In-store lens evaluation - what would you check ?

[tps58]

Hi guys, Sorry, I know some of this has been done to death on various forums/groups, but its a slightly different angle... For my upcoming holiday I really want an all-day lens to go with my D80 18-70mm setup. I fancy the Nikon 18-200m VR but for me the varied reviews and conflicting opinions tend to indicate there are good and bad copies out there (dunno - QC issues ?). Anyway its a lot of money to pay for something that may possibly deliver lower IQ for the majority of my holiday pics.So an idea is to go to a reputable store and try a couple and compare A/B B/A. My question is - if you had limited time but a camera/access to a laptop (and possibly highstreet printing facilities around the corner) what are the few key shots you'd take in-store (fL,app,range) to compare and what would you look for in the image samples to try and id a "good" lens ?Thanks for your thoughts. Cheers T

[Yandros]

Hmm, I'm not altogether convinced by this 'sample variation' issue that plagues camera forums. I suspect some people need to get out more .

HOWEVER, if you do want to test, I'd suggest using a tripod and switching VR off, and testing at 18mm and 200mm. The two issues usually reported are vignetting and distortion at 18mm, and softness as you approach 200mm.

Don't bother testing handheld with VR on, as you'll get variation from shot to shot with the same lens, and end up driving yourself nuts.

I'm certainly happy with my copy incidentally

[salubrious_k]

This isn't specific to the lens whatsoever. But I'd take some shots at the widest aperture of the buildings across the street (so everything should be in focus) at a few different focal lengths. And then I'd check on the laptop for excessive softness at the edges.

Of course you should do this with your existing lens first so that you have something to benchmark it against.

[onefivenine]

tps58 if you are comparing these two lenses:-
Nikkor AF-S 18-70mm f/3.5-4.5 G IF-ED DX
Nikkor AF-S 18-200mm f/3.5-5.6 G IF-ED VR II DX

... you might be disappointed with the 18-200 image quality compared to the 18-70. It wouldn't surprise me, as it's an 11x zoom, so something has to compromise! Maybe the VR makes up for it... up to you to decide.
Have a look at the test results in those two links.
They ought to give you an idea of what to expect.

[Yandros]

In terms of sharpness, in the real world my 18-200VR is pretty much indistiguishable from my 50mm f1.8 and 105mm f2.8VR macro. Pixel peeping shows that the primes are marginally sharper, but you have to try really hard to tell them apart. Considering how much I love my 105 VR, and how much I wanted it to demolish the 18-200VR, this should tell you something.

I'd say that the 18-70 and 18-200 will be ridiculously close. I saw a side-by-side group test of all Nikon's kit lenses (18-55, 18-70, 18-135 and also the 18-200VR), and the 18-200 and 18-70 were top of the pile.

[tps58]

Thanks for the thoughts. As Yandros says I really do need to get out more. I'm made up with the D80 and the 18-70mm (body new, lens was s/h as part of the deal). I wanted the 18-200mm from the outset but cost prevented. Now I can afford it I'm having second thought. Too many long dark evenings studying Internet reviews, comparisons and alternatives.RegardsT

[PoisonJam]

Originally Posted by Yandros

Hmm, I'm not altogether convinced by this 'sample variation' issue that plagues camera forums. I suspect some people need to get out more .

Easy to dismiss it if you've never experienced it first hand. I doubt sample variance is much of an issue with this Nikon lenses but I do believe sample variance affects lenses like the Sigma 10-20mm.

But then again you could never experience something that doesn't exist, if it in fact doesn't exist

[Yandros]

Originally Posted by tps58

Thanks for the thoughts. As Yandros says I really do need to get out more. I'm made up with the D80 and the 18-70mm (body new, lens was s/h as part of the deal). I wanted the 18-200mm from the outset but cost prevented. Now I can afford it I'm having second thought. Too many long dark evenings studying Internet reviews, comparisons and alternatives.RegardsT

That wasn't a dig at you btw, just internet forums in general, where paranoia and rumours develop a life of their own.

Here's a little test I did a while ago, between the 18-200 and my 105mm macro lens and 50mm prime
105VR

18-200VR

105VR crop

18-200VR crop

18-200VR

50mm f1.8

18-200VR crop

50mm f1.8 crop

[tps58]

Nice pics. The point about the wealth of internet review seems to be:- The lens was considered ground-breaker in range for Nikon, It got excellent reviews and became in extremely short supply. Which lead to my speculation that in an effort to ramp up production to meet demand QC suffered and consequently there are some poor examples out there - and its a model that was already pushing the envelope (range, size, VR, etc). So seeing any samples pictures no matter how good/bad wont necessarily be representative of the model you purchase. Such an issue is common in the guitar world (my other passion) when dealing with organic material (wood) no two instruments can ever be identical and whilst accomplished musicians (not me) can instantly feel differences, even I can A/B B/A examples and pick the good 'un. But maybe its all tosh and doesn't work in the photographic world. Cheers T

[Yandros]

Originally Posted by tps58

Nice pics. The point about the wealth of internet review seems to be:- The lens was considered ground-breaker in range for Nikon, It got excellent reviews and became in extremely short supply. Which lead to my speculation that in an effort to ramp up production to meet demand QC suffered and consequently there are some poor examples out there - and its a model that was already pushing the envelope (range, size, VR, etc). So seeing any samples pictures no matter how good/bad wont necessarily be representative of the model you purchase. Such an issue is common in the guitar world (my other passion) when dealing with organic material (wood) no two instruments can ever be identical and whilst accomplished musicians (not me) can instantly feel differences, even I can A/B B/A examples and pick the good 'un. But maybe its all tosh and doesn't work in the photographic world. Cheers T

Agreed. I was more aiming at onefivenine's comment about the 18-200VR possibly being a disappointment. It won't be if yours is as good as mine Even if you only have one in the shop to test, your 18-70 should be an excellent benchmark. If the results are similar, I'd suggest you keep it.

[salubrious_k]

Nice pics. Although from looking at the lens test results on Photozone, the 18-200 is let down by its edge performance, whereas the centre performance is excellent. Therefore I would think a better comparison would include a subject where there was a lot of detail in focus throughout the frame.

Just my tuppence worth... (Plus I'm a self-confessed pixel-peeper)