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01-24-2014, 05:24 PM   #1246
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QuoteOriginally posted by Parallax Quote
You just validated my point.
Right... Care to explain how so?

01-24-2014, 05:51 PM   #1247
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At magnification you can see the difference, fit to screen you can't; so the screen has little to do with it,
Pixel peeping is a useful tool to compare one lens to another, but it puts an unreasonable burden on a lens to be judged excellent, good, etc. Make an 8x10 print from each. I doubt anyone could tell which lens took which picture, just as you can't tell on screen which is which.
01-24-2014, 06:01 PM   #1248
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Your comment in 1244 and your comment in 1248 don't seem to be consistent.
01-24-2014, 06:05 PM   #1249
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QuoteOriginally posted by Parallax Quote
At magnification you can see the difference, fit to screen you can't; so the screen has little to do with it,
Pixel peeping is a useful tool to compare one lens to another, but it puts an unreasonable burden on a lens to be judged excellent, good, etc. Make an 8x10 print from each. I doubt anyone could tell which lens took which picture, just as you can't tell on screen which is which.
That was not your argument as I understood it. The following quote appears to contradict what you just wrote.
QuoteOriginally posted by Parallax Quote
I wonder why people judge how good a lens is by how the picture looks at screen resolution. That's roughly the equivalent of judging a lens in the pre-digital days by how a huge poster size print looked. Viewing the entire image (fit to screen) on 21" monitor from an APS-c sensor (Slightly more than 1" Diagonal) is a 21x enlargement, or roughly the equivalent of viewing a print of 12x18. A print from a 35mm negative (roughly 1.5" diagonal) at the same 21x enlargement would be about 18x27. The "standard" was typically 8x10 (or 8x12 for 3:2 purists), an enlargement of only 8x, so even without pixel peeping we're judging lenses at more than 2.5 times the magnification that we used to.
Also, are you arguing that we should view lenses at resolutions/magnfication such that it is not possible to tell the difference between a $1300 lens and a kit lens (besides DOF)?


Last edited by Cannikin; 01-24-2014 at 06:18 PM.
01-24-2014, 06:08 PM   #1250
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Yeah. What I was intending to say was the way I understand cannikin's post 1243 even the kit lens out resolves monitors.
01-24-2014, 06:10 PM   #1251
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So... 31 and 18-55 are almost the same. They both produce acceptable photo.
All cars are almost the same. You can drive any functional car.
All clothing is almost the same. You can wear any clothing with proper size.
All knives are almost the same. You can cut using any sharp knife.
All cameras are almost the same. You can make pictures using any functional camera.
All ... are/is almost the same. You can ... using functional/proper ...
01-24-2014, 06:50 PM - 1 Like   #1252
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This discussion would go much better if you didn't try and put words in my mouth.
I confirmed what cannikin said. Without enlarging you can't tell. All cars almost the same? Just like lenses, it depends on how you measure. If you and I each left the same place at the same time, you in a corvette an I in a Toyota Corolla, and drove across town to the same destination at the speed limit we would arrive at same time. So without being told, no one would know which of us drove which.
The enlargement size is the speed limit. Raise that and eventually differences become apparent. So does that mean that because of those two cars only the Corvette is any good because the Toyota doesn't go as fast?
My point is that the standard we use for deciding whether a lens is bad, good, or great is much higher than it used to be.

Last edited by Parallax; 01-25-2014 at 09:46 AM.
01-24-2014, 08:23 PM   #1253
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QuoteOriginally posted by Parallax Quote
This discussion would go much better if you didn't try and put words in my mouth.
Sorry dude. I did not mean to offend you.
It was just an association with the phrase “Make things as simple as possible, but not simpler.” (Albert Einstein)

Indeed, "the kit lens out resolves monitors", but...

01-24-2014, 11:52 PM   #1254
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QuoteOriginally posted by Quicksand Quote
But your original (rather harsh, IMHO) response was directed to several OWNERS of the lens who have used it personally. Do you own it? Have you used it?

I did not mean to be harsh, only straightforward. If a small zoom with great build quality and decent image quality fits a photographer's needs, the 20-40 should be a fine lens. If one wants top-notch image quality at pixel-peeping levels, there are likely better choices. Of course, as someone suggested, Adam could have tested a subpar copy.

I would be more interested in the Sigma 18-35, but I have no problem with large lenses, as I almost always work on a tripod.
01-25-2014, 08:48 AM   #1255
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There must be sample variations of the 20-40 out there, because both Karen and I are snobs when it comes to good glass and our copy has none of the bad issues Adam documented, not one. And we shot the snot out of it after we got it. And its not just this lens, the Tamron 17-50 we got is much better than the Pentax Forum tested one, the Tamron 70-200 f2.8 a very little worse, and the DA*200 f2.8 much better esp the AF. And the 16-50 DA* that people here usually love we have never found an acceptable copy of, and we tried 5 times. We even skipped the black friday price on that lens because of that. No real conclusion other than sample variation is very real, and it happens to all brands.

David
01-25-2014, 09:28 AM - 1 Like   #1256
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QuoteOriginally posted by David&karen Quote
There must be sample variations of the 20-40 out there, because both Karen and I are snobs when it comes to good glass and our copy has none of the bad issues Adam documented, not one.
David
How do they test lenses? Do they use AF? If so, you're not testing the lens performance but the lens performance + AF performance with that particular lens and body. Discrepancies in any of those parametres can make even the best lens look bad.
01-25-2014, 09:28 AM   #1257
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Finally, light appeared
01-26-2014, 05:27 PM   #1258
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QuoteOriginally posted by jimr-pdx Quote
True, it seems confusing - but Pentax does have DA35 and 50 'competing' with the Limiteds so they've been here before.
Really I'd prefer a 24-70WR but of course those are "always" FF lenses, no one could possibly want a 36-105mm equivalent on their aps-c cameras. Except me?
I agree this is actually a very useful range on APS-C!
01-26-2014, 05:47 PM   #1259
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QuoteOriginally posted by tram57 Quote
I agree this is actually a very useful range on APS-C!
The A 35-105 was a popular lens on film, same range of view angles.
01-26-2014, 10:57 PM   #1260
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It will be 18-70.
And also the 150-450, FF image circle. Also refreshed FA limiteds. And something new in the DA* forefront.
Wait till CP+, and then revisit this thread.
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