Although studying is considered a legitimate scientific nowadays, it is still a very young one. In the early 1970s, a psychologist named J. Guilford was one of the first academic researchers who dared to conduct a study of creativity. One of Guilford’s most famous studies was the nine-dot puzzle. He challenged research subjects to connect all nine dots using just four straight lines without lifting their pencils from the page.

Today many people are familiar with this puzzle and its solution. In the 1970s, however, very few were even aware of its existence, even though it had been around for almost a century. If you have tried solving this puzzle, you can confirm that your first attempts usually involve sketching lines inside the imaginary square. The correct solution, however, requires you to draw lines that extend beyond the area defined by the dots. At the first stages, all the participants in Guilford’s original study censored their own thinking by limiting the possible solutions to those within the imaginary square (even those who eventually solved the puzzle). Even though they weren’t instructed to restrain themselves from considering such a solution, they were unable to “see” the white space beyond the square’s boundaries. Only 20 percent managed to break out of the illusory confinement and continue their lines in the white space surrounding the dots.

The symmetry, the beautiful simplicity of the solution, and the fact that 80 percent of the participants were effectively blinded by the boundaries of the square led Guilford and the readers of his books to leap to the sweeping conclusion that creativity requires you to go outside the box. The idea went viral (via 1970s-era media and word of mouth, of course). Overnight, it seemed that creativity gurus everywhere were teaching managers how to think outside the box. Consultants in the 1970s and 1980s even used this puzzle when making sales pitches to prospective clients. Because the solution is, in hindsight, deceptively simple, clients tended to admit they should have thought of it themselves. Because they hadn’t, they were obviously not as creative or smart as they had previously thought, and needed to call in creative experts.

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Or so their consultants would have them believe. The nine-dot puzzle and the phrase “thinking outside the box” became metaphors for creativity and spread like wildfire in, management, psychology, the creative arts, engineering, and personal improvement circles. There seemed to be no end to the insights that could be offered under the banner of thinking outside the box. Speakers, trainers, training program developers, organizational consultants, and university professors all had much to say about the vast benefits of outside-the-box thinking. CCGen.rar. It was an appealing and apparently convincing message. Indeed, the concept enjoyed such strong popularity and intuitive appeal that no one bothered to check the facts. No one, that is, before two different research —Clarke Burnham with Kenneth Davis, and Joseph Alba with Robert Weisberg—ran another experiment using the same puzzle but a different research procedure.

Both teams followed the same protocol of dividing participants into two groups. The first group was given the same instructions as the participants in Guilford’s experiment. The second group was told that the solution required the lines to be drawn outside the imaginary box bordering the dot array.

In other words, the “trick” was revealed in advance. Would you like to guess the percentage of the participants in the second group who solved the puzzle correctly? Most people assume that 60 percent to 90 percent of the group given the clue would solve the puzzle easily. In fact, only a meager 25 percent did.

What’s more, in statistical terms, this 5 percent improvement over the subjects of Guilford’s original study is insignificant. In other words, the difference could easily be due to what statisticians call sampling error. Let’s look a little more closely at these surprising results.

Solving this problem requires people to literally think outside the box. Yet participants’ performance was not improved even when they were given specific instructions to do so. That is, direct and explicit instructions to think outside the box did not help. That this advice is useless when actually trying to solve a problem involving a real box should effectively have killed off the much widely disseminated—and therefore, much more dangerous—metaphor that out-of-the-box thinking spurs creativity. After all, with one simple yet brilliant experiment, researchers had proven that the conceptual link between thinking outside the box and creativity was a myth. Of course, in real life you won’t find boxes. But you will find numerous situations where a creative breakthrough is staring you in the face.

They are much more common than you probably think. *From Copyright 2014 Drew Boyd. There are many theories of creativity.

What the latest experiment proves is not that creativity lacks any association to thinking outside-the-box, but that such is not conditioned by acquired knowledge, i.e., environmental concerns. For example, there have been some theories such as those of Schopenhauer (see his remarks about Genius) and Freud (see his remarks about Sublimation) that propose creativity is something more like a capacity provided by nature rather than one acquired or learned from the environment.

Rather than disproving the myth, in other words, the experiment might instead offer evidence that creativity is an ability that one is born with, or born lacking, hence why information from the environment didn't impact the results at all. It's an interesting experiment, but the author's conclusion cannot possibly follow from the results of it. I conduct soft skills training and outbound training for Corporates and individuals. To enhance creativity we motivate the participants to approach the problems from variety of vantage points. Even repeatedly checking the boundary conditions we are able to come up with variety of ways of solving the problem. This is akin to checking the walls of the box. Looking inside the box for additional information, additional resources also helps.

Looking at the box from bird's eye view triggers some different creative solutions. Let us not get tied down to the mechanics but free ourselves to find the solution. I will give an example. You are playing football with family and friends at a distant ground and someone gets bruised badly. No first aid kit is available. Your priority is to get the person to a hospital ( at a distance of 2 hours ). The wound is bleeding and needs to be kept clean and bacteria free till the person reaches the hospital.

What will you do? Think of a solution. It is quite close to you. With all due respect, Professor Boyd, your argument is not at all compelling. It seems that you are taking the 'thinking outside the box' (TOTB) metaphor much more literally than it is intended (or, at least, as I and may others infer). Let me point out a few false and/or negligent statements that you make: 1.

To refer to TOTB as 'dangerous' is naive, at best. I, personally, have seen the positive, tranformative effects of not only the 9-dots exercise, but also the occasional use of the term to remind individuals after-the-fact about the value of thinking differently. The experiment you refer to doesn't even come close to proving what you suggest that it does. To use the term 'proving' in an argument like this is laughable. In real life, you absolutely WILL find boxes.that is, if you understand what the term 'box' refers to. Here, the term is not literal; rather, it refers to a mindset, a perspective, a belief, or an assumption. It is precisely how the human mind works.

We all think in boxes all the time. The 'sin,' if you will, is not in thinking inside of a box.but the neglect to readily switch from one box to another, nimbly (see Alan Iny's new book, 'Thinking in New Boxes'). A different -- and very healthy, positive, and productive -- way to think about TOTB is to understand that it merely represents an insight that can remind an individual to consciously become aware of limiting assumptions.

And, upon such awareness, to open ones mind and imagination to actively explore new possibilities beyond the obvious or initial answer. If you don't regard this as valid contribution to creativity, then I suggest you consider spending a bit more time outside of that 'box' that you've presented here.

I couldn't have said it any better. TOTB is a beautiful skill to have. We are born into multiple boxes that are created upon social agreements (e.g. Illustrated by the hermeneutic circle) but the ones who dare to think outside of what is considered as social or scientific correct (all the boxes together) are the minds whom are absolute free and open towards new moralities, paradigms, innovations and creativity in general. Saying that TOTB is a negative thing is a very conservative statement and someone who has such a belief is scared of change, scared of diversity and scared of anything that is abstract and out of order. I'm all about TOTB and the best way to TOTB is to fully understand the box in the first place and why some people are scared of TOTB hence also lacking the ability to do so.

Fold the paper so all the dots ovelap. Use four lines to connect four dots. Hold the folded paper up to the light.all dots connected; Thinking outside The Box.

For that matter, you could fold the paper until all the dots overlapped and you would not need to waste any pencil lead; Thinking outside The Box. Use a very wide pencil lead or charcoal block for that matter, connect all the dots in one fell swoop; Thinking outside The Box.

Forego a pencil altogether and use a bucket of paint to create a huge blot over all the dots; Thinking outside The Box. Question the dots and why they need to be connected in the first place; Thinking outside The Box. Erase the dots; they are a distraction to Thinking outside The Box. Create your own dots and lines in any fashion you desire; Thinking outside The Box. People that say, it's a misguided idea,, do not know how to think outside the box, I can look /listen/ at anything an tell you how to fix it. I play chess with my pc, an beat it all the time, and the reasoning is I do not think logically, like the pc does. It has a set of rules that it was programed with an you were in college, I do not play by the rules, I can play without the queen.Also when you go the a school that teaches how to think about something, that is all you know how to do.I have had engineers come to my deck, hand me a set of blueprints, because that was the way they were taught.

They are never taught to look at it, in there mind to see it working. What I do is show them how wrong they are, an ask them what tool in the world can cut a square hole inside the middle of two long tubes.

They can not think outside the box, that they were taught to do. If was going to tell you about an airplane the TR-3B, it travels a little bit under light speed, an it uses nuclear fusion, which turns into plasma an powers the craft, that was built outside the box. An if you do not believe me type it into your search engine, you can also look it up at the library of congress under new patients.

You my brother, do not have the inkling of understanding to think outside the box. That's why you are a psychologist an nothing more.

Introduction Sony A7s with Zeiss 18mm 2.8 E Batis The Zeiss Batis 18mm 2.8 is the latest addition to Zeiss’ line up of modern autofocus lenses and also the widest AF prime lens to date for Sony E-Mount. As many people (include me here) are now engaged in landscape astrophotography I am especially interested how the new Batis fares in this regard. I have neither moved the camera nor the focus-target but only changed the focus setting. In the “before” shot the correct focus setting was chosen. The distance scale on the camera says 0.3 m and the display on the lens says 0.3 m +0.01 -0.00 (the target is a measured 0.25 m away from the camera sensor).

For the “after” shot I turned the focusing ring a bit towards infinity (as can be seen by the bar on the camera display), the target is clearly out of focus now but the camera display still shows a focusing distance of 0.3 m and the display on the lens says 0.3 m +0.01 -0.01. What is giving me quite a headache here is this: I have clearly and substantially changed the focusing distance but the values on the displays simply don’t show me that. The situation isn’t that much better near infinity. The correct setting for infinity is at the turning point between XX.X m and infinity but the focusing ring can still be turned way farther and you are focusing behind infinity then, meaning nothing is in focus at all.

Still the display on the lens will tell you infinity is sharp, which is not the case when having focused behind infinity, not even at f/11. To me this matters, especially for astrophotography, but it may be no issue at all for you, as in case you solely rely on autofocus, you probably won’t even notice this. Vignetting and colorcast Wide open there is some visible vignetting in the extreme corners which according to my measurements is around 2.6 EV and stopped down to f/4.0 around 1.9 EV. Zeiss’ shows only the values after the internal corrections which leads to only 1.4 EV wide open and around 0.8 EV by f/5.6. There is no Lightroom profile yet and color cast is unsuprisingly not an issue.

Sharpness infinity Sharpness across frame is very very good right from the maximum aperture. On the 12mp sensor I can see slightly reduced contrast in the extreme corners wide open, but otherwise simply excellent performance here. There is also no visible field curvature. One thing to notice: in the compilation above I increased the exposure on the corner crops to make them comparable in terms of sharpness. The centering quality of the review sample is very good, but I have to mention that another copy which Jannik from our team bought was visibly decentered.

Close focus Sharpness and contrast are unsuprisingly very good at close focus distances, even wide open. I already expected this because of the floating elements design. There is no softness and loss of contrast at closer distances seen in many of our reviews of older lenses. Flare resistance Sony A7s Batis 18mm 2.8 f/16 With the sun near the border or the corner of the frame it is possible to catch a rather unobstrusive red ghost and a little more obstrusive sickle shaped green ghost. The contrast seems to be not affected at all and stays on a very high level. With the sun outside the frame the performance is excellent even without the lens hood.

Coma According to Zeiss one of the main applications of this lens is astrophotography, so I was very curious about the coma performance, which is indeed very good to say the least. Wide open even the extreme corners only show a negligible amount of coma but things get very interesting when comparing the Batis to my two main astro lenses (see my corresponding astro-landscape ), the Nikon AF-S 14-24mm 2.8G and the: Nikon AF-S 20mm 1.8G – Zeiss Batis 18mm 2.8 E – Nikon AF-S 14-24mm 2.8G In this comparison the Batis 18mm 2.8 E is clearly the best showing the least coma. I will soon try taking some shots of the milky way with this lens and adding them to the samples section. Both Nikon lenses were adapted using the metabones adapter. My finding is that even this expensive adapter does not have the same exact flange distance as a native Nikon camera which can have a negative influence on the optical qualities, especially on lenses with floating elements design (which is the case with the 20mm 1.8G).

Nevertheless I long ago made a comparison between the A7s with the metabones adapter and the Nikon D800 and in terms of coma I didn’t notice a visible difference with the 20mm 1.8G (corner sharpness wide open is better on the D800 though). Use for astrophotography Sony A7s Batis 18mm 2.8 f/2.8 ISO6400 20s unedited shot This lens is advertised by Zeiss as a lens well suited for astrophotography and after having tested coma and vignetting I also had high hopes for it.

Luckily I had the opportunity to shoot the milkyway under quite good conditions and the lens proved to be an excellent performer here. Stars are a little more forgiving to coma than cityscapes and I couldn’t find any traces of coma when shooting them at all. This is neither the widest (see Nikon 14-24mm 2.8G) nor the fastest (see ) lens for astrophotography but the sum of it’s parts makes it one of the best choices for astrophotography available to date, not just for E-mount but in general. Distortion Distorion characteristics of Zeiss Batis 18mm 2.8 There is some barrel distortion (mustache style) which can also be clearly visible in architectural shots (see full resolution example below).

This will be corrected in newer firmware versions (I am still running 2.0) and to my experience this lens will probably be included with the next Lightroom update as well. Bokeh Sony A7s Batis 18mm 2.8 f/2.8 shot at minimum focus distance With the 18mm focal length and a maximum aperture of f/2.8 you have to be close to your subject to throw the background visibly out of focus. The bokeh is quite nice without harsh outlinings but the bokeh balls can show an onion ring structure due to the many aspherical elements, as can be seen in this 100% crop: 100% crop of photo above Take a look at the following example to see what the bokeh looks like with the subject farther away: Sony A7s Batis 18mm 2.8 f/2.8 shot at ~0.8 m distance Sunstars You probably know by now I prefer sunstars produced by straight aperture blades but putting this aside sunstars produced by the Batis 18mm stopped down are well defined and quite nice. Chromatic aberrations longitudinal Sony A7s Batis 18mm 2.8 f/2.8 50% crop, minimum focus distance Only some slight traces of green and magenta outlining can be found, pretty good performance here. Lateral There is an embedded profile when using Lightroom for correcting the lateral CA which cannot be turned off.

So to show you what it looks like without the correction, I took some shots without electronic contact between lens and camera. Sony A7s Zeiss Batis 18mm 2.8 f/4.0 CA 100% crop without correction (before) / corrected with embedded profile (after), extreme corner As there are only minor CA this is a very good performance for an ultra wide anlge lens. The remaining CA can easily be corrected in post, as can be seen above. Alternatives: We got asked a lot about this comparsion – so I will try to go a little bit into detail here – but nitpicking between the optical qualities of these two lenses is pretty much pointless as they are both excellent performers in almost every regard.

Nevertheless, I think the Batis’ coma correction is a little better while the Loxia has better flare resistance and nicer sunstars, but what should really drive your decision here are the focal length and handling differences. A horizontal field of view of 90° (18mm) versus 81° (21mm) is quite a meaningful difference and here it mostly comes down to your preferences and the other lenses in your kit.

You may get by with the 18mm being your widest lens and I could think of it nicely complementing an AF-kit for landscaping/archtitecture already consisting of the Sony 28mm 2. Hino Explorer Keygen Crack. 0 and Sony/Zeiss 55mm 1.8. What really matters are the handling differences: the Batis is a designated AF-lens and pretty much meant to be used that way (I am not really fond of the fly by wire focusing ring and the OLED distance scale for manual focusing) while the Loxia is an all manual lens (when properly calibrated with hard infinity stop), which is also significantly smaller. There is no simple “lens x is better than lens y” here, actually, there rarely ever is. You are of course loosing AF, Exif-data and 2mm but you also gain 4/3rds of a stop maximum aperture and more subject isolation.

But the 20mm 1.8G also has higher vignetting, especially at infinity, and worse coma, so as of today, the Batis 18mm 2.8 would be my choice for astrophotography among lenses with a focal length of 18 to 21mm.: This is your widest option with AF and OSS and of course more flexible in terms of focal lengths. In case you don’t need the faster maximum aperture or the superior image quality of the Batis this may be a good choice for you. Older manual SLR lenses: There are many legacy 20mm and even some 18mm and 19mm lenses availabe. Some are quite cheap on the used market (Minolta MD 20mm 2.8 or Canon FD 20mm 2.8) while others are unbelievably expensive (Leica-R 19mm 2.8). You might start taking a look at our.

In case you are running on a tight budget this is where you should take a look. Conclusion good • coma correction • very good sharpness and contrast already at maximum aperture across the whole frame at all distances • sunstars • CA correction average • vignetting • distortion • flare resistance not good • price • manual focus experience (in case you intend to use manual focus with this lens) In case you took a look at the table above you probably know by now this is a very good lens with no real flaws. The optics are great (at all distances and aperture values), the build quality ins’t bad either and the coma correction is really outstanding.

Because of the last point I was also really tempted to buy this lens but I didn’t. While the lens is really lightweight it is also quite big, especially with the lens hood, and I am not a fan of fly-by-wire focusing and the OLED distance scale. Someone at Zeiss knew people would have different opinions on how the ideal lens feels and operates like and decided to settle for two different lines: Batis (lightweight but rather big, modern OLED display, AF, fly-by-wire-focusing, 9 rounded aperture blades) and Loxia (a little more solid (= heavier), all manual, smaller size, 10 straight aperture blades). In my opinion this was a really smart move.

I am more of a Loxia person. For my landscape work I mostly use manual focus and I highly value the smaller size, the smaller filter diameter and the 10-bladed aperture. But this does not mean the Batis 18mm 2.8 is a bad lens, it is actually a damn good one. So, who is this lens for? Anyone, who looks for a very good, native ultra wide angle E-mount lens with AF, nice build quality and very good optical properties or simply one of the best lenses for landscape astro photography available to date. Of course this is no cheap lens and compared to the 16-35mm 4.0 you give up quite a bit of flexibility, so you better be sure this is the right focal length for you before buying one. Apart from this I have no reservations recommending this lens.

You can find this lens on (affiliate link ) and it is now also available on / (affiliate link). Sample Images Sony A7s Batis 18mm 2.8 f/11 Sony A7s Batis 18mm 2.8 f/2.8 Sony A7s Batis 18mm 2.8 f/2.8 Sony A7s Batis 18mm 2.8 f/2.8 Further Reading • • •. I gather from reviews both the 18mm and the 21mm are brilliantly good lenses if you can get past the characteristic heavy vignetting at wide apertures. Obviously, the 21 is manual focus. The other difference that is important to astro photographers is that the 18 has better coma performance.

I don’t quite understand why Phillip feels that the display is a big issue on the 18mm. Yes, it is true that you have to be careful to click just once from xx meters to the infinity mark, but having done that, infinity focus is spot on. Plus, there are definite positive clicks in the focus ring to ensure you are just where you should be. While I generally very much appreciate your work here at phillipreeve.net, I do not really understand why to test a presumably highly resolving lens on today’s least demanding 12 MP body. I mean, we all have our (mostly SLR) history, which is full of such cases. In my case it’s Nikon, where almost all (full frame) lenses perform well on the good old 12 MP D700, but take a D800 class camera and you will see that the pool of useful lenses is shrinking rapidly – I could tell a painful story here.

In the Sony case: while I perfectly understand that an A7s(II) may have it’s merits, I would at least prefer 24 MP to challenge a lens. Thank you for your feedback!

I personally think sharpness is heavily overrated and there are quite some people out there (lensrentals and dxomark to just name two) with expensive equipment to measure it way more exact than I could ever do (and they probably will do that in the near future). Finding reviews that are about the photos and not about the pixels on the other hand has become quite difficult but this is exactly what I want to provide: A review from a user’s standpoint and not from a technician or an optics engineer. So I put my efforts into providing useful sample images as well as information on handling, bokeh, sunstars and coma which are things the more technical reviewers often don’t cover and are also mostly not affected by the megapixel count. Apart from this I also see this as a lens for astrophotography and the A7s(II) is challengened by no other camera in this category so far. But I of course do understand the importance of the sharpness measurements for some of you and I will try to get hand on an A7rII and repeat the sharpness test as the difference between 12mp and 24mp is not nearly as meaningful as it sounds.

Dear Jerre, of course getting hands on an A7rII should be less of an issue for Zeiss (in comparison to me at least), but they also lend the lenses to some real photographers for these images. As someone who sells architecture and landscape photos from time to time I can say customers mostly don’t care about the pixels. I can sell a 36mp D800 photo or a 12mp A7s photo, no one cares for or even sees the difference. Most of these images are printed in magazines or used for presentations or on websites, not printed on house walls. When shooting weddings I usually upload all the photos with 2000px (long side) in my dropbox to get them as fast as possible to the customer and always say to contact me when in need for higher resolution shots. Never ever happened. Most stock agencies’ (considering the ones I worked with) biggest upload size is 3000px (long side).

I always welcome more pixels, all else equal, but rarely is all else equal. So I can understand, not every landscape or architecture photographer is using a 36mp+ camera. Dear Bastian, I am confused with how to set infinity focus. I received today my batis 18mm, and as i am an astro/landscape photographer set infinity focus is really important to me. I saw on oled that when we see infinity mark first time we can continue turn focus wheel and oled continue to show infinity mark. So where is really the infinity focus?

Normaly in other lens this also happen but we have a small mark above infinity mark to set with percision infinity focus. You said “Just looking at the OLED screen may not be sufficient, but I found Infinity is best at the turning point between the infinity symbol and something like 20-200m.” This not look loje to be really precisecan you explain a litle more? Thanks in advance!!! Excelent review.

Dear Brian, regarding micro contrast the Zeiss may be a little bit better but not by much. This is more like splitting hairs here. The Loxia lenses – at least to my knowledge – are more optimized for contrast and I can absolutely say that for the 21mm and the 35mm. The corner-to-corner sharpness highly depends on the adapter you are using. With my D800 (36mp) corner sharpness of the 20mm 1.8G ist at least good wide open, on the A7s (12mp) with the metabones adapter I had to stop down to f/2.8 for the same level of sharpness.

I have not yet found the perfect adapter and lenses with floating elements design (like the 20mm 1.8G) suffer from incorrect flange distance. The safe bet would definetly be the 18mm 2.8 Batis here. In case you have any further questions dont hesitate to ask! Thanks for this review but almost regret to have gone for the Loxia 21mm Would have preferred wider, 18mm is nice, but maybe there will be a Loxia 14mm somewhere in the future.

But when I look at this review I must say that I’m hesitating again about buying the Nikon 14-24mm f2.8. Weight and a number of lenses is always a problem when traveling. Must say that I don’t like to change lenses to often (changing filters, danger of dropping.) For the moment I’m using the A7r2, A7s plus as wide angles for day-landscaping the Sony 16-35mmF4 + Loxia 21mm and for astrophotography the Samyang 14mm f2.8 + sometimes the Samyang 24mm and/or 35mm F1.4, recently also the Loxia. Would prefer a lens like the Nikon 14-24mmF2.8 but I’m hesitating because I don’t know how it performs on the A7R2 (would not sell the Loxia but definitely the others). You seem to mention that the Nikon 14-24 is performing as good on the A7 series as on the D800. Would be nice to see a review of this lens in combination with the A7 series, A7r2 if possible.

Until now, I didn’t find any review of this combo (A7 + Nikon) but could you, or someone else, confirm that the IQ is no issue. Friendly greetings. Thanks, Bastian, and to Philip, for this very thorough review. I’m shooting the Sony Zeiss Distagon 35 1.4 and absolutely love the lens though I’m primarily shooting portraits these days with the Batis 85 1.8, which I’m very very happy with and not regretful for not further (italics) waiting for the Sony 85 1.4 as I frankly find the Batis bokeh charming and full of character I also find the Distagon does fantastic portrait/environmental captures!

Sharp, clear, lovely. At any rate, I’ll often want something wider when out shooting nature – the Batis 24 or Loxia 21 or now the Batis 18. These reviews help with my thinking. I downloaded the library shot and the evening lake/town photographs.

Goodness, what a great lens! Peace, thanks again, and happy shooting. Thanks for such a detailed review! I just purchased the Zeiss Batis 18mm. At first, I was really happy with the overall sharpness of this lens on landscape shots vs my Sony 16-35. The corner sharpness is so much better than the 16-35.

With that being said, I took the Batis out for some Milky Way shots last night and was really disappointed with the results on both my A7rii and A7s. I was getting star trailing with 13sec exposures. I switched to 10sec and still had the same results. Tried putting the lens on my A7s and still same issues.

I refocused a number of times without any luck. Just for kicks, I put my Sony 16-35 on and did the same tests with the same settings. It produced perfectly rounded sharp stars with no trailing. I’m really disappointed as the Batis 18mm was supposed to be my go to lens for Astro and was to replace my Sony 16-35.

Any suggestions or ideas would be very much appreciated! It’s relatively slight, but a metre or so if you focus centrally, the optimum focus is a little behind the nominal plane of focus at the periphery. Enough that if you are picky you might want to bear it in mind.

Not enough to worry about (and *much* less than the opposite tendency in the old f3.5 ZF). You might want to check, though! Unlikely to be sample variation, but you never know.It’s only field tests that tell me this; I haven’t mirror aligned a chart and focussed on the centre and edges separately. Hi BastianK, I am struggling with choosing a ultra wide angle lens for aurora and astrophotography as I am going to Finland next Feb. I prefer to have a lens with light weight and you can insert a normal filter (like CPL) on it. Now I am thinking of two lenses: Batis 18 F2.8 and Laowa 15 F2. Laowa is wider and the aperture is faster, but I am not sure which one has a better quality or do I need the lens to be so wide?

The most important thing is the brand: Zeiss vs Laowa. It seems that to have a Zeiss lens is much more happy, haha.

Which one you will suggest according to my situation?