Site Sponsors
Page 2 of 2 FirstFirst 1 2
Results 51 to 58 of 58

Thread: 36mp Full Frame A99 SLT rumour

  1. #51
    Senior Subscriber Member
    Join Date
    Nov 2007
    Location
    San Francisco, CA
    Posts
    1,306
    Post Thanks / Like

    Re: 36mp Full Frame A99 SLT rumour

    Quote Originally Posted by edwardkaraa View Post
    All this talk about the AA filter, while there is actually a piece of plastic, called translucent mirror, in the optical path. That would be more detrimental to the IQ than the AA filter. Actually the mirror may be playing the role of an AA filter, partially at least.
    I don't see how a solid polycarbonate block is going to act like an AA filter. That's just not going to happen. As it ages it may yellow somewhat though. An AA filter is a deliberate construct made from a sandwich of (usually) quartz half wave plates. Each plate is a stop filter (with a peak at a particular frequency), and a series of plates in progression is needed to get a low-pass filter. A clear piece of optical plastic isn't going to act as one.

  2. #52
    Senior Subscriber Member
    Join Date
    Nov 2007
    Location
    San Francisco, CA
    Posts
    1,306
    Post Thanks / Like

    Re: 36mp Full Frame A99 SLT rumour

    Quote Originally Posted by mjm6 View Post
    I do agree that the a900 is a little less than it could be... If they used a very light AA filter, it would have produced a sharper image and better contrast overall. The 18MP M9 simply smokes it for pixel-level sharpness, using comparable lenses, etc. That wouldn't happen but for the AA filter, all things created equal.
    I think my a850 and the M9 are comparable in the sense that they output roughly the same amount of image. The M9 files are slightly easier to work with and more robust. Once I got LR3 set for the M9 I've found very few surprises, mainly due to I think the excellent optics. Post proc is mainly interpretive/expressive rather than clean-up. I've never had a dust spot with the a850; while my M9 right now is a bit dirty and in need of a cleaning (procrastination alert).

    So give or take, they have their strengths and weaknesses. Personally I prefer rangefinders, and i think Leica M glass is unsurpassed, but from a purely technical standpoint either camera is IMO a source of high-quality print work up to 16x24 or 22x36 in a pinch. Beyond that prints just get bigger with no additional detail, so an image with subject detail that requires a print 22x36 or bigger will suffer to some degree. Up to 22x36 there's no compromise to speak of.

  3. #53
    Senior Member edwardkaraa's Avatar
    Join Date
    Feb 2009
    Location
    Bangkok
    Posts
    1,470
    Post Thanks / Like

    Re: 36mp Full Frame A99 SLT rumour

    Quote Originally Posted by Jan Brittenson View Post
    I don't see how a solid polycarbonate block is going to act like an AA filter. That's just not going to happen. As it ages it may yellow somewhat though. An AA filter is a deliberate construct made from a sandwich of (usually) quartz half wave plates. Each plate is a stop filter (with a peak at a particular frequency), and a series of plates in progression is needed to get a low-pass filter. A clear piece of optical plastic isn't going to act as one.
    I didn't mean it as an exact scientific term, but rather that it softens the image and creates halos around high contrast subjects, so it does more damage to image quality than the AA filter. By the way, what do you mean by solid PC block? The mirror is very thin and flexible piece of plastic glued to a metallic frame.
    M262 ZM 25/2.8 35/1.4 50/2 85/2

  4. #54
    Senior Member mjm6's Avatar
    Join Date
    Jul 2009
    Location
    Sacramento, CA
    Posts
    526
    Post Thanks / Like
    Images
    15

    Re: 36mp Full Frame A99 SLT rumour

    Quote Originally Posted by edwardkaraa View Post
    ...so it does more damage to image quality than the AA filter.
    Edward,

    I doubt this is the case. If it were, it's likely that they would not put an AA filter on the sensor at all, and with coated glass (plastic, in this case), the losses and aberrations associated with the mirror are likely to be small. If the mirror functions like a piece of optical glass, then it will be no more significant than a filter placed on the back of the lens (between the last element and the sensor).

    I suspect that if it is a problem, you will be able to see a marked difference in performance from the top of the mirror to the bottom as a result of the difference in distance from the focal plane to the mirror material. Is this observable in samples from the SLT cameras available now?

    --Michael
    a7r, a7rII, FE 16-35, FE 24-70GM, FE 70-200, Loxia 21mm, 35mm, 50mm

  5. #55
    Senior Member
    Join Date
    Nov 2007
    Posts
    498
    Post Thanks / Like
    Images
    8

    Re: 36mp Full Frame A99 SLT rumour

    Quote Originally Posted by fotografz View Post
    BTW, does the A77 have one? That would also be a strong indicator.
    This is pure conjecture, but the images I have seen from the A77 at 100% view are not quite the equal of the A900, so I assume it does have an AA filter.

  6. #56
    Super Duper
    Senior Member
    jonoslack's Avatar
    Join Date
    Nov 2007
    Location
    East Anglia & Cornwall (UK)
    Posts
    11,778
    Post Thanks / Like
    Images
    1

    Re: 36mp Full Frame A99 SLT rumour

    I'm sure it does have an AA filter
    I doubt that the mirror has much of an effect on the iq (apart from the reduced light) - apart from anything else it's much further from the sensor than the AA filter - I can envisage it getting scratched, but I guess it could be replaced without too much problem.

    It will be very interesting to compare the image quality of the A77 with that from the NEX 7 - it seems to me that's the only real way to work out the implications of the SLT mirror.

    all the best

    Just this guy you know

  7. #57
    Senior Member edwardkaraa's Avatar
    Join Date
    Feb 2009
    Location
    Bangkok
    Posts
    1,470
    Post Thanks / Like

    Re: 36mp Full Frame A99 SLT rumour

    Here is an interesting link:

    http://thesybersite.com/sony/a55/ind..._image_quality

    I don't think the image degradation is spectacular but it's there.
    M262 ZM 25/2.8 35/1.4 50/2 85/2

  8. #58
    Member
    Join Date
    Oct 2011
    Posts
    23
    Post Thanks / Like

    Re: 36mp Full Frame A99 SLT rumour

    I wonder… if there has been people trying to create ghosting on the A77, which was a problem in the A55, unsuccessfully, wouldn't it be conceivable that there could be an improvement on the A99 (even on the A77)? Even more, considering that the A77 is shooting upmarket (and moreso the A99), wouldn't it be possible that by improving the materials used on the more upmarket cameras the image degradation could be reduced to a bare minimum, hence making this whole worry barely academic?

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •