lenses: pincushion increases normally in the inner part of the field, then reverses in the outer part.

It would be interesting to see photos of the Noctivid interior like the ones in my post taken under the conditions that cause the veiling glare you described. There must be some visible cause near or within the exit pupil.

Henry

Henry, thanks a lot, more food for thought.

About moustache distortion, you´re of course right and I took similar notes when testing the 8x32 SV, it has pincushion in the center changing to, well, at least less pincushion towards the edge (whereas normally - so on Wikipedia - mustache distortion is defined as barrel in the center, pincushion at the edge.).

About veiling glare in the Noctivid, sorry I don´t have photos as I was using the little periods of sunshine to observe... but it´s really remarkable that annoying crescent flares were non existent. I will check when I get the 8x42.

So AMD basically means barrel distortion.

Still I am wondering if field curvature does give images extra 3dimensionality beyond pure stereopsis or sort of overlays the distortion pattern somehow. In classic pincushion designs like FL or Ultravid the image center sometimes seems to slightly bulge out a bit towards the viewer (like in barrel distortion) and when I put three wineglasses in a row and view them with one of these glasses they seem to get smaller towards the field edge. And what role does astigmatism play in that.
 
So AMD basically means barrel distortion.

I am new to the technical side of things, but I don't think that's quite right. Henry or someone please correct me if I'm wrong, but angular magnification distortion is caused by the lack of pincushion distortion (though maybe it can be caused by barrel distortion as well?). By keeping the lines straight, AMD is introduced.

For me, looking through my Swarovision 8.5x42 it looks like objects brought to the top or bottom edge shrink relative to their normal size when seen through the center (for some odd reason I don't see this on the left or right, even when I look through one eye with the binocular turned sideways). This distortion is what causes rolling ball for some people. I think the only way to correct AMD is to introduce a certain amount of pincushion. Thus it is not possible to have a binocular free of both rectilinear distortion and AMD.
 
The link does seem to imply that Angular Magnification Distortion and Barrel Distortion are the same thing, but as Jack said, that is not correct. However, I'm finding that explaining or illustrating the relationship between the rectilinear distortions and AMD is not so easy. The figure below is the best I've come up with.

The horizontal line represents rectilinear distortion. Barrel increases toward the left and Pincushion toward the right, with the point of zero rectilinear distortion at the intersection of the vertical and horizontal lines.

AMD is represented by the dashed diagonal line. Positive AMD increases toward the upper left and negative toward the lower right with the zero point for AMD occurring at the intersection of the dashed line and horizontal line along the Pincushion part of the line.

Notice that there is substantial AMD at the zero point for rectilinear distortion and substantial Pincushion at the zero point for AMD. One increases as the other decreases. That is why a distortion free field is not possible.

With binoculars we are mostly concerned with the little triangle made by the two intersections of the dashed and solid lines and the intersection of the the two solid lines. The distortions of most binoculars fall somewhere along the pincushion line and the AMD line of that triangle. Less Pincushion means more positive AMD and the changeover to Barrel just means even more positive AMD. More pincushion beyond the point of zero AMD changes the AMD from positive to negative (shapes at the field edge become radially stretched instead of squashed). I've only seen one example of a binocular (Leica 8x42 Ultravid) with enough Pincushion for negative AMD and only one where I suspected there was a small amount of Barrel at the field edge (Zeiss 8x42 SF).
 

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Thank you for that Henry. I was wondering where your previous response went. I am glad you posted something even better. The graph is a great visualization.

So does the amount of field curvature have any effect on AMD? Would it be possible to have a 'flat field' design like the swarovision, but introduce enough pincushion to bring AMD to its zero point?
 
So does the amount of field curvature have any effect on AMD? Would it be possible to have a 'flat field' design like the swarovision, but introduce enough pincushion to bring AMD to its zero point?

To the first question: none at all. To the second question: yes, Nagler eyepieces, for instance, correct both astigmatism and field curvature well and have such strong pincushion that AMD at the field edge is negative rather than positive.
 
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