Had the opportunity last night to do a little testing of a vortex viper 6.5-20 vs my duralyt 3-12. In the interest of fairness both scopes were kept on 8x.
I have to be honest I fully expected the zeiss to wipe the floor with the vortex given its prestige and also the fact that its a fair chunk more expensive.
My findings were as follow
Zeiss won out over the vortex in terms of glass clarity, Not by a long margin but still notably. The difference was more noticable as the light faded and i was able to pick out fine details better with the zeiss. That been said the vortex crosshair didnt disappear as readily when held against a dark backdrop, although this is attributable to the fact it is thicker in the first place so a double edged sword, worth noting though it is not too thick. In terms of usability both scopes would cope well right out till last light time last night. (overcast with some clear sky)
The vortex has a slightly more fussy eye releif but then given the extra zoom offered its to be expected really. Where the vortex wins out over the zeiss is in the quality of the turrets which are a far more robust feeling and positive clicking system than what is equiped on the duralyt. And also the overall finish of the scope such as having metal as opposed to plastic turret caps, the magnification selection wheel offers more resistance but feels to be better quality and has knurled rubber to assist in grip.
Also worth noting is the warranty offered with the vortex, it truely is buy once cry once as once you have purchased it you could run over it in your landy and they will replace it no quibbles. This was recently proved when my friend wrote off his binoculars which were replaced in less than a week.
Overall I feel it would be a tough decision if I were in the position to be buying new and I was certainly surprised by the vortex. The zeiss has the prestige and edges it in terms of glass quality. But then the Vortex keeps up impresivly well with the glass and surpases the zeiss with its crosshair in low light conditions and its turret adjustment system. The larger magnification is largly a personal preference but its worth noting the viper is only under an inch longer than the 3-12 duralyt and barely heavier.
Please note that all of the above is my opinion from what I have seen in my own testing, I am neither a profesional stalker nor writer but though this review may be of use to some people.
For the minute the zeiss will be staying on my stalking rifle but given time and watching to see how my friend gets on with the vortex I may well sell up and get one myself. Even the comfort of knowing the warranty is a big selling point as I'm not sure about you lot but its alot of money that I dont have to replace should my zeiss be broken by a slip or fall.
Well, more testing was done last weekend. I followed your advice caorach and I ended up printing off an a4 eye test and laminating it to take into the field.
With low light testing it was conducted with a little ambiant light in the background. I set the eye test out to 30ish yards and proceeded. In the interest of fairness once again the magnification was at 8x.
Streight away the vortex stood out as the better perfomer in this test. With the light rapidly fading it consistently provided a crisper and brighter image than what I could acheive with the zeiss. I think though, in part that this was to do with the vortex having a paralax adjustment which the zeiss does not.
That been said it was tested between 3 people (2 stalkers and my brother who has barely touched anything rifle wise). All three of us agreed that the vortex was clearer to us and easier to read the letters.
Also worth noting was again i found the zeiss reticule a little on the thin side for the low light testing.
Next day was off to the field to test them at differing ranges. The conditions were interesting to say the least with horizontal rain greeting us. We decided for these tests to go for 12x mag and also then tested the vortex at 20 just because it was available. But all I will report on is the direct comparison as I'm sure we can all decide the higher mag scope would make things seem larger at given distance.
100 yards - Both scopes were capable of picking out the top line or so of letters. At this distance youd be splitting hairs really to say that one stood out beyond the other.
75 yards - The presence of the paralax adjustment in the vortex seems to be making a difference as although you can see the same amount of letters they are more clear in the vortex than the zeiss. The zeiss does however seem more vivid in its colours as there is a bush with some red berries in the background and we agreed that they seemed more vibrant through the zeiss.
50 yards - the difference is becoming more clear and all parties can see the next line down to read aloud compared to the zeiss, again this is more than likely attributable to the parralax adjustment
30 yards - other than the paralax difference making it slightly more crisp the scopes are pretty identical at this range. Although something I did notice was that the vortex has less distortion of the letters around the extremities of the scope. the vortex seemed to stay true right up to the edge.
The final test was that we ranged a tractor parked in a field at 300ish yards. At 12x mag on the zeiss we all found we could make out the reg plate of the tractor relatively accurately ( couldnt tell between a B and an R ) although it took quite a long time and a fair amount of squinting to figure it out.
The vortex performed slightly better with the letters, still a little confusion on the B and R. Although we were all able to instantly start reading the reg rather than having to process the information and de cypher what we were reading. Obviously once put to 20x the vortex was easy to read the correct registration for all partys. Having a good look around the field we all agreed that the zeiss seemed to offer a more vivid colour again. When i say more vivid it was actually a more true representation of what you could see with the naked eye whereas the vortex while still showing the colours and making it easy to differenciate shades was not quite at the same level as the zeiss.
A bit more glassing found a house at 600 yards, we chose a window to look at. The vortex provided the more clear image of the window and surrounding structure however the zeiss remained the leader with colours and also the difference in the crosshair thickness was starting to show at this range for precision shooting. The zeiss crosshair didnt cover up as much of what you were looking at. So what was its weakness in low light was now becoming a strength at more extended ranges.
(worth noting the vortex is second focal plane and the zeiss I beleive is first.)
Truth be told when luke_manic ordered the viper I expected it to be a reasonable performer but not for one second did I think it would come close to the zeiss let alone to surpass it in most areas.
I hadnt even contemplated selling my duralyt until I had field tested the viper and then as some of you may have seen, I actually ended up selling the zeiss to put the vortex on top of my stalking rifle.
Now I know that the vortex doesnt have the same prestige as zeiss. And it performed better in some areas and not quite to the zeiss standard in others. But for me personally and I know for luke_manic who all the tests were conducted with it won in the more important areas.
The real stand out point other than the quality of the optics and dare I say it superior build quality of the vortex (mainly due to metal turret caps rather than plastic) is the votex unlimited lifetime warranty.
I dont know about you lot, but I for one dont have £500 sat waiting to spend on a new scope should mine have an unfortunate accident. And while zeiss does have a fairly comprehensive warranty it wont cover my scope should i run over it in my 4x4 (No i havnt done this, but ive seen storys of people who have, and I'm known for being slightly clumsy and forgetful at times) The fact that vortex will replace your item no questions asked for the lifetime of the product is unbeleivable.
For the doubters of that warranty luke_manic dropped his vortex binoculars on a slate floor a little while back putting a premature end to them. Within 3 working days he had a new set on his doorstep ready for stalking.
Worth acknowledging again is the fact that neither myself nor luke_manic are proffesional stalkers or writers. Although what we do, is always put maximum research into a product and try to get maximum product for the money being spent, and on that front zeiss cannot compete with vortex.
I hope you have enjoyed this comparison and maybe even found a few bits useful.