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36mp Full Frame A99 SLT rumour

ptomsu

Workshop Member
Yikes a 36mp FF sensor?? OMG, Besides the 85mm and 135mm Sony Zeiss lenses, I'm not sure if any of the the other Sony lenses will do the camera any justice also to add precise focus and either very high shutter speed or a tripod.
I still struggle with my MF 33MP Leaf Back in regards to getting a sharp image, and thats using MLU, Tripod and release, yet when I get one, it's for sure with the extra effort .

Jono, so far it sounds like you are pleased with the A77, in comparison to your A900 at base ISO, I am thinking about getting one myself, since I am not a WA shooter or a high ISO shooter, the A77 maybe just the ticket.

Steven
Steven,

I almost never struggle with my H3D39 when it is set to the right mirror pre release. And I think you had the same camera, so did you have problems?

BTW, do you still shoot the Pentax 645D or completely switch to another MFDB?

Peter
 

jsparks

Member
One thing that should help the anti-shake of the A77 and A99 is the lack of a moving mirror. If it will or not, who knows (other than some Sony engineers), but I have read reports of people being able to hold the A55 at slower speeds than previous SLRs with moving mirrors.

I haven't even seen an A77, but the specs list AF micro adjust like the A900.
 
I seriously doubt that there will be that big of a difference in sheer resolution between the current 24 meg A900 and a 36 meg A99. How that additional data is handled is another story ... and frankly, is the core question yet to be answered.
I'm kind of in a wait and see pattern with gear right now. If they use the 36 mp as a reason to skip the AA filter, this could be quite a camera. If the A99 is the A77 with more pixels I may just pickup an A77 or another A900 as a backup. That said, I have been watching the rumors on the Nikon D800, and if it turns out to be a Sony A900 with 36 MP, I could be very interested.

My issue with the A900 that I have been very vocal about (but no one seems to agree with me) is that, while it is a great camera, it doesn't seem to do as much with its 24 MP as I would expect. 36 MP is getting to the point where files are starting to be BIG. It would have to be a big leap over the A900 for me to make the jump. The A900 is already at the point that I can tell which tripod I shot an image on based on sharpness.

I suppose what I am saying is that I am quite intrigued, but I'm not putting a deposit on one.
 

mjm6

Member
...while it is a great camera, it doesn't seem to do as much with its 24 MP as I would expect.

The A900 is already at the point that I can tell which tripod I shot an image on based on sharpness...
Don't these two comments seem to contradict each other?

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.

---Michael
 

kuau

Workshop Member
I think having an AA filter would be a deal breaker for me, yet I am sure sony will have one in place.
I can't imagine much of an increase in over all quality of a 36mp FF body with a AA filter over the current 24mp FF cameras with an AA filter. I don't care what lens you have attached.
As Michael pointed out an M9 having owned own, does simply smoke all the current 24mp FF cameras out there in terms of pixel level sharpness. To date I have yet to see a more sharp image coming off any dslr as sharp as an M9. Heck even all my expensive digital MF stuff sometimes can't match the M9...

I think my dream DSLR would be Lecia M9 with sony's new EVF with there peak focusing. I can dream

Oh well we wills see.
 

edwardkaraa

New member
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.
 
Don't these two comments seem to contradict each other?
No. You clearly know what I am saying as you readily admit the M9 does more with it's 18 than the Sony does with 24. As for the tripod, 24 MP is enough to show errors in technique -- whether focus or stability -- pretty clearly. Of course stability becomes moot at higher shutter speeds.

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.
Excellent question and I don't know enough about optics to answer intelligently.
 

fotografz

Well-known member
There is a very detailed and informative article in the most recent issue of LFI titled "Lens Verses Sensor" which explains the role each plays in resolution/sharpness, and how they work in concert with one another.

It also explains the effect of any interruptions in the optical path ... like what an AA filter actually does at the pixel level, which I didn't quite understand until reading this.

Of interest was the fact that Canon already has a 120 meg sensor that's slightly larger than the M8's sporting a pixel pitch of 2.2 nm (which is larger than those of a current P&S) ... and, get this, a 36 X 24 sensor resolving 200 meg is currently possible and would effectively eliminate the issue of morie' ... something not possible even if 35mm sensors went to 40 meg. This may answer the question as to whether Sony will eliminate the AA altogether even at 36 meg ... since Sony sells cameras to the average consumer, I doubt the A99 will not have an AA. BTW, does the A77 have one? That would also be a strong indicator.

Personally, I wish Sony would offer a camera like the A99 in an "advanced" version sans the AA and I'd be willing to take my chances with morie' ... something I already do with the M9 ... but I'm not holding my breath on that one.

Unfortunately, with a gain to the degree of 200 meg comes a massive loss of dynamic range and signal-to-noise ratio to an unusable level, which is explained in detail. This somewhat clarifies the balancing act between increased meg count and higher ISO performance ... or at least tempers expectations of a super cam of 36 meg with the high ISO performance of a camera with 1/3 or even 1/2 the meg count.

-Marc
 

Jan Brittenson

Senior Subscriber Member
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.
 

Jan Brittenson

Senior Subscriber Member
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.
 

edwardkaraa

New member
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.
 

mjm6

Member
...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
 

jonoslack

Active member
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
 

llumiombres

New member
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?
 
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