The *ist mount - the sad truth :(

[BJL]

I also like manual focus.

Me too on occasion, and I even own (and like) a Pentax M lens, and mourn for the passing of manual focusing aids in the viewfinder. But since the viewfinder on the *istD, like all other competing DSLR's has a far smaller image than on the Pentax MF bodes and lacks those manual focusing aids, it is not going to be much fun with MF anyway: the sad market reality is that no camera maker is going to spend any effort on helping customers to avoid buying new lenses by continuing to use twenty year old totally non-automated ones at the cost of making the cameras even slightly more expensive or inconvenient for users of new equipment.

If I were going to organize a quixotic campaign in favour of the glories of the past, I would aim instead at reviving those viewfinder focusing aids!

 

[Peter Spiro]

If the specs can be believed the *istdD is going to have a viewfinder with 95% magnification, almost as big as in the old days, and much bigger than most recent SLRs. That would have made it a contender for manual focussing, which makes it all the more unfortunate that it doesn't work with the M lenses. A nice viewfinder that's good for manual focussing should be one of the features of a DSLR that sets it apart from simpler cameras. I like the EVF on my Dimage 7, but the detail in it is not enough for easy manual focussing (it can be magnified, but that is a cumbersome extra step).

I also like manual focus.

Me too on occasion, and I even own (and like) a Pentax M lens, and
mourn for the passing of manual focusing aids in the viewfinder.
But since the viewfinder on the *istD, like all other competing
DSLR's has a far smaller image than on the Pentax MF bodes and
lacks those manual focusing aids, it is not going to be much fun
with MF anyway: the sad market reality is that no camera maker is
going to spend any effort on helping customers to avoid buying new
lenses by continuing to use twenty year old totally non-automated
ones at the cost of making the cameras even slightly more expensive
or inconvenient for users of new equipment.

If I were going to organize a quixotic campaign in favour of the
glories of the past, I would aim instead at reviving those
viewfinder focusing aids!

 

[Roland Karlsson]

If the specs can be believed the *istdD is going to have a
viewfinder with 95% magnification, almost as big as in the old
days, and much bigger than most recent SLRs.

If you read the press release - it is 95% with a 50 mm 1.4.
But - that is a short tele with the crop factor. So it is
not so surprising that it is 95%.

Roland

 

[Roland Karlsson]

Yes, and you use the same 645/K adaptor ( for the film based SLR ).
The 645 lens work stop down and manual of course

The problem I have with this urge to use medium format
lenses on the *istD is that medium format lenses are not
all that sharp. Is it worth it?

Roland

 

[BJL]

If the specs can be believed the *istdD is going to have a viewfinder with 95%
magnification, almost as big as in the old days,
and much bigger than most recent SLRs.

It does have the best viewfinder magnification of any vaguely affordable DSLR, and I really like that, but due to the smaller sensor size, this still means an image size about as for 0.63x on a 35mm format camera. (All competitors are equivalent to about .55x or less when adjusted for sensor size.)

I think that size will be nice for composition, but nothing on the glorious .88x of my Pentax K-1000 when it comes to manual focusing.

 

[digital_ray_of_light]

Ulysses found this website ( http://forums.dpreview.com/forums/read.asp?forum=1028&message=5822713 ) that has a slide on the Viewfinder. I don't know wich cameras are A and B.

I also like manual focus.

Me too on occasion, and I even own (and like) a Pentax M lens, and
mourn for the passing of manual focusing aids in the viewfinder.
But since the viewfinder on the *istD, like all other competing
DSLR's has a far smaller image than on the Pentax MF bodes and
lacks those manual focusing aids, it is not going to be much fun
with MF anyway: the sad market reality is that no camera maker is
going to spend any effort on helping customers to avoid buying new
lenses by continuing to use twenty year old totally non-automated
ones at the cost of making the cameras even slightly more expensive
or inconvenient for users of new equipment.

If I were going to organize a quixotic campaign in favour of the
glories of the past, I would aim instead at reviving those
viewfinder focusing aids!

 

[cyberstudio]

I have played around with a cheap M lens, and I believe it might be
actually quite simple with a little drilling and other
modifications to convert an M lens into an A lens, with full matrix
metering. I'll keep you posted.

Please understand that the incompatibility involved is not due to the A contacts, which like you said can be drilled on the mount and it will even really give you matrix metring.

The incompatibility is due to the stop down lever. For an A lens it is guaranteed each bit of movement of the stop down lever translates to the same amount of f-stop difference. If it moves 1mm to open up one stop it will always be 1mm to open up another stop. The K and M lenses offer no similar guarantees.

I am sure it can still be done, but it will be more elaborated than you might want to hear, and make sense only for the exotics such as 15mm, 500/4.5, 28 shift, etc.

 

[Robert Gonzalez]

Yes, I realize that the A lenses make the aperture activator linear, and I wonder how far off M lenses are from this ideal. If its impractical, then its back to meter at wide open and compensate the shutter in manual. Oh well, we'll have to wait and see won't we?

thanks,

rg

I have played around with a cheap M lens, and I believe it might be
actually quite simple with a little drilling and other
modifications to convert an M lens into an A lens, with full matrix
metering. I'll keep you posted.

Please understand that the incompatibility involved is not due to
the A contacts, which like you said can be drilled on the mount and
it will even really give you matrix metring.

The incompatibility is due to the stop down lever. For an A lens it
is guaranteed each bit of movement of the stop down lever
translates to the same amount of f-stop difference. If it moves 1mm
to open up one stop it will always be 1mm to open up another stop.
The K and M lenses offer no similar guarantees.

I am sure it can still be done, but it will be more elaborated than
you might want to hear, and make sense only for the exotics such as
15mm, 500/4.5, 28 shift, etc.

--
Gonzomatic

P e n t a x - the whole gamut

 

[J Simpson]

Robert, tell me it ain't true.....give up 5 or 6 K worth of M glass
to go
to Canon just because something in Photography does come easily??
I suspect that whilst you have earned the right to have to have things
come easily in Photography, as have I (or so I would like to believe).
I think a better way to approach this would be to wait until the
Pentax
IST* Digital camera hits the shelves and go down with one of your M
lenses and try it out and see what the level of difficulty is in
getting
one of your lenses to work to yoiur satisfaction. I had a chance
to play
with a pre-production model and it worked well enough with my A series
lens and seemed to work quite easily with an M series 15mm lens but,
truth be told, I didn't set it up and use it but I did get my
picture
taken with it (((( Now that is a sad thing......to see {WINK].

How/where did you get to play with the pre-prod model? Are you a
Pentax rep or dealer?

Hi Robert,

I work in a camera shop and am a avid Pentax SLR user, albeit a digital
G2 user......for now

Cheers,

Jack

I am going to at least do this, i.e. go down when they arrive and
play with one and some lenses. I suspect though, that M lenses
will only be fully usable completely wide open. Otherwise you have
to turn on the parameter that lets the shutter fire without the A*
setting, and put it in manual so you can set the shutter speed
according to the actual aperture setting. While this is ok for
studio work, its completely unacceptable for field work, except
maybe landscapes.

I have played around with a cheap M lens, and I believe it might be
actually quite simple with a little drilling and other
modifications to convert an M lens into an A lens, with full matrix
metering. I'll keep you posted.

Also, when you played with the 15mm M, did you get any usability on
other apertures other than wide open?

So, hopefully, you like myself will wait and weather the storm and if
worse comes to worse you could always trade/sell your M glass and
but the $ £ towards some KA/KAF etc...glass.

Cheers,

Jack

--
Gonzomatic

P e n t a x - the whole gamut

--
It's amazing what one can do when one doesn't know what one is doing!

 

[Roland Mabo]

• The *ist D is more compatible with screwmount, 645 and 67 lenses than with K and M mount (1976-1982). Screwmount and medium format lenses works on the *ist D as on other Pentax bodies.

• The *ist D can take images with K and M lenses (K-mount), but the meter will not function.

• The *ist D is fully compatible with manual focus A-lenses (KA-mount) and newer lenses. This is the same bacwards compatibility as the Nikon D2H has. The Nikon can meter with Nikon Ai lenses and newer - the Ai lenses are similar as Pentax A lenses. The D2H has problems with older Nikon bayonet lenses. So, Pentax has the same backwards compatibility as Nikon's new super DSLR, at a much lower price.

• The new flash system in the *ist D (P-TTL), needs information that M and K lenses can't provide.

• Pentax A-lenses was the most complete manual focus serie on the market in the 80's. Great lenses, great performance, great looks. Unfortunately, few bought them so some of the optics are rare on the used market. I believe that the reason for Pentax owners not buying the A-lenses, was that they had M and K lenses already and the new cameras was backwards compatible. Why buy new lenses when the old ones are good enough? This is Pentax dilemma and this backwards compatibility has seriously damaged Pentax lens sales. Pentax sells very few prime AF lenses, why? I guess it's because the cameras can use the M and K lenses and since they're good enough, why buy a new AF lens? But the AF lenses are very good, many lenses has better optical performance than the old M and K lenses had. (For example, the FA 28 f/2.8 AL outperforms the M 28 f/2.8...). But I guess that Pentax users are nostalgic ones. Why fix things that aint broken? Why buy a new lens when the old one works?

But why should Pentax make new lenses if the users still prefers using the old ones?

Because new cameras contains new technology and this technology needs to be supported by the lenses.

USM and IS is on it's way in Pentax mount. The modern lens mount has a gold plated contact, this is a power contact that can be used to control USM and IS lenses and it's a much simpler and more cost efficient solution to use this contact to control the lenses, than to use the power zoom contacts. But the power zoom-contacts solution may give better lens compatibility with older lenses. Yes, I do believe that the *ist D has support for Pentax coming USM and IS lenses and it uses the gold plated power contact for this, and the internal electronics gets upset if a K and M lens is used. A screwmount and 645 and 67 adapter may not upset the internal electronics in the same way, and that's the reason for the compatibility issues. This is what I believe. Time will tell if I'm right or not.

Best wishes
Roland

 

[Franka T.L.]

The problem I have with this urge to use medium format
lenses on the *istD is that medium format lenses are not
all that sharp. Is it worth it?

Roland

If you stick with the newer 645 Lens ( especially the AF ones ), that should be no problem with the sharpness. After all you are only using the very center of the Sweet-Spot of the lens when you mate it with the *ist-D. I've had no problem with these lens on my Film based K bodies. It would be interesting to observe how they work out in this new body.

The one complain I had still is with Macro, I have yet to find a proper solution for attaching special Macro lens ( say Luminar ) with a bellow allowing me to Shift and tilt. I need that when I work down to 3X or even 5X mag ratio, some calculation later and I've come up with the figure that if I need the same pic with the *ist-D, I will need 1X to 3X mag ratio, and that still mean special lens and bellow required.

--
Franka

 

[Franka T.L.]

Very well documentaed, but I would just like to add a note here

With regard to the Nikon D2H using Manual focus lens. Actually its more complicated than it sounds. The AI Nikkor had several version, namely AI, AI-S, and AI-P , all of which will be working with the D2H, but only the AI-P will give full function as its the equvalent of Pentax "A" series lens and do have thge CPU and electronic needed in the lens. All other MF nikkor are mechanical linked, but then the Matrix metering will still work. Most people tend to think Matrix metering will require lens communication. Then truth is though its desirable to have that bit of information, it is not essential. Matrix metering and certainly center weighted and spot metering will work even wothout this set of data. Nikon done that before with F4, and Contax did it with their Aria. The AI and AI-S are very much in the like of the K & M lens

So in effect what Nikon did with the D2H is probaly the best Manual Focus support on a digital body so far on a 35mm based system. Much I like Pentax, I must say Nikon score on this. It would be most interesting to see if Nikon would continue this in their Amateur/Prosumer offering ( replacement for D-100 ? ).

--
Franka

 

[tcom]

Hi everyone

The new FA J 18-35 has no aperture ring.

Is it possible to use such a lense on a non *ist camera such MZ-5 or MZ-S ?

Thanks
Dominique

 

[Pete Fang]

The new FA J 18-35 has no aperture ring.

Is it possible to use such a lense on a non *ist camera such MZ-5
or MZ-S ?

I don't know about the MZ-5 but the MZ-S has only one control dial on the body. So if you use FA-J lenses on the MZ-S, you can only use Program (P) and Shutter Piority (Tv) auto modes and cannot use Aperture Priority (Av) or Manual modes because there's no way to set the aperture from the body side. Cameras with two control dials (such as the older Z-1/PZ-1 series) will not have this limitation when using FA-J lenses.

Best,

Peter Fang

 

[BryanB1]

I have an idea for this K-mount back-compatibility issue. Give the camera a special manual mode. Call it 'K' exposure mode. When in 'K' mode, you must set the aperture ring to your desired aperture AND you must set the aperture on the camera to the same aperture. In this way, the camera knows what aperture you're setting, and can adjust the exposure meter appropriately.

When you make an exposure in 'K' mode, the aperture release lever extends itself all the way, just like in my old MX, allowing the lens to set the aperture.

It would be a little annoying to have to set the aperture twice, but it seems like a small price to pay to get the exposure meter to work. It should be possible to implement 'K' mode just by changing the software in the camera. I'd suffer the hassle to use my collection of (mostly) K mount lenses.

Any thoughts? Does this make sense? Any idea how to get Pentax interested in implementing it?

 

[BJL]

Pentax has apparently said that many lenses not fully supported will work with an adaptor and/or some restrictions. So maybe they have already implemented on idea like yours.

 

[Roland Karlsson]

I have an idea for this K-mount back-compatibility issue. Give the
camera a special manual mode. Call it 'K' exposure mode. When in
'K' mode, you must set the aperture ring to your desired aperture
AND you must set the aperture on the camera to the same aperture.
In this way, the camera knows what aperture you're setting, and can
adjust the exposure meter appropriately.

Something like this would work - but you also have to tell the
camera the maximum aperture of the lens. Another idea is
to extend the exposure compensation function to more stops
and then tell how many stops you have stopped down the lens.
Then you will (probably) miss with a fraction of a stop if the
max lens aperture is not at an even stop.

Roland

 

[Greg Erker]

On a non-A lens the body doesn't know what the max aperture of
the lens is since there are no contacts.

Thus to make your idea work you'd have to tell the camera how
many stops down from wide open you've set the aperture ring
rather than the actual aperture.

Still a great idea, though I doubt it will come to pass.

Cheers - Greg

I have an idea for this K-mount back-compatibility issue. Give the
camera a special manual mode. Call it 'K' exposure mode. When in
'K' mode, you must set the aperture ring to your desired aperture
AND you must set the aperture on the camera to the same aperture.
In this way, the camera knows what aperture you're setting, and can
adjust the exposure meter appropriately.

When you make an exposure in 'K' mode, the aperture release lever
extends itself all the way, just like in my old MX, allowing the
lens to set the aperture.

It would be a little annoying to have to set the aperture twice,
but it seems like a small price to pay to get the exposure meter to
work. It should be possible to implement 'K' mode just by changing
the software in the camera. I'd suffer the hassle to use my
collection of (mostly) K mount lenses.

Any thoughts? Does this make sense? Any idea how to get Pentax
interested in implementing it?

 

[Roland Karlsson]

On a non-A lens the body doesn't know what the max aperture of
the lens is since there are no contacts.

Said that 2 minutes ago

Thus to make your idea work you'd have to tell the camera how
many stops down from wide open you've set the aperture ring
rather than the actual aperture.

This also

Still a great idea, though I doubt it will come to pass.

You could use it (if Pentax just activated the exposure
meter) for up to stopping down the lens 3 stops.

Roland

 

[BryanB1]

but you also have to tell the
camera the maximum aperture of the lens.

I think I understand why this would be the case. But how did the older K mount cameras correct the exposure meter? There was no indication of the max aperture before the A mount.