Tamron adaptall 2 SP lenses +*istD

I have a battery of tamron SP lenses from 17mm to 500mm which I have been keeping for the day Pentax released a digital SLR. At present they are all fitted with KM interchangeable mounts.

Somewhere I have a brand new, never used, KA mount. The question is what are my options

If I can find the KA mount will it give me full manual and aperture priority metering?

If I can find an old adaptall 2 Pentax screw mount and a screw to K mount adaptor will I be able to use stop down metering correctly in aperture priority mode (Av)? (none of the lenses have a auto/manual diapraghm switch)

If I dismantle one of the KM mounts and remove the the aperture coupling ring and tension spring so that the lens stops down when the aperture ring is turned will this give me correct aperture priority or manual metering?

Since repalcement of the seven lenses and two SP converters would cost well over £5000 at todays prices please tell me one of these options will work!!!

Dave

--
http://members.lycos.co.uk/freyas_photographs/

dave said:

I have a battery of tamron SP lenses from 17mm to 500mm which I
have been keeping for the day Pentax released a digital SLR. At
present they are all fitted with KM interchangeable mounts.

Click to expand...

I only have the 90/2.5 1:2 Adaptall II lens so my experiences are coming from there. I have both K and K/A mounts for it.

Member said:

Somewhere I have a brand new, never used, KA mount. The question is
what are my options

If I can find the KA mount will it give me full manual and aperture
priority metering?

Click to expand...

Yes.

Member said:

If I can find an old adaptall 2 Pentax screw mount and a screw to
K mount adaptor will I be able to use stop down metering correctly
in aperture priority mode (Av)? (none of the lenses have a
auto/manual diapraghm switch)

Click to expand...

Yes, but you would have to open the lenses wide open to focus them (or deal with a dim viewfinder). The camera has nothing to push on the diaprahm switch for a screw mount lens so they are always stopped down. Using the P/KA adapter is a better choice.

B&H still sells these for $35 a piece:

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=53489&is=USA

alex

Alex

Thanks for your help, after 2 hours looking I've just found the old KA mount inside a developing tank in the garage!!! Still fully boxed and never used.

Looking at the standard Tamron K mount it would be possible to remove the diapraghm coupling lever and fix the stop down lever in the up position so that the iris stayed set at whatever aperture you choose, presumably this would then behave like a screw mount, giving stop-down auto metering, I've got 6 standard K mounts so its worth dismantling one to give it a try

I have a Pentax Super Takumar M42 screw mount 17mm full frame fisheye with K mount adaptor and the Tamron SP17mm. I find that the depth of field is so large with these UW lenses that I just set the lens on the hyperfocal distance, on my Pentax LX the viewfinder is still plenty bright enough, even at f11 to compose, so I'd be quite happy with stop down metering on these two.

I guess that the 500mm f8 CAT willl work fine in Aperture Priority or manual So I could use the KA mount on the 300 f2.8 and the 90mm macro where accurate focussing and auto exposure are more or less essential for action and natural history shots. I guess the Ka mount would also be fine with the SP 1.4x and 2x converters.

I read in a recent article in "what digital camera" that the *ist D seemed a bit soft with older lenses, are you happy with the results from the 90mm ? as this was always reckoned to be one of the best lenses in its class (certainly better than the Pentax 100mm macro that I swapped it for).

Must go and try these in the local Jessops before I buy

Dave

alex wetmore said:

dave said:

I have a battery of tamron SP lenses from 17mm to 500mm which I
have been keeping for the day Pentax released a digital SLR. At
present they are all fitted with KM interchangeable mounts.

Click to expand...

I only have the 90/2.5 1:2 Adaptall II lens so my experiences are
coming from there. I have both K and K/A mounts for it.

alex wetmore said:

Somewhere I have a brand new, never used, KA mount. The question is
what are my options

If I can find the KA mount will it give me full manual and aperture
priority metering?

Click to expand...

Yes.

alex wetmore said:

If I can find an old adaptall 2 Pentax screw mount and a screw to
K mount adaptor will I be able to use stop down metering correctly
in aperture priority mode (Av)? (none of the lenses have a
auto/manual diapraghm switch)

Click to expand...

Yes, but you would have to open the lenses wide open to focus them
(or deal with a dim viewfinder). The camera has nothing to push on
the diaprahm switch for a screw mount lens so they are always
stopped down. Using the P/KA adapter is a better choice.

B&H still sells these for $35 a piece:

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=53489&is=USA

alex

Click to expand...

--
http://members.lycos.co.uk/freyas_photographs/

dave said:

I read in a recent article in "what digital camera" that the *ist D
seemed a bit soft with older lenses, are you happy with the results
from the 90mm ? as this was always reckoned to be one of the best
lenses in its class (certainly better than the Pentax 100mm macro
that I swapped it for).

Click to expand...

I only shot with the 90/2.5 on the day that I bought the camera, so I was spending more energy getting used to the camera more than composing nice photographs or doing a great job of focussing. I'm happy with the results that I got with the 90/2.5 then, but should probably try it again and evaluate further.

Here are some 90/2.5 images:
http://phred.org/~alex/pictures/pentax-istd/reduced/seeds.jpg
http://phred.org/~alex/pictures/pentax-istd/reduced/berries.jpg

I don't have EXIF for those online, but I think they were shot at ISO 1600.

This was also shot with the 90/2.5, but I really needed more DOF. The problem was that the wind was blowing so I needed a faster shutter speed to keep motion blur down. In the end it isn't a very exciting shot:
http://phred.org/~alex/pictures/pentax-istd/reduced/IMGP1347.JPG

This is the same thing with less macro and better composition, but it might have been shot with a A 50/1.4.
http://phred.org/~alex/pictures/pentax-istd/reduced/IMGP1348.JPG

The *ist D sharpens much less by default than most cameras, so many magazines are complaining about that rather than actual lens sharpness. So far I've been doing most of my shooting with older prime lenses (A 24/2.8, A 50/1.4 and a bit with the Tamron 90/2.5).

alex

I have been trying to follow this thread, but I'm just not
that familiar with all the different Pentax mounts. My
Pentax equipment is from the early screw-mount
days and I can't figure out what I would need and
how the lenses would function if I tried to use them.

I have 2 screw-mount lenses for the old Pentax H1a.
Which adapter would work best and is it possible to have any
aperture automation? Would I normally be focusing
with the aperture wide open and then stop down manually?
Would the camera be used in the manual mode? I understand
I would meter with a hand-held meter.

I also have a Tamron zoom lens with the adaptall II adapter
for the Pentax H1a (screw-mount). Would that lens be used
with a different adapter? Will it have any degree of aperture
automation given that its auto-aperture is all mechanical?

Your discussion seems to be the most knowledgeable I have
found. I'd appreciate some help if you have time.

Thanks,
Darrell

Darrell Spreen said:

I have been trying to follow this thread, but I'm just not
that familiar with all the different Pentax mounts. My
Pentax equipment is from the early screw-mount
days and I can't figure out what I would need and
how the lenses would function if I tried to use them.

I have 2 screw-mount lenses for the old Pentax H1a.
Which adapter would work best and is it possible to have any
aperture automation? Would I normally be focusing
with the aperture wide open and then stop down manually?
Would the camera be used in the manual mode? I understand
I would meter with a hand-held meter.

Click to expand...

There is no way to make screw mount lenses stop down automatically with a K-mount camera. Using screw mount lenses on a K-mount camera would be like shooting with your H1a with the lenses switched to the "manual" position all of the time.

You could use the meter on the camera though. You only need to use a external meter when shooting with M and K lenses since there is no way to operate them in stopped down mode.

Depending on the lenses you might be happier finding a A or better replacement for them so you can get full functionality. I'm betting one of them is the 50/1.4 or 50/1.7 and while those are wonderful lenses the modern equivelents don't give up anything.

Member said:

I also have a Tamron zoom lens with the adaptall II adapter
for the Pentax H1a (screw-mount). Would that lens be used
with a different adapter? Will it have any degree of aperture
automation given that its auto-aperture is all mechanical?

Click to expand...

If you get the P/KA adapter then you can use this as a full auto lens. The P/KA adapter acts as an A lens and allows you to control the aperture using body controls.

alex

alex wetmore said:

If you get the P/KA adapter then you can use this as a full auto
lens. The P/KA adapter acts as an A lens and allows you to control
the aperture using body controls.

alex

Click to expand...

Alex I've just got a P/KA adapter to use on my *ist D with an Adaptall 2 and the Tamron 70~210/3.5~4.

It works fine using 'Manual' and the Green Button, except I can't figure out what it does when I set the lens to the AE position.

Am I right in thinking it won't work properly because this 70~210 is an old manual version?

Regards

Francis E said:

Francis E said:

If you get the P/KA adapter then you can use this as a full auto
lens. The P/KA adapter acts as an A lens and allows you to control
the aperture using body controls.

alex

Click to expand...

Alex I've just got a P/KA adapter to use on my *ist D with an
Adaptall 2 and the Tamron 70~210/3.5~4.

It works fine using 'Manual' and the Green Button, except I can't
figure out what it does when I set the lens to the AE position.

Am I right in thinking it won't work properly because this 70~210
is an old manual version?

Regards

Click to expand...

Francis, I don't know about the 70-210 but I have the Tamron SP17mm on the Adaptall 2 P/KA mount and it works fine in all auto modes (my standard is the P - Hyper-Program mode) when set to AE.

Brett

If you use the KA mount, the lens will act exactly like a pentax A lens.
(the body can set aperture)

With a K.M or K mount the lens acts like a pentax K lens.

(body can't set aperture, but you can use the stop-down metering fix implemented in the firmware upgrade - lens gets stopped down to the aperture selected on the lens, body meters for shutter speed, lens opens up again. Alternatively you can select shutter speed and aperture (on lens) simultaneously using DOF preview)

I use a tamron 90/2.5 (the metal 52B version) for macro. Unfortunately there seems to be a problem that results in a big white splodge or haze in the centre of the image (severity seems to depend on aperture). I've yet to determine what this is, but I do know that it disappears when I use the tamron 2x TC (a good combination for macro work I've found).

The 500/8 is no problem at all - the body meters fine (though it can't actually get a value for aperture)

David

dave said:

Alex
Thanks for your help, after 2 hours looking I've just found the old
KA mount inside a developing tank in the garage!!! Still fully
boxed and never used.

Looking at the standard Tamron K mount it would be possible to
remove the diapraghm coupling lever and fix the stop down lever in
the up position so that the iris stayed set at whatever aperture
you choose, presumably this would then behave like a screw mount,
giving stop-down auto metering, I've got 6 standard K mounts so its
worth dismantling one to give it a try

Click to expand...

It would be easier if you upgrade your camera's firmware. The new one will allow K mout lenses to meter stopped down.

Member said:

I have a Pentax Super Takumar M42 screw mount 17mm full frame
fisheye with K mount adaptor and the Tamron SP17mm. I find that
the depth of field is so large with these UW lenses that I just set
the lens on the hyperfocal distance, on my Pentax LX the
viewfinder is still plenty bright enough, even at f11 to compose,
so I'd be quite happy with stop down metering on these two.

I guess that the 500mm f8 CAT willl work fine in Aperture Priority
or manual So I could use the KA mount on the 300 f2.8 and the 90mm
macro where accurate focussing and auto exposure are more or less
essential for action and natural history shots. I guess the Ka
mount would also be fine with the SP 1.4x and 2x converters.

Click to expand...

That is correct.

Davidavid said:

If you use the KA mount, the lens will act exactly like a pentax A
lens.
(the body can set aperture)

With a K.M or K mount the lens acts like a pentax K lens.
(body can't set aperture, but you can use the stop-down metering
fix implemented in the firmware upgrade - lens gets stopped down to
the aperture selected on the lens, body meters for shutter speed,
lens opens up again. Alternatively you can select shutter speed and
aperture (on lens) simultaneously using DOF preview)

I use a tamron 90/2.5 (the metal 52B version) for macro.
Unfortunately there seems to be a problem that results in a big
white splodge or haze in the centre of the image (severity seems to
depend on aperture). I've yet to determine what this is, but I do
know that it disappears when I use the tamron 2x TC (a good
combination for macro work I've found).

Click to expand...

Probably fungus on one of the elements in the lens.

Davidavid said:

The 500/8 is no problem at all - the body meters fine (though it
can't actually get a value for aperture)

David

Click to expand...

dave said:

I have a battery of tamron SP lenses from 17mm to 500mm which I
have been keeping for the day Pentax released a digital SLR. At
present they are all fitted with KM interchangeable mounts.

Somewhere I have a brand new, never used, KA mount. The question is
what are my options

If I can find the KA mount will it give me full manual and aperture
priority metering?

If I can find an old adaptall 2 Pentax screw mount and a screw to
K mount adaptor will I be able to use stop down metering correctly
in aperture priority mode (Av)? (none of the lenses have a
auto/manual diapraghm switch)

If I dismantle one of the KM mounts and remove the the aperture
coupling ring and tension spring so that the lens stops down when
the aperture ring is turned will this give me correct aperture
priority or manual metering?

Since repalcement of the seven lenses and two SP converters would
cost well over £5000 at todays prices please tell me one of these
options will work!!!

Dave

--
http://members.lycos.co.uk/freyas_photographs/

Click to expand...

Just find some KA adaptall II mounts,new or used. Saves a lot of work.

I've only used the 90 as well as 90 w/ the 2x converter and a 60-300sp. 90 alone is quite sharp and contrasty. Love it. 60-300 is such a tank that I actually worry about hanging it on the ist-d. Had a problem w/ improper registration with 2 mounts where they don't make good electrical contact w/ the camera. Light twist on the lens barrel and it's fine. Aalways thought my old Superprogram was at fault but it popped up on the ist-d as well.

I think softness in old glass is lens specific,no general rule applies.I assume if it was slightly soft on film it will be even softer on the ist-d but who knows.

Dave,

I assume you mean you are having Tamron's mount for the Pentax K instead of KA, since the KA adeptor ( model 63C ) can work mush like a Pentax SMC-A lens thus using it on the *ist-D would allow all the function except of copurse AF .

Check Tamron's web site

--
Franka

Brett St Pierre said:

Francis, I don't know about the 70-210 but I have the Tamron SP17mm
on the Adaptall 2 P/KA mount and it works fine in all auto modes
(my standard is the P - Hyper-Program mode) when set to AE.

Click to expand...

Brett, I set to AE, and took a shot out of the window. The exposure was 1/4, and when I looked at 'information' it told me that the aperture was f4. (wide open on this lens)

I've tried a few experiments, and it always seems to shoot wide open when set to AE.

The correct exposure for the shot was 1/90; this was using 'manual' and the green button, and this exposure was confirmed by a hand held meter.

BTW, on the read out I get F--- for AV; this is the same as with my screw mount manuals so I'm concluding that this Tamron lens is subject to similar limitations.

I'm actually not very good at this stuff, and sometimes can't figure out what's amiss.

Regards

Francis

jeffkrol said:

Probably fungus on one of the elements in the lens.

Click to expand...

Now that would be an easy problem to diagnose! The lens is clean, and your hypothesis does not explain why the problem disappears when the TC is used.

Personally I'm beginning to suspect something like reflection off the sensor. Pure speculation but I can't think of anything else. The rear element of the TC is different to the lens's, so it's not a problem then. But if this is the case, why has noone else had this problem? It's a puzzler, but I'm not too worried, the macro results with this combo are great. Quality suffers for longer distance shots though.

David

Davidavid said:

Davidavid said:

Probably fungus on one of the elements in the lens.

Click to expand...

Now that would be an easy problem to diagnose!

Click to expand...

Sometimes. I've seen tiny perfect little colonies in one of the elements buried deep in a lens that was not really naked eye visible. Not that it would affect the lens much. Maybe element seperation or misalignment problem. I'm just working with you here. I've never seen anyone here w/ the same problem. Regardless of the cause it still seems to point to a lens problem to me.

Davidavid said:

The lens is clean,
and your hypothesis does not explain why the problem disappears
when the TC is used.

Click to expand...

Maybe it isn't as obvious as you get more light falloff w/ the teleconverter.
Seems similar to the stopping down effects.

Davidavid said:

Personally I'm beginning to suspect something like reflection off
the sensor. Pure speculation but I can't think of anything else.
The rear element of the TC is different to the lens's, so it's not
a problem then. But if this is the case, why has noone else had
this problem? It's a puzzler, but I'm not too worried, the macro
results with this combo are great. Quality suffers for longer
distance shots though.

Click to expand...

I consider my 90 1:2 older manual focus lens as one of the sharpest I personally own. Little flair,little CA,tack sharp.



I know I cause more problems than the lens

Davidavid said:

David

Click to expand...

Francis E said:

Francis E said:

Francis, I don't know about the 70-210 but I have the Tamron SP17mm
on the Adaptall 2 P/KA mount and it works fine in all auto modes
(my standard is the P - Hyper-Program mode) when set to AE.

Click to expand...

Brett, I set to AE, and took a shot out of the window. The exposure
was 1/4, and when I looked at 'information' it told me that the
aperture was f4. (wide open on this lens)

I've tried a few experiments, and it always seems to shoot wide
open when set to AE.

The correct exposure for the shot was 1/90; this was using 'manual'
and the green button, and this exposure was confirmed by a hand
held meter.

BTW, on the read out I get F--- for AV; this is the same as with my
screw mount manuals so I'm concluding that this Tamron lens is
subject to similar limitations.

I'm actually not very good at this stuff, and sometimes can't
figure out what's amiss.

Regards

Francis

Click to expand...

Francis,

You are right, it sounds like the limitations of that particular lens means you don't have AV/TV auto exposure modes. Of course f4 might be selected correctly by the camera if the light conditions aren't bright enough.. have you tried in brighter conditions? In P mode can you adjust the displayed aperture setting by using the thumb wheel?

My Tamron SP17 (with AE setting -- and for that matter my Zeiss 28mm with A setting and Pentax 50/1.4 with A setting) all work correctly as per the modern AF lenses. Also the AV value is properly displayed when viewed in the camera and in the Pentax Browser software. That would indicate to me that it is fault of your lens and not the Adaptall P/KA mount. If I understand correctly however it is working fine for you when using the green button stop down metering for Manual lenses? --- an inconvenient solution for you though I am sure.

Brett

Hi, Brett,

Brett St Pierre wrote:
Of course f4 > might be selected correctly by the camera if the light conditions

Brett St Pierre said:

aren't bright enough.. have you tried in brighter conditions?

Click to expand...

I actually tried setting the program line to 'depth' and 'sensitivity correction' to on, and it then worked in P mode because the ISO altered to 1600. We're in the middle of Winter here and the light conditions today weren't good which is why it was selecting f4 but there was no matching aperture at ISO 200 which is my default.

In P

Brett St Pierre said:

mode can you adjust the displayed aperture setting by using the
thumb wheel?

Click to expand...

No, the aperture value doesn't show, but the PV does. I understood that the AE mode on these lenses was 'shutter priority'.

When I'm not in AE mode, I adjust the aperture manually on the lens.

I've actually got two Tamron Adaptall 70~210s, the 3.5~4 and the 4~5.6 and both behave in the same way, so what's happening is a design limitation of the lenses.

I actually shoot Manual and Green Button quite a lot with my screw mount lenses, so it's not really a bother.

Thanks for the help, I really appreciate it.

Regards

It is likely your Tamron KA adapter is failing. The "AE" pin (contact) in the adapter gets pushed up and stuck in its insulator. If the pin is nearly flush with the face of the adapter, it is stuck. It can be fixed but requires disassembly of the adapter. It happens on lots of the KA adapters and appears to be a result of the insulator hole being slightly too small for the pin. If the pin is stuck it either makes intermittent contact (unreliable exposure setting) or no contact (the lens behaves as if the adapter was a plain "K" type).

Francis E said:

Francis E said:

Francis, I don't know about the 70-210 but I have the Tamron SP17mm
on the Adaptall 2 P/KA mount and it works fine in all auto modes
(my standard is the P - Hyper-Program mode) when set to AE.

Click to expand...

Brett, I set to AE, and took a shot out of the window. The exposure
was 1/4, and when I looked at 'information' it told me that the
aperture was f4. (wide open on this lens)

I've tried a few experiments, and it always seems to shoot wide
open when set to AE.

The correct exposure for the shot was 1/90; this was using 'manual'
and the green button, and this exposure was confirmed by a hand
held meter.

BTW, on the read out I get F--- for AV; this is the same as with my
screw mount manuals so I'm concluding that this Tamron lens is
subject to similar limitations.

I'm actually not very good at this stuff, and sometimes can't
figure out what's amiss.

Regards

Francis

Click to expand...

Bruce Kolber said:

It is likely your Tamron KA adapter is failing. The "AE" pin
(contact) in the adapter gets pushed up and stuck in its insulator.
If the pin is nearly flush with the face of the adapter, it is
stuck. It can be fixed but requires disassembly of the adapter.
It happens on lots of the KA adapters and appears to be a result of
the insulator hole being slightly too small for the pin. If the
pin is stuck it either makes intermittent contact (unreliable
exposure setting) or no contact (the lens behaves as if the adapter
was a plain "K" type).

Click to expand...

Where is this pin?

I only see the 3 obvious contacts on the bottom. Center ball bearing contact w/ a flat pin contact on l and r side of it which are quite flush w/ black plastic insulator. Black "a" lock buttom on side seems fine.Got any "exploded" diagrams of mount per chance?
From my earlier post.

Had a problem w/ improper registration with 2 mounts where they don't make good electrical contact w/ the camera. Light twist on the lens barrel and it's fine. Aalways thought my old Superprogram was at fault but it popped up on the ist-d as well.