[RMabo]

Pentax D FA 50 Macro, D FA 100 Macro has screwdrive. The new 24x36 camera is top of the line, if Pentax wants to go screwless then they will start from bottom to up not from top to bottom... But I believe most, probably all, new Pentax AF lenses will have in-lens motors.

[awaldram]

I think they will add contacts to the new DF A series lenses in order to allow the body to automatically set crop and full frame modes. I fully expect to be able to also manually set this. I'm also thinking that these new lenses appear to have optical shake reduction and they will need a way to tell the camera that this is enabled so it can shut off in body stabilization in that situation.

None of which would indicate that the kaf3 mount is losing screw drive.

Kaf3 mount is non-screw drive it is used on the 17-70 , 70-200 and 150-450

Though I think when they refer to bodies the sale bods get confused and mean KAF3 compatible when they say Kaf3

[boriscleto]

How about a body/mount that enables aperture-preferred automation with M-series lenses? I think it would work if the body had an option to meter after the lens stopped down. Rather than reading light reflected off the film (LX), the system could directly read what falls on the sensor - maybe? is it possible?

Green Button stop down metering is what you are going to get. Live with it or buy an LX and get it CLA'd while there are still parts.

[sterretje]

How about a body/mount that enables aperture-preferred automation with M-series lenses? I think it would work if the body had an option to meter after the lens stopped down. Rather than reading light reflected off the film (LX), the system could directly read what falls on the sensor - maybe? is it possible?

What's the difference with green button metering for M/K lenses? Lens is stopped down, camera meters, lens is opened again.

What you describe is TTL versus pTTL. Some older digital models had it (ist series, not sure which ones). Problem seemed to have been that the reflection from film is different from reflection from a sensor.

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Last edited by sterretje; 02-06-2015 at 08:15 AM. Reason: Fixed typo

[awaldram]

You say fiction... But how else would Pentax generate any profits from such a camera? The typical Pentaxian that demanded FF, needs it BECAUSE they want to use it with their existing FF lenses. Hence, no lens sales will be generated from selling to that specific group.

Of cause you could just release a FF camera that costs more the 50p

[Stone G.]

You say fiction... But how else would Pentax generate any profits from such a camera? The typical Pentaxian that demanded FF, needs it BECAUSE they want to use it with their existing FF lenses. Hence, no lens sales will be generated from selling to that specific group.

For all I know Pentax generates (good) profits from their 645D and 645z - no change of mounts here either.


(And don't tell me that the 645D and 645z are excessively priced for their class).

[boriscleto]

Kaf3 mount is non-screw drive it is used on the 17-70 , 70-200 and 150-450

And the 18-135, 18-270, 16-85, 20-40, 55/1.4, & 560.

The last lenses Pentax released that had screw AF were the 35/2.4, 50/1.8 and 40/2.8 XS.

[awaldram]

What's the difference with green button metering for M/K lenses? Lens is stopped down, camera meters, lens is opened again.

What you describe is TTL versus pTTL. Some older digital models had it (ist series, not sure which ones). Problem seemed to have been that the reflection from film is different from reflection from a sensor.

No the problem is all cmos sensor have different reflectivity so implementation costs are high.

Pre flash TTL metering does not suffer from this and is a low cost option for manufacturers

[WPRESTO]

What's the difference with green button metering for M/K lenses? Lens is stopped down, camera meters, lens is opened again.

What you describe is TTL versus pTTL. Some older digital models had it (ist series, not sure which ones). Problem seemed to have been that the reflection from film is different from reflection from a sensor.

I'm thinking no green button. Menu select "M-series lens," mode dial at "A," select f-stop with aperture ring, focus, shoot. No need to set meter & shutter speed with the green dial.

[DeadJohn]

If the spec at photorumors is correct, the camera will have a KAF3 mount. Bye bye screw drive lenses?

link: Rumored Pentax full frame DSLR camera specifications | Photo Rumors

As others have said, unlikely. Many of the current full frame lenses are only screw drive: FA 31, 43, 77; D-FA 50, 100 macros. Add all the APS-C lenses that are only screw drive. Imagine the reaction from customers with relatively new lenses that can't be used.

Sony would love this decision

[UncleVanya]

Not to mention the fact that there are few sdm only apsc lenses and this body is planning an apsc mode to allow the use of the da lenses.

[RuiC]

Could KAF3 also be something to do with support for the new AF modes and buttons on the new D-FA zooms?

My guess is more / different contacts to enable better comms between body / lens. Looking forward to finding out anyway.

They can't change the mount contacts for different comms. That would turn older lenses obsolete.

[awaldram]

They can't change the mount contacts for different comms. That would turn older lenses obsolete.

Pentax lens support serial digital data over the lens contacts 'digital info' pin the rest are legacy to define aperture.

The protocol is secret but can obviously support a large amount of communication hence why AF buttons and af zone presets have appeared on the new 150-450 the protocol isn't static but is not flouted on 'sales blurb' hence is not defined as any monicker.

Similarly GPS addon extended p-ttl data transference but no-one wanted to know the new name for the hot shoe mount

Courtesy of Welcome to Bojidar Dimitrov's Pentax K-Mount Page

[WPRESTO]

Pentax/Ricoh wont be screwing around with the AF linkage.

[VisualDarkness]

Pentax already got a barren FF lens selection and to cut out most of the lenses they already got would be a financial waste worthy of "Pentax is doomed!".