"Biting" sterile sharpness, or do you want AA filters?

Discussion in 'Casual Photo Conversations' started by ruslan, Oct 20, 2018.

  1. Examining full resolution pictures of some new cameras (my cousin's Sony A5000, Leica M10, Nikon D850) I see that bare sharpness at pixel level which was not present in older cameras (my old Olympus E-420 was infamous for soft pictures shooting focused at the infinity even with fairly sharp 25/2.8 ZD). I like that sharpness when examining faraway objects like structures and building and I hate it when I see moire on textures, false colors, people's faces and skin (modern lenses are already sterile, sharp with high microcontrast) ouch... it is pain to see those portraits. I have a camera with AA filter. Comparing portraits taken with my Pentax K-50 with Sony A5000 (I also add some film like emulation in Silkypix) I find mine more pleasing, old - school, calm and flowing with amount of sharpness. Shooting portraits I do not apply sharpening at all. Shooting film we don't have that sterile super sharp look, we don't see pixels directly, do we?
    Speaking of printing large prints, many pixels, more pixels and high dpi are more important than no-filter sensors so Canon EOS 6D Mk2 wins the filterless Olympus E-M1 Mk2 anytime.
    What would be your choice?
  2. Once you get up to and beyond 18mp or so AA starts to not matter as much. Much more of an issue in the days of sub 10mp sensors.

    What you shoot is also relevant. Portrait or product shooters are obviously going to be fussy when it comes to moire rearing its ugly head on fabrics. When you shoot a lot of landscapes like I do I can do without AA.

    Medium format and larger transparency films, especially long density range ones like EPP easily match digital in terms of being overly clinical when it comes to skin tones. Magazine printing helped mask the problem, but drum scans showed how brutally detailed MF trans could be. Air brush anyone? Its 35mm and print films that set a standard for fluffy skin tones. Don't want to retouch as much? Then shoot Vericolor III or Reala. Of course everybody's skin tones all looked the same.
  3. AA filters have just gotten to the point where they are no longer needed to prevent moire most of the time and they had the effect of making the image less sharp. You can always select your lens to undo this if you wish. Use a vintage lens or a lens that is known to have a different intention (maybe the 7 artisans lenses?). Heck Leica made a whole lens (the Thambar I think, and they're re-introducing it) which is designed to soft focus those portraits.

    The AA filter always seemed like something of a crazy idea to me. Maybe it's because I rarely shot pictures of people and you tend not to see moire on trees!
  4. If you hand-hold without benefit of image stabilization, every sensor is a 6 MP sensor (at shutter speed = 1/f). That's easily demonstrable by simple algebra. Not so easy to generalize, without detailed data on each lens, is that lenses designed for film, or 12 MP sensors (Nikon has only broken 20 MP recently), may be the limiting factor against Moire.

    The presence or absence of an AA filter is not going to make a camera better or worse for taking portraits. That is a matter of lens quality, freedom from camera shake or subject motion, and careful focusing. There are lenses and low-pass filters which may help with portraits. Thus use of so-called "beauty filters" for videography in or around Congress, is or was considered mandatory, at least according to the Schneider website at one time. (The use of low-pass filters is spotty, from what I see in TV these days.)

    At the worst, an AA filter will reduce effective resolution by about 30%, e.g., from 24 MP to 16 MP. That's not enough to eliminate wrinkles and pores from a portrait, and has surprisingly little effect on landscapes. While on a photo-vacation in Ireland this spring, I used a Sony A9 (24 MP, AA) and A7Rii interchangeably. The main difference was in extremely fine detail. At 24 MP you can see sheep grazing a mile away. At 42 MP (no AA) you can tell which direction they're facing. If counting sheep is your passion, try cutting back on caffeine ;)
    Jochen likes this.
  5. I'm dating myself, but a smear of Vaseline on a UV filter isn't unknown when you need a bit of softness.
  6. To really date myself, I actually have a diffuser 55mm filter that is a bit more subtle than vaseline but the effect is not dissimilar. The Thambar is the crazy expensive and more versatile version. In some sense, cameras like the Leica M8 with their IR sensitivity might give you a bit more of a touch of glow on the face due to the IR aspect. Certainly IR film tends to do that much more strongly, but part of that is also the red filter which lightens the face.

    I’ve seen some YouTube videos from people who like their adapted vintage lenses on their modern mirrorless cameras precisely for the way they look in portraits.
  7. Turn the sharpness down inside the camera...
  8. Is there an example for moire in a human skin somewhere? - I only saw it happening on for portraiture irrelevant clothing.

    Why should I have a choice in sensors? If I want a Canon lens; I'll have to live with an AA filter's data junk output and capture my B&W through a Bayer pattern.

    I guess it is easier to tame sharpness in portraits than to post-process it into landscapes? Bad lenses for big sensors seem cheap.
  9. I pretty much concur.

    In the earlier days of digital cameras I was looking at a lot of cameras for a chain portrait outfit (shooting film to that point). The potential for moire was a big deal; we decided that we just could not accept any camera that could produce it. (There had been a prior bad experience in a new venture trial - perhaps a couple hundred cameras out; the camera in use produced either random moire or severe sensor dust depending on where the lens aperture was set.)

    I think the overall best option is to have an adequate AA filter. But you can get by without one if you are shooting the sort of subjects that don't have repetitive patterns. Or if you do, be aware of the situations where moire might occur and check for it (very slight magnification changes can fix problems).
  10. I have a 24 MP Sony with an AA filter, and a 42 MP Sony without. Neither create Moire patterns of any significance. You might see Moire with the 42 MP camera under exceptions conditions, like a fence on the horizon, iron railings on distant buildings, or twisted power lines at the edge of visibility. Oddly my Leica M9 is only 18 MP and has no AA filter, and I've never had a problem with Moire. A 16 MP Hasselblad was really problematic with buildings, and there's no effective way to handle Moire in post.

    Low pass filters, like B+W Softars, eliminate both Moire and the signs of age. They come in three strengths. Medium and large format cameras have a shallow DOF, which is an effective tool as well for portraits.
  11. jakenan

    jakenan Guest

    i just have a dirty filter or a plastic bag i shoot through and i don't have any problems at all...
    its amazing how companies charge top dollar for stuff that can be done for almost nothing.
  12. You're joking, of course. A good low-pass filter is sharp where needed and soft for details (like Moire) you wish to avoid. The virtue of Softar filters is that eyes and identifying facial features are sharp, but age lines not. Best of all, the effect is virtually independent of the aperture.

    A dirty filter has inconsistent effects depending on the subject, aperture and phase of the moon. I haven't seen any pertinent standards on "dirtiness." A plastic bag messes everything up. They say anything goes in a rock session. If you want to sing into a fish bowl, someone will put it on a track. Perhaps there's a place for freezer bags in photography, but not for things a client will pay for. You need to find a properly perverted curator.
  13. In my view, the biting sharpness is more due to the design of modern lenses than it is due to the AA-filter.
    Comparing the same lenses on a D700 (with a rather aggressive AA filter) versus a D810 (no AA filter) shows that the older lenses still record bucketloads of details on the D810, but don't have that coarse biting sharpness that the newer lenses have. They just render different, and in my opinion more attractive - I frequently find images with the modern lenses sterile indeed. I'll gladly take a tad less resolution for a more pleasant rendering any day.
    ruslan likes this.
  14. FWIW, I have one camera where I have issues with moire, but it's not surprising.

    That camera is the Kodak DCS 14/n(I'd expect the 14/c, SLR/n, and SLR/c to have similar issues). It is a 14mp full-frame sensor without an AA filter. It's the only AA-less camera I have, and the resolution is low enough that I've had it "bite" me on stuff like the fabric I use for backdrops in the studio. I've seen it in grass when the conditions are just right. I suspect the issue is the combination of relatively large photosites without a low-pass filter to prevent it. On the other hand, though, using the same lens it seems to record a fair bit more detail than my D3s, which is 12mp behind a fairly strong AA filter. The 2mp resolution difference in the two is insignificant, but I know that the AA contributes a fair bit to it.
  15. jakenan

    jakenan Guest

    nope, not joking. your commentary was kind of funny though.
    lot of magic bullets people chase
    lot of $$ spent on filters and photoshop actions packs, and workshops
    dirty filters, and plastic bags are a viable solution and cheap.
    btw my black moore doesn't speak english and i only speak oranda.

    good luck with that softar.
    Last edited by a moderator: Oct 23, 2018
  16. In order to form Moire patterns in the absence of an AA filter, something in the image must have a repetitive pattern at roughly the same frequency as spacing of the cells in the sensor, and the lens must be capable of resolving these patterns. The higher the resolution of the sensor, the smaller these patterns become, hence less obtrusive to the casual observer.

    From the "studio" examples in DPReview, you can find examples of many cameras and lenses. With extremely sharp lenses, you see color bands in the finest resolution targets. The lesser the lens, the wider the spacing where Moire appears, if at all. The gorilla in the room is AA filtration, which disrupts the patterns at the sensor level.

    The high resolution of Hasselblad lenses, combined with the relatively low resolution of early, 16 MP digital sensors, combine to produce nasty Moire patterns. The high resolution of Nikon D800 sensors (36 MP) make these patterns less obtrusive, and the low resolution of lenses designed for film and 12 MP sensors tend to eliminate them altogether.

    Image stabilization, oddly enough, also tends to mitigate Moire. Random motions of the camera and IS mechanism itself tends to blur the image over a couple of pixels. In order get the ultimate sharpness, to satisfy even the most impulsive pixel-peeper, you must turn IS off, use a heavy tripod, and a remote release which does not transmit vibrations to the camera. Fortunately, subject which merit this attention seldom have repetitive patterns.
  17. Soft-focus-lenses-etc.jpg
    Left - Sima Soft Focus, center - Portragon, right - Vignetar
    +T-mount adapter
    (just a small sample of an accumulation)

    I like gadgets. Some of them work, others not so much, but I love 'em all.

    The Sima is a sort of poor person's Imagon.
    Last edited: Oct 23, 2018
  18. You are correct, I suppose, if you value novelty over consistency.
  19. I will prefer sharpness. I have one camera with an AA filter, I wish it did not, and I have one camera without an AA filter. I have never said I wish this camera had an AA filter. That thought has never crossed my mind.
  20. jakenan

    jakenan Guest

    Sorry to disappoint, but in 30 years I have never had problems with consistency.
    Maybe I should talk to my moor or oranda again and see what they think?

    Good luck with your consistent AA Filters.

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