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08-03-2011, 04:50 AM   #151
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QuoteOriginally posted by froeschle Quote
On the other hand, a K-x/-r is not that much more expensive (about $500).
No, but the adapter would much better keep its value ...

A true SLR would still win because of its optical VF.

But the rumored K-mount mirrorless (back to the thread's topic) will have to be measured against the LA-EA2. Anything less from Pentax now will be a disappointment.

08-03-2011, 05:53 AM   #152
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QuoteOriginally posted by tsammyc Quote
Agreed. The question is whether one uses the EVIL as a primary or secondary body. For me, its a secondary body to my K5 for obtaining the same IQ without advertising myself as a DSLR shooter.

The BIG question to me is how good Pentax's EVIL specific lenses are. If they are Sony's disasterous E-mount image quality then I will never use them. I presume Pentax will have a K-mount adapter that allows auto focussing. Sony has one for E to A-mount, but autofocus is unacceptably slow so its almost useless. So another BIG question is the autofocus performance of Pentax's EVIL to K-mount adapter.
These kind of fully-functioning adapters also exist in the M43 world:

Panasonic DMW-MA1 Mount Adapter to Mount Four Thirds DMW-MA1 B&H

Word on the street is that AF is dog slow for lenses not optimized for CDAF. Sony appears to be including a PDAF sensor in it's adapter (via a pellicle mirror), which to me suggests that they faced a similar challenge.

Pentax no doubt will face a similar hurdle, as well as providing SDM and screwdrive support. Sound like this is a nontrivial challenge.

Question for the group - what makes a lens CDAF-friendly?
08-03-2011, 06:22 AM   #153
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QuoteOriginally posted by falconeye Quote
A true SLR would still win because of its optical VF.

But the rumored K-mount mirrorless (back to the thread's topic) will have to be measured against the LA-EA2. Anything less from Pentax now will be a disappointment.
I'm not so sure that an OVF such as the pentamirror in a K-r will actually be preferred over that new 3million dot OLED EVF Sony is about to release. I can see someone making the case for a high magnification glass prism finder; but I've still yet to use a pentamirror I've liked.

Sony's new PDAF adapter is exactly what I think Pentax should do as well. Now that Ricoh owns Pentax it seems like the most logical thing would be to just work with the GXR System. I'd like to see a new Ricoh GXR body with built in EVF similar to the NEX-7, then just make a K-Mount PDAF translucent mirror module for it.
08-03-2011, 06:15 PM   #154
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QuoteOriginally posted by johnmflores Quote
Word on the street is that AF is dog slow for lenses not optimized for CDAF. Sony appears to be including a PDAF sensor in it's adapter (via a pellicle mirror), which to me suggests that they faced a similar challenge.

Pentax no doubt will face a similar hurdle, as well as providing SDM and screwdrive support. Sound like this is a nontrivial challenge.
I've been using Sony's peaking focus function on the NEX-C3 with a variety of K-mount Pentax, Sigma and Tamron lenses and can achieve sharp manual focus very quickly by obtaining a halo around objects. This technology is no doubt based on CD and seems to work well with every one of the eight K-mount lenses I have. I'm mystified why this process cannot be automated to produce acceptably fast CDAF and the need for PDAF in an adapter.

If one observes the sharp improvement in CDAF speeds (to acceptable) in the overall EVIL world, especially from Olympus and Panasonic (EP3 & G3), one presumes that technology exists for Pentax to produce a high performance adapter that uses CDAF. There is strong evidence that Pentax already have the technology in the significant live view CDAF improvement in the K5 over the K7/KX. I'd be happy if Pentax's EVIL K-mount adapter was able to CDAF at K5 speeds.

08-03-2011, 06:22 PM   #155
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QuoteOriginally posted by Art Vandelay II Quote
Sony's new PDAF adapter is exactly what I think Pentax should do as well. Now that Ricoh owns Pentax it seems like the most logical thing would be to just work with the GXR System. I'd like to see a new Ricoh GXR body with built in EVF similar to the NEX-7, then just make a K-Mount PDAF translucent mirror module for it.
What a brilliant idea! So Pentax-Ricoh actually already have an EVIL camera. They just need to make a new GXR module that focuses fast with K-mount lenses. I would think with the improvement in CDAF speeds in the latest Olympus/Panny cameras, they may not even need to acquire esoteric technology like translucent mirror PDAF. Perhaps Pentax can transfer the K5's quick liveview CDAF technology to enable Ricoh to produce this GXR module.
08-03-2011, 06:37 PM   #156
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QuoteOriginally posted by Art Vandelay II Quote
I think your contact is out of the loop:
I'd say he was laughing at me for a different reason than I thought.
08-03-2011, 07:51 PM   #157
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K-mount version of this

08-03-2011, 08:22 PM   #158
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man i like the looks of that Nex-7. That's where i want a viewfnder on a camera too, used to it being in that corner somewhere.

One thing i never understood, is why every camera maker just have an in-focus indicator that lights up in the viewfinder or the LCD, when one is manually focussing a lens. The focus peaking in Sony cams is an improvement.

What i'd really want is tactile feedback, like if the lens focus ring were to give increasing amounts towards, and a tiny peak of, resistance at the point where the camera AF sensor sees focus. That'd make me happy to spin away at that ring.

08-04-2011, 12:35 AM   #159
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My youngest daughter has borrowed my K10D on some occasions, and has discovered that she's grown out of P&S. But she has also tried her brother's E-PL1, and she has nothing against LV composing, and would like something less bulky than even a K-r. So now she's asking me when a Pentax mirrorless is coming (with already several Pentax lenses in the family, she's hoping for something compatible)...
08-04-2011, 07:59 PM   #160
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QuoteOriginally posted by tsammyc Quote
I
If one observes the sharp improvement in CDAF speeds (to acceptable) in the overall EVIL world, especially from Olympus and Panasonic (EP3 & G3)
actually that will be GH2... the rest are just using its 120 readouts/sec technology (w/ EP3 still being a looser in a low light)
08-18-2011, 11:37 AM   #161
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There actually is a company making such a camera since 1954 - digital since 2006 or so. No mirror. And they have a lot of trouble covering full 35 mm format with symmetric - read: close to the sensor - lens designs. Nice wish, but does anyone remember the introuction of the 4/3 system. Olympus wrote many articles why the lenses had to be longer than actually required for a film based camera. m4/3 did not syet olve this problem. APS-C size camera will be much more difficult to make. I already hear people complaining about the price tag on the horizon.
The APS-C lenses for the K5 already take advantage of an "effectively shorter" between rear lens element and the movng mirror.
I hope to see such a camera - but I don't think they can just make one. The K5 is essentially the size of the M9, how small do you want to make the camera? The K5 is already quite small for most hands... using K-mount lenses on a smaller camera wouild not just llok stupid, but make no sense at all. The advantage of a smaller camera is a new series of smaller lenses - a completely new system!
There is a nice article on the web regarding mirrorless cameras as if cameras would need a mirror. We are just so accustomed to SLR cameras that we forgot all about the basics of cameras design and the troubles involved in SLR desgins.
08-18-2011, 02:22 PM   #162
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QuoteOriginally posted by zapp Quote
There actually is a company making such a camera since 1954 - digital since 2006 or so. No mirror. And they have a lot of trouble covering full 35 mm format with symmetric - read: close to the sensor - lens designs.
you wouldn't be referring to leica by any chance would you? this is a specific issue with their camera to the extent that they have had kodak make the sensor with offset micro lenses to help out. There was also a thread somewhere that some makers, I believe it was canikon, were having ISO modified as a function of sensor location , to offset the issue with vignetting
QuoteQuote:
Nice wish, but does anyone remember the introuction of the 4/3 system. Olympus wrote many articles why the lenses had to be longer than actually required for a film based camera. m4/3 did not syet olve this problem. APS-C size camera will be much more difficult to make. I already hear people complaining about the price tag on the horizon.
The APS-C lenses for the K5 already take advantage of an "effectively shorter" between rear lens element and the movng mirror.
can you run this one past me, the K moutn to sensor is constant 46.46mm the mirror may be smaller due to the coverage area being smaller, but there isno reduction in distance to the mirror, otherwise some lenses wouldhit the mrror
QuoteQuote:
I hope to see such a camera - but I don't think they can just make one. The K5 is essentially the size of the M9, how small do you want to make the camera? The K5 is already quite small for most hands... using K-mount lenses on a smaller camera wouild not just llok stupid, but make no sense at all. The advantage of a smaller camera is a new series of smaller lenses - a completely new system!
There is a nice article on the web regarding mirrorless cameras as if cameras would need a mirror. We are just so accustomed to SLR cameras that we forgot all about the basics of cameras design and the troubles involved in SLR desgins.
just as an aside, the bottom line is that any K mount camera will be 46.46mm plus the thickness of the sensor and viewing screen as an absolute minimum, regardless of what else is done, because the regestry distance is part of the K mount definition.

Perhaps, however, a mirrorless camera can have a shorter register distance, and a simple hollow tube to connect the K mounts to reduce the thickness every where exccept the lens area.

maybe, without the mirror there is enough room to put the aperture coupling back
08-19-2011, 09:14 AM   #163
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QuoteOriginally posted by Lowell Goudge Quote
you wouldn't be referring to leica by any chance would you? this is a specific issue with their camera to the extent that they have had kodak make the sensor with offset micro lenses to help out. There was also a thread somewhere that some makers, I believe it was canikon, were having ISO modified as a function of sensor location , to offset the issue with vignetting can you run this one past me, the K moutn to sensor is constant 46.46mm the mirror may be smaller due to the coverage area being smaller, but there isno reduction in distance to the mirror, otherwise some lenses wouldhit the mrror

just as an aside, the bottom line is that any K mount camera will be 46.46mm plus the thickness of the sensor and viewing screen as an absolute minimum, regardless of what else is done, because the regestry distance is part of the K mount definition.

Perhaps, however, a mirrorless camera can have a shorter register distance, and a simple hollow tube to connect the K mounts to reduce the thickness every where exccept the lens area.

maybe, without the mirror there is enough room to put the aperture coupling back
Leica is redesigning (bigger) lenses and use sofware to compensate for the vigneting. So this is not purely a sensor and microlens design issue.

The iso offset is not about vigneting but about the difference F stops and T stops. It comes from the fact that the more complex a design become, with more glass absorbing light. The more glass there is, the less light is coming through.

You can easily lose half a stop of light at the same aperture between say a Tessar and a more complex design (like a 24-70 2.8).
08-21-2011, 03:32 AM   #164
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50MP with noiseless ISO50,000 and post-shot selective DOF by 2020. In a compact.

It's interesting to hypothesise about the immediate future, but 2020 isn't far off, and by then it will seem like we were discussing which breed of horse is better with what type of wagon over what terrain and distance.

'Scuse me, off to photograph the sunset!
08-21-2011, 07:06 AM   #165
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QuoteOriginally posted by Unsinkable II Quote
50MP with noiseless ISO50,000 and post-shot selective DOF by 2020. In a compact.

It's interesting to hypothesise about the immediate future, but 2020 isn't far off...
Whenever I read comments like this, I have to respond ...

A digital revolution is nice. But it won't beat the laws of physics. At least, there are no signs whatsoever this will happen any time soon

Read about quantum efficiency and photon shot noise. And you'll see that current dSLRs are deceivingly close to the physically possible. Another stop in quantum efficiency, another stop now lost in color filters and maybe another stop in black noise. And that it is. Only exception is dynamic range which can be made arbitrarily large by adding a digital frame buffer into the sensor. Needing more? Use bigger lenses. Better images need more photons. As simple as this. Really. Look at owls

Of course, you can play with stacking images in camera, aligning and removing movable parts etc. All possible in the digital domain. Already possible now in post processing and I use it. I know the limitations. It helps in some cases (mostly where a tripod would do too) but won't help in others (like in action photography). So, in general, by 2020, things won't be much different from now.

And "post-shot selective DOF" (read Lytro) is another take at raping off venture capital firms. Lytro's Ng can't beat Heisenberg's uncertainty relation (not even a Stanford degree can help here ). So, read optics textbooks and understand why a plenoptics light field camera only produces low resolution (sub MP) images. German Raytrix does a bit better (actually now owning all the patents) but use a kind of prefocus, a suitable compromise between fully refocussable and fuly prefocussed. This achieves resolution suitable for movies but not still images.

Last edited by falconeye; 08-21-2011 at 07:18 AM.
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