Anyone Using Takumars?

If the adapter is too thick then I would think you won't get to infinity. This is only a problem with the 5D bodies. All cropped DSLRs should be fine. I actually am planning on carefully taking a dremel to the back of my SMC Pentax to get the required clearance. Or I might just sell it because my Contax Zeiss 50/1.4 is just as good or better.
--
Long live the HMS Beagle
Critiques always welcome!

jamesdak said:

If the adapter is too thick then I would think you won't get to
infinity. This is only a problem with the 5D bodies. All cropped
DSLRs should be fine. I actually am planning on carefully taking a
dremel to the back of my SMC Pentax to get the required clearance.
Or I might just sell it because my Contax Zeiss 50/1.4 is just as
good or better.

Click to expand...

James,

I've just looked at the SMC Tak 50/1.4 again (am not sure whether the
SMC Pentax 50/1.4 is the same design though, as it might have been
changed by Ashai in a meantime). There is a glass fixing ring (on the
moving part) which extends deepest into a body at infinity. If you'll
look at the corresponding part at the zeiss 50/1.4 (again I assume that
you may have a T*, whereas I have a HFT, but they might be identical),
it is not flat, but a little bit planned in a skew way - with the piece
facing furthest from electrical contacts, but closest to a moving
mirror's path, planned almost to a glass surface.

I'd suggest to do the same trick on the SMC. I've a repair manual
here showing a cross-cut and it seems to be safe to unscrew the
glass fixing piece on SMC before sanding it with a Dremel, or just by
hand on a flat surface. Sanding in a glass vicinity and with all lens'es
innards in almost immediate contact does not sound like a good idea.

And after sanding it will need to be matted black again - all in all
perhaps a hour of work ,

FWIW,
jpr2

Dale Buhanan said:

That's why I asked you about the 10D earlier. If the 5D has a
problem, perhaps the 10D does also? I have a 10D, 20D and 40D. I
believe the 20D and 40D will be OK, since they are EF-S compatible.
But I don't know about the 10D... or the 5D either.

Click to expand...

Dale,

no need to worry - the 10D should not be different in this respect
from 20/40d as all of them are 1.6x crop bodies,

Dale Buhanan said:

The two 50 f1.4's that I have are both older ones. One is the Super
Takumar, the other is the Super Multicoated Takumar. I don't know if
the newer SMC version with the rubber focusing ring extends further
back than these Spotmatic versions or not... Perhaps you do.

Click to expand...

it is easy to find out - even without adapter ring, actually esp. without -
just put them to infinity, then place both on a table front down,
and measure with some precision, how far the rim of a metal glass fixing
ring extends from the flange plane. If you don't have any precision measuring
device, you can still do it with any of your cameras - just take pisc. with
your best magnifying lens set with it's axis on a level of both Taks flange
surface, and then do some simplest arithmetics

jpr2

OT: since you have both 20d and 40d, and you were showing some interest
in the thread on long lenses' problems with SIFs, perhaps you'd be willing
to engage in some simple experiment - just look at this link:
http://forums.dpreview.com/forums/read.asp?forum=1019&message=26878346

and then tell me please how would you feel shooting such artificial "bird"
with exactly the same lens (preferably long tele), from the same vantage
point, and all other things equal, using AI Focus and AI Servo, first with the
20D, and then with the 40D - noting all differences in a contexts discussed
in SIFs subthread?

s23chang said:

I have a bunch too manual focus converted to EOS mount too.
Rollie 50/1.4 HFT

Click to expand...

S23chang,

could you share pls. which adapter you're using for this one (a source too)?
I got a cheap one off e-bay, but I-st it does not push an aperture's pin deep
enough (it hardly pushes it at all), and II-nd the securing spring broke off
very shortly after putting the adapter to use, it still can be used, but
not easy to get the adapter off lens, and a lens moves a bit on an
adapter thus making it a bit tough to glean a distance scale

• so, now I'm looking for something more durable and

better made,

jpr2

Dale Buhanan said:

My gracious! That's more than you could carry around even with a
good sized bag! Wow!

Click to expand...

Dale,

they are all so much different, then usually when going on assignment
one is taking only on or two, few at most, and do not forget about
their smallness:
http://www.flickr.com/photos/8497177@N03/1113850102/

btw. due to your repeated interest, I took both Taks 35/2 and 50/1.4
for a long outing yesterday lunch time with 40d and that new focusing screen,
what a pleasurable experience - it was like going back 1/4 of century )
oil smooth focusing, and actually seeing all focal plane changes on screen,
with their effect on composition, clouds and their shadows making a
difference, and all this stuff akin to using a vintage view camera

and the effects with Ef-s were not comparable in a least

jpr2

jpr2 said:

they are all so much different, then usually when going on assignment
one is taking only on or two, few at most, and do not forget about
their smallness:
http://www.flickr.com/photos/8497177@N03/1113850102/

Click to expand...

Yes... they are tiny, but not really light. Solid machined metal and glass.

jpr2 said:

btw. due to your repeated interest, I took both Taks 35/2 and 50/1.4
for a long outing yesterday lunch time with 40d and that new focusing
screen,
what a pleasurable experience - it was like going back 1/4 of century
)
oil smooth focusing, and actually seeing all focal plane changes on
screen,
with their effect on composition, clouds and their shadows making a
difference, and all this stuff akin to using a vintage view camera

Click to expand...

Very well worded, jpr2. I could feel the experience myself just from reading your words. It brought back many old memories. I'm looking forward to the experience for myself.

However, I don't yet have the better manual focusing screen that you have gotten, and my eyes have dimmed somewhat, so manual focusing without a micro-prism is trickier than it used to be. As a result, I'm afraid I'll have to rely on the focus confirmation blinks.

I realize though that from your experience I may get disallusioned when I see the soft results, and the focus plane somewhere where I didn't intend it to be, and bite the bullet and take the next step just as you have done. How difficult was it to install the new screen anyway? I'm a bit afraid of dropping a screwdriver on the mirror. LOL

jpr2 said:

and the effects with Ef-s were not comparable in a least

Click to expand...

Ooooops! Especially not the oil smooth focusing, right?

I brought all my Takumars out from cold storage yesterday and looked them all over and made sure all of them still worked OK. They were all perfect. They really are very nice lenses aren't they. BTW, I have the same two lenses you took for a lunch outing myself in my collection. I was disappointed though to find that my 28mm f2.8 turned out to be a Vivitar rather than a Tak though. It was a good hand-selected one, and is pretty good, but it isn't the Tak. That's one on a crop that I imagined I might use quite a bit.

It will still be a couple of weeks before I get my adaptor. (It is supposed to be mailed tomorrow and then take two weeks after that.) So, I am trying not to get too excited. Plenty to keep me occupied though. My G9 and 40D are both less than a month old, and I am still learning and playing with their various features and attributes. Which for me is about as much fun as taking real pictures.

--
kind regards
Dale

Dale Buhanan said:

Very well worded, jpr2. I could feel the experience myself just from
reading your words. It brought back many old memories. I'm looking
forward to the experience for myself.

Click to expand...

Dale,

I wouldn't like to sound like centenarian, however, memories are just
flooding back = like buying huge cans of a DIN 15 (yeah, it was measured
in DIN and ASA then ) B&W film bulk. To have it cheaper - so either 60,
80, or even 120 meters of it in one go, then cutting it into 36 exp. strips
and putting them into reusable cartridges, taking care not to scratch it, nor
spoiling a cartridge itself, etc. Somehow a dust was not a problem those
days, I do not remember why, but it really wasn't! And these fantastic
shadows and highlights after developing it for like seemed hours no
end with Rodinal diluted to some crazy degree .

Dale Buhanan said:

However, I don't yet have the better manual focusing screen that you
have gotten, and my eyes have dimmed somewhat, so manual focusing
without a micro-prism is trickier than it used to be. As a result,
I'm afraid I'll have to rely on the focus confirmation blinks.

I realize though that from your experience I may get disillusioned
when I see the soft results, and the focus plane somewhere where I
didn't intend it to be, and bite the bullet and take the next step
just as you have done. How difficult was it to install the new
screen anyway? I'm a bit afraid of dropping a screwdriver on the
mirror.

Click to expand...

no screwdriver is involved in changing screens on 40d at all, and the whole
"operation" can be completed in 2mins. perhaps much less given enough
routine.

The problem was to... FIND a good one - and it took me a long time
indeed. The third party screens are offered by: Haoda Fu, Rachel Katz,
BrightScreens (rather expensive stuff), and FocusingScreens. These are
sources I'm aware of. Perhaps there might be others. But of course I started
with Ef-s like everyone else. It was an improvement (and you can read
about experiences of others on such path in many places), but I wasn't
quite happy with MF while using WA and UWA lenses.

Hence, in an effort to find out more I engaged in some rather involved
activities [thanx to S3 and JimH - without them perhaps there would not
had been so much determination in me to continue]. You might find
them here, each within the context leading to them [and also to some
afterthoughts] - just follow these links if you may have some spare time:
http://forums.dpreview.com/forums/read.asp?forum=1029&message=26635130
http://forums.dpreview.com/forums/read.asp?forum=1029&message=26540829

I guess so many details must be way too much, but... this was my way,
and all I can say is that it payed off very generously in the end

best,
jpr2

I've been using my old Taks almost from the time I bought my 40D with fairly good results, and find them preferable as walk around lenses in many lighting conditions...BUT, on certain of them, such as the 35mm f3.5, I often get a lens communication error message when first mounting it...have to lossen it a little. Do you know what may be causing this?

wildplaces

jpr2 said:

I have quite few Taks M42 and Pantax-K lenses, all performing
reasonably well.

Click to expand...

--
http://www.pbase.com/wildplaces/galleries

wildplaces said:

I've been using my old Taks almost from the time I bought my 40D with
fairly good results, and find them preferable as walk around lenses
in many lighting conditions... BUT, on certain of them, such as the
35mm f3.5, I often get a lens communication error message when first
mounting it... have to lossen it a little. Do you know what may be
causing this?

Click to expand...

and if not, that is if you happen to have more than one M42 --> EOS
with a confirm chip, then try to swap adapters and see it the error
conditions would remain with the 35/3.5 Tak, or rather (as I expect)
will go after the adapter in question itself?

And if this turns out to be a case... just unglue the chip gently, taking care
not to crush it etc. End then put it back with super-glue - it might help
if you photography it first (taking care to do it on lens axis, so there will
not be any paralax), and also some other lens/adapter, or maybe extension
tubes, such... that you'd have a possibility to put all these pics. on stack,
and to compare which way the culprit contacts might be misaligned,

jpr2

PS I'm assuming that you've cleaned adapter's contacts already.

jpr2 said:

I wouldn't like to sound like centenarian, however, memories are just
flooding back = like buying huge cans of a DIN 15 (yeah, it was measured
in DIN and ASA then ) B&W film bulk. To have it cheaper - so either
60,
80, or even 120 meters of it in one go, then cutting it into 36 exp.
strips
and putting them into reusable cartridges, taking care not to scratch
it, nor
spoiling a cartridge itself, etc. Somehow a dust was not a problem those
days, I do not remember why, but it really wasn't! And these fantastic
shadows and highlights after developing it for like seemed hours no
end with Rodinal diluted to some crazy degree .

Click to expand...

LOL... Yes... I remember the good old days also. I used to have a darkroom and did all my own processing too. I only tried Rodinol once and evidently over developed it, because the negatives were way too contrasty and grainy. I don't think I tried it again. I mostly used D76 for film and Dektol for papers.

I never did do the bulk loader thing, although I was aware of it. I always shot either plus X or Tri-X and had good results with D76. I did shoot a lot of film though and remember fondly being in the dark and loading those rolls into the developing tank with the back and forth rachet motion turning of the two ends... I'm sure you rmember that ... while being able to smell the fixer. It was always such an exciting process wondering how the shots would all turn out and how the exposure was, etc. The suspense was part of the fun. And I still think in terms of ASA. I just call ISO - ASA. I tried the occasional roll of Panatomic X if I was going to enlarge a lot. Tried color for a while, but found it very finicky and very expensive and had to throw away far too many sheets that just didn't look right.

I don't think dust was a problem back then because it was always a brand new frame of film out of the canister for each shot, freshly scrubbed free of dust by the velvet strip coming out of the cartridge. And the next shot also got a brand new fresh piece of film. If any dust was stubborn enough to keep clinging it got washed loose when you agitated the developer.

jpr2 said:

no screwdriver is involved in changing screens on 40d at all, and the
whole
"operation" can be completed in 2mins. perhaps much less given enough
routine.

Click to expand...

Yeah... That was an attempt at humor.

jpr2 said:

The problem was to... FIND a good one - and it took me a long time
indeed. The third party screens are offered by: Haoda Fu, Rachel Katz,
BrightScreens (rather expensive stuff), and FocusingScreens. These are
sources I'm aware of. Perhaps there might be others. But of course I
started
with Ef-s like everyone else. It was an improvement (and you can read
about experiences of others on such path in many places), but I wasn't
quite happy with MF while using WA and UWA lenses.

Click to expand...

Which one did you end up with?

jpr2 said:

Hence, in an effort to find out more I engaged in some rather involved
activities [thanx to S3 and JimH - without them perhaps there would not
had been so much determination in me to continue]. You might find
them here, each within the context leading to them [and also to some
afterthoughts] - just follow these links if you may have some spare
time:
http://forums.dpreview.com/forums/read.asp?forum=1029&message=26635130
http://forums.dpreview.com/forums/read.asp?forum=1029&message=26540829

Click to expand...

Thanks for the links. I have some reading to do.

jpr2 said:

I guess so many details must be way too much, but... this was my way,
and all I can say is that it payed off very generously in the end

Click to expand...

I'm glad that you passed along the bounty. Knowlege is power, and I need all I can get.

What business are you in by the way? How do you earn a living, jpr2? I am a retired Electronics engineer. I spent my career designing and developing Integrated circuit chips for Motorola. Cell phone, Satellite, memories, processors, stuff like that. So I'm quite familiar with most electronic circuits.. Feedback loops and digital logic, etc. Used to teach amplifiers and digital logic out at the college in the evenings just for fun.

--
kind regards
Dale

Thanks for the suggestions, jpr2...I have a separate FA M42 adapter on each lens. I tried swapping adapters, with the same result. I also tried cleaning the contacts. The 35mm f3.5 usually ends up with the lens communication error when I first mount it. It resolves after I loosen the lens mount a little by releasing the adapter from the EOS using the lens lock release button and backing it up a little. Your idea of comparing the adapters is an interesting one, but must be related to some property of the lens itself.

wildplaces

jpr2 said:

wildplaces said:

I've been using my old Taks almost from the time I bought my 40D with
fairly good results, and find them preferable as walk around lenses
in many lighting conditions... BUT, on certain of them, such as the
35mm f3.5, I often get a lens communication error message when first
mounting it... have to lossen it a little. Do you know what may be
causing this?

Click to expand...

and if not, that is if you happen to have more than one M42 --> EOS
with a confirm chip, then try to swap adapters and see it the error
conditions would remain with the 35/3.5 Tak, or rather (as I expect)
will go after the adapter in question itself?

And if this turns out to be a case... just unglue the chip gently,
taking care
not to crush it etc. End then put it back with super-glue - it might
help
if you photography it first (taking care to do it on lens axis, so
there will
not be any paralax), and also some other lens/adapter, or maybe
extension
tubes, such... that you'd have a possibility to put all these pics.
on stack,
and to compare which way the culprit contacts might be misaligned,

jpr2

PS I'm assuming that you've cleaned adapter's contacts already.

Click to expand...

--
http://www.pbase.com/wildplaces/galleries

wildplaces said:

It resolves
after I loosen the lens mount a little by releasing the adapter from
the EOS using the lens lock release button and backing it up a
little.

Click to expand...

Funny you should mention that. I bought a secondhand Canon EF-12II extension some time back. It wouldn't autofocus with my 50mm II unless I rotated the tube slightly in the dismount direction. Everything about the tube and contacts looked correct and showed little or no wear; it simply wouldn't work reliably. I ended up returning it to the seller and buying one new from Adorama. The replacement works perfectly, just like all my Canon lenses. I still don't know the cause of the problem, but I'll bet it was the same thing that's afflicting your adapter.

Jack

--
http://jackandkelly.zenfolio.com/

wildplaces said:

wildplaces wrote:

I have a separate FA M42 adapter on each lens. I tried swapping adapters,
with the same result. I also tried cleaning the contacts. The 35mm f3.5
usually ends up with the lens communication error when I first mount it.
It resolves after I loosen the lens mount a little by releasing the adapter
from the EOS using the lens lock release button and backing it up a little.
Your idea of comparing the adapters is an interesting one, but must be
related to some property of the lens itself.

Click to expand...

nopa
It might be related to how you're handling lenses of different sizes
and weight when mounting them on your body. Just put your
misbehaving 35/3.5 + worst offender of your adapters on a body - in
such a way that it reproduces an error. And then gently unscrew
that lens (without loosening an adapter mount as described above),
and screw another M42 Tak into it's place.

I'm a simpleminded CS, whereas you need somebody versed it electronics
and hardware to explain all this (JimH jumps to mind immediately )
instead a software person. However, available repair manual for AF canon
lenses describes a mounting sequence of events like this:

"when the lens is mounted, the power is supplied to each IC in the lens
through VDD at the mount contact pin; each logic circuit operates on VD1
(4V) that is produced by regulating the VDD voltage with IC; when CPU
receives power from VD, internal oscillation starts with the set frequency
(8MHz) by oscillator CF; when the reset signal is received from the voltage
detection circuit IC, the program execution begins; the CPU sets LCKL
communication line with the camera to the LO level; then outputs the busy
signal to the camera, stores the contents of the EPROM, including the lens
adjustment data, in the RAM; then initializes internal registers and RAM;
after initialization the CPU cancels the busy signal, sets both LCKL and
DCL pins to the LO level, and outputs the request signal to the camera
to set the HALT state = CPU stops" (EF 300/4L IS repair manual, 1997).
Sound sort of familiar, and yet a hardware mumbo-jumbo jargon makes it
hard to understand ).

Since you do not have any CPU in any of your Taks, the confirm chip just
dupes a camera body into believing that what is mounted is a valid AF lens.
But perhaps sometimes it fails to do it properly; hence, manual manipulation
might help. But it only indicates some faulty contacts - nothing to do with
the lens in question whatsoever )

FWIW,
jpr2

jpr2 said:

"when the lens is mounted, the power is supplied to each IC in the lens
through VDD at the mount contact pin; each logic circuit operates on VD1
(4V) that is produced by regulating the VDD voltage with IC; when CPU
receives power from VD, internal oscillation starts with the set
frequency
(8MHz) by oscillator CF; when the reset signal is received from the
voltage
detection circuit IC, the program execution begins; the CPU sets LCKL
communication line with the camera to the LO level; then outputs the
busy
signal to the camera, stores the contents of the EPROM, including the
lens
adjustment data, in the RAM; then initializes internal registers and
RAM;
after initialization the CPU cancels the busy signal, sets both LCKL and
DCL pins to the LO level, and outputs the request signal to the camera
to set the HALT state = CPU stops" (EF 300/4L IS repair manual, 1997).
Sound sort of familiar, and yet a hardware mumbo-jumbo jargon makes it
hard to understand ).

Click to expand...

Great explanation, and I can understand how it works for real EF lenses, because the lens is able to provide positional data to the internal logic, telling it where it is on the focus range... close or far, etc. However, how you can get a focus confirm from the Takumars still aludes me.

You can't get in focus information from the sensor, because the shutter has it covered up until you actually shoot... unless you are in live view mode. But for the normal case the sensor can't provide any information until the shutter is clicked. And the confirm chip on the adaptor has no idea where the focus ring on the Takumar is turned, so it can't sense positional information from the lens. So I am really kind of baffled where the focus confirm information comes from.

The only thing I can figure is that the AF sensor in the camera that would originally tell the lens where to move, senses the phase between the left and right half of the lens image and sounds a focus confirm. It's got to be something like that. In which case, it would only work up to f5.6 or so, regardless of whether the image was in focus or not, simply because the phase detectors need f5.6 or faster to work. I don't know if I am just blowing smoke here or not, but that's the only way I can figure that it could possibly work.
--
kind regards
Dale

Dale Buhanan said:

The only thing I can figure is that the AF sensor in the camera that
would originally tell the lens where to move, senses the phase
between the left and right half of the lens image and sounds a focus
confirm. It's got to be something like that. In which case, it
would only work up to f5.6 or so, regardless of whether the image was
in focus or not, simply because the phase detectors need f5.6 or
faster to work. I don't know if I am just blowing smoke here or not,
but that's the only way I can figure that it could possibly work.

Click to expand...

EXACTLY, image sensors (with a possible exception of some Evolts,
peraps) of DSLRs are not dealing with AF at all - this is a role of a
separate path which gets about 40% of light to do a focusing job.

However, the [in]famous f/5.6 rule is an artificial level set in FW by
designers to make sure that we [the end users] would not mess up things
too badly and then be running to their quality people screaming
a pure murder;

however, with manual lenses seating on third party adapters, and using
confirm chips, things are getting quite interesting - esp. as it is very easy
to discover, that one is getting quite often a good focus and a crisp
confirmation beep at as little as f/8, and sometimes (in a good external
light) even as little as f/11 - and I'm not kidding, you'd be able to check it
out very soon indeed;

with AF there are two issues (at least two, as the field is ridden with issues
and problems):

• autofocus system's sensitivity to light and contrast;
• it's accuracy in detecting the amount of correction which will be necessary

with each particular lens (with or without TCs);

And also one HUGE problem - on canon's bodies it is an open loop system
(even on 1Dx series), which never bothers to check which/whether a critical
focus was actually achieved [which usually it is not, but then the result is
hidden in DOF = the so called "within specs" mantra - a Central Dogma in
a Canonite Lands, which of course is not unique to these lands alone, others
have it too, but they are somehow better in specific the acceptable "in specs"
levels, so these problems are not jumping to light so often there];

There is a very interesting link, which is quickly becoming my favorite
Citation Classic on DPR, and for a good reason too:
http://forums.dpreview.com/forums/read.asp?forum=1019&message=26696220
about an accuracy of AF, the ways it is supposedly implemented, and some
problems. Esp. specific to the 40D's implementation, which is very akin to
the one installed in 1DmkIII.

All in all quite a complex set of solutions, issues and problems - and [it seems]
still quite far from a definite set of answers,

sorry for my rants [just analyzed about 1k of shots from last outing - what a
mixed bag: many excellent ones, yet messed by quite puzzling assortment
of bads; not something I'd expect as a normal level after over 6 months
of a heavy experience with my 40d - just over 31k actuations]

kind regards,
jpr2

Interesting story, and on the the surface seems to be the same problem...but the adapter does not seem to be the problem, for I have tried M42 adapters that work perfectly with other Takumar lenses, and I have the same problem with the 35mm f3.5. May have something to do with the lens itself, but haven't quite figured it out.

wildplaces

Filmluvr said:

wildplaces said:

It resolves
after I loosen the lens mount a little by releasing the adapter from
the EOS using the lens lock release button and backing it up a
little.

Click to expand...

Funny you should mention that. I bought a secondhand Canon EF-12II
extension some time back. It wouldn't autofocus with my 50mm II
unless I rotated the tube slightly in the dismount direction.
Everything about the tube and contacts looked correct and showed
little or no wear; it simply wouldn't work reliably. I ended up
returning it to the seller and buying one new from Adorama. The
replacement works perfectly, just like all my Canon lenses. I still
don't know the cause of the problem, but I'll bet it was the same
thing that's afflicting your adapter.

Jack

--
http://jackandkelly.zenfolio.com/

Click to expand...

--
http://www.pbase.com/wildplaces/galleries

I was not convinced that the adapter is the problem...and the thought of solving a firmware question with Karnough diagrams (digital logic problem solving charts) sends shivers of anxiety through my brain !; > ( However, I did re-test just now with all 4 Takumar lenses, and decided you and Jack must be right about a defect in the adapter (1 of 4 I ordered from Roxen in HK) I'll send an email to Roxen and see if they're willing to send a replacement adapter.

Thank you for the input...will let you know if the replacement M42 adapter solves the problem.

wildplaces

jpr2 said:

nopa
It might be related to how you're handling lenses of different sizes
and weight when mounting them on your body. Just put your
misbehaving 35/3.5 + worst offender of your adapters on a body - in
such a way that it reproduces an error. And then gently unscrew
that lens (without loosening an adapter mount as described above),
and screw another M42 Tak into it's place.

I'm a simpleminded CS, whereas you need somebody versed it electronics
and hardware to explain all this (JimH jumps to mind immediately )
instead a software person. However, available repair manual for AF canon
lenses describes a mounting sequence of events like this:

"when the lens is mounted, the power is supplied to each IC in the lens
through VDD at the mount contact pin; each logic circuit operates on VD1
(4V) that is produced by regulating the VDD voltage with IC; when CPU
receives power from VD, internal oscillation starts with the set
frequency
(8MHz) by oscillator CF; when the reset signal is received from the
voltage
detection circuit IC, the program execution begins; the CPU sets LCKL
communication line with the camera to the LO level; then outputs the
busy
signal to the camera, stores the contents of the EPROM, including the
lens
adjustment data, in the RAM; then initializes internal registers and
RAM;
after initialization the CPU cancels the busy signal, sets both LCKL and
DCL pins to the LO level, and outputs the request signal to the camera
to set the HALT state = CPU stops" (EF 300/4L IS repair manual, 1997).
Sound sort of familiar, and yet a hardware mumbo-jumbo jargon makes it
hard to understand ).

Since you do not have any CPU in any of your Taks, the confirm chip just
dupes a camera body into believing that what is mounted is a valid AF
lens.
But perhaps sometimes it fails to do it properly; hence, manual
manipulation
might help. But it only indicates some faulty contacts - nothing to
do with
the lens in question whatsoever )

FWIW,
jpr2

Click to expand...

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wildplaces said:

must be [....] a defect in the adapter
(1 of 4 I ordered from Roxen in HK) I'll send an email to Roxen and
see if they're willing to send a replacement adapter.

Click to expand...

if at all, just them to send you a confirmation chip alone (esp. is the
adapter in question allows infinity and is overall of decent mechanical
quality);

but before you do - there is one more thing to check, both quicker
and also giving you some new input - your faulty one might be a so
called "thin adapter"; sometimes it suffices to un-glue it very gently with
a lancet blade or a razor, then glue it again, but this time by putting
also a thin piece of a high quality paper (280-300 g/m2) of about
0.5-1mm thickness beneath it (and remembering to blacken it with
an ink before;

this was the way I "fixed" two of mine six adapters - no problems
whatsoever afterwards; just not good enough electrical contact
was their only "problem",

jpr2

wildplaces said:

I'll send an email to Roxen and
see if they're willing to send a replacement adapter.

Click to expand...

Sorry that you're having this problem. If you have time, would you let us know the outcome with Roxen? I've refused to buy from them in the past due to their auction return policies. Hopefully, they'll take care of you on this.

Jack

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jpr2, Mine is the chrome-plated nickel type...not sure how you are suggesting I separate parts of the adapter? I noticed a couple of nicks and imperfections in the metal on the Takumar lens side surface and and a significant pit on the EOS side of this particular adapter, but do not know if this is causing the problem. Also, wonder if the position of the stop screw could be the problem, since I sometimes am able to wiggle the adapter into a positioni that works

wildplaces

jpr2 said:

but before you do - there is one more thing to check, both quicker
and also giving you some new input - your faulty one might be a so
called "thin adapter"; sometimes it suffices to un-glue it very
gently with
a lancet blade or a razor, then glue it again, but this time by putting
also a thin piece of a high quality paper (280-300 g/m2) of about
0.5-1mm thickness beneath it (and remembering to blacken it with
an ink before;

this was the way I "fixed" two of mine six adapters - no problems
whatsoever afterwards; just not good enough electrical contact
was their only "problem",

jpr2

Click to expand...

--
http://www.pbase.com/wildplaces/galleries