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The *ist mount - the sad truth :(

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Roland Karlsson

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Look here:

http://digilander.libero.it/aohc/pshw2003/monte.htm

It shows that the *ist uses a KAF-crippled mount
(as the entry level cameras MZ-30, MZ-50 and MZ-60.

Pentax claims that it is a KAF2 mount. But this is not
correct. The actual mount lacks the "power zoom contacts"
and the "diaphragm simulator coupling".

So - if the *istD uses the same mount as *ist, this is
a real negative surprise indeed. My collection of M lenses
is not all that useful.

As a kind of "fix", the *ist camera (according to the manual)
even refuses to take any pictures if you don't set your
lens at A setting. This super ugly "fix" can be removed by
changing the special function setting 17. But, then the
camera turns off the exposure meter (at least in manual
mode).

Ouch - why - oh why Pentax?

Roland
 
Hi Roland,

I'm not familiar to Pentax mounting issues but I'm wondering:
Is it possible to mount other lenses on this Pentax-body??
(perhaps Nikon? or SIGMA...I've no idea!!!!)

Regards, Arno
Roland Karlsson said:
Look here:

http://digilander.libero.it/aohc/pshw2003/monte.htm

It shows that the *ist uses a KAF-crippled mount
(as the entry level cameras MZ-30, MZ-50 and MZ-60.

Pentax claims that it is a KAF2 mount. But this is not
correct. The actual mount lacks the "power zoom contacts"
and the "diaphragm simulator coupling".

So - if the *istD uses the same mount as *ist, this is
a real negative surprise indeed. My collection of M lenses
is not all that useful.

As a kind of "fix", the *ist camera (according to the manual)
even refuses to take any pictures if you don't set your
lens at A setting. This super ugly "fix" can be removed by
changing the special function setting 17. But, then the
camera turns off the exposure meter (at least in manual
mode).

Ouch - why - oh why Pentax?

Roland
Click to expand...
--
Arno
 
arno said:
Hi Roland,

I'm not familiar to Pentax mounting issues but I'm wondering:
Is it possible to mount other lenses on this Pentax-body??
(perhaps Nikon? or SIGMA...I've no idea!!!!)
Click to expand...
As far as I remember, the Pentax body is one of the thinnest
bofies around. And I think you can get converters. But - then
you would probably lose all possibilities for coupling to the
camera house.

Roland
 
I thought Phil's review said it would work with KAF2 lenses?
Roland Karlsson said:
Look here:

http://digilander.libero.it/aohc/pshw2003/monte.htm

It shows that the *ist uses a KAF-crippled mount
(as the entry level cameras MZ-30, MZ-50 and MZ-60.

Pentax claims that it is a KAF2 mount. But this is not
correct. The actual mount lacks the "power zoom contacts"
and the "diaphragm simulator coupling".

So - if the *istD uses the same mount as *ist, this is
a real negative surprise indeed. My collection of M lenses
is not all that useful.

As a kind of "fix", the *ist camera (according to the manual)
even refuses to take any pictures if you don't set your
lens at A setting. This super ugly "fix" can be removed by
changing the special function setting 17. But, then the
camera turns off the exposure meter (at least in manual
mode).

Ouch - why - oh why Pentax?

Roland
Click to expand...
--
I see your schwartz is as big as mine.
 
Roland Karlsson said:
Pentax claims that it is a KAF2 mount. But this is not
correct. The actual mount lacks the "power zoom contacts"
and the "diaphragm simulator coupling".
Click to expand...
Pentax claims it is a KAF mount. But this is not true either.
The "diaphragm simulator coupling" is missing. Which still
makes it hard (impossible?) to use older lenses with
exposure meassurement.

Back to sunny f/16 rule :)

Roland
 
Hej said:
I thought Phil's review said it would work with KAF2 lenses?
Click to expand...
I thinkt does. The only difference IMHO between KAF and KAF2
is that KAF2 supports power zoom lenses. So, KAF2
lenses without power zoom is KAF lenses.

There could be some more info sent via the digital contact
in KAF2 than in KAF - don't know. In that case we have a problem.
But I don't know this.

Roland
 
If I want to use one of the new SIGMA-lenses on the new Pentax-body
is that possible??

I've looked on the following link:
http://www.sigma-photo.com/html/lenschart.htm

There a table that says P-annotation for most of the SIGMA-lenses for Pentax. I don't know if this also the fact for this *ist body.

Arno
Roland Karlsson said:
Roland Karlsson said:
Pentax claims that it is a KAF2 mount. But this is not
correct. The actual mount lacks the "power zoom contacts"
and the "diaphragm simulator coupling".
Click to expand...
Pentax claims it is a KAF mount. But this is not true either.
The "diaphragm simulator coupling" is missing. Which still
makes it hard (impossible?) to use older lenses with
exposure meassurement.

Back to sunny f/16 rule :)

Roland
Click to expand...
--
Arno
 
arno said:
If I want to use one of the new SIGMA-lenses on the new Pentax-body
is that possible??

I've looked on the following link:
http://www.sigma-photo.com/html/lenschart.htm

There a table that says P-annotation for most of the SIGMA-lenses
for Pentax. I don't know if this also the fact for this *ist body.
Click to expand...
Any lens that you can set in auto aperture (A) mode can
be used. I assume that those new lenses have that possibility.
It is not reasonable that any lens of the K-mount type is made
today. But - of course - I can promise nothing :)

BTW - if you get such a lens - then you cannot use the aperture
ring on the lens. You have to set the aperture on the display at
the camera body. There was a fix for this (setting the extra
function 17 or what it was called), but the manual was very
unclear what this really meant.

Roland
 
In my opinion al modern SIGMA lenses have Pentax AF mounting and
Pentax AF is compatible with KAF2. So there's no problem.

Still missing something????!!!

Arno
Roland Karlsson said:
arno said:
If I want to use one of the new SIGMA-lenses on the new Pentax-body
is that possible??

I've looked on the following link:
http://www.sigma-photo.com/html/lenschart.htm

There a table that says P-annotation for most of the SIGMA-lenses
for Pentax. I don't know if this also the fact for this *ist body.
Click to expand...
Any lens that you can set in auto aperture (A) mode can
be used. I assume that those new lenses have that possibility.
It is not reasonable that any lens of the K-mount type is made
today. But - of course - I can promise nothing :)

BTW - if you get such a lens - then you cannot use the aperture
ring on the lens. You have to set the aperture on the display at
the camera body. There was a fix for this (setting the extra
function 17 or what it was called), but the manual was very
unclear what this really meant.

Roland
Click to expand...
 
The *ist D has a funny lens mount. It's not the same as the "crippled" KAF mount in the *ist, because the *ist D reads the MTF information from the lenses and other digital data which the "crippled" KAF mount can't. Perhaps we can say that the *ist D has a "crippled" KAF2 mount? For the new *ist and *ist D, Pentax has changed the transmission protocol for the aperture information so that body controlled aperture is now more precise than it was in the Z-serie. (the new FA-J and DA lenses uses this new protocol, which is compatible with the old one).

The *ist D is fully compatible with lenses from 1982 and newer (KA, KAF and KAF2 lenses). It can even use screwmount lenses (and yes, it will meter with them). The problem is with K and M lenses 1976-1982. I understand that many still has Pentax first bayonet lenses and haven't upgraded since the mid 70's, but I believe many more has KA, KAF and KAF2 lenses...

I believe that the *ist D has supports for new functions in lenses and it might have been too expensive to retain compatibility with 1976-1982 lenses, while still being able to use the new lenses that Pentax are working on. (I'm talking about IS and USM technology).

The *ist D is, to my knowledge, the only DSLR on the market that takes lenses from 1982 with multisegment metering and other modern electronic features.

Best wishes
Roland
 
Hey Roland, From what we heard from the PDML the K and m lenses will work in open aperture metering, what the problem may be is stopping down, the camera won't know how much it is stopped down to! My guess is that it may also be able to do openapertiure stoped down metering ( as it would with screw mount lenses ) we will all know soon but any lens with an "A" setting or contstant aperture ( F8 mirror ) will work fine..
Roland Mabo said:
The *ist D has a funny lens mount. It's not the same as the
"crippled" KAF mount in the *ist, because the *ist D reads the MTF
information from the lenses and other digital data which the
"crippled" KAF mount can't. Perhaps we can say that the *ist D has
a "crippled" KAF2 mount? For the new *ist and *ist D, Pentax has
changed the transmission protocol for the aperture information so
that body controlled aperture is now more precise than it was in
the Z-serie. (the new FA-J and DA lenses uses this new protocol,
which is compatible with the old one).

The *ist D is fully compatible with lenses from 1982 and newer (KA,
KAF and KAF2 lenses). It can even use screwmount lenses (and yes,
it will meter with them). The problem is with K and M lenses
1976-1982. I understand that many still has Pentax first bayonet
lenses and haven't upgraded since the mid 70's, but I believe many
more has KA, KAF and KAF2 lenses...

I believe that the *ist D has supports for new functions in lenses
and it might have been too expensive to retain compatibility with
1976-1982 lenses, while still being able to use the new lenses that
Pentax are working on. (I'm talking about IS and USM technology).

The *ist D is, to my knowledge, the only DSLR on the market that
takes lenses from 1982 with multisegment metering and other modern
electronic features.

Best wishes
Roland
Click to expand...
 
arno said:
In my opinion al modern SIGMA lenses have Pentax AF mounting and
Pentax AF is compatible with KAF2. So there's no problem.

Still missing something????!!!
Click to expand...
Nope - I don't think so. I am just cautious. Don't want
to be blamed if you buy a useless lens :)

Roland
 
Brendan Bhagan said:
Hey Roland, From what we heard from the PDML the K and m lenses
will work in open aperture metering, what the problem may be is
stopping down, the camera won't know how much it is stopped down
to! My guess is that it may also be able to do openapertiure stoped
down metering ( as it would with screw mount lenses ) we will all
know soon but any lens with an "A" setting or contstant aperture (
F8 mirror ) will work fine..
Click to expand...
Ok - it sounds like there is a small chance that the *ist D is
better than the *ist then. Maybe.

BTW - is there any PDML archive? So I can search old mails
in order to find this info.

Roland
 
Careful inspection of the *ist-D mount from published photo suggested that the mechanical Aperture Stop down lever is there but the Aperture index lever is not, so any original SMC - Pentax or SMC - M lens will work ( sort of ) but the body will have no way to know how many stop the lens will be doing when shooting.

While I can understand how the M42, or 645 and 67 lens will work, since they can all be mated to the body with an adaptor and the lens either set to M or simply by itself stop down by default. The K mount lens will by default, when mounted remain open. So any realistic metering will need you keep your finger twisted on the Power/Stopdown lever .... This do not seems to make much sense in usage. Or will the body only meter when stop down is activated ( much like the old Spotmatic ) ????

Interesting though, even though the Power Lead for the KAF2 is not there, the Lead platform is there. So perhgaps a later even higher speced body will have the index lever and the Power lead, this make sense ( just my guess ) if you figure the *ist-D will be a hobbyist grade body with a Consumer grade ( lesser speced ) and a semi-Pro / Pro body ( higher speced ) follow.

I do however think the missing Aperture Indexing making the old MF lens unusable is a most stupid decision. Pentax gain its name long ago with them and there's still a whole lot of them around in hands of thousands of hobbyist ( aka Potenetial customer ). Forcing them to switch to new Optics is certainly not Customer savey appraoch. This is a very important aspect of backward compatibility as Nikon discover and now had to provide MF lens support on their newest D2H ( even though its cumbersome )

--
Franka
 
the nikon d2h will matrix meter with AI lenses
Roland Mabo said:
The *ist D is, to my knowledge, the only DSLR on the market that
takes lenses from 1982 with multisegment metering and other modern
electronic features.

Best wishes
Roland
Click to expand...
 
The *ist D works without problems with manual focus lenses from 1982 (KA-mount). Even the multisegment metering and P-TTL works! (to my knowledge, Nikon can't use matrix metering with manual focus lenses). Having a MF A-lens on the *ist D, is like having an AF lens but with MF instead. Can Nikon do that?

Best wishes
Roland
Franka T.L. said:
I do however think the missing Aperture Indexing making the old MF
lens unusable is a most stupid decision. Pentax gain its name long
ago with them and there's still a whole lot of them around in hands
of thousands of hobbyist ( aka Potenetial customer ). Forcing them
to switch to new Optics is certainly not Customer savey appraoch.
This is a very important aspect of backward compatibility as Nikon
discover and now had to provide MF lens support on their newest D2H
( even though its cumbersome )
Click to expand...
 
There is something about this topic in the "Concert" part, but it gets lost in the computer translation.

http://babelfish.altavista.com/babelfish/urltrurl?url=http%3A%2F%2Fwww.digitalcamera.jp%2F&lp=ja_en&tt=url
Roland Mabo said:
The *ist D has a funny lens mount. It's not the same as the
"crippled" KAF mount in the *ist, because the *ist D reads the MTF
information from the lenses and other digital data which the
"crippled" KAF mount can't. Perhaps we can say that the *ist D has
a "crippled" KAF2 mount? For the new *ist and *ist D, Pentax has
changed the transmission protocol for the aperture information so
that body controlled aperture is now more precise than it was in
the Z-serie. (the new FA-J and DA lenses uses this new protocol,
which is compatible with the old one).

The *ist D is fully compatible with lenses from 1982 and newer (KA,
KAF and KAF2 lenses). It can even use screwmount lenses (and yes,
it will meter with them). The problem is with K and M lenses
1976-1982. I understand that many still has Pentax first bayonet
lenses and haven't upgraded since the mid 70's, but I believe many
more has KA, KAF and KAF2 lenses...

I believe that the *ist D has supports for new functions in lenses
and it might have been too expensive to retain compatibility with
1976-1982 lenses, while still being able to use the new lenses that
Pentax are working on. (I'm talking about IS and USM technology).

The *ist D is, to my knowledge, the only DSLR on the market that
takes lenses from 1982 with multisegment metering and other modern
electronic features.

Best wishes
Roland
Click to expand...
 
i have to agree with you, if they make it difficult for old M lenses to be used, then they have alienated a lot of loyal customers, including myself. I have alot of M glass, maybe 5 or 6 thousand dollars worth, and if they will not work easily, then I will probably defect and go with Canon, as they seem to be more spread out over the DSLR spectrum. I'm sure somebody will buy my lenses on ebay. So Pentax, say it isn't so., TELL us that the *istD will not be unusable with M glass.
Franka T.L. said:
Careful inspection of the *ist-D mount from published photo
suggested that the mechanical Aperture Stop down lever is there but
the Aperture index lever is not, so any original SMC - Pentax or
SMC - M lens will work ( sort of ) but the body will have no way to
know how many stop the lens will be doing when shooting.

While I can understand how the M42, or 645 and 67 lens will work,
since they can all be mated to the body with an adaptor and the
lens either set to M or simply by itself stop down by default. The
K mount lens will by default, when mounted remain open. So any
realistic metering will need you keep your finger twisted on the
Power/Stopdown lever .... This do not seems to make much sense in
usage. Or will the body only meter when stop down is activated (
much like the old Spotmatic ) ????

Interesting though, even though the Power Lead for the KAF2 is not
there, the Lead platform is there. So perhgaps a later even higher
speced body will have the index lever and the Power lead, this make
sense ( just my guess ) if you figure the *ist-D will be a hobbyist
grade body with a Consumer grade ( lesser speced ) and a semi-Pro /
Pro body ( higher speced ) follow.

I do however think the missing Aperture Indexing making the old MF
lens unusable is a most stupid decision. Pentax gain its name long
ago with them and there's still a whole lot of them around in hands
of thousands of hobbyist ( aka Potenetial customer ). Forcing them
to switch to new Optics is certainly not Customer savey appraoch.
This is a very important aspect of backward compatibility as Nikon
discover and now had to provide MF lens support on their newest D2H
( even though its cumbersome )

--
Franka
Click to expand...
--
Gonzomatic

P e n t a x - the whole gamut
 
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