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Vortex Razor UHD 18x56 ? (1 Viewer)

As David indicates in posts 15 & 19, there are a whole range of considerations, including variations depending on the light intensity/ degree of darkness

For the technically inclined, Holga Merliz ( http://www.holgermerlitz.de/bino_performance/bino_performance.html ) has both:
- provided a link to 2 original articles by Berek (in German)

- and has also published a 2015 article in English, explaining the work of Berek and others - see the attached PDF

And Danial Vukobratovich’s 1989 article ‘Binocular Performance and Design’ also explores several of the same issues - again see the attached PDF
(it’s from: https://wp.optics.arizona.edu/optomech/wp-content/uploads/sites/53/2016/10/Vukobratovich-1989.pdf )


I’ve also attached 3 graphs from Merlitz and 1 from Vukobratovich as an encouragement to look at the articles
While I’ve read through Holga’s article on several occasions, due to the amount of detail (even when setting aside the equations), I still don’t think I fully understand all of the points made in it!
However as an encouragement, I’d suggest first starting with the summary at the end, and then going back to the start of the article

continued . . .
 

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John,

Since it was a Twilight Factor comment that launched this discussion, I thought it best to mostly stick to effective acuity, but would agree that Holger's paper, based on the work of Berek on threshold contrast is very important too. Unfortunately the mathematics puts a lot of people off, but it's worth persevering as you say.

The Vukobratovich plot has been posted here quite a number of times, but thank you for the complete article. It has somewhat confirmed my suspicions that the plot is rather out of date. Coating technology in particular has advanced conserably and I've certainly found that the supported binocular results are virtually indistinguishable from the theoretical with the better modern roofs.

I'm sure we are all familiar with the detrimental effects of hand shake. It's something that varies considerably between individuals, but muscle tension, load and duration are some of the contributing factors. Modern designs and use of high tech materials have provided us with a much wider range of options for weight, balance and comfort in the hand than there were prior to Vukobratovich's paper. I certainly find some binoculars much steadier than others, and for the best examples, hand held, the efficiency line would be quite linear between 6x and 12x.

Just to come back to the twilight story. I noticed when I did those binocular comparisons in near darkness that the effect of shake on visible detail almost disappeared. The loss of acuity due to shake was swamped by the loss of acuity due to low light levels. A 6x and 12x seemed equally shake free to my eyes, though my hands told a different story.

Cheers,

David
 
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typo said:
Dennis,

That isn't a resolution test. It's called a brand and model awareness study.

David
Click to expand...
Even the authors said it was a far from scientific study but it still makes me feel good when 50 people agree with me that there is not a lot of difference between the Vortex Viper HD and the Razor. I have always thought the Vortex Viper HD's were a good value at their price point.

"The huge surprise to me and just about everyone was how well the new 2018 Vortex Viper HD’s ($499) performed. They were right behind the Vortex Razors in every category, and tied the Razors on the score target. I am pretty much convinced that if you had both the Razors and the Viper HD’s side by side, I would have a hard time telling them apart. They were really that good. With a street price of under $500, the Viper HD’s are definitely the best bang for your dollar. Look for a detailed review later this summer!"
 
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Dennis,

In all likelyhood there wasn't a single person out of that test group that could spot a resolution difference between any of those binoculars using that chart, and as an average of 50 users, not a hope in hell. I'll try to explain why.

I'll assume that target they used was printed to scale and the distance was 70 yards, though it doesn't actually make any difference to the arguement if they weren't. The numbers on the chart are cycles per millimetre. With a distance of 70 yards you can convert quite easily to a 20/20 acuity scale. So that first value of 0.25 on the chart becomes 20/21.5 and so on.
0.25 = 20/21.5
0.28 = 20/19.2
0.32 = 20/16.8
0.35 = 20/15.3
0.40 = 20/13.4
0.24 = 20/11.9

Those first column values would cover the acuity range of a typical random selection of 50 individuals between about 15 and 65. The critical line for distinguishing the best from worst in that binocular group would be the 0.71 pattern in the second column or 20/7.5. The best theoretically possible result would be 20/6.4. It is very unlikely that anyone in that test could distinguish between those binoculars using such a test chart with a naked eye. I guess it is possible that someone in that club had truly exceptional acuity, but it most certainly couldn''t explain a 30% difference in total resolution score between best and worse result.

The organisers were quite aware of the potential problem with such a test. " We found last year that there seemed to be a lot of brand loyalty going in to some of the responses, and we thought that the numbered target would help see through some of that...." Evidently it didn't solve the problem.

Dennis, I believe you when you say you cannot tell the difference between a Viper HD and Razor HD, and apparently 50 other people couldn't either but I'm sorry, this 'test' is no evidence that there isn't one.

Hope that makes sense.

David
 
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The point is the article doesn't really say there is NO difference between the Viper HD and the Razor. It is just saying 50 people could not tell much difference within the limits of their eyesight. In the real world that means a lot regardless of the validity of their test methods. To me it means unless you have exceptional eyesight or you are especially critical when evaluating optics that you probably won't notice much difference either. I don't notice much difference between the Viper HD or Razor so to me that is what matters most. Our reality is determined by what we perceive not what actually exists.
 
Dennis,

That test is functionally no different than that letter chart your optometrist uses. It just assesses your visual acuity, yet that report shows that a significant number in that test group imagined they could see a resolution difference between the two Swarovskis and the Vortex models, and also between the Vortex and the Kowa. They ranked the brand, thats all.

The reality is that, for the Japanese versions at least, the Razor HD has better colour, contrast, and effective resolution than Viper HD. I couldn't tell you what percentage in a blind comparison would appreciate those difference in broader testing, but I suspect it would be rather more than there would be between the Razor and the Swaros. Plenty of binocular industry professionals have assured me that like many industries it's primarily prestige value that sells rather than better performance.

If you have realised you cannot tell a Viper from a Razor it's a really valuable lesson. Now how many Swaros have you owned over the years? ;)

David
 
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"The reality is that, for the Japanese versions at least, the Razor HD has better colour, contrast, and effective resolution than Viper HD. I couldn't tell you what percentage in a blind comparison would appreciate those difference in broader testing, but I suspect it would be rather more than there would be between the Razor and the Swaros."

All right, all right you convinced me. I just traded my Vortex Viper HD 12x50 in for a Vortex Razor 12x50. You better be right or I will come over to the UK and find you.;) I do think the ergonomics, armour, focuser and diopter are a little nicer on the Razor. I like the Vortex 50mm's because they are light usually less than 28 oz. and compact. The 12x50 format is good for twilight and spotting birds and game at distance. I don't like to spend $2K on a 12x for as much as I use it. I am sure the Swarovision 12x50 SV is the best.
 
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[email protected] said:
"The reality is that, for the Japanese versions at least, the Razor HD has better colour, contrast, and effective resolution than Viper HD. I couldn't tell you what percentage in a blind comparison would appreciate those difference in broader testing, but I suspect it would be rather more than there would be between the Razor and the Swaros."

All right, all right you convinced me. I just traded my Vortex Viper HD 12x50 in for a Vortex Razor 12x50. You better be right or I will come over to the UK and find you.;) I do think the ergonomics, armour, focuser and diopter are a little nicer on the Razor. I like the Vortex 50mm's because they are light usually less than 28 oz. and compact. The 12x50 format is good for twilight and spotting birds and game at distance. I don't like to spend $2K on a 12x for as much as I use it. I am sure the Swarovision 12x50 SV is the best.
Click to expand...


I'm glad I kept my Nikon SE 12x50 CF!:t: I have the Tripod Adaptor for it too.o:D

Bob
 
Dennis...

I hope you didn't really get the Razor HD...

For ONE.....David is referring to the MIJ models which as you know, there are no more. SECONDLY.....in all due respect to David, I owned the 8X42 Viper HD and Razor HD MIJ models both, and I actually preferred the Viper HD. Just look at the Allbinos review for the MIJ Viper HD. It's would be hard for the Razor HD to beat it and I don't really feel like it did optically. The main difference was FOV which the Razor HD WAS an improvement. Beyond that....nah. I shudder to think about the MIC Razor HD. PERHAPS the Razor HD will be what the MIJ Viper HD WAS. That Razor HD really has zero armoring on it and the finish is pretty easy to scratch. The one binocular in the Viper HDs price range that DID better it, slightly was the Endeavor HD II.
 

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[email protected] said:
"The reality is that, for the Japanese versions at least, the Razor HD has better colour, contrast, and effective resolution than Viper HD. I couldn't tell you what percentage in a blind comparison would appreciate those difference in broader testing, but I suspect it would be rather more than there would be between the Razor and the Swaros."

All right, all right you convinced me. I just traded my Vortex Viper HD 12x50 in for a Vortex Razor 12x50. You better be right or I will come over to the UK and find you.;) I do think the ergonomics, armour, focuser and diopter are a little nicer on the Razor. I like the Vortex 50mm's because they are light usually less than 28 oz. and compact. The 12x50 format is good for twilight and spotting birds and game at distance. I don't like to spend $2K on a 12x for as much as I use it. I am sure the Swarovision 12x50 SV is the best.
Click to expand...

Dennis,

The CA is creeping a bit in the Razor HD 12x50. The 10x50 would be my choice from the range.

David
 
chill6x6 said:
Dennis...

I hope you didn't really get the Razor HD...

For ONE.....David is referring to the MIJ models which as you know, there are no more. SECONDLY.....in all due respect to David, I owned the 8X42 Viper HD and Razor HD MIJ models both, and I actually preferred the Viper HD. Just look at the Allbinos review for the MIJ Viper HD. It's would be hard for the Razor HD to beat it and I don't really feel like it did optically. The main difference was FOV which the Razor HD WAS an improvement. Beyond that....nah. I shudder to think about the MIC Razor HD. PERHAPS the Razor HD will be what the MIJ Viper HD WAS. That Razor HD really has zero armoring on it and the finish is pretty easy to scratch. The one binocular in the Viper HDs price range that DID better it, slightly was the Endeavor HD II.
Click to expand...
I went over to Cabella's yesterday and compared the Vortex Viper HD 12x50 to the Vortex Razor 12x50 since this discussion started and I actually preferred the Razor by a small margin. I liked the thinner armour better, the focuser was smoother and the diopter was superior on the Razor. I like the appearance of the Razor better also. It just looks more streamlined and higher quality to me. The weight and size on both of them is about the same at about 28 oz. so they are light for a 50mm. I compared the optics very closely and the FOV is about the same same and IMO the Razor did have slightly better color, contrast and resolution. It just was a tad sharper IMO. I haven't had any problems with the majority of the MIC Vortex's I have tried outside of one 10x42 Razor that would not focus properly. I contacted Vortex about it and told them their quality was suffering because they were MIC and they sent me a FREE pair of MIJ Vortex's 10x42. Now that is service! Anyway I ordered a pair of Vortex Razor 12x50's from B&H. I am not afraid of the MIC Vortex's because if they are defective they will send you a new pair.;) Chuck, if that is your Vortex Razor 12x50 in the picture it looks like the older model which is different than the new model. Here is a picture of the new model Razor 12x50.

https://www.opticsplanet.com/reviews/reviews-vortex-razor-hd-12x50-roof-prism-binocular-green.html
 

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typo said:
Dennis,

The CA is creeping a bit in the Razor HD 12x50. The 10x50 would be my choice from the range.

David
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That could be but I want a 12x50 for long distance wolf and bear spotting in Yellowstone National Part in twilight when they are moving in the early morning. I already have a 10x32 SV and a 10x40 Habicht. I wonder if the Vortex Razor UHD 12x50 is any better for CA? it has a puny FOV 236 feet and it is heavy @36 oz.! I have heard they have AK prisms though.

https://www.sportsmans.com/hunting-...9YcE3dwn9pQ0UX58pFUgAqYYY3OF7dnRoCL3wQAvD_BwE
 
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Chuck,

Are you referring to the Allbino 2011 test of the Viper HD 10x42 that scored 140.9/170? Back then the Viper had dull, distinctly creamy colour balance, the contrast and effective resolution and CA were nothing special. The 2016 Swarovski SLC was yards better on all those points yet scored just 139.8/170. I know as an astrophysicist Arek likes flat fields of view and low distortion so it's no surprise the Vanguard Endeavour EDII 10x42 scored well, but that very odd colour balance kills contrast after sunset, and the super critical eye positioning on the 10x42 makes it a bit of a pain to use. Regardless of a score of 144.8/170 I wouldn't put it anywhere close to the top of my tree.

I should acknowledge the colour of the Viper HD has improved since 2011, but not enough to sway my own opinion on the advantages of the Razor. If you're not convinced that the Razor HD offers better optical performance than the Viper HD, then stick with the Viper. Please, just be wary of justifying it with an Allbinos score.

Cheers,

David
 
[email protected] said:
......... I wonder if the Vortex Razor UHD 12x50 is any better for CA? it has a puny FOV 236 feet and it is heavy @36 oz.! I have heard they have AK prisms though.....
Click to expand...

Dennis,

I first heard excited whispers about a new top spec Kamakura AK x42 model being offered 3 or 4 years ago, but the weight and price was the show stopper then. Looks like Vortex have taken up the challenge and I'm certainly looking forward to checking them out. Hoping they will arrive for Birdfair next month. I won't know about the CA until then.

Unfortunately Vortex made multiple errors in their description and specifications when the range was announced, and last thing I heard from the British distributor was they still hadn't sorted out the mess. On most websites the FoV of the 12x50 is given as 5.5°, but then 236ft@100yards is only 4.5°. The Vortex website now shows a more probable 288ft/1000yards, but who knows?

David
 
typo said:
Dennis,

I first heard excited whispers about a new top spec Kamakura AK x42 model being offered 3 or 4 years ago, but the weight and price was the show stopper then. Looks like Vortex have taken up the challenge and I'm certainly looking forward to checking them out. Hoping they will arrive for Birdfair next month. I won't know about the CA until then.

Unfortunately Vortex made multiple errors in their description and specifications when the range was announced, and last thing I heard from the British distributor was they still hadn't sorted out the mess. On most websites the FoV of the 12x50 is given as 5.5°, but then 236ft@100yards is only 4.5°. The Vortex website now shows a more probable 288ft/1000yards, but who knows?

David
Click to expand...
They look interesting. You can tell they have AK prisms by the shape of the binocular.
 
[email protected] said:
They look interesting. You can tell they have AK prisms by the shape of the binocular.
Click to expand...

It's not something I would rely on, but objectives of an AK would be a little more widely separated than the eyepieces, and are usually a bit longer than their SP equivalents.

One of the major discrepancies I mentioned is that the Vortex website doesn't mention AK prisms, but the material they sent out to their distributors clearly does.
http://www.newprouk.co.uk/vortex/product/vortex-razor-ultra-hd-12x50-binocular.html

David
 
typo said:
It's not something I would rely on, but objectives of an AK would be a little more widely separated than the eyepieces, and are usually a bit longer than their SP equivalents.

One of the major discrepancies I mentioned is that the Vortex website doesn't mention AK prisms, but the material they sent out to their distributors clearly does.
http://www.newprouk.co.uk/vortex/product/vortex-razor-ultra-hd-12x50-binocular.html

David
Click to expand...
The Vortex UHD's look similar to the Maven B.2's which have AK Prism's. Kamakura design similarity?
 

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typo said:
Unfortunately Vortex made multiple errors in their description and specifications when the range was announced, and last thing I heard from the British distributor was they still hadn't sorted out the mess. On most websites the FoV of the 12x50 is given as 5.5°, but then 236ft@100yards is only 4.5°. The Vortex website now shows a more probable 288ft/1000yards, but who knows?
Click to expand...

Years ago I had an exchange of mails pointing out to the German Vortex distributor that he was doing himself a disservice by converting FoV in ft. directly into metres. 100 yds.(300 ft.) @ 1000 yds. is exactly the same angle as 100 m @ 1000 m, so conversion is simply a multiplication or division by 3.
Even the specification sheet delivered with my 2011 built Swarovski ATM 65 shows a 42 m FoV as 138 ft.!!!

Incidentally, I think an offset of the optical axis can be achieved with either S-P or A-K prisms but is only mandatory on binoculars with large objectives to achieve an acceptable minimum IPD.
As these were intended for low light applications, S-P prisms would have been the poorer choice, needing an aluminized or silvered reflecting surface up to the turn of the century, and also requiring two additional air/glass surfaces compared to A-K prisms.
Many binoculars with S-P prisms show a small discrepancy between ocular and objective spacing.

John
 
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