Is A7 here because APS-C cameras are about as good as they're going to get?

Discussion in 'Sony Alpha E-Mount Cameras' started by Bill, Feb 13, 2014.

  1. Bill

    Bill TalkEmount Veteran

    339
    Oct 22, 2012
    Brisbane, Australia
    Bill
    ASP-C (NEX) cameras are great. They're images are better than those from medium format film. Has Sony brought full-frame cameras to the masses to fill a real need, or just to give us something to buy? No place to go, but up?

    Does any of that really matter?
     
  2. WoodWorks

    WoodWorks Super Moderator

    Dec 12, 2012
    Ashland, OR, USA
    David
    "Prediction is very difficult, especially if it's about the future."
    -Niels Bohr

    But I'd say betting against Sony's sensor designers would be a losing bet. Given how far we've come from just ten years ago, I see no reason that ten years from now the current state of the art will look just as sad.
     
  3. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    Sensor design is only limited by physics, and we're not even close to what's possible with APS-C sensors. The A7 is here because Sony sees a market where they can actually be a market leader.
     
  4. davect01

    davect01 Super Moderator

    Aug 20, 2011
    Fountain Hills, AZ
    Dave
    The original NEX's were innovative, but had some shortcomings. The 6 and 7 were proof that the NEX line can be taken seriously by serious photographers. The A7 pushes this even further, for those willing to pay the price. As always, just by buying new equipment, does not mean you will have improved pictures.

    From here on out I fell it is simply refining the product by trying out different features and form functions and seeing which ones catch on. Clearly people like the extra dial wheels, having a flash and viewfinder built in. The 5 series touchscreen seems to be a popular feature, some love it, some could care less. 3D seems to come and go, but I have not seen many people use it.

    For 90% of photographers and 90% of shots the 16MP in the NEX-6 and 24MP in the NEX-7 and now the A6000 is more than enough. The AF speed keeps getting better and better. The 6 provided a much better AF response, especially in those troublesome dark shots. With this new A6000 promising lighting fast AF, this should no longer be a concern.

    Myself, I am well pleased with my 6. It is all I need, and I see no need to upgrade for the next few years. Despite my non desire to upgrade now, I am pleased to see the form factor continuing, especially at such reasonable prices. When I do get to the point of upgrading, this new A6000 will be on the top of my list.
     
  5. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    I wouldn't say we are far from physical limits. Visible light is about 500 nm and present sensors are about 8 times that (24mm/6000 is about 4 um). The "hole" must be much larger than wavelength of photon for it to hit the bottom.

    For the dynamic range there is similar limit, one cannot have 12 bits of range if less than 4000 photons will register (assuming no thermal noise) for maximum exposure. I think that present sensors collect something like 50 000 electrons for maximum white (~2^16) and that demands at least 50 000 photons so there is a definite limit.

    I am not saying that significant improvements in sensor technology are not coming but we are not going to see similar improvement what we have seen (Canon EOS-1D had 4MP in APS-H sensor in 2001, A6000 24 MP in ASP-C in 2014 so pixel density has increased something like (6*1.2)^0.5=2.7 times, usable ISO something like 16 times or more).

    I think that the real problem is in lens manufacture so sensor limits are not even meaningful. To make a lens that has so well grind surfaces and geometries (taking into account color dispersions in optical materials) that we can take full advantage of present sensors will be really costly. I can't estimate how many photons will hit single sensor cell so there may be much more improvement in noise figures.

    I personally think that ASP-C is pretty fine now from sensor standpoint for me. A bit better high ISO would be nice.
     
  6. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    With current technology, the resolution limit is the diffraction limit, not the lens design. I'm pretty confident my 24mm Sonnar can resolve even more than the 24MP of my NEX-7, as it really doesn't have any problem with that sensor. As for diffraction - the higher the pixel density, the "sooner" (larger aperture) you'll reach the diffraction limit. So the optimum performance always will be where the smaller resolution number from diffraction limit and theoretical lens resolution will be the biggest.

    Not saying that there is no limit, but I'm sure it is NOT reached with the current 24MP resolution we get. Don't forget that 36MP is only 50% more resolution, i.e. the same difference than from 4MP to 6MP. It's not a big stretch to assume that it's no problem to build a 36MP APS-C sensor with current technology while still getting usable images - high quality lenses provided.

    And I am also pretty confident that there will be a technology to avoid the diffraction limit or to stretch it at least. I've already seen an experiment from an university where they got well above the currently valid diffraction limit by using a double sensor array with a small mirror system to spread different wavelengths of light to different sensors and using a special algorithm to calculate the final image with an immensely high resolution. Such a system is not yet viable in consumer electronics, but it proves that there are ways to go with sensor designs - just making them bigger is not a long term solution.

    Edit: Also, a very interesting read I recommend all the time when it comes to such discussions: Do sensors outresolve lenses by The Luminous Landscape. Short answer: It depends, but higher resolving sensors, while not necessarily an advantage every time, are never a disadvantage.
     
  7. Hawkman

    Hawkman TalkEmount Top Veteran

    943
    Sep 10, 2013
    Virginia, USA
    Steve
    Well, if the admin over at SAR is correct with his latest rumor, it looks like there will be no A7000 APS-C "true "successor" to the NEX-7 this year after all, contrary to some earlier rumors/speculation (in the comments) on that same site and elsewhere.

    http://www.sonyalpharumors.com/sr5-...-coming-in-2014-main-focus-on-fe-from-now-on/

    So it looks like the APS-C E-mount lineup for much of 2014 will be:
    A3000
    A5000
    NEX-5T
    A6000
     
  8. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    Is the NEX-5T still a "current" camera? I thought it has been replaced by the A5000. Whatever, I still think Sony will announce an A7000 at some point, SAR just says it's not this year.
     
  9. Hawkman

    Hawkman TalkEmount Top Veteran

    943
    Sep 10, 2013
    Virginia, USA
    Steve
    That's a good question re: the NEX-5T. Sony's US store site is so much of a mess that it is hard to figure out which cameras are current and which are not (can anyone tell me if the other Sony sites are any better?). I suspect that will all be sorted out by April when the A6000 actually starts shipping... or I hope it gets sorted out (Sony needs to get their marketing message nailed down).

    While it really seems that the A5000 replaces the NEX-3N - it was announced about a year after the 3N, it has basically the same ports, controls, and feature set as the 3N (and the A3000's sensor) - it does add some of the 5T's features like WiFi and NFC, and in its looks it's like a cross between the 3N and 5T. So I think the A5000 may ultimately be intended to replace both the 3N and the 5T in the Axxxx lineup, just as the A6000 seems to essentially replace both the NEX-6 and NEX-7, while leaning more toward the NEX-6. My guess would be the NEX-5T will stick around in the "current model" lineup through the summer at least. After that, who knows?
     
  10. Jefenator

    Jefenator TalkEmount Top Veteran

    876
    Nov 23, 2012
    Oregon, USA
    Jeff
    I didn't think of APS-C resolution as being max'd out at 24MP until I got my [24MP full frame] A7 and did a bunch of side-by-side comparisons with the [24MP APS-C] NEX-7. Every single time I found (and continue to find) that achieving critical pixel-level detail on the full-frame camera is so. Much. Easier.

    The NEX-7 can get pretty close, but only in certain parts of the frame and only with a very narrow range of settings and only with critical focus absolutely nailed. Even at infinity at f/5.6, critical focus is extremely touchy. And there's still a visible difference (at least at 100%). 36MP with APS-C would only make things more difficult.

    Advances in optics and diffraction reduction may help somewhat, but if someone really wants maximum detail at 24MP or above, in my opinion he/she would be much better served by a larger format. Especially now that digital full-frame is becoming ever more affordable.

    Every format represents some kind of compromise between practicality and IQ and I think APS-C will continue to make a ton of sense for many users. (Including me on occasions. I look forward to one day having a compact, inconspicuous APS-C rig with autofocus that truly kicks butt.)
     
  11. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    Yes, but the article is dated as pixel densities have grown:

    'Only for highly corrected lenses (with better performance at f/5.6 than f/8) do higher sensor resolutions make sense. For instance, you can put 60 million of pixels into a 35mm sensor, but only a diffraction-limited lens at f/5.6 would take advantage of it.'

    Now the A6000 is going to have 24 MP in APS-C and that corresponds to 48 MP in FF.

    I think that higher pixel density and very heavy (too heavy for cameras but maybe ok for PP [my not so fast graphics card has got 384 cores at 1 GHz]) algorithms it is possible to calculate the original image from the diffracted one. Diffraction basically causes every object point to form concentric circles in image. Now it may be possible to calculate the image that would cause the diffracted image.

    I think that they are able to increase pixel densities by factor of two or something (that needs something to defeat the well [the real sensing cells sit at bottom of a hole, microprisms etc. are used for that] problem).

    Does anybody know about photon densities (photons hitting sensor/area/time) in typical low light situations? That and thermal noise might give some clues how much sensor sensitivity can be increased
     
  12. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    Yep, in the case of the A6000 that's 48 MP that benefits of lenses that are diffraction limited at or before f/5.6. Basically what they are saying is that you can increase resolution as much as you want as long as your lens can resolve enough at the aperture where the diffraction limited resolution is smaller than the resolution the sensor has. In case of current E-Mount cameras with 24MP sensors, I'm pretty sure there is some room left with the absolutely top of the line lenses (the 24mm Sonnar and the Touits) that are available for the system.

    As for calculating an original image out of the diffraction limited ones - I'm not sure that's possible without introducing some kind of artifacts. But maybe someone is smart enough to figure an algorithm that can actually do that.

    It would be interesting to know how small pixels can be until the signal-to-noise ratio is too bad to achieve good files, especially in low light. Maybe someone can tell us. But still, I'm sure that 24MP is not a hard limit for APS-C sensors - why should it be? Increasing the resolution by a factor of 1,5 or 2 should be possible without too many problems in the near future.
     
  13. jai

    jai TalkEmount Top Veteran

    589
    Feb 4, 2013
    I am trying to tell myself that I need to just stick with APSC, where I have already invested in native lenses.

    I need to stick with APSC, were I have already invested in native lenses.

    I need to stick with APSC....
     
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  14. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    Just ask me - for every ff pro you tell me I can tell you why APS-C sensors are just as good in that category. ;)

    Also, you have some great photos on your Tumblr, and I don't think they'd be any better when shot on ff. If you need further reassurance, feel free to click on the 500px link in my signature, there are some difficult lightning situations which even my old NEX-5 handled great.
     
  15. jai

    jai TalkEmount Top Veteran

    589
    Feb 4, 2013
    Thanks!

    Yeah, I only just got my 5R 6 months ago and actually I really love it. It's a lost more portable than an A7, so actually if I had one I would probably wish for my 5R back.

    But its hard to deny FF envy ;)
     
  16. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    After buying the 50mm Touit (which I already pre-ordered) I spent almost €4000 on APS-C E-Mount lenses, so it's easy for me. ;)
     
  17. Bill

    Bill TalkEmount Veteran

    339
    Oct 22, 2012
    Brisbane, Australia
    Bill
    Can I suggest the Sony Zeiss 55mm (full frame FE). It works great on the NEX-6 and 7. It's not a macro, but it great for portraits. SLR Gear and DXO have each tested it on both the A7 and the NEX-7. It's in the same size range as the 24mm and balances nicely (for me) on the NEX-7.

    Bill

    The SLR Gear review is here:
    http://slrgear.com/reviews/showproduct.php/product/1656/cat/82/date/1381913431
     
    • Like Like x 2
  18. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    Thank you for your suggestion, Bill! I read quite a bit into this lens, and it seems great.

    However, I plan on using the 50mm for about 30% macro, 50% landscape and only 20% portrait & event. For both, landscape and - of course - macro work, the Touit should be better suited. For portraits, it's hard to tell without a direct comparison, but I honestly doubt the Touit will do any worse than the 55mm - Zeiss Makro-Planar lenses have an exceptional reputation for portraits. As for events - yep, the 55mm one would be better as it's two stops faster (and the focus ring is better knowing both my Touit 12mm and Sony Zeiss 24mm), but I don't shoot enough events to invest in that just yet.

    I actually prefer the design of the Sony Zeiss 55mm over the Touit, but I wanted to experiment with macro since I bought my NEX-5 almost four years ago, and now there finally is a high quality macro lens.
     
  19. dbmiller

    dbmiller TalkEmount Top Veteran

    778
    Mar 2, 2012
    New England
    I think APS-C and m4/3 people have been spoiled. We get to use all these fast legacy lenses, and don't have to worry as much about how narrow the Depth of Field is compared to Full Frame. So we get the faster shutter speed or lower ISO and can take great portraits with fewer worries about having only one eye in focus.

    Shooting with the A7 and A7R in the local camera store has reminded of this. FF can give you a look that is much harder, if not impossible to get on smaller sized sensors. People love that look. Getting it in a smaller package than DSLRs is just technology making progress in miniaturization.

    Have APS-C gotten as good as they are going to get? I don't think so. FF is making a great leap forward with the RX1 and now the A7/A7R. There's a lot of room for improvements there too.

    All of the different sized sensors have issues to solve. We're close to losing the AA filter for good. The A6000 appears to have proven that fast, on-sensor PDAF is possible. Foveon or Foveon-style sensors could soon bring a massive jump in resolution. IBIS would make lenses smaller once again, but we still have AF motors we're paying for that MF lenses don't incur.

    Sensors still don't perform like film. They have CA, smearing, and other issues to solve. Micro-lenses are a band-aid approach. Modern lenses are being designed so that the light hitting the sensors is at a better angle.

    So no, we're not done yet. Not by a long shot.
     
  20. Jefenator

    Jefenator TalkEmount Top Veteran

    876
    Nov 23, 2012
    Oregon, USA
    Jeff
    I'm in an entirely different boat - I've been sitting on a bunch of old [full frame] legacy lenses I'd been aching to try in their native format. And my investment in APS-C optics was relatively light and easily recoverable (or so I thought :confused:).

    If you've invested in a bunch of optics you really like and your IQ needs are being met, by all means, just shake off the GAS! :cool: