p.35 #1 · Official: Voigtlander 15mm f/4.5 III E-mount
AGeoJO wrote:
I remember a way of doing this, which I never had the "courage" of doing it though. I simply couldn't do it although some folks apparently do it on a regular basis. You buy 3-5 copies of the lens at the same time. You test them one by one, pick the best and return the rest. Of course, if all of them are bad, you go back to square one .
I thought of this too but probably wouldn't do it myself. You would probably need to buy at least 10 to get one decent copy...
p.35 #2 · Official: Voigtlander 15mm f/4.5 III E-mount
My limit will be five. If I didn't manage to find a good one in five sample I will give up altogether with this lens. And will probably never try another Voigtländer lens.
p.35 #3 · Official: Voigtlander 15mm f/4.5 III E-mount
I have 6 Voigtlander lenses including a 15mm v1 I have had for 20 years, all good first time with not a dud one among them.
I think in general I would expect Voigtlander to be better than Sony at producing a higher percentage of good 'uns judging by what I read round here.
And I would bet Batis and Loxias come from Voigtlander.
p.35 #4 · Official: Voigtlander 15mm f/4.5 III E-mount
With these reports of bad copies of the lens after multiple tries, I wonder if it is even worth to ask for the replacement of my current CV15 or just return it and stick with either Batis 18 or my good copy of 16-35. Feel bad for the folks with multiple bad copies of the lens. Shamed on CV for their terrible QC!
p.35 #5 · Official: Voigtlander 15mm f/4.5 III E-mount
tsdevine wrote:
Wow, this winner to loser ratio is horrendous. What is amazing is how the bad ones seem to be very consistent in their performance. It's almost like the good ones accidentally slipped through.
-Tim
Like I said earlier, it looks like the good ones are the exception and the bad ones are the rule. I received my 3rd copy today but I haven't had time to test it yet. I am not holding my breath.
p.35 #6 · Official: Voigtlander 15mm f/4.5 III E-mount
They are probably all produced at the Cosina factory in Japan. At least the Loxia and Voigtländer, not so sure about about the Batis.
But my guess is, that the QC of Zeiss lenses will be different compared to the Voigtländer lenses even if they a produced in the same factory.
In adition if I get a bad sample of a Zeiss lens I would send it to Oberkochen and would get it back perfectly adjusted in a couple of weeks. I've done this in the past with great success.
As far as I know that's not possible with Voigtländer lenses, at least not in Germany.
p.35 #7 · Official: Voigtlander 15mm f/4.5 III E-mount
I don't think the expensive and mighty Zeiss FE 35/1.4 fares any better. There were also lots of Loxia 21's that were way off. The Zeiss 55/1.8 was very bad as well once users got around to testing it. Early 35/50 Loxia's had mechanical wobble. So CV has poor QA on one lens... Hang em high!!!
Bobu, I know you did have experience sending your Loxia 21 in to Zeiss to get it adjusted, but I haven't heard that happening with any of the Zeiss AF lenses. I don't know of a single 55/1.8 that was adjusted.
Of all the lenses I have owned, my Samsung NX (ooops, not PC!) lenses have the best record for QA reliability
p.35 #9 · Official: Voigtlander 15mm f/4.5 III E-mount
I would say the QC of 'real' Zeiss lenses is slightly better than average, but they are definitely not perfect. But the quality of their service in Oberkochen is quite good in my opinion.
p.35 #10 · Official: Voigtlander 15mm f/4.5 III E-mount
And I really like the mechanical construction, haptics and small size of the CV 15mm. It's not far from Zeiss and Leica in my opinion. Otherwise I wouldn't be willing to try 5 samples. So I'm not (yet) hanging em high ...
p.35 #11 · Official: Voigtlander 15mm f/4.5 III E-mount
I'm not sure they would do the same for a Batis either? And the option of returning to Zeiss doesn't work nearly as well to those of us not living in Germany. The fact seems to be that Zeiss QA is not much (any?) better than the other mass retailers. CV in general doesn't seem to be any worse.
p.35 #12 · Official: Voigtlander 15mm f/4.5 III E-mount
The CV lenses I have owned in the past have actually been quite good. It's really too bad that their level of quality has dropped so much recently. Nobody should really have to go through multiple copies of any lens for a good one but I suppose it happens every now and then. Just because some other manufacturers have quality issues doesn't make it any easier to accept....
p.35 #13 · Official: Voigtlander 15mm f/4.5 III E-mount
Here's a thought, though I don' know if its true.
If all the CV15s has a bit of extreme corner mush, we wouldn't be complaining. We'd just think it was a pretty good lens, pity about the extreme corner (indeed that's what Fred thought before he tested Choppy)
What if the mush is the expected outcome by design, because some of the elements are such that that's what you will typically get given the level of precision of manufacture? And it's just that there's some chance that you'll get better than expected extreme corners, if it happens that a number of elements, by chance, align perfectly?
Now if that's possible you could guarantee that it happened more often by a different, more precise and repeatable manufacturing process. But that would cost more - maybe much more. That's part of what you pay for Leica for (aside from small numbers, expensive boutiques etc)
So maybe the problem is not a QC problem. The corner mush lenses pass QC; Choppy and his brethren surpass expectations.
I guess it depends on what the design expectations are: and since CV don't publish MTFs we don't know what those expectations are.
p.35 #14 · Official: Voigtlander 15mm f/4.5 III E-mount
Congratulations Fred on the awesome WATE Great lens and thank you for your tests! I do regret selling mine but there were many new lenses coming out and you just cannot keep them all.
Gary Clennan wrote:
The CV lenses I have owned in the past have actually been quite good. It's really too bad that their level of quality has dropped so much recently. Nobody should really have to go through multiple copies of any lens for a good one but I suppose it happens every now and then. Just because some other manufacturers have quality issues doesn't make it any easier to accept....
I have another theory is that specific lens designs are very critical of manufacturing tolerances and I suspect the CV 15 is one of them. It may prove hard to get a great copy. Is it lens alignment or lens geometry. If it is just lens alignment, there are many camera labs that will pull the lens apart and realign the elements to the optimum possible for a relatively low cost I have done this with about 10 different Leica M lenses and the improvement was quite dramatic in a number of lenses, like the 50 Lux Asph, 50 Cron DR. In the end in may prove more cost effective and knowing exactly how your lens performs on the bench.
p.35 #16 · Official: Voigtlander 15mm f/4.5 III E-mount
charles.K wrote:
Congratulations Fred on the awesome WATE Great lens and thank you for your tests! I do regret selling mine but there were many new lenses coming out and you just cannot keep them all.
I have another theory is that specific lens designs are very critical of manufacturing tolerances and I suspect the CV 15 is one of them. It may prove hard to get a great copy. Is it lens alignment or lens geometry. If it is just lens alignment, there are many camera labs that will pull the lens apart and realign the elements to the optimum possible for a relatively low cost I have done this with about 10 different Leica M lenses and the improvement was quite dramatic in a number of lenses, like the 50 Lux Asph, 50 Cron DR. In the end in may prove more cost effective and knowing exactly how your lens performs on the bench.
Charles makes a great point here. If the problem is that with the chosen level of manufacturing precision it's just unlikely that you'll get the "perfect storm" of alignment that gives you choppy, rather than play roulette, you might be better off sending it to a trusted collimator and getting it optimised. That's hard for AF lenses, but this lens is traditional enough in construction that it ought work. You might pay a couple of hundred for that precision work - but imagine if CV spend a couple of hundred extra on hand optimising in the factory - by the time the production run was reduced to match the smaller market for the more expensive lens, the price adjusted up to the smaller run, and the raw cost run through markups, you'd pay a thousand more at least. A dollar at the factory, more than ten on the retail, goes the saying.
p.35 #17 · Official: Voigtlander 15mm f/4.5 III E-mount
charles.K wrote:
Congratulations Fred on the awesome WATE Great lens and thank you for your tests! I do regret selling mine but there were many new lenses coming out and you just cannot keep them all.
I have another theory is that specific lens designs are very critical of manufacturing tolerances and I suspect the CV 15 is one of them. It may prove hard to get a great copy. Is it lens alignment or lens geometry. If it is just lens alignment, there are many camera labs that will pull the lens apart and realign the elements to the optimum possible for a relatively low cost I have done this with about 10 different Leica M lenses and the improvement was quite dramatic in a number of lenses, like the 50 Lux Asph, 50 Cron DR. In the end in may prove more cost effective and knowing exactly how your lens performs on the bench.
Thanks Charles. I have some Leica lenses that might benefit from an alignment. I know you are in Australia, could you please recommend a lab here in the US? TIA.
p.35 #19 · Official: Voigtlander 15mm f/4.5 III E-mount
I was hoping to trade out the M-mount version (which has good corners) for a Native E-mount version for an upcoming trip - perhaps I will make do and see how the QC issues resolve themselves.
p.35 #20 · Official: Voigtlander 15mm f/4.5 III E-mount
I can also attest to QC issues. This is interesting but maybe not surprising. The first copy of my M-mount 15mm III was really bad at the corners. It didn't line up with what I was seeing with online reviews, so I and returned it and ordered another copy from another retailer. Corners on the second copy were much better. The quality control issues do seem to be real.
.
Great lens and thank you for your tests! I do regret selling mine but there were many new lenses coming out and you just cannot keep them all.