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09-25-2012, 09:59 PM   #16
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It doesn't make sense that SR is the reason Pentax hasn't come out with a larger-sensored camera. They could put a sensor in there that is notably larger than their current sensors, but smaller than the 135 frame to accommodate SR; this would be equivalent of (or larger than) Canon's "APS-H" sensors. Yes, there are economies of scale that come into play, but we simply don't know enough about sensor pricing to comment on this issue.

Would they be afraid of launching a sub-135-frame camera for fear that it isn't truly 135-frame? No, because Canon and Leica have gotten away with that successfully. Their customers may have grumbled, but Pentax should have gotten used to that by now; regardless, customers put their money on the counter and walked away with product.

Would Ricoh be afraid of launching a 135-frame camera, with SR, for fear that their legacy lenses won't be fully backwards compatible? No, because they could limit compatibility in software (automatically, even) and protect the value of the lenses they release alongside their new camera, much like other brands offer both IS and non-IS lenses for cameras that have no sensor SR.

Would they be afraid of launching a 135-frame camera because they can't afford to support systems with 645, 135, APS-C, and 1/2.3" sensors? Quite plausibly.

Does Ricoh have deep enough pockets to fund four interchangeable-lens camera systems, each (theoretically) with different levels of bodies? Yes. Does that make business sense? Only they can answer that.

It seems to me that the Pentax camera lineup which makes the most sense looks like this:
  • high-end 645 body ($10k+)
  • low-end 645 body ($4k)
  • high end APS-C body ($2k)
  • moderate APS-C body ($1k)
  • low end APS-C body ($600)
  • high end Q body ($600)
  • low end Q body ($300)

While I would personally be keenly interested in--and willing to part with a significant amount of money for--a 135-frame Pentax DSLR, from a market strategy point of view, Pentax should invest in the existing 645 system before it invests in a new system. If they release both a 135-frame system and a low-end 645 system (that has fast operation and shooting, but slow frame rates, AF, and processing), even if the 645 body costs twice as much, I'd probably want to save my shekels for the 645... and I bet I wouldn't be alone. Would I be willing to use an electronic viewfinder to make that 645 camera more compact and compatible with my current DA and FA lenses? You bet.

Someday soon--we're already seeing a bit of this, note the price overlap in my suggested Q and APS-C systems--the size of the sensor won't matter so much in terms of cost but in terms of system size and weight. I'm looking forward to a GXR-style system that can accommodate everything from a 1/2.3" superzoom to a 645 heavyweight. Now, that would be a perfect combination of halo effect and system buy-in. Of course, the design of that would take a genius. (Multiple grips along with multiple screens/finders, all compatible with multiple lensors and lens mounts. From slim, simple, and lightweight to robust, sealed, and configurable. All at a cost comparable to, if slightly higher than, all-in-ones.) Genius, I say, and the risky investment in R&D to see if it can be done.

And, of course, this post is as much uninformed ranting as most other future-looking posts here. Maybe my only good idea here is to offer both K-mount and Q-mount for the GXR system.

09-25-2012, 10:04 PM   #17
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QuoteOriginally posted by vonBaloney Quote
I'm too lazy to go look this up, but are all of the other full-frame sensors out there the same exact size, or do they vary like "APS-C" sensors which is really just a ballpark? If Pentax used a "90% size" FF sensor, could they get away with IBIS and still have compatibility with all those FF lenses out there? (DAs are another story.)
There is some very small variation. I went ahead and looked up a few examples. The D4 and D3s are 36mm by 23.9mm while the D800, D600 and D3x are 35.9mm by 24mm. The Canon 6D is 35.8mm by 23.9mm and the 5D MkIII just says approximately 36mm by 24mm. I'm pretty sure that most lenses' image circles extend slightly past 36x24 anyway and I imagine the movement of the SR mechanism is no more than a few pixels width in distance. I base this assumption of the small distance that the SR mechanism travels on my interpretation of this article here. I'd gladly defer to someone who has more knowledge than I do though.

I wouldn't be surprised if there are some hurdles to overcome with implementing SR on a FF camera but I don't think that the image circle of lenses is one of them. Whatever the case I really do hope that Pentax will include SR on any future FF camera they release because I would really like to take advantage of it and believe it would be a big selling point for photographers who shoot a lot with a normal zoom or any wide-angle to medium telephoto prime lens since they are the ones who don't benefit from the VR and IS included on the telephoto lenses.

I'd be curios to hear how Sony users have liked, and been able to do more, using their fast primes on a FF body with IBIS. Though the SLT design does counteract some of the light gathering benefit of IBIS.
09-25-2012, 10:11 PM   #18
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You can probably judge the amount the SR is able to move with the "composition adjust" feature in liveview on newer models where you can put the camera on a tripod and move the sensor around to your liking to make small lateral adjustments -- it is more than a few pixels, but it is not a huge amount either.
09-25-2012, 10:14 PM   #19
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Many years ago, there was mention that Pentax had a patent for in body image stabilisation of a 35mm full frame camera.

It was mentioned back then that this technology would have been incorporated into the successor of the Pentax MZ-S, but the advent of digital killed further 35mm full frame development.

So they obviously thought it was possible back then, it should be even more possible now with everything that they have learned from the first implmentation in the K10D.

ogl or voff may be able to shed some additional light on this.

Regards

Chris Stone

09-25-2012, 10:30 PM   #20
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QuoteOriginally posted by JonPB Quote
high end APS-C body ($2k)
Is there a single photographer using any system that would ever consider any APS-C body at $2k?! I take that back, I'm sure a Leica user would consider it a bargain and I guess a few Sigma SD1 shooters have spent that much. The only things I can think of that could possibly make an APS-C camera command that price are if it had the best AF with tracking and fastest FPS that beat other cameras by a significant margin. I don't foresee Pentax being able to offer either of those, best AF or fastest FPS. Now if Pentax were to offer a FF camera with little more than what the K-5II has feature-wise for roughly $1k more, putting it either at or slightly above the new Canikon "budget" FFs, and I can imagine that being a real hit like the first K-5 was, though it should also have what the K-30 has (focus peaking and better video) along with more AF points to be even more of a serious contender.
09-25-2012, 10:33 PM   #21
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QuoteOriginally posted by vonBaloney Quote
You can probably judge the amount the SR is able to move with the "composition adjust" feature in liveview on newer models where you can put the camera on a tripod and move the sensor around to your liking to make small lateral adjustments -- it is more than a few pixels, but it is not a huge amount either.
You could be on to something with that.
09-25-2012, 11:58 PM   #22
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QuoteOriginally posted by Winder Quote
As a full format lens the 31mm f/1.8 enjoys a sweet spot advantage on Pentax APS-C DSLRs. Nonetheless vignetting can be quite obvious at wide-open aperture (1EV). The problem is gone by f/2.8.
Canon and Nikon lenses in this FL (well, 35mm) don't fare much, if any, better.


Canon 35mm f/1.4 L on APS-C
QuoteQuote:
On an APS-C DSLR the EF 35mm f/1.4 USM L enjoys a sweet spot effect here. However, this doesn't seem to be enough to produce low vignetting at max. aperture. Admittedly f/1.4 is a rather extreme setting specifically for a wide-angle lens so vignetting is quite high at ~1EV here. At f/2 the problem is already reduced to a very acceptable degree and from f/2.8 the issue is negligible.

Canon 35mm f/1.4 L on FF
QuoteQuote:
Vignetting at large apertures is a weak spot on full format cameras and the EF 35mm f/1.4 USM L has its problems here as well. At f/1.4 it shows a 2.4EV light fall-off in the corners. This isn't quite as extreme as on the EF 24mm f/1.4 USM L II but it's still not impressive. The amount of edge shading is still hefty at f/2 so it's generally a good idea to stop down to f/2.8 if this is a problem for your application. The aspect is not really field relevant anymore from f/4 onwards.

Canon 35mm f/2 on APS-C
QuoteQuote:
Despite being tested on an APS-C DSLR the EF 35mm f/2 exhibited a fairly pronounced degree of vignetting (1.1EV) at its largest aperture setting. However, from about f/2.8 the issue is reduced to a quite negligible degree.

Canon 35mm f/2 on FF
QuoteQuote:
Vignetting is a major weakness of this lens - an edge deterioration of more than 2.2EV @ f/2 is massive and easily visible in most situations. The problem is reduced at f/2.8 but still not negligible. Vignetting is well controlled from about f/4 onwards but this is rather "late".

Nikon 35mm f/2 on APS-C
QuoteQuote:
Being a FX lens, the Nikkor profits from the sweet spot advantage on DX cameras, but nonetheless shows visible light fall-off towards the corners wide open. Stopping down reduces vignetting to a negligible level, though.
This lens showed vignetting of .63 EV at f/2, which is the best of the 35mm bunch.


Nikon 35mm f/2 on FF
QuoteQuote:
Typical for most fast primes the lens shows visible vignetting, reaching almost 1.5 EV wide open. There's a moderate level of vignetting left at f/2.8 which is reduced further to a negligible degree stopped down to f/4.0 and beyond.

Nikon 35mm f/1.4 on FF
QuoteQuote:
Fast lenses tend to suffer from high vignetting on full frame cameras and the AF-S 35/1.4 is no exception to this rule. In fact, with almost 2.2 EV wide open the amount of vignetting is exceptional (in a negative sense) and higher than on any other lens we've measured so far on the D3x. Such a huge amount of corner darkening is of course clearly visible in the final image. Stopping down helps to reduce vignetting, but even at f/2 the amount of light falloff remains rather high. From f/2.8 onwards vignetting is no longer field-relevant, except for really critical scenes.

All quotes taken from Photozone tests. The 28mm lenses did about the same though with a few coming below 1EV vignetting on APS-C but most coming in close to or above 2EV on FF. There aren't any tests available for Sony in this FL on PhotoZone and there are no lens tests at all for Leica on the site.

Take the minimal distortion and CA along with the excellent sharpness of the FA31, and of course its otherworldly bokeh, and you have a lens that can go up against any other lens in its approximate focal length. I have no reason to not expect this will remain the case on FF. All of these lens issues can be corrected to an extent in post processing anyway, and pulling back one or two EVs in the corners with these new Sony sensors isn't much of a big deal. I actually like a little, or even a lot of, vignette usually. All in all, the FA31 is a marvelous lens that can contend with the best there are. I'm not even sure it will really need an update with the eventual emergence of a Pentax FF, but that new HD coating might hold some promise for it, and I doubt anyone would complain if it were to get quick-shift focusing. There's really not much that could be done to improve on the optics of this lens.
09-26-2012, 07:56 AM   #23
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All good points.

I want to see how the new Sigma 35mm F/1.4 does on a FF mount. The rear element is huge and it appears to be a telecentric lens design which should eliminate those problems.

We see the same huge rear element on the Fuji X100 and the Sony RX1. I doubt we see any real vignetting on the RX1.

09-26-2012, 08:19 AM   #24
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I want APS-H anyway!

I read that to and it just makes more sence to my desired APS_H camera. Large 4:3 or 30x20mm traditional form. I'm in for it!



QuoteOriginally posted by Winder Quote
They are all 36x24mm.

APS-H (70%) was Canon's answer to exactly what you are suggesting, but without IBIS. Canon went to 70% APS-H for 2 reasons.

1. APS-H gave them the best performance (largest sensor) with their existing glass line-up.
2. APS-H was the largest sensor size that could be produced in a single mask at that time. FF required 3 separate masks. Now FF is produced in a single mask and that has reduced the cost significantly.

Canon has redesigned all of its film era glass to be digital friendly and handle high resolution FF sensors. The 31mm LTD already loses 1.09 stops to vignetting when used wide open on APS-C imagine how much it vignettes on a FF sensor wide open? I don't think there is much room to spare.

Vignetting

As a full format lens the 31mm f/1.8 enjoys a sweet spot advantage on Pentax APS-C DSLRs. Nonetheless vignetting can be quite obvious at wide-open aperture (1EV). The problem is gone by f/2.8.
09-26-2012, 09:26 AM - 1 Like   #25
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QuoteOriginally posted by RonHendriks1966 Quote
I read that to and it just makes more sence to my desired APS_H camera. Large 4:3 or 30x20mm traditional form. I'm in for it!

I would definitely be interested. I prefer 4:3 as it makes better use of the image circle and there is nothing magical about 24x36mm. I want a sensor with as much surface area as possible, but I don't want bigger that what my glass can handle as far as IQ, CA, & vignetting. Of course my wish list would have a monochrome sensor with no AA or color filter.

I guess I am one of the few people who focus and recompose in the VF. People keep saying that edge quality is not as important, and for people who shot everything dead center and crop for composition in post that is true. I compose in the VF and moving a subject off center and with a lens like a 30mm Sigma F/1.4 that often puts them in a soft area of the lens. For people who use outer AF point it means that you will have trouble getting sharp images in the outer areas.

I really do worry about how well the FA lenses will work on a FF sensor. The images I have been able to find (31mm LTD) are on a Canon 5DII and he only posts the ones stopped down to F/5.6 - F/11. I sent the guy a message requesting wide open shots, but he has not responded.
09-26-2012, 10:05 AM   #26
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Either they make the SR plate smaller to fit it into the K-5 size body, or, return it to the K10/K20 size altogether (the latter is improbable) Or, they can also use in-lens IS for FF lenses..

though I'd still contest that SR is one of Pentax's big points, they won't leave it out.
09-26-2012, 09:19 PM   #27
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Video of Sony A900 SR in action. See how much it moves? I would say 3-4mm, but maybe my sense of scale is off. It requires a good bit of movement.
09-26-2012, 11:32 PM   #28
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I don't think it require that much movement. I did a not too scientific test on my K10D some years ago, and 4 stops shake reduction had to take care of 40-50 pixels movement. (~0.50mm).

The sensor has to be able to move more than it can compensate for, as it has to accelerate and deaccelerste between shots. So the total amount of movement might have to be a few mm.
09-27-2012, 09:48 AM   #29
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QuoteOriginally posted by Fogel70 Quote
I don't think it require that much movement. I did a not too scientific test on my K10D some years ago, and 4 stops shake reduction had to take care of 40-50 pixels movement. (~0.50mm).

The sensor has to be able to move more than it can compensate for, as it has to accelerate and deaccelerste between shots. So the total amount of movement might have to be a few mm.
But the Sony FF does not even get 4 stops of SR. When I tried the A900 I thought it gave me maybe 2 stops. Maybe the A99 is better and can get 4 stops, but right now it's not 4 stops.
09-27-2012, 02:35 PM   #30
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QuoteOriginally posted by Winder Quote
But the Sony FF does not even get 4 stops of SR. When I tried the A900 I thought it gave me maybe 2 stops. Maybe the A99 is better and can get 4 stops, but right now it's not 4 stops.
Maybe so, but there's much more to effective SR than gross movement distance.

The difference might simply be faster processors, better algorithms, and more sensitive MEMS sensors than were available in the A900 era.

I, for one, would lose interest in a Pentax FF that required lens-based stabilization. IBIS is one of the primary reasons I bought into the system in the first place.
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