[Ash]

This may have been discussed before, but I can't seem to find a thread on it here.
Much has been said about the problems the DA *16-50 has had in QA, but how does a good copy of the DA* 16-50 compare with that of the trusty DA 16-45?

Well, I thought I'd give it a try myself with some garage door shots, and here are the comparisons at 16mm wide open (to bring out the biggest deficiencies in both lenses).

Equally lit and shot in the same position:
16-45 at f/4


16-50 at f/2.8


Yes, I know, you can't compare f/4 with f/2.8 but I'm interested in wide open performance. Here, I've found slightly more vignetting with the 16-50 at the wide end, regardless of the aperture, and significantly more barrel distortion. As for sharpness, when looking at f/4 shots together, it's hard to tell the difference between these lenses.

So this is a very informal and unscientific test, but what about the lab controlled ones published online?

Well, I've looked it up and have only found Photozone.de to publish MTF data on the 16-50 and 16-45 together.

Pentax SMC DA* 16-50mm f/2.8 ED [IF] SDM - Test Report / Review
Pentax SMC-DA 16-45mm f/4 ED AL - Review / Test Report

Sample size of 1, but if their testing is systematic and accurate, the results should be quite authoritative. So what did they say?

Overall, the 16-45 is optically better than the 16-50 (test winner - W):

Barrel distortion at 16mm:
16-45 - 2.5% W
16-50 - 3.6%

Vignetting at wide end:
16-45 - 1.17 EV at f/4 W comparing them wide open
16-50 - 1.24 EV at f/2.8 and 0.85 EV at f/4 W comparing them at f/4

And the crux of the tests - the MTF 50 in LW/PW:
f/2.8
16mm - 16-50
Centre: 2085 (acceptable, but definitely not stellar)
Border: 1403 (quite poor, actually)

24mm - 16-50
Centre: 2159
Border: 1614

f/4
16mm - 16-50
Centre: 2354 W
Border: 1779

16mm - 16-45
Centre: 2281
Border: 1899 W

24mm - 16-50
Centre: 2294
Border: 1777

24mm - 16-45
Centre: 2296 W
Border: 1959 W

50mm - 16-50
Centre: 2009
Border: 1496 (getting bad again)

45mm - 16-45
Centre: 2024 W
Border: 1890 W+

Border CA in pixels
f/2.8 - 16-50
16mm: 2.7 (shockingly high)
24mm: 2.0 (no great improvement here)

f/4 - 16-50
16mm: 2.6 (still remains high)
24mm: 1.95 (and still not improved)

f/4 - 16-45
16mm: 2.3 W
24mm: 1.93 W

and so on...

So according to this test, the DA 16-45 is on par with and even exceeds the DA* 16-50 in all the IQ tests, making me wonder why one would upgrade to the DA*. If it's only for the SDM and weather sealing, is it really worth that much more?

Now to you all... despite these numbers, how do you find the DA* 16-50 compares with the DA 16-45, practically?

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Last edited by Ash; 02-01-2009 at 03:34 PM.

[BBear]

very intersting..

maybe you have the numbers all right and all... and after all the IQ is very much the same and both are outstanding glasses...


I've had the DA* for a week and bought the 16-45 used... and for me, i always had pre-programmed that the DA* had better color rendition (it blew my mind) and obviusly a GREAT feeling/built quality. But i had chosen to buy the 50-135 instead due to FL preferences..

So i needed something to replace the kit, enters DA 16-45: bought used, feels cheaper than DA* and, i hate to say that, never got any love from me: lost caps, tossed around, etc... BUT always performed well.

After reading your report, it came to me: DA is indeed a good lens, but because supposedelly there is something better, so i tend to under apreciate the DA lens i have.

I am not sure, because the whole experience with the DA* is superb, and besides MTF and all, it renders colors that spell LIFE.

Anyway, good research, maybe i should apreciate my DA 16-45 a bit more...

[nostatic]

I find my 16-45 to take great pictures though I rarely use it as I prefer my primes. But garage doors and brick walls aren't my idea of great pictures (at least not as represented here) so I have no comparison.

My advice is to shoot real photos rather than tests and see if you like them. Tests are pretty meaningless in the end imho.

[GaryM]

The Photozone test shows the 16-45 as having more consistant performance, but the 16-50 having better peak performance. In fact, the f8 numbers seems to be the best of any Pentax zoom in that range. Looks like an ideal landscape lens - I wish they made a smaller and lighter, less expensive f4 version and kept the weather sealing.

[asdf]

Thanks for the informative post.

The Marx brother seems to be the product of a liberal arts college and his useless post-modern advice should be ignored.

[Ash]

@ nostatic:
Yes, I do take my lens to shoot real images, but these tests and data reflect what results you will get in the real world. So they're not irrelevant and meaningless IMO.

@ BBear:
At the price it is, the DA 16-45 almost doesn't deserve the same TLC that a Limited or DA* warrants, but its performance speaks for itself.

@ GaryM:
That's a good summary - I'm not dismissing the 16-50, as I too have upgraded to it from the 16-45 - but I am producing the data as food for thought.

I'm yet to see real world tests to compare their performances, so if anyone could shed light on this it would be most welcome and appreciated.

[Acliffalay]

This post makes me feel a little better about missing out on a 16-50mm second hand for £320 as an upgrade from my 16-45mm.

But now its snowing outside...

[nostatic]

Thanks for the informative post.

The Marx brother seems to be the product of a liberal arts college and his useless post-modern advice should be ignored.

well, liberal arts for undergrad but a slightly more technical school for my phd

Not useless advice imho. Far too many people here focus (pun intended) on "machine" tests, specifications, and other numbers that have some degree of bias. In the end, the act of taking a photograph is a human/machine interaction, and as such there are many intangibles that come into play. I just believe that numbers not only can't tell the whole story, they often get in the way of *any* story, and are swallowed as "objective" when in fact they are not.

The bottom line is that I get images I like from the 16-45, and didn't from a copy of a 16-50*. All the tests and reviews in the world would not have given me the amount of information that a few minutes shooting did. That isn't a slight against the 16-50*, and I would recommend that anyone else make their own decision. To me the power of this forum is people sharing their personal experiences. Quoting online test numbers doesn't really quality as a PE (though I suppose you could find some post-modern philosopher to argue that), but I'm evidently in the minority so ymmv.

[EricT]

The Photozone test shows the 16-45 as having more consistant performance, but the 16-50 having better peak performance. In fact, the f8 numbers seems to be the best of any Pentax zoom in that range. Looks like an ideal landscape lens - I wish they made a smaller and lighter, less expensive f4 version and kept the weather sealing.

YES! I would be all over such a lens. I actually made a thread about it here: https://www.pentaxforums.com/forums/pentax-news-rumors/49423-will-pentax-rele...ed-lenses.html
Although such a lens would not be entry-level, it would still make an awesome addition to the Pentax lens lineup.

[leeak]

The 16-45/4 vs 16-50/2.8 debate comes up regularly from time to time, because the 16-45/4 is such a good performer. I liked mine when I had it last year. However as good as the 16-45/4 is, I think the 16-50/2.8 is a very solid package w/ SDM and weathersealed. In fact, I wonder how many of us end up keeping the 16-45/4 when they have a good copy of 16-50/2.8?

[Ash]

Agreed nostatic.
Hence my request for folk with a 16-45 and a 'good' 16-50 (if there are any) to show us the same subject matter taken with these lenses on the same settings to compare real life results.

leeak, yes the DA 16-45 is not just a good performer, it's actually excellent. The question I have for those who upgraded is: have you noticed a real difference in the quality of images from the two lenses?

[Gooshin]

Agreed nostatic.
Hence my request for folk with a 16-45 and a 'good' 16-50 (if there are any) to show us the same subject matter taken with these lenses on the same settings to compare real life results.

leeak, yes the DA 16-45 is not just a good performer, it's actually excellent. The question I have for those who upgraded is: have you noticed a real difference in the quality of images from the two lenses?

between f2.8 and f3.9999999999, the DA* is infinitely better than the 45

[Ash]

I'll keep that in mind... Glad you told me!

[Gooshin]

I'll keep that in mind... Glad you told me!

no seriously, why bother making such threads?

its like buying a truck and an econobox and then going on a forum and asking "which is the better car?"

the DA* is much more expensive, but also comes with usefull features, and is faster.

as far as picture quality goes, pixel peeping will get you nowhere,

neither lens is an upgrade to each other, they are designed for different things.

so really, the question is "which set of features do i need more", and that is a question you should be asking yourself, not us.

[Ash]

Well then, perhaps you can enlighten the ignorant such as myself as to what the two lenses are designed for (if they are for different purposes) apart from the obvious one extra stop, SDM and weather sealing?