3d look

<p>Justin said: "To me the 31mm is probably the most overpriced lens made." <br>

Within a k-mount lenses I can see how you might say that, especially if you have not used one for a period of time. But compare it out side of the Pentax system to Canon "L" primes, Zeiss, some Olympus glass and let's not even talk about Leica; The 31mm is a bargain. Those are the lenses the FA 31 and FA 77 compete with from a build quality and rendering stand point. No they are not for everyone but having gone though just about all of Pentax's better current production glass as long as I shoot this system they are the last two lenses I will let go of. The reason is the bokeh and the subtle rendering qualities none of my zooms nor the DA limiteds can match them.</p>

<p>Yeah, for L quality glass it is not unreasonable. And it is compact and doesn't weigh too much to boot. Personally I don't think the 77mm is quite as good as the 31mm bokeh-wise, but it seems you pay a premium for the 31mm so there you go. I don't think the 43mm is nearly as good as the other two.</p>

<p>It would be nice to see Pentax make a similarly compact 24mm limited (non-pancake) but I won't hold my breath.</p>

<p>I haven't been too impressed with the pics I've seen from the new 55mm 1.4. Sure, it's nice but bokeh is pretty ordinary. The sigma eats it for breakfast. The pentax is really quite pricey too so you expect something really top notch. It is weather sealed though.</p>

<p>I really should start saving my pennies to get a 31mm...</p>

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<p>I might start saving for the 24mm. Of course, I'd rather like the 50mm and 30mm (DC) f1.4 as well</p>

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<p>I'm confused about the 30/1.4. It seems a little smaller than the other wide sigmas ? but the actual quality is where I'm lost. The reviews seem to suggest it doesn't really perform like a prime... takes a long time to sharpen up and generally has quite poor border/corner performance. Yet there seem to be a handful (I haven't heard of many) that really like the lens. I guess if you need 1.4 and you don't pixel peep, it's a very good option. I used to love 50mm on APS-C, but haven't really picked mine up (a Minolta lens) since getting an 85mm lens. Still, you can't really beat 50mm for those quick reaction type shots, nor really on optical quality...</p>

<p>I've always loved the idea of pancakes/very compact lenses like you folk have and had wanted Sony to bring some to market for ages. But I'm not too bothered anymore. I think if I were using pancake type lenses I'd want a tiny body too - Samsung NX style :)</p>

<p>Interesting discussion with some nice pictures. I agree with the general definition of "3D quality" and agree that lenses, not just lighting and DOF characteristics, have something to do with it. The Limiteds show this best of any lens I have seen/used.</p>

<p>For my part I reach for the FA43 over the FA77 when this look is a goal. Yes the FA77 can have nice bokeh and throw the background out of focus. But there is something more to the FA43 and I don't know what it is. For example, in the following picture there is not enough of the background visible to achieve the classic "front sharp, back blurred" look many have illustrated. But it still "pops" to me. And I don't think any lens other than the FA43 would have done this. Maybe not even the FA31 (which I do not own).<br>

<a title="film still 5917 by robin746, on Flickr" href=" title="film still 5917 by robin746, on Flickr"><img src="http://farm4.static.flickr.com/3625/3596158469_47af764801_o.jpg" alt="film still 5917" width="800" height="533" /> </a></p>

<p>Richard, I wouldn't worry about the reviews of the 30mm f1.4. Generally they say that it is very sharp in the centre, and pretty soft at the edges. However, when you are shooting wide open it's rare for the subject to be at the edge of the frame. Usually that part is out of focus anyway. Plus because the OOF areas are generally very blurred, it tends to make the in focus areas appear sharper than they actually are.</p>

<p>The only real concern, for me, with the 30mm is getting a decent copy with no front or back focus. If you have a k20d and can adjust for this then it's no big deal. I suspect a lot of the comments on poor focusing with the Siggy are simply due to people not being aware of exactly how shallow the DOF is at 1.4.</p>

<p>I generally select lenses not by reading MTF charts or pixel peeping, but looking at images people have taken with the lens. I'm not looking for flaws which only become apparent at 100% -- I'm looking for flaws which are apparent even at web resolution, because that is how most of my images are viewed. Hence why I place a high emphasis on bokeh quality as it is impossible to correct in post processing and is readily apparent at all resolutions.</p>

<p>You can see some shots from the 30mm f1.4 shot wide-open at http://www.rytterfalk.com/2008/05/31/sigma-30mm-f14/. If you search around his site you'll find some other nighttime shots of at parties and weddings using the 30mm.</p>

<p>Robin, I'm going to disagree with you there and say that your 43mm image has "pop" because of four main factors:<br /> 1. Her face is in sharp focus<br /> 2. The other areas of the picture are either nicely soft... look at her neck for example... or in darkness. Darkness has a similar effect of allowing the subject to jump out at you.<br /> 3. The lighting and shadows help to emphasise the shape of her face... lips, chin etc. Our brains get a lot of shape information from surface shading.<br /> 4. Her chin and lips "pop" out of the image in particular, because they are the sharpest, and are surrounded by areas with little detail (or darkness)</p>

<p>I really do believe that it is possible to account for each and every apparent "3D effect" by a combination of depth of field, perspective, lighting, subject arrangement and good bokeh. Good contrast and sharpness of the lens obviously add to the effect by highlighting the in focus area of the subject.</p>

<p>Fair enough about the image; I agree with your analysis. I suppose it remains a subjective preference I have for the 43mm. I still know it renders differently from any other lens I have used, but I cannot exactly say why. Believe me, I'd rather some of my other lenses also showed the same characteristics!</p>

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<p>The only real concern, for me, with the 30mm is getting a decent copy with no front or back focus.</p>

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<p>Alas, my Sigma 70-200 is going in for calibration next week :(. Back focus. Luckily, it will be done free though (warranty).</p>

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<p>The Limiteds show this best of any lens I have seen/used.</p>

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<p>Can I say Minolta STF without being shot down in here ;-) ?</p>

<p>Ahh the Minolta STF, a lens designed from scratch with it's main purpose to produce perfect bokeh. I never made the jump from my Minolta x-700 MF gear to Maxxum AF gear, and have not had the privilege of playing with one, but it looks amazing. I think there is somthing about the 135mm range that produces nuce bok eh. Closest I can get is my old M42 Pentacon 135mm f/2.8 which some people call "the bokeh monster" It's bokeh is creamy wonderful, but it lacks in sharpness and CA is a problem with anything back lite. If I shot Sony I'd be seriously Jonesing for a copy of the 135 STF it is a one of a kind lens.</p>

<p>Some people may sneer at the mere mention of a 3D look in photographic images, but I found out that it does exist some years ago, when I got my first set of prints back from a Contax G2 with Zeiss 45/2G lens. My jaw dropped when I saw what appeared to be rich modelling of solid objects and a sense of space around them. My point of reference at that time was Nikon with some pretty decent glass.</p>

<p>Over the years, I have come to appreciate three dimensionality when I see it, but sometimes I cannot see it unless I have something else to look at as a reference. Nowadays, I like to compare different image editing software. I will process the same image file with two or more programs and then view them on my monitor. The differences can be striking. Some software is much better at creating what I regard as a 3D look. My hypothesis is that this look is largely the result of microcontrast with subtle separation of tones. Fine detail helps, but a blurred background is not necessarily part of the equation.</p>

<p>Rob</p>

<p>OK, as a doubter I have a challenge for those who believe the '3d look' is mostly about the quality of the lens. Grab your favourite lens which gives you good '3d', and another crappy lens which doesn't. However, make sure the second lens can be set to the same focal length and aperture as the first.</p>

<p>Now go and take some pictures. Whenever you take a photo with the first lens, take the exact same photo with the second. Obviously this will preclude pictures of moving objects, but that's not too much of a limitation. Make sure all the camera settings and lens settings (focal length, aperture) are the same in each case. In fact, you may need to apply a tiny bit of exposure compensation since when a lens says "f2.8" it is not always actually f2.8. Anyway, you get the idea. Try and capture identical images.</p>

<p>Then come back and show us two pictures of the same subject (same focal length, aperture, focus point etc). If one lens truely is "3d" capable then it should stand out in a side-by-side comparison.</p>

<p>Do you have someone who would sponsor such a project. If so, I'm in!</p>

<p>I agree with Robert Goldstein. Aside from out-of-focus background, there is a difference in image quality and realism based on contrast, sharpness, gradation and color rendition. I don't know how many here have seen the flat look of images from mediocre lenses that are lacking in these areas. The opposite of such lenses are those whose performance excells, well above average in these areas.</p>

<p>S Brown, I'm not going to take the time to look back at all the posts (feel free), but I don't think anyone said the look comes from mostly the lens. The lens is a key factor, but if you take a picture while locked in a room with not light... the picture will be black. As for your challenge, I'd like to see that also. Preferably the 31 ltd, vs a phoenix 28-80, or a quantaray zoom. </p>

<p>Also, if all you are concerned about is the center of the frame, i'd say the sig 30mm is nice, but if you ever wanted to have something in focus on the edges... its no good. The edges turn almost every shot into mush, very noticable in prints (I don't print larger than 8x10). For me, the lack of versitility killed the value of the lens; subjects can only be in the center of the frame and stopping down really didn't help the corners, so it becomes a specialty lens.</p>

<p>There is a whole scientific field dealing with visual perception, and one of its main areas of inquiry has to do with how the human brain converts a two dimensional representation into a three dimensional one using a variety of visual cues. Artists have long understood, often intuitively, how it is possible to create a sense of realistic depth in their drawings. By varying their technique, they can produce drawings that appear to be relatively flat or deep. It stands to reason that the same can hold true for photographs, i.e. they can convey a greater or lesser sense of depth depending on a variety of factors. As I mentioned in my previous post, this can easily be seen using different software to edit the same image files, but it can also be seen using a single piece of software to edit the same image files in different ways. Just try making simple adjustments to clarity and sharpening while keeping this in mind.</p>

<p>Rob</p>

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