[kh1234567890]

Also, showing great photos as "proof" that a lens is good is a flawed method. You should search for the worst photo made with that lens. If you cannot find a photo with bad light/bad bokeh/whatever, then maybe the lens is special in that way. Or maybe you just haven't found that photo yet. Either way, the question remains WHY you are trying so hard to PROVE that that lens is so great. It's not a very useful thing to do I think.

Exactly. It is the boring shots of people's backyards, dogs, garden flowers, holiday snaps etc. that tell more about a lens than carefully set up, post-processed to death, teletubbyland images (no offence Rondec). It may be all about the light but sometimes the light is cr*p and the world is dingy and grey

[Rondec]

I'm not sure I can judge too much from your photo. I can tell that sharpness seems to be decent across the frame, although the sky doesn't have much detail in it. Can't tell much about colors or contrast either.

Most photos worth keeping (in my humble opinion) are worth doing some processing on. I have presets that don't take very long at all to use that please me. I'm not really making photos for others at this point, although I do share them on the forum. I don't sell my images, if I did, I guess I would value their opinions more, but at this point I'll keep looking for good lighting and pitch the photos where it isn't great.

[mecrox]

Exactly. It is the boring shots of people's backyards, dogs, garden flowers, holiday snaps etc. that tell more about a lens than carefully set up, post-processed to death, teletubbyland images (no offence Rondec). It may be all about the light but sometimes the light is cr*p and the world is dingy and grey

Dingy and grey are sometimes excellent shooting opportunities, imho. It makes me look for strong shapes, texture, atmosphere and feel, and so forth. All can produce something much more evocative than a very colourful image. In fact, colourful images can often be rather drained of any atmosphere at all (I'm not referring to any images posted in this thread, just a general point). Colourful images can very easily be one step away from a postcard, i.e. the technically proficient but sterile image that anyone could have taken and so which no one took. It's a trap which is always around and I fall into it time over time.

I'll admit I love PP and few shots I take don't benefit from it. Imho, This is particularly the case with a camera like the K5 which has quite a heavy AA filter, and with some lenses. There may be some unsightly CA to deal with or perhaps a lack of contrast or a colour cast. Overall, I'd call it a lack of punch, sometimes. I use the Topaz Lab plugins, particularly their BW Effects, and have found them both very helpful and interesting to learn. For example, I love using platinum emulation in some b/w images, as a deliberate device to distance the viewer. The viewer is then nudged towards looking at the image as a whole, or a unity, rather than plunging into details in the image which might distract because, for example, they are brightly coloured.

No one looks at a great photograph because it tells them about the lens. They look because it tells them what it's like to be alive.

[Nicolas06]

Exactly. It is the boring shots of people's backyards, dogs, garden flowers, holiday snaps etc. that tell more about a lens than carefully set up, post-processed to death, teletubbyland images (no offence Rondec). It may be all about the light but sometimes the light is cr*p and the world is dingy and grey

Maybe one should not look for "absolute" good/bad photo. Maybe one should look to the kind of photo they are after. If that the kind of photo you like and you want to see how the lense can render such photo, that great for me.

Me I'am more after this kind of photos:


















So I will look more at something that I find interresting to me see how it turned out and if the gear finally helped me or not achieve the goal. And the gear include the lense rendering that's for sure, but post processing too. No way I could have got B&W image out of RGB bayer sensor without some processing.

There point to see pictures like you did if you plan to shoot many like that... not if you are never going to take any one. Why should one optimize for this is never going to do? This is counter productive! Would be like an outdoor shooter that use tripod & f/8 all the time for landscape that would insist on having f/1.4 lense and of the OOF rendering because it could perform better in low light and portraiture even through he never does. Or a guy that never do macro insisting that he need a lense with magnification greater than 1.

Having taken time to review the DA20-40 thread and what they get out of it, I have the impression that this guy would have been a good candidate for the B&W, the shoot with the cow, the tags, the boats. The other do not fit typically because the focal length or the deph of field is not exactly a match for the lense. But I have an FA77 for this kind of case or a DA15.

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Last edited by Nicolas06; 01-23-2015 at 05:52 AM.

[starbase218]

It is more interresting to me to look to many photos you take yourself and other take and see how it fare. The DA20-40 continuously see great rendering of its own.

On photos I made myself: I don't post many here, but I have taken some shots with my 17-70, that I really liked. If you got to my PPG, almost all of those photos were made with the 17-70 (Pentax). The shot of the two stone figures sitting in front of a temple was made with the 55-300, but I really got very nice contrast out of it in post (if I do say so myself). And I got more (I never get around enough to uploading them, or processing for that matter). I shot one in a marketplace in Thailand where they had colorful textile "balls", and I really liked the color in that shot. I shot a berry in Kenya, I think it was. They grow coffee there, and when a berry turns red, that means it can be picked (it's nicknamed "readyberry"). I noticed one of the berries on a branch had turned red while the others had not. So I selectively focussed on that berry and took the shot, using the 16-50 this time. This shot with the 20-40 actually reminded me of that photo.

So yeah, light is important. It has so much influence on a photo. And some lenses are more resistant to e.g. flare than others. And yes, images from some lenses will have more contrast than images from others. But my 17-70 has good contrast and doesn't cost so much. So to say the 20-40 is worth it's money because of the contrast... I don't know.

And other than that, I don't think there's a terribly big difference in how most lenses render light. And even if there is, I have "bigger fish to fry", like being there at the right moment, taking my time, etc to make the most out of a shot with the gear I have and know.

This is very visible and interresting. that is have only good border performance closed down instead of perfect... This has no practical impact on the shoots anyway.

I guess it depends. I took a shot with the 17-70 at 70mm and f/8 of an Island in Khao Sok National Park, Thailand. I choose f/8 because I wanted everything sharp, and the island was a long way away anyway. But I wanted to get the borders sharp as well. And they are (well, maybe not "prime" sharp, but for such a lens, they're damn good ).

One other thing I would like to say about objective lens tests and "numbers". I actually agree somewhat with the sentiment that numbers don't mean anything, but probably for a different reason than most of you do. I think that numbers only mean something if you know the testing methodology as well. E.g. did the reviewer refocus for corner sharpness tests or did he just use one photo to determine sharpness across the photo? Did he properly focus (using manual focus and a magnified view)? It's really hard to get testing right I think. But if you don't know HOW a test was carried out, the numbers are indeed meaningless.

[Nicolas06]

One other thing I would like to say about objective lens tests and "numbers". I actually agree somewhat with the sentiment that numbers don't mean anything, but probably for a different reason than most of you do. I think that numbers only mean something if you know the testing methodology as well. E.g. did the reviewer refocus for corner sharpness tests or did he just use one photo to determine sharpness across the photo? Did he properly focus (using manual focus and a magnified view)? It's really hard to get testing right I think. But if you don't know HOW a test was carried out, the numbers are indeed meaningless.

Actually I never refocus my border and I don't use manual focus. So for sure if a tester rely on manual focussing & border refocussing the number he get are meaningless to me because I will not get that from the lense in practice. As for the border refocussing that really anoying for the DA15.

[starbase218]

Actually I never refocus my border and I don't use manual focus. So for sure if a tester rely on manual focussing & border refocussing the number he get are meaningless to me because I will not get that from the lense in practice. As for the border refocussing that really anoying for the DA15.

I don't normally use manual focus either, but that's not my point. My point is that if a reviewer wants to test the lens for sharpness, he should choose an approach that allows him to isolate that variable to the best of his abilities. The result he gets may not be irrelevant to me, for a number of reasons. First of all, I have a different camera (even if it's the same model), so the focus of the lens he tested on my camera may be different than on his. Second, I can use focus adjustment to compensate for focus errors caused by that particular lens and body. And I actually do that.

This is why it's important to try to isolate the variable you want to test. And focus accuracy is a different variable.

I also actually move my focus point around, especially when taking wide-angle shots and off-center subjects. If I wouldn't do that, and I want to focus-and-recompose, the focus will be off when I actually take that shot. And yes, I have come across this in the field.

This is actually why I would like the next Pentax camera to have a wider field of AF sensors. The K-3 still has all of them pretty much in the center, which reduces usability to me.

Also, when e.g. taking landscape shots, I sometimes just use manual focus and hyperfocal distance to make sure everything is in focus. In which case I am again very interested in resolution of a lens without the impact of autofocus errors.

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Last edited by starbase218; 01-23-2015 at 08:59 AM.

[kh1234567890]

This is actually why I would like the next Pentax camera to have a wider field of AF sensors. The K-3 still has all of them pretty much in the center, which reduces usability to me.

You can't. One of the failings of phase detect AF. The secondary mirror can't be any bigger 'cause it wouldn't fit ...

[starbase218]

You can't. One of the failings of phase detect AF. The secondary mirror can't be any bigger 'cause it wouldn't fit ...

Well, the 25 center points are fairly close together, while the 2 side points are closer to the border, but they are non-cross-type points, so I usually don't rely on them.

What I would like is 25-30 or more cross-type points, spread out evenly across the same area that we have now (which also covers the two side points).

---------- Post added 01-23-2015 at 06:10 PM ----------

We are diverting from the topic though. But limiteds and DA*s follow a different philosophy. If you like the limited philosophy, get that (although I wouldn't get the 20-40, but that's no secret by now). If you like the DA* philosophy, get that.

IMHO that's way more important than quality/rendering differences.

O yeah, and get good copies. I learned the hard way.

[northcoastgreg]

So to say the 20-40 is worth it's money because of the contrast... I don't know.

That depends on how important lens contrast is to you. I have come to agree with Mike Johnston, who contended that

lens contrast of fairly large image structures is a primary determinant of subjective optical quality in a camera lens.

I used to believe that sharpness was the primary determinant of "subjective optical quality." But having shot with more than 30 lens of various grades of quality over the last five years, I have come to appreciate the importance of lens contrast. And while it is true that contrast can be "simulated" via post processing, I have found that the kind of contrast you get out of a lens just looks better than the kind you get from moving sliders in Lightroom or other image processing software. PP merely extrapolates from a given data set. With lens contrast, you get a better, higher quality data set to work from. For example, with a less contrasty, flare prone lens, if I try to recover details in shadows, I often do so at the expense of contrast. When exposure values in shadows are raised they end up looking washed out. With a contrasty lens, I can recover those shadows while more easily preserving a decent contrast level.

Lens contrast also improves color rendition, leading to more brilliant, saturated colors combined with greater variety of tones. If I'm shooting the sky reflected on water, the DA 15 will produce a richer color palette, with more aesthetically piquant tones, than my DA 17-70.

I have found through trial and error that lens contrast tends to produce images that are easier to produce stunning prints. With lens contrast, you get images that have a lot of brilliancy and pop and yet at the same time feature very good tonal gradations throughout the entire image. Simulated contrast and saturation via PP, while it sometimes can look pretty impressive on screen, doesn't always transfer well to prints. Cranking up the contrast in post can damage the sensitive tonal gradations of an image, leading to areas of poorly differentiated tones -- something that doesn't always print up well. And over-saturation can sometimes push the image into tones that printers can't handle, leading to washed out-looking prints.

When it comes to lens contrast, I'm merely a pragmatist. I just find that the more contrasty lens tends to make it easier for me to produce images that I'm satisfied with than a less contrasty lens. To be sure, there are some types of light where the differences are insignificant. If I'm shooting redwoods in fog, my DA 17-70 can more than hold its own with my DA 15. But if I'm shooting reflections on water with sunlight involved, the DA 15 will give me a better data set to work with in post.

[emalvick]

This is all interesting. Ultimately, we're all artists (without getting into what exactly defines an artist), and out cameras, lenses, computers, etc. are our tools, our brushes if you will.

As an artist, you should strive to get the image you want or envision. If your lenses can get what you want then you are doing well. We shouldn't worry about whether a lens works or not for others as what they want from a lens won't necessarily match what another person wants. Of course, when it comes to shopping for lenses, it helps to be aware of others opinions and experiences, but you do have to see the grander picture of what you need when considering opinions.

As far as picking out items of sharpening, color, contrast, and even post-processing when evaluating lenses and sample output... It all has to be important to some extent. Post-processing is always going to be a factor. Even if you look at sample JPGs out of the camera, they have been post-processed by the camera itself. I rarely worry about that because I want to see what the final output is. If an image looks fantastic, it's not like it can happen if the image is bad to begin with. Processing can't save a bad picture.

Corner sharpness I sometimes think is a little over emphasized, not because it isn't important, but because it most cases when the corners are important, I'm shooting at f/8 anyway. I've rarely thought to myself that I wish I could shoot at f/4 or f/2.8 and have a sharper image at the corners.

In most my lenses, where the corners really do show as a problem, I think most of the issue is the fact that the focus distance is actually difference at the corners. If you are shooting an image with a 15 mm, 20 mm, even 30 mm lens, the distance to the subject at the corners is different than the distance right in front of you. If you are shooting at an aperture with a narrow depth of field, it shouldn't be too difficult to imagine that the corners might fall out of that sharp depth of field. I think it's something that many of us forget. This doesn't mean corner softness can't still be a problem either based on the limitation above or just the lens design itself.

[kh1234567890]

We are diverting from the topic though. But limiteds and DA*s follow a different philosophy. If you like the limited philosophy, get that (although I wouldn't get the 20-40, but that's no secret by now). If you like the DA* philosophy, get that.

IMHO that's way more important than quality/rendering differences.

I would fully agree with that.

[Nicolas06]

I don't normally use manual focus either, but that's not my point. My point is that if a reviewer wants to test the lens for sharpness, he should choose an approach that allows him to isolate that variable to the best of his abilities. The result he gets may not be irrelevant to me, for a number of reasons. First of all, I have a different camera (even if it's the same model), so the focus of the lens he tested on my camera may be different than on his. Second, I can use focus adjustment to compensate for focus errors caused by that particular lens and body. And I actually do that.

This is why it's important to try to isolate the variable you want to test. And focus accuracy is a different variable.

I also actually move my focus point around, especially when taking wide-angle shots and off-center subjects. If I wouldn't do that, and I want to focus-and-recompose, the focus will be off when I actually take that shot. And yes, I have come across this in the field.

This is actually why I would like the next Pentax camera to have a wider field of AF sensors. The K-3 still has all of them pretty much in the center, which reduces usability to me.

Also, when e.g. taking landscape shots, I sometimes just use manual focus and hyperfocal distance to make sure everything is in focus. In which case I am again very interested in resolution of a lens without the impact of autofocus errors.

I understand why the tester does like this. I also typically use of center AF point. Still this only give optimize the focus at this point. Depending of the lense field curvature and of the scene, this is going to be a problem or not.

The way of testing sharpness typically mean that the corners and border are good/great at f/8 and I use f/8, all should be fine.

Still if I focus on center I get border OOF and if I focus on corner I get center or other border OOF. This is not the deph of field itself but really field curvature issue. If I take another lense... The issue is solved because this one has less field curvature. The review should tell me that because it is very important. Field curvature can make the thing so bad that it far outweight the sharpness number from the charts.

After all we have measurement as high as 3500 lp/lw but for a typicall screen 1200 lp/lw (full HD 2MP) is what you need. And this means it would make a decent print of same size as the screen. Here for me at work or home the computer screen are 22 or 23". That already decently sized. Bigger print are likely to be seen futher away so that not much an issue.

But no lense even get such bad results in reviews at f/8. A weak lens get maybe 1700 or 2200 on borders on a 24MP sensor. Meaning more than enough. Still the border can look quite weak anyway with purple friging, field curvature...

Then there the AF, some reviewer include AF test that's true, but the AF behavior to me if more important than the ultimate sharpness because if the focus fail to work, the picture is blured then you miss the shoot.

Some lenses like the FA50 for example are difficult to use with AF of K5. This is an important factor. Typically reviewers fail to do real focussing test that would say work fine on this body, terrible on this other body. Even through this is essential to the user experience.

As an opposite, almost most reviewers except maybe DxO review the lense on one body or something like that. So when you read their review, it is biased by the sensor used. If the lense is soso sharpness wise but is reviewed on a 10MP sensor it will still be able to get good rating and bar charts at the top even at wide apperture and on border. But if you test the same lense on a higher resolution camera like 24MP, this is the same lense and the picture will look at good as before or even better printed or on screen... But the lense will get a lesser score because this time the border softness will show more.

Many still think Pentax lenses are crap because most are tested on 10-16MP sensors with low pass filter while lenses on other system where typically tested on an FF with lot of resolution (20MP+, often 24 or 36MP).

In the end, I don't really care what the lense can do in theory if it isn't going to perform in practice. No reason for me to buy another one that would perform well on Nikon D800. No reason for me to buy a lense with better border if the additionnal field curvature mean I'am not getting overall decent sharpness. No reason for me again to buy a sharp lense if it can't focus consistently.

And that's without counting the contrast discussion we have.

Still the sharpness is the key benchmark we see everywhere and we speak of everywhere. Lenses are choosed and considered mainly because of theses results by many instead of actual capacity to perform in real life. That really the tree that hide the forest to me.

[starbase218]

Still if I focus on center I get border OOF and if I focus on corner I get center or other border OOF. This is not the deph of field itself but really field curvature issue.

I was talking about using the focus-and-recompose technique with an off-center subject and a wide-angle lens. When recomposing, the distance to your subject (perpendicular to the sensor plane) will change from the distance at which the lens is focused. This can - and in some cases will - lead to the subject being out of focus. Field curvature has nothing to do with that.

[mwilky55]

Hey all!
Next month will be exactly two years of photography for me and hopefully the start of my last lens and gear buying spree, "for a good while at least." So this should be my last purchase related question. I have a few Ltd lenses and plan to buy two or three * lenses, but never used a * lens. I know like everyone else that, both the Ltd and * series lenses are the top of the line but, I would like to ask:
Overall, which series do you prefer and do you think one series is better, or do you think they're equivalent?
My problem is waiting to find out for myself (doing LBA research), as I've yet to find anything stating one series is superior to the other overall.

For argument's sake, remember everyone is entitled to their own opinion. NO WRONG ANSWERS
Thanks once again!

I don't own the DA*50-135, but have the 16-50 and the 60-250. If you told me I could only own two lenses, it would be those two because they give me a lot of focal range, are pretty fast for zooms, have good to great IQ and are weather resistant. I'm fortunate to also have a few DA limiteds (15,35,70). I feel like that puts me in great shape for APS-C cameras.

But, I'm also hedging my bets on a Pentax full frame someday AND, as much as I like my DA Limiteds, the FA Limiteds are legendary and can be used on film/full frame. I also have a *FA 24 (which I love) and a *F-300 (which I don't, mainly cuz I haven't mastered it). To my thinking, the Limiteds are stronger than the *'s in the F/FA series.

I guess my advice, FOR WHAT IT'S WORTH, would be weather resistant *'s for your zooms and limiteds for your primes.