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03-08-2013, 07:42 AM   #241
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Thank you for the link, normhead. Excellent site.

03-08-2013, 08:42 AM   #242
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Well, from the two points of view, we don't necessarily have an "incorrect" one.
I understand what normhead, froeschle &co are saying; indeed, real life usage and lab measurements are different things. But, that doesn't mean to abandon tests altogether; better, more relevant tests are the answer IMO (unless we would give up trying to find non-obvious differences between lenses).

I'm with Falk on this one, a poorly made test is useless; but a well made one, and with a correct understanding about what it measures, can be useful. A poorly made test would be one which can't control variable factors (e.g. vibration, focus, alignment); so, the lens must be rock solid even if that's not possible on the field. His hints made sense, and should be considered by a tester (unless a better alternative is found).
Of course, one can purposely test how vibration prone a certain lens is, or the focus accuracy, and then other factors will have to be made constants. But I strongly disagree with tests measuring "everything" at once.
03-08-2013, 09:22 AM - 1 Like   #243
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QuoteOriginally posted by normhead Quote
Does a lens that produces the best images in a test chart, produce the best images in the field? Until that question is answered, test charts are essenitally meaningless.
This is a really odd statement from someone who not infrequently cites photozone.de as a resource. Lab tests have their place in lens evaluation, and are especially useful for super-tele lenses where sharpness and control of aberrations are so important for the uses to which these lenses are typically put.
03-08-2013, 10:16 AM   #244
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QuoteOriginally posted by baro-nite Quote
This is a really odd statement from someone who not infrequently cites photozone.de as a resource. Lab tests have their place in lens evaluation, and are especially useful for super-tele lenses where sharpness and control of aberrations are so important for the uses to which these lenses are typically put.
I don't disagree with that, but to me real-world examples are much more informative than raw numbers. I know what MTF means, I know what resolution and microcontrast mean. But a lens is more than just a sum of its parts. How does it render a white eagle on top of a tree? How does it render a finch in a bunch of branches? How well does it cope in backlit situations? All things which cannot be read from a test chart and resolution figures.

But maybe it's just me and my personal preferences. I love to shoot with old primes which -again: to me!- render much better than most new lenses, even though newer lenses will be sharper and more contrasty. I honestly think that sharpness/resolution tests are overrated when there's so much more to a lens than just that. Maybe there's some truth in the statement that we should stop pixelpeeping and just go out and shoot more!

03-08-2013, 10:19 AM   #245
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Last edited by beholder3; 08-11-2013 at 07:13 AM. Reason: [deleted]
03-08-2013, 10:42 AM   #246
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* fast and accurate DC autofocus

Lesser cons :
* short distance resolution
* wide open MTF
* wide open vignetting
03-08-2013, 01:14 PM   #247
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QuoteOriginally posted by baro-nite Quote
This is a really odd statement from someone who not infrequently cites photozone.de as a resource. Lab tests have their place in lens evaluation, and are especially useful for super-tele lenses where sharpness and control of aberrations are so important for the uses to which these lenses are typically put.

You just get to a point where, you have lenses like the 21, which is not all that great on the charts, and two other great lenses that cover it;s range, the 18-135 and the Tamron 17-50, both of them better on paper. Yet I find myself reaching for that lens in certain situations. There is more than sharpness to a lens. Once you've bought a bunch of sharp lenses, you find yourself reaching for them at appropriate situations not based on a couple hundred LW/PH, but on how they render.

So I love the test charts, but in the field, I don't select based on test charts or resolution. I select on which lens is most appropriate. IN terms of telephoto's you are absolutely correct. I've returned a number of telephotos because they did so poorly at long range... but never because of their performance at 8-10 feet. At that distance, as long as you're past minimum focus, almost every telephoto is good.


A 21 Ltd image, I propose, higher res, wouldn't be better.
03-08-2013, 01:18 PM   #248
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Can we agree that we should have both resolution tests and real world tests? Resolution test so we can understand how the lens stacks up against competitors like the Sigma 500 F4.5, and real world tests so we understand how the micro-contrast, colour rendition, bokeh, flare resistance, CA, etc appear in normal shooting conditions.

Seems kinda silly to argue for one test over the other, when I don't think it's an issue for the reviewers to do both kinds of tests before they have to send the lens back in 3 weeks.

03-08-2013, 01:43 PM   #249
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QuoteOriginally posted by normhead Quote
I've returned a number of telephotos because they did so poorly at long range... but never because of their performance at 8-10 feet.
Falk was suggesting 20m.
03-08-2013, 02:06 PM   #250
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I'm guessing 20 meters would be good, but generally I just go over to Opeongo Lake and shoot the top of the cliff a Km and a half away, the soft bad lenses look just awful.
03-08-2013, 07:28 PM   #251
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A few resolution shots of test charts at 15-20 meters away aren't going to harm anyone and aren't that complicated to shoot. I would be surprised if the 560 doesn't outresolve the K5iis sensor, even wide open. At least in the center. But it's much harder to take advantage of the peak resolution of such a lens in the wild. ISOs are the main ennemy, but shake, atmospheric turbulence, wind, etc will all eat up that resolution in no time. Pentax lends the lens for 3 weeks for a reason: there's a LOT more that needs reviewing: AF performance, handling, CA control, flare, rendering, the polarizer, maybe even the WR... Of course there should be a nice album with full res photos of birds and wildlife in in the review. As a matter of fact, that could be the preview!
03-08-2013, 08:38 PM - 1 Like   #252
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QuoteOriginally posted by Asahiflex Quote
I honestly think that sharpness/resolution tests are overrated when there's so much more to a lens than just that.
I would generally agree with your statement. Except here, where we talk about a very expensive ultra tele lens. This lens is MADE to resolve detail other lenses can't. After all, you could use a DA* 300/4 and crop into the image to get the same results than from a DA560 which isn't tack-sharp. Esp. when using a 24MP body.

So please everybody, come to your senses and realize what this lens has to deliver to make any sense. And how it can be verified that it does. I do agree that flare, focus, bokeh etc. all are relevant criteria too. But easier to review.

Having said this, I do agree that real life images need be shown. But be provided by Pentax and be technically top notch as otherwise, they would be meaningless. And in full size if course.
Something like http://chsvimg.nikon.com/lineup/dslr/d7100/img/sample/img_04_l.jpg from Nikon | Imaging Products | Still Images - Nikon D7100 which is a 24 MP APS-C crop from the Nikkor 500/4G. If Nikon can do it to showcase a body, why can't Pentax do it when showcasing a lens?

Last edited by falconeye; 03-08-2013 at 08:58 PM.
03-08-2013, 08:44 PM   #253
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I agree. Real world experience is about handling, some lenses are easier to use, will be at hand, etc. But if it isn't sharp, there is a problem.
03-09-2013, 03:39 AM   #254
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QuoteOriginally posted by falconeye Quote
I would generally agree with your statement. Except here, where we talk about a very expensive ultra tele lens. This lens is MADE to resolve detail other lenses can't. After all, you could use a DA* 300/4 and crop into the image to get the same results than from a DA560 which isn't tack-sharp. Esp. when using a 24MP body.

So please everybody, come to your senses and realize what this lens has to deliver to make any sense. And how it can be verified that it does. I do agree that flare, focus, bokeh etc. all are relevant criteria too. But easier to review.
I think this is very important, but DA*300mm already is excellent.

This image is from a soccermatch and for this I could have used a 600mm lens since it was in a far distance. Only 1762x2467 pixels in the image that I cut out from the original and settings f4.5 iso5000. Made an A3 print for my exhibition because off the wonderfull scene and the players involved. So there is a lot possible, but the DA560mm needs to beat this!

03-09-2013, 01:52 PM   #255
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So we now have a ~$7,000.00 super telephoto available. I would be more interested in either a `150 mm or 200 mm macro lens in the $1,100 - $1,400 range. At the current price , how many of them are they really going to sell?

Jake
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