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Vortex Razor UHD 18x56 ? (1 Viewer)
- Thread starter gonz33
- Start date
Ontario
Well-known member
Ryan Avery has been testing them for the past two weeks. He is very impressed.https://www.rokslide.com/forums/threads/maven-b-5-18x56.117494/
Your Conquest HD is a nice, quality binocular with a track record of good performance. I wouldn't think a 18X56 is going to do THAT much over a 15X56. Of course low light performance is going to be best with the 15X56.
If I were in the market for a 18X56, I'd probably take the hardest look at the Maven B.5. Great company and you can try one and return if you don't like it.
https://shop.mavenbuilt.com/collections/stock-optics/products/b-5-black-gray
If I were in the market for a 18X56, I'd probably take the hardest look at the Maven B.5. Great company and you can try one and return if you don't like it.
https://shop.mavenbuilt.com/collections/stock-optics/products/b-5-black-gray
" I wouldn't think a 18X56 is going to do THAT much over a 15X56. Of course low light performance is going to be best with the 15X56."
A 15x56 is not necessarily going to have better low light performance than an 18x56 because the "Twilight Factor" of the 18x56 is going to be better than the 15x56. The 15x56 might be brighter because of it's bigger exit pupil but the 18x56 will resolve more detail because of the higher magnification. Here is a resolution test on Youtube where the Vortex Kaibab 18x56 out resolved the Swarovski 15x56 SLC under low light. I think the New Vortex Razor UHD's could be just marketing hype. I had several pairs of Vortex Razor HD's and several pairs of Vortex Viper HD's and I thought the Viper HD's were just as good as the Razor's. I just bought a Vortex Viper HD 12x50 and it is an excellent 12x for under $500.00. MIC but no quality problems at all. If I were you and you want an 18x56 I would buy the Vortex Kaibab 18x56. Here is a new one on Ebay for $899.00.
https://www.ebay.com/itm/Vortex-Kai...751892&hash=item340e9d259e:g:Ve0AAOSwRkJdJ3KL
https://www.youtube.com/watch?v=SYoU7ZSX0FQ
A 15x56 is not necessarily going to have better low light performance than an 18x56 because the "Twilight Factor" of the 18x56 is going to be better than the 15x56. The 15x56 might be brighter because of it's bigger exit pupil but the 18x56 will resolve more detail because of the higher magnification. Here is a resolution test on Youtube where the Vortex Kaibab 18x56 out resolved the Swarovski 15x56 SLC under low light. I think the New Vortex Razor UHD's could be just marketing hype. I had several pairs of Vortex Razor HD's and several pairs of Vortex Viper HD's and I thought the Viper HD's were just as good as the Razor's. I just bought a Vortex Viper HD 12x50 and it is an excellent 12x for under $500.00. MIC but no quality problems at all. If I were you and you want an 18x56 I would buy the Vortex Kaibab 18x56. Here is a new one on Ebay for $899.00.
https://www.ebay.com/itm/Vortex-Kai...751892&hash=item340e9d259e:g:Ve0AAOSwRkJdJ3KL
https://www.youtube.com/watch?v=SYoU7ZSX0FQ
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Ontario
Well-known member
The 18x56 are already sold out.
If anyone is interested there is a used one up for sale on archerytalk the seller is sticking with his 15x56.
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775/5000
Hello, I have just received the new Razor UHD 18x56 and I have only been able to make a couple of observations with them, I used a tripod and I must be honest, to be so powerful with 18x the image is very clear. I thought it was I would see something dark, but it was not like that, I have the Razor HD 12x50 and although they are two different powers, the 18x has very good lighting and sharpness, I am very happy with these 18x56 UHD. I use them for observations of natural landscapes and see airplanes, I love this. When I use them without a tripod although they have a weight of 41.6 oz they feel very manageable in my hands, the Zeiss Conquest 15x56 HD is much heavier and tiresome in my hands, conclusion, I give 4 stars of 5 to these Vortex UHD in my very personal opinion
Some time ago, I was able to observe a Canon 18x56 stabilized and the resolution was fantastic although when pressing the magic button there was some kind of "artifact" in the image, let's call it "tremor" or something similar ... for astronomical observation also very good , the Moon fantastic! I imagine that this model of Vortex will have good quality too ... no?
Pluto.
Pluto.
Wow! "Twilight Factor" is such a NEW concept to me! :smoke:
Of course I considered twilight factor....BUT I also considered that the 15X56 will have a 3.73mm exit pupil and the 18X56 has an 3.11mm exit pupil. All but the very dead are going to have pupil dilation of greater than 3.11mm at dusk. Most are going to have more dilation than 3.73mm too. So I'll take the 15X56 and run with it and I bet I'm in the majority and I'll take any bet that I'm correct too!
One internet "test" does not a result make. You are old enough to know that. Who did the test? Are they affiliated with Vortex at all? Doesn't that sound fishy?
I wouldn't be too hasty.
Of course it all depends on what what metric you use to judge performance and the exact light level you mean, but you are stacked up against studies by Zeiss, Leica (Leitz) and at least three US universities.
David
if you are looking for detail at twilight you will see more with the 18x56 than the 15x56. I have personally observed it myself many times with binoculars of various formats. The 15x56 will appear brighter. The extra magnification makes seeing detail easier even under low light just like it does in daylight. Chuck you said in another thread that you actually preferred more magnification over a bigger exit pupil in twilight yourself.
"The difference in a 8X56 and 10X56 is....not much. Most of the comparisons I've done have been at dusk and not true darkness. I would prefer a 10X56 every time."
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I wouldn't be too hasty.
Of course it all depends on what what metric you use to judge performance and the exact light level you mean, but you are stacked up against studies by Zeiss, Leica (Leitz) and at least three US universities.
David
David,
Are you saying Zeiss, Leica, and 3 US universities have all proven a 15X56 is better at low light than a 18X56? If so, I'd sure like to see that.
Dennis,
I sure did not say that. Did you completely miss the 8X56 and 10X56 in the post you are referring to? No mention of 15X56 OR 18X56.
10X56= 5.6mm exit pupil
15X56= 3.73mm exit pupil
18X56= 3.1 mm exit pupil
That's a LOT of difference...5.6mm to 3.1mm...
A straight quote off of swarovskioptik.com:
Twilight Factor
The twilight factor defines the optical system’s performance in poor light. The statement “the greater the twilight factor, the better the suitability for twilight” only applies if the exit pupil is larger than or at least as big as the eye’s pupil.
Chuck,
I think most of the optics industry has forgotten that when Köhler and Leinhos of Zeiss published their results they specifically stated that the formula usually referred to now as the 'twilight factor' only applied to the range of leight levels between 0.1 and 0.003 stilb or cd/m2 in SI units. That means moonlight to most of us. At higher light levels magnification is the predominant factor and below that exit pupil.I think most birders would be on their way home well befor the twilight factor formula applies.
Although they didn't go beyond 15x, they found that at levels above the TF light level range and what we might call birding twilight, a 3.3mm, 2.3mm and 1.6mm exit pupils made no difference to the average apparent acuity in their study. Certainly their work predicts that an 18x56 would show more detail than a 15x56 for our kind of use.
Berek from Leitz (Leica) took a rather different approach. He looked at the threshold of target detection. My understanding is that magnification is significantly more important at moonlight levels and beyond than for apparent acuity, but again in birding twilight magnification in the primary determinant. It's a very long time since I had a look at the US studies, but as I recall they came up with very similar findings to Zeiss but produced much more complex formulae.
There appear to be a couple of things going on here. In normal daylight the detail limiting factor is optical resolution of the lens complex of the eye. It seems the potential optical advantage of a dilated pupil is normally offset by increasing aberrations. So, on average, the acuity is more or less constant over much of the daylight (photopic) range. It is at the onset of twilight where the eye starts to switch between daylight colour vision and night monochromatic vision that the retinal illuminance increasingly determines not only the level of detail you can see but also the threshold of contrast detection and starts to explain Köhler and Berek's results. I should point out that all these studies were probably conducted on conscription age men and our results mat differ. Holger factored in age in his paper on the subject.
Just to add a little twist to this story. All those studies were done on fixed black and white inert targets, but is that how things always work? I've had a just a few attempts at trying to see how magnification and exit pupil work for me. I've seen enough to be satisfied that both the acuity and contrast approaches work more or less as predicted by those studies for me. However on a couple of occasions animals have appeared in the field. A cat hunting a mouse at the bottom of my garden on one occasion,and a fox hunting a rat on the far side of the field out the back on the other. It was absolutely obvious that both the threshold for detection and the level of visible detail increased dramatically, when I detected movement, and magnification was the main determinant deep at those moonlight light levels. We know our brains exercise some control over the way the eye functions and most certainly how the incoming information is processed. Just seems it might shift up a gear when predators or prey are involved. I've found no relevant publications on this subject, but at least in principle it might make evolutionary sense.
Cheers,
David
I think most of the optics industry has forgotten that when Köhler and Leinhos of Zeiss published their results they specifically stated that the formula usually referred to now as the 'twilight factor' only applied to the range of leight levels between 0.1 and 0.003 stilb or cd/m2 in SI units. That means moonlight to most of us. At higher light levels magnification is the predominant factor and below that exit pupil.I think most birders would be on their way home well befor the twilight factor formula applies.
Although they didn't go beyond 15x, they found that at levels above the TF light level range and what we might call birding twilight, a 3.3mm, 2.3mm and 1.6mm exit pupils made no difference to the average apparent acuity in their study. Certainly their work predicts that an 18x56 would show more detail than a 15x56 for our kind of use.
Berek from Leitz (Leica) took a rather different approach. He looked at the threshold of target detection. My understanding is that magnification is significantly more important at moonlight levels and beyond than for apparent acuity, but again in birding twilight magnification in the primary determinant. It's a very long time since I had a look at the US studies, but as I recall they came up with very similar findings to Zeiss but produced much more complex formulae.
There appear to be a couple of things going on here. In normal daylight the detail limiting factor is optical resolution of the lens complex of the eye. It seems the potential optical advantage of a dilated pupil is normally offset by increasing aberrations. So, on average, the acuity is more or less constant over much of the daylight (photopic) range. It is at the onset of twilight where the eye starts to switch between daylight colour vision and night monochromatic vision that the retinal illuminance increasingly determines not only the level of detail you can see but also the threshold of contrast detection and starts to explain Köhler and Berek's results. I should point out that all these studies were probably conducted on conscription age men and our results mat differ. Holger factored in age in his paper on the subject.
Just to add a little twist to this story. All those studies were done on fixed black and white inert targets, but is that how things always work? I've had a just a few attempts at trying to see how magnification and exit pupil work for me. I've seen enough to be satisfied that both the acuity and contrast approaches work more or less as predicted by those studies for me. However on a couple of occasions animals have appeared in the field. A cat hunting a mouse at the bottom of my garden on one occasion,and a fox hunting a rat on the far side of the field out the back on the other. It was absolutely obvious that both the threshold for detection and the level of visible detail increased dramatically, when I detected movement, and magnification was the main determinant deep at those moonlight light levels. We know our brains exercise some control over the way the eye functions and most certainly how the incoming information is processed. Just seems it might shift up a gear when predators or prey are involved. I've found no relevant publications on this subject, but at least in principle it might make evolutionary sense.
Cheers,
David
David,
That IS interesting.... Wouldn't black and white targets give the advantage to magnification? What kind of optics did they use in these tests?
When using spotting scopes I don't really find this to be true. I can go from 25-30X to 70X with a 82-88mm objective. On cloudy overcast days during early morning/late afternoon(poor light conditions), I can get to a point where the magnification tends to overwhelm the objective size. In other words I can't use maximum magnification in poor light conditions because the subject/image becomes too dim for identification.
I'll play Devils Advocate.... Since exit pupil size doesn't matter as much as magnification in these test....would you rather have an 12X30 OR a 10X56 at dusk?
That IS interesting.... Wouldn't black and white targets give the advantage to magnification? What kind of optics did they use in these tests?
When using spotting scopes I don't really find this to be true. I can go from 25-30X to 70X with a 82-88mm objective. On cloudy overcast days during early morning/late afternoon(poor light conditions), I can get to a point where the magnification tends to overwhelm the objective size. In other words I can't use maximum magnification in poor light conditions because the subject/image becomes too dim for identification.
I'll play Devils Advocate.... Since exit pupil size doesn't matter as much as magnification in these test....would you rather have an 12X30 OR a 10X56 at dusk?
Here's a nice resolution test which supports my observation's that the Vortex Viper HD is very close to the Vortex Razor HD in performance for way less money.
https://blog.sandsarchery.com/2018-optics-demo-and-binocular-shootout/
https://blog.sandsarchery.com/2018-optics-demo-and-binocular-shootout/
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Chuck,
I'm sure the choice of target was a factor in those results. They also looked at 0.3 fold contrast and produced rather similar response curves. The contrast threshold approach by Berek that was the subject of Holger's paper appears tomhave a more practical relevance to me, but both these studies were really exploring lower light levels than most birding.
All the studies I referred to used binoculars. It looks like the Zeiss subjects were young with better than 20/10 eyesight which might explain how they were able to get the equivalent of 20/10 results with a 1.6mm exit pupil. I don't know about you, but I couldn't match that any more. Personally I find it counterproductive to go beyond a 1.8mm exit pupil, or about 45x with an 82mm scope, due to the decrease in contrast, and limiting resolution. Others will differ of course.
A 12x30 or10x56 at dusk? It rather depends on how you define dusk. In terms of level of detail the 12x30 would normally have the advantage for me, in terms of effective acuity for at least some time after sunset, (in the summer months). A 12x50 would have the advantage over 10x56 for longer than you might imagine, but once into moonlight levels the 10x56 would win out. Choose a different measurement of binocular performance and you would get a different answer.
David
I'm sure the choice of target was a factor in those results. They also looked at 0.3 fold contrast and produced rather similar response curves. The contrast threshold approach by Berek that was the subject of Holger's paper appears tomhave a more practical relevance to me, but both these studies were really exploring lower light levels than most birding.
All the studies I referred to used binoculars. It looks like the Zeiss subjects were young with better than 20/10 eyesight which might explain how they were able to get the equivalent of 20/10 results with a 1.6mm exit pupil. I don't know about you, but I couldn't match that any more. Personally I find it counterproductive to go beyond a 1.8mm exit pupil, or about 45x with an 82mm scope, due to the decrease in contrast, and limiting resolution. Others will differ of course.
A 12x30 or10x56 at dusk? It rather depends on how you define dusk. In terms of level of detail the 12x30 would normally have the advantage for me, in terms of effective acuity for at least some time after sunset, (in the summer months). A 12x50 would have the advantage over 10x56 for longer than you might imagine, but once into moonlight levels the 10x56 would win out. Choose a different measurement of binocular performance and you would get a different answer.
David
