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06-09-2016, 03:02 AM   #151
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QuoteOriginally posted by Simen1 Quote
Technically and hypothetically its possible to have CDAF detection on the same chip as the PDAF chip, but in practice I don't think that is done by any company yet.
AFAIK the first SLR autofocus systems were using CDAF instead of PDAF. PDAF just works better.

06-09-2016, 03:23 AM   #152
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We were asking for faster AF and probably this is the answer. The only thing is, though it's a k-mount, it's not usable in older models which would still make it incompatible. I hope they'll provide an adapter or something for older cameras. It's fun to have cameras that can use both old and new lenses. I've always thought I could grow into a system without having to give up a camera because lenses won't work and they become obsolete. Though I have a k-3II, I still love the results of my k-5II.

Oh, just a question. Old lenses uses the mechanical aperture level. Will old lenses be usable with the k-70?

Last edited by totsmuyco; 06-09-2016 at 03:24 AM. Reason: added to the message
06-09-2016, 03:27 AM   #153
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You can't have the cake and eat it, too
Yes, the K-70 supports the old lenses. Actually the kit is with the 18-135.
06-09-2016, 03:27 AM   #154
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QuoteOriginally posted by Kunzite Quote
AFAIK the first SLR autofocus systems were using CDAF instead of PDAF. PDAF just works better.
Actually, the very first were using an electronic rangefinder including a CCD for triangulation purpose and not for TTL contrast detection. TTL contrast detection came only second, from mid-80s onwards.

06-09-2016, 03:40 AM   #155
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QuoteOriginally posted by Mistral75 Quote
There is no such thing as OVF CDAF. When the optical viewfinder is active, the mirror is down and no light is gathered by the imaging sensor, which performs contrast detection (and, with K-70, includes phase-detect AF points as well).
sorry I meant PDAF (phase detection).
06-09-2016, 04:14 AM   #156
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QuoteOriginally posted by anu l Quote
sorry I meant PDAF (phase detection).
If so the PLM technology provides for smoother and more silent focus but not quicker.
06-09-2016, 04:16 AM   #157
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At least for the 55-300 PLM RE, it does provide faster AF (Ricoh says so). I guess a significant part of it is the lens' construction, though.
06-09-2016, 04:23 AM   #158
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Indeed, the press release says:
QuoteOriginally posted by Ricoh Imaging:
With the adoption of a rear-focus system, the lens is almost 10 percent lighter than the PENTAX’s previous 55-300m lens—the HD PENTAX-DA 55-300mm F4-5.8ED WR. By driving this focusing lens using a pulse motor (PLM), which is directly linked to a lead screw, this zoom lens also operates faster — approximately 8.3 times at its wide-angle end and approximately 1.7 times at its telephoto end —and quieter than its predecessor. When mounted on the new PENTAX K-70 digital SLR camera body (also announced today), it assures smoother, faster AF operation with dimly lit subjects, thanks to an improved AF algorithm that exchanges AF data between the camera body and the lens with greater precision.
Most of the gain is linked to the lighter focusing group (= with less inertia) and the remaining to the new communication protocol between lens and body (and the improvement in the autofocus algorithm allowed by it).

06-09-2016, 04:26 AM - 2 Likes   #159
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well lets see how this new algorithm breaks compatibility with sigma lenses then

---------- Post added 09-06-16 at 13:41 ----------

Comparison with the 'old' 55-300:

Compare | Lenses | Products | RICOH IMAGING

---------- Post added 09-06-16 at 13:50 ----------

Optical formula new:


Old:


AF drive mechanism:


1 lead screw. 2 plm drive 3 focus lens.


aperture unit

MTF chart:
06-09-2016, 05:40 AM   #160
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QuoteOriginally posted by jatrax Quote
[...] there must be hardware to support it.
You absolutely have no evidence to support that statement. The truth is people outside of Ricoh have no idea. It might require hardware, or it might be totally doable in software. We'll probably never know, just like we don't know if the K-3 could have done pixel-shift or if there's something genuinely new in the SR hardware of the K-3II.

QuoteQuote:
  1. It is just a firmware update and Ricoh chooses not to make it available to older cameras to shaft their users and force them to buy new cameras. This of course is the cynical choice, but personally I don't buy it.
You don't seem to understand the realities of software development. Even if it is "just" a software update, there is still work involved, and thus cost. You have to backport a bunch of new code to the software tree of the older camera. The work involved can be substantial, and gets more likely to be a real headache as the camera model you're porting to gets older (and its code base further from your current development tree). Even if it's "just software", you have to draw a line somewhere. (Of course, there is also a financial incentive in pushing owners of your older equipment to upgrade.)

Personally, I think the decision to go to KAF4 makes sense, but the one to not support a flagship model from 2.5 years ago is painful. Even assuming the best case scenario of this being a hardware issue, I wish Ricoh would do something to extend a hand to buyers of this flagship (or perhaps even older models). What this could consist of depends entirely on how they handle future lens releases. If, for the next 1.5 years (until the K-3 is 4 years old), most new lens released still have the aperture lever (and thus can be used on the K-3, and even older bodies), then everything is fine and nothing more is needed.

But if every new lens from now on will be KAF4 only, then I would like some kind of rebate program for body upgrades. (For this, I personally think the line should be at the K-5 II(s), but even if it's just for K-3 owners, that would still be pretty good.)

Last edited by Doundounba; 06-09-2016 at 06:49 AM.
06-09-2016, 05:46 AM   #161
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QuoteOriginally posted by UncleVanya Quote
A reminder, one reason pentax enjoys auto aperture with samyang is the simplicity of a mechanical aperture.

The change may well be useful, but it feels like it tosses the baby out with the bathwater.I'm taking a cautious wait and see view.
What baby got tossed out? The K-70 would still provide everything needed to a Samyang lens (or any other with auto aperture) for proper function. Throw a 16mm f2 Bower on a K-70 and it will work in the A position on the aperture ring.

This seems all about giving lens manufacturers, 3rd party or Pentax, a more modern way of controlling the aperture. My hope is that Ricoh is working behind the scenes with 3rd party manufacturers to get them back on K-mount.
06-09-2016, 05:52 AM - 1 Like   #162
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Lenses that will work with AF-C in movie mode:

HD PENTAX-DA 16-85mmF3.5-5.6ED DC WR
smc PENTAX-DA L 18-50mm F4-5.6 DC WR RE
HD PENTAX-DA 18-50mmF4-5.6 DC WR RE
smc PENTAX-DA 18-135mmF3.5-5.6ED AL[IF] DC WR
HD PENTAX-DA 20-40mmF2.8-4ED Limited DC WR
HD PENTAX-D FA 28-105mmF3.5-5.6ED DC WR
HD PENTAX-DA 55-300mm F4.5-6.3ED PLM WR RE
HD PENTAX-D FA★70-200mmF2.8ED DC AW
HD PENTAX-D FA 150-450mmF4.5-5.6ED DC AW
HD PENTAX-DA 560mmF5.6ED AW
06-09-2016, 06:30 AM   #163
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QuoteOriginally posted by pres589 Quote
What baby got tossed out? The K-70 would still provide everything needed to a Samyang lens (or any other with auto aperture) for proper function. Throw a 16mm f2 Bower on a K-70 and it will work in the A position on the aperture ring.

This seems all about giving lens manufacturers, 3rd party or Pentax, a more modern way of controlling the aperture. My hope is that Ricoh is working behind the scenes with 3rd party manufacturers to get them back on K-mount.
Other manufacturers lenses from Samyang lack automation. This is due to the electronic aperture. However with their announcement of autofocus lenses this may have changed.
06-09-2016, 06:32 AM   #164
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QuoteOriginally posted by Doundounba Quote
You absolutely have no evidence for that statement. The truth is people outside of Ricoh have no idea. It might require hardware, or it might be totally doable in software. We'll probably never know, just like we don't know if the K-3 could have done pixel-shift or if there's something genuinely new in the SR hardware of the K-3II.

You don't seem to understand the realities of software development. Even if it is "just" a software update, there is still work involved, and thus cost. You have to backport a bunch of new code to the software tree of the older camera. The work involved can be substantial, and gets more likely to be a real headache as the camera model you're porting to gets older (and its code base further from your current development tree). Even if it's "just software", you have to draw a line somewhere. (Of course, there is also a financial incentive in pushing owners of your older equipment to upgrade.)

Personally, I think the decision to go to KAF4 makes sense, but the one to not support a flagship model from 2.5 years ago is painful. Even assuming the best case scenario of this being a hardware issue, I wish Ricoh would do something to extend a hand to buyers of this flagship (or perhaps even older models). What this could consist of depends entirely on how they handle future lens releases. If, for the next 1.5 years (until the K-3 is 4 years old), most new lens released still have the aperture lever (and thus can be used on the K-3, and even older bodies), then everything is fine and nothing more is needed.

But if every new lens from now on will be KAF4 only, then I would like some kind of rebate program for body upgrades. (For this, I personally think the line should be at the K-5 II(s), but even if it's just for K-3 owners, that would still be pretty good.)
Yes I believe that if KAF4 will be the standard lenses in the future, it will be painful. One of the main reasons that I chose Pentax was the continuity of the K-mount. Having a lens that can be mounted on older cameras but won't function like other lenses is still deviating from the original design. It's like killing it in a different way. I guess if this is the way it goes to make Pentax lenses faster, maybe we should bite the bullet. But again, it's painful and a very bitter pill.
06-09-2016, 06:34 AM   #165
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QuoteOriginally posted by Imp Quote
Lenses that will work with AF-C in movie mode:

HD PENTAX-DA 16-85mmF3.5-5.6ED DC WR
smc PENTAX-DA L 18-50mm F4-5.6 DC WR RE
HD PENTAX-DA 18-50mmF4-5.6 DC WR RE
smc PENTAX-DA 18-135mmF3.5-5.6ED AL[IF] DC WR
HD PENTAX-DA 20-40mmF2.8-4ED Limited DC WR
HD PENTAX-D FA 28-105mmF3.5-5.6ED DC WR
HD PENTAX-DA 55-300mm F4.5-6.3ED PLM WR RE
HD PENTAX-D FA★70-200mmF2.8ED DC AW
HD PENTAX-D FA 150-450mmF4.5-5.6ED DC AW
HD PENTAX-DA 560mmF5.6ED AW
So dc will work but SDM and screw drive won't. Too bad the Tamron rebrands won't either.
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