1. Reminder: Please use our affiliate links for holiday shopping!

A7s image quality comparable to medium format.

Discussion in 'Sony Alpha E-Mount News and Rumors' started by WestOkid, Jun 17, 2014.

  1. WestOkid

    WestOkid TalkEmount All-Pro

    Jan 25, 2014
    New Jersey, USA
    Gary
  2. WoodWorks

    WoodWorks Super Moderator

    Dec 12, 2012
    Ashland, OR, USA
    David
    Well, Michael Reichman is not someone prone to hyperbole so I tend to take him at his word.
     
  3. WestOkid

    WestOkid TalkEmount All-Pro

    Jan 25, 2014
    New Jersey, USA
    Gary
    It would be great if the A7s quality is really that high and customers bought into it. Maybe other camera makers would focus on image quality vs increased megapixels.

    That said,DXO just released thier findings saying it falls short of A7 andf A7r in image quality. This is a situation where the eyes are in conflict with the DXO's measurables. People say that's the case with Canon and DXO.
    http://petapixel.com/2014/06/17/sonys-a7s-usurps-nikons-dx-become-dxo-marks-new-low-light-king/
     
  4. Bill

    Bill TalkEmount Veteran

    339
    Oct 22, 2012
    Brisbane, Australia
    Bill
    • Like Like x 3
  5. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    Great he denied that. Because those statements don't make sense at all. Remember when everybody said the NEX-7 has IQ close to full-frame? That simply doesn't make sense. Under which criteria? Using what technology? Which lenses? Which cameras? Of course you can get quality as good or better than full frame on APS-C, but the circumstances need to allow it.

    Oh, and by the way, the DxO rating behind the link show that increasing the resolution (up to a certain point) does not have any disadvantages besides a slight high-ISO hit.
     
  6. Bill

    Bill TalkEmount Veteran

    339
    Oct 22, 2012
    Brisbane, Australia
    Bill
    When the NEX-7 was rated in 2011 (if we ignore medium format cameras and backs) there were only three cameras that had higher DXO sensor scores: The Nikon D3X with 87, the Nikon D3S with 82, and the Pentax K5 with 82. Pretty impressive stuff.
     
  7. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    It is very hard to compare so different technologies. With film the image is made from small silver crystals left from silver halides after photon hit and development (developer is reducing agent that reduces silver halide back to silver and fixer solves remaining silver halides away). Therefore film has huge "resolution" but is bi-tonal and tonality is created with dithering. I think that there are something like 200M silver halide crystals in FF film and similar medium format film (6 cm*6 cm) would have about 800M. If you need bi-tonal images (for example for etching masks) you can't match film with sensors. For tonal images the situation is completely different, dithering isn't as effective as digital sensor measuring actual photon count.

    I don't know how many grains is needed for 10-bit tonality but it is definitely much more than 1000. Even with 1000 the "resolution" of FF film would be only 20MP.

    For me Nex-7 is far superior to FF film as I tend to use high ISO quite lot and at ISO 1600 Nex-7 makes still very nice looking photos.

    Tomorrow is nice night to test Nex-7 low light performance. It is midsummer (aka evacuate Helsinki in 3 hours weekend) and I will spend the night outside with friends if weather permits.
     
  8. Bill

    Bill TalkEmount Veteran

    339
    Oct 22, 2012
    Brisbane, Australia
    Bill
    Since Michael Reichmann's name has come up as well as the question of medium format. I thought I would add this from a blog post of mine from last December:

    Yesterday I was watching a Luminous Landscape Video Journal (#9, from late 2003–ten years ago). In one of the segments, Michael Reichmann talks about when he determined that his $7k, 11mp, Canon 1DS was delivering better images than 120 film in every regard. (Not just 35mm film, but medium format film.)

    What struck me was that every NEX camera, and even the RX100, has a better DXO sensor score than that early 1DS.​

    If we're talking about medium format film, APS-C has it beat.
     
  9. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    I think that too (with native lenses). I don't have any calculations etc. but I think that images from Nex 7 are better than MF, at least with cheap lenses. I have a friend who is pretty good with mathematics (doctoral thesis in mathematical physics) and I have to discuss with him some day about film versus sensor from theoretical point of view.

    Most MF lenses didn't have great resolution but I don't even know typical resolution figures. Image area is 8 times that of APS-C but for example Sigma 60mm total resolution is very good:

    http://www.photozone.de/sony_nex/841-sigma60f28nex?start=1

    Comparing it to a well known good FF lens:
    http://www.photozone.de/canon_eos_ff/535-zeiss50f2eosff?start=1

    This is bit comparing apples to oranges, I know.

    I think that Sigma did pretty intelligent choice by designing these lenses only for aperture 2.8, cheap and pretty good image quality.

    I might get FF some point in future, especially 7s interests me. Not for resolution but for great high iso performance.
     
  10. Poki

    Poki TalkEmount Hall of Famer

    Aug 30, 2011
    Austria
    I will just wait. The 7s has not even a two stop advantage over my NEX-7. How long can it take until APS-C cameras are two stops better than my camera which launched two-and-a-half years back? Yeah, only a few years. ;)
     
  11. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    Yes. Same here. If ASP-C cameras will have significantly better high ISO performance then newer and I will put my money into native optics.