Spotmatic F, ES, ESII | Third-party Lens Compatibility

stevebrot · 11-16-2019, 08:06 PM - **2 Likes**

Having an operational and recently CLA'ed Spotmatic F in the pool has allowed me some time with its signature feature, that being open-aperture metering with S-M-C/SMC Takumar lenses with stop-down meter support for other lenses. The good news is that the open-aperture feature is robust and effectively allows the Spotmatic F to function similar to the later KM when matched with supporting lenses.1

The mixed news is that backward support with stop-down metering is not universal. I had seen cryptic comments hinting at less-than-broad backward compatibility in various reviews on the SP F, ES, and ESII, but was able to qualify the behavior this last week with a newly CLA'ed body in hand. In summary:

Asahi Super Takumar

Full and transparent stop-down metering compatibility as if the lens were being used on prior model metered Spotmatic bodies
Uncomplicated automatic aperture automation
Uncomplicated use of A/M switch

Non-coupled Bellows and Extension Tubes (Asahi and Third-Party)

Full and transparent stop-down metering compatibility as if it were being used on prior model metered Spotmatic bodies

Third-Party Lenses/Accessories

Mixed compatibility with some lens being full and transparently compatible and others carrying a risk of severe damage to the camera's open-aperture linkage mechanism.
The severity of this risk cannot be overstated.
Details in discussion below.

What does not work and why it matters

The short answer is that using a non-S-M-C/SMC lens has two requirements. The first is that the lens rear clears the couplings used for open-aperture metering. The second is that the aperture actuator pin (if present) be capable of passing through a narrow slot in the aperture ring position coupler without bottoming out or binding. Failure of the first is obvious in its implications (crunch); failure of the second, somewhat less so until it happens.

For most lens with an aperture actuator pin, the pin is challenged by the "slot" well before the lens is fully engaged in the mount. If the pin is too fat, too deep, or aligned too far inboard/outboard, it will catch on the aperture ring position coupler and swing it to the full extent of its travel at which point there will be an abrupt contest of strength between lens and coupler with potential for damage to both; at least this is the case unless the problem is noticed by the user and the attempt to mount aborted.

For cases where the pin is well-aligned, but too deep, it is tempting to attempt a mount with with the A/M switch in the M position using gravity as an assist to keep it in a retracted position through several revolutions until the lens is full seated. While there is potential for success, the larger risk is potential to not be able to clear the coupler for unmount. In such case, the lens will be stuck on the camera with few obvious options for freedom.

To Detect Incompatibility

Use these screening tests at your own risk. I make no guarantee of safety or effectiveness.

First screen for the second issue, actuator pin interference. To do so, slowly screw the lens on to the mount (A/M switch in the "A" position) paying careful attention to any resistance or feeling of scraping. Full interference is expressed by the pin moving the coupler against its tensioning spring. This last is very obvious when it happens and is a clear signal to back off and never attempt to mount that lens again on that camera.

For lenses with outsized rear elements, most should not present an issue if they have adequate clearance to work with Spotmatic models having the traditional mount. This may be assessed on those bodies by examination from the rear with the shutter locked open in "B" mode (use a locking cable release) and the lens with the A/M switch in the M position and the focus at closest position. That should allow the lens to fully seat onto the mount flange with the lens rear well away from the mirror and actuator flipper. Slowly move the focus ring to infinity while confirming clearance.

Doing the same as above is possible with the open-aperture mount, but greater care should be taken at all steps taking note that interference with the aperture ring position coupler may happen well in advance of the lens actually approaching full engagement with the mount face. Because of that interference, it is best to leave the A/M switch in the A position until almost fully seated.

If the above tests are not clear, take the safe route and only use Asahi/S-M-C/SMC Takumar lenses on your camera.

Compatible Third-Party Lenses From My Shelf
These are provided for information only and are not indication of suitability of your lenses on your camera.

Vivitar 28mm f/2.5, ser#22440767
Vivitar 135mm f/2.8, ser#2813776
Vivitar 200mm f/3.5, ser#28401094
MMZ Helios 44-3 58mm f/2.0 (pre-set)
Tamron Adaptall-2 M42 adapter (labeled "for Pentax")
Vivitar Automatic Tele Converter 2X-1 (M42)

Incompatible Third-Party Lenses from My Shelf
While not necessarily an indication of what your results might be, my intuition is that if you have one of these, it probably won't work.

Auto Rikenon 50mm f/1.7 (Tomioka)
Auto Rikenon 55mm f/1.4 (Tomioka)
Auto Mamiya/Sekor 55/1.8 (black finish, ribbed metal grip, black snout with fine chrome edge)
KMZ Helios 44M 58mm f/2.0

Steve

1 Supporting lenses for open-aperture metering on the Spotmatic F, ES, and ESII include most Asahi S-M-C and SMC Takumars as well as Tamron lenses adapted with that brand's ES adapter.

Last edited by stevebrot; 11-17-2019 at 05:21 AM.

Aaron28 · 11-16-2019, 08:27 PM

great stuff Steve!! helpful info.....have an ES that I would like to be in 'regular use'

lesmore49 · 11-16-2019, 10:15 PM

Interesting post. Thank you for the thoroughness of your report. Here's my more limited experience compared to yours .

I have an ES ll bought new around '74 or so. I have two Pentax screw mount lenses, a 50 Tak that came with it and a 135 F 3.5 Tak...which both work great on this camera and also my older S1a.

I also bought in the 1970's , to my regret, a Bushnell 90-230mm and 35mm F 3.5 Bushnell. I believe I saved $ 30 getting the Bushnell 35 over the equivalent 35mm Pentax Tak and it wasn't a worthwhile saving, IMO. The Bushnells were not at the same level as the Takumars.

As a result of this early experience, I've always kept to original manufacturer's lenses until 2013, when I bought a Sigma 150-500, which is an ok lens and while the photos have been good...every lens I've bought since then have been Pentax lenses for Pentax cameras.

Reason, I do have a K1 and realize there is a fitment issues with this Sigma and my K1...the Sigma leaves scratches on the K1 body. I realize I could send it away to Sigma to have this addressed, but it does confirm to me, that I would prefer to continue with my old policy of buying just Pentax lenses for Pentax cameras. Buying 3rd party in my case...always seems to have some disadvantage. I realize my experience might be unusual, not typical of others with 3rd party lenses...and may just come down to bad luck on my part.

As it is I use my K5/ K10D with the 150-500...get more reach that way...with ASP-C vs K1 FF.

**pentaxus** · 11-16-2019, 11:54 PM - **1 Like**

Tamron made an adaptall-2 mount for Pentax ES/Spotmatic F. It worked well for me. I no longer have it but I believe it is labeled mount for ES. There are a lot of nice Tamron SP lenses that can fit on your SPF with that adapter.

womble · 11-17-2019, 02:34 AM

Thanks for the info. I'll play it safe and stick with my Taks. I am very fond of my ES/ESII and really don't want to contribute to their demise.

I have a Tamron zoom with the ES adaptor I used once. I should sell it I guess.

stevebrot · 11-17-2019, 04:55 AM

Originally posted by womble

I have a Tamron zoom with the ES adaptor I used once. I should sell it I guess.

I am not sure why. That adapter allows your Tamron lenses to emulate an SMC lens. It should be quite safe.

Steve

stevebrot · 11-17-2019, 04:58 AM

Originally posted by pentaxus

Tamron made an adaptall-2 mount for Pentax ES/Spotmatic F. It worked well for me. I no longer have it but I believe it is labeled mount for ES. There are a lot of nice Tamron SP lenses that can fit on your SPF with that adapter.

That is quite true and I probably should have explicitly called out that adapter as being compatible. I will update the post.

Steve

**TwoUptons** · 11-17-2019, 05:41 AM

Very handy Steve, thanks for posting.

With the Adaptall mount, that just confirms the aperture linkage won't foul, right?

We would still need to check if the rear elements protrude behind the mount, wouldn't we?

-Eric

stevebrot · 11-17-2019, 06:13 AM

Originally posted by TwoUptons

Very handy Steve, thanks for posting.

With the Adaptall mount, that just confirms the aperture linkage won't foul, right?

We would still need to check if the rear elements protrude behind the mount, wouldn't we?

-Eric

Pretty much, yes.

Steve

womble · 11-17-2019, 09:24 AM - **1 Like**

Originally posted by stevebrot

I am not sure why. That adapter allows your Tamron lenses to emulate an SMC lens. It should be quite safe.

Steve

I only have one Tamron lens which is a mediocre zoom (as most of those early ones were). Nothing to do with not being safe, I just don't use it. Shelf space is at a premium...

Cheers, Kris.

BarneyL · 05-04-2020, 02:58 AM - **1 Like**

If the list is open for additions, I'd like to submit the following:

Compatible:
- Auto Mamiya/Sekor 135mm F/2.8 (there are a few versions of this lens, I'm talking about the latest for TL/DTL cameras)

Not compatible
- Rollei HFT (Zeiss) Sonnar 85mm F/2.8
- Rollei HFT (Zeiss) Planar 50mm F/1.8
- Auto Mamiya/Sekor 55mm F/1.4 (supposedly Tomioka-made)

cigardoc · 10-15-2020, 06:51 PM

hey,

long-time troller, first time poster, here. i have a spf and a new, to me, jupiter 37a. will this lens mount to this camera? thanks for all replies

david

g026r · 10-15-2020, 08:36 PM

Originally posted by cigardoc

long-time troller, first time poster, here. i have a spf and a new, to me, jupiter 37a. will this lens mount to this camera? thanks for all replies

Just going from memory, since it's been a while since I owned a Jupiter-37A, but you should be safe:

It's a manual aperture lens, so no aperture pin to worry about.
The rear element is a fair distance up the lens body itself. Since nothing sticks out beyond mount threads, there's nothing to interfere with the open aperture linkage.

stevebrot · 10-15-2020, 10:08 PM

Originally posted by cigardoc

hey,

long-time troller, first time poster, here. i have a spf and a new, to me, jupiter 37a. will this lens mount to this camera? thanks for all replies

david

Since the J-37a has a preset aperture mechanism, it has no aperture actuator pin to foul your SP F's aperture position coupler. From what I have seen in photos of the rear, there should be little risk of mirror box interference either.

How you choose to meter and shoot will depend on how you decide to use your lens' preset aperture feature and whether shutter speed or a particular aperture setting are more important. Learning will be fun.

Enjoy your lens!

Steve

cigardoc · 10-16-2020, 08:01 PM

Originally posted by stevebrot

Since the J-37a has a preset aperture mechanism, it has no aperture actuator pin to foul your SP F's aperture position coupler. From what I have seen in photos of the rear, there should be little risk of mirror box interference either.

How you choose to meter and shoot will depend on how you decide to use your lens' preset aperture feature and whether shutter speed or a particular aperture setting are more important. Learning will be fun.

Enjoy your lens!

Steve

thanks for your reply.

i took a chance and gingerly screwed the lens on, took much longer than i anticipated, but it worked.

i already shoot a nikon f2as, fe2 and f100, so it’s going to be a brand new thinking process, much more basic but, fortunately, i am acquainted with exposure, so it’s just a matter of establishing a workflow.

again, thanks!

11-16-2019, 08:06 PM - 2 Likes	#1
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Spotmatic F, ES, ESII \| Third-party Lens Compatibility Having an operational and recently CLA'ed Spotmatic F in the pool has allowed me some time with its signature feature, that being open-aperture metering with S-M-C/SMC Takumar lenses with stop-down meter support for other lenses. The good news is that the open-aperture feature is robust and effectively allows the Spotmatic F to function similar to the later KM when matched with supporting lenses.1 The mixed news is that backward support with stop-down metering is not universal. I had seen cryptic comments hinting at less-than-broad backward compatibility in various reviews on the SP F, ES, and ESII, but was able to qualify the behavior this last week with a newly CLA'ed body in hand. In summary: Asahi Super Takumar Full and transparent stop-down metering compatibility as if the lens were being used on prior model metered Spotmatic bodies Uncomplicated automatic aperture automation Uncomplicated use of A/M switch Non-coupled Bellows and Extension Tubes (Asahi and Third-Party) Full and transparent stop-down metering compatibility as if it were being used on prior model metered Spotmatic bodies Third-Party Lenses/Accessories Mixed compatibility with some lens being full and transparently compatible and others carrying a risk of severe damage to the camera's open-aperture linkage mechanism. The severity of this risk cannot be overstated. Details in discussion below. What does not work and why it matters The short answer is that using a non-S-M-C/SMC lens has two requirements. The first is that the lens rear clears the couplings used for open-aperture metering. The second is that the aperture actuator pin (if present) be capable of passing through a narrow slot in the aperture ring position coupler without bottoming out or binding. Failure of the first is obvious in its implications (crunch); failure of the second, somewhat less so until it happens. For most lens with an aperture actuator pin, the pin is challenged by the "slot" well before the lens is fully engaged in the mount. If the pin is too fat, too deep, or aligned too far inboard/outboard, it will catch on the aperture ring position coupler and swing it to the full extent of its travel at which point there will be an abrupt contest of strength between lens and coupler with potential for damage to both; at least this is the case unless the problem is noticed by the user and the attempt to mount aborted. For cases where the pin is well-aligned, but too deep, it is tempting to attempt a mount with with the A/M switch in the M position using gravity as an assist to keep it in a retracted position through several revolutions until the lens is full seated. While there is potential for success, the larger risk is potential to not be able to clear the coupler for unmount. In such case, the lens will be stuck on the camera with few obvious options for freedom. To Detect Incompatibility Use these screening tests at your own risk. I make no guarantee of safety or effectiveness. First screen for the second issue, actuator pin interference. To do so, slowly screw the lens on to the mount (A/M switch in the "A" position) paying careful attention to any resistance or feeling of scraping. Full interference is expressed by the pin moving the coupler against its tensioning spring. This last is very obvious when it happens and is a clear signal to back off and never attempt to mount that lens again on that camera. For lenses with outsized rear elements, most should not present an issue if they have adequate clearance to work with Spotmatic models having the traditional mount. This may be assessed on those bodies by examination from the rear with the shutter locked open in "B" mode (use a locking cable release) and the lens with the A/M switch in the M position and the focus at closest position. That should allow the lens to fully seat onto the mount flange with the lens rear well away from the mirror and actuator flipper. Slowly move the focus ring to infinity while confirming clearance. Doing the same as above is possible with the open-aperture mount, but greater care should be taken at all steps taking note that interference with the aperture ring position coupler may happen well in advance of the lens actually approaching full engagement with the mount face. Because of that interference, it is best to leave the A/M switch in the A position until almost fully seated. If the above tests are not clear, take the safe route and only use Asahi/S-M-C/SMC Takumar lenses on your camera. Compatible Third-Party Lenses From My Shelf These are provided for information only and are not indication of suitability of your lenses on your camera. Vivitar 28mm f/2.5, ser#22440767 Vivitar 135mm f/2.8, ser#2813776 Vivitar 200mm f/3.5, ser#28401094 MMZ Helios 44-3 58mm f/2.0 (pre-set) Tamron Adaptall-2 M42 adapter (labeled "for Pentax") Vivitar Automatic Tele Converter 2X-1 (M42) Incompatible Third-Party Lenses from My Shelf While not necessarily an indication of what your results might be, my intuition is that if you have one of these, it probably won't work. Auto Rikenon 50mm f/1.7 (Tomioka) Auto Rikenon 55mm f/1.4 (Tomioka) Auto Mamiya/Sekor 55/1.8 (black finish, ribbed metal grip, black snout with fine chrome edge) KMZ Helios 44M 58mm f/2.0 Steve 1 Supporting lenses for open-aperture metering on the Spotmatic F, ES, and ESII include most Asahi S-M-C and SMC Takumars as well as Tamron lenses adapted with that brand's ES adapter. Last edited by stevebrot; 11-17-2019 at 05:21 AM.

10-15-2020, 08:36 PM	#13
g026r Pentaxian Join Date: Sep 2013 Location: Toronto Photos: Gallery Posts: 2,074	Originally posted by cigardoc long-time troller, first time poster, here. i have a spf and a new, to me, jupiter 37a. will this lens mount to this camera? thanks for all replies Just going from memory, since it's been a while since I owned a Jupiter-37A, but you should be safe: It's a manual aperture lens, so no aperture pin to worry about. The rear element is a fair distance up the lens body itself. Since nothing sticks out beyond mount threads, there's nothing to interfere with the open aperture linkage.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Question Spotmatic ES Reviews Page : lens compatibility note	stevebrot	Site Suggestions and Help	3	07-21-2019 08:41 PM
K 1 ll and third party lens compatibility.	Terry C	Pentax K-1 & K-1 II	10	05-15-2018 07:27 AM
Third Party Lens Compatibility - M42 Mount	pendennis	Pentax SLR Lens Discussion	14	12-27-2017 06:49 AM
ES / ESII case	womble	Film SLRs and Compact Film Cameras	2	01-06-2014 04:59 PM
Older third party flashes and Pentax P3 compatibility	CanadianPhotoLuddite	Film SLRs and Compact Film Cameras	6	04-23-2013 01:56 PM

11-16-2019, 08:27 PM	#2
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 7,131	great stuff Steve!! helpful info.....have an ES that I would like to be in 'regular use'

11-16-2019, 10:15 PM	#3
lesmore49 Pentaxian Join Date: Nov 2007 Location: Western Canada Posts: 12,344	Interesting post. Thank you for the thoroughness of your report. Here's my more limited experience compared to yours . I have an ES ll bought new around '74 or so. I have two Pentax screw mount lenses, a 50 Tak that came with it and a 135 F 3.5 Tak...which both work great on this camera and also my older S1a. I also bought in the 1970's , to my regret, a Bushnell 90-230mm and 35mm F 3.5 Bushnell. I believe I saved $ 30 getting the Bushnell 35 over the equivalent 35mm Pentax Tak and it wasn't a worthwhile saving, IMO. The Bushnells were not at the same level as the Takumars. As a result of this early experience, I've always kept to original manufacturer's lenses until 2013, when I bought a Sigma 150-500, which is an ok lens and while the photos have been good...every lens I've bought since then have been Pentax lenses for Pentax cameras. Reason, I do have a K1 and realize there is a fitment issues with this Sigma and my K1...the Sigma leaves scratches on the K1 body. I realize I could send it away to Sigma to have this addressed, but it does confirm to me, that I would prefer to continue with my old policy of buying just Pentax lenses for Pentax cameras. Buying 3rd party in my case...always seems to have some disadvantage. I realize my experience might be unusual, not typical of others with 3rd party lenses...and may just come down to bad luck on my part. As it is I use my K5/ K10D with the 150-500...get more reach that way...with ASP-C vs K1 FF.

11-16-2019, 11:54 PM - 1 Like	#4
pentaxus Site Supporter Join Date: Jun 2010 Location: Central Coast, CA Posts: 1,313	Tamron made an adaptall-2 mount for Pentax ES/Spotmatic F. It worked well for me. I no longer have it but I believe it is labeled mount for ES. There are a lot of nice Tamron SP lenses that can fit on your SPF with that adapter.

11-17-2019, 02:34 AM	#5
womble Pentaxian Join Date: Apr 2010 Location: Hertfordshire Photos: Gallery Posts: 4,324	Thanks for the info. I'll play it safe and stick with my Taks. I am very fond of my ES/ESII and really don't want to contribute to their demise. I have a Tamron zoom with the ES adaptor I used once. I should sell it I guess.

11-17-2019, 04:55 AM	#6
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007 Original Poster	Originally posted by womble I have a Tamron zoom with the ES adaptor I used once. I should sell it I guess. I am not sure why. That adapter allows your Tamron lenses to emulate an SMC lens. It should be quite safe. Steve

11-17-2019, 04:58 AM	#7
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007 Original Poster	Originally posted by pentaxus Tamron made an adaptall-2 mount for Pentax ES/Spotmatic F. It worked well for me. I no longer have it but I believe it is labeled mount for ES. There are a lot of nice Tamron SP lenses that can fit on your SPF with that adapter. That is quite true and I probably should have explicitly called out that adapter as being compatible. I will update the post. Steve

11-17-2019, 05:41 AM	#8
TwoUptons Loyal Site Supporter Join Date: Nov 2015 Photos: Albums Posts: 4,215	Very handy Steve, thanks for posting. With the Adaptall mount, that just confirms the aperture linkage won't foul, right? We would still need to check if the rear elements protrude behind the mount, wouldn't we? -Eric

11-17-2019, 06:13 AM	#9
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007 Original Poster	Originally posted by TwoUptons Very handy Steve, thanks for posting. With the Adaptall mount, that just confirms the aperture linkage won't foul, right? We would still need to check if the rear elements protrude behind the mount, wouldn't we? -Eric Pretty much, yes. Steve

11-17-2019, 09:24 AM - 1 Like	#10
womble Pentaxian Join Date: Apr 2010 Location: Hertfordshire Photos: Gallery Posts: 4,324	Originally posted by stevebrot I am not sure why. That adapter allows your Tamron lenses to emulate an SMC lens. It should be quite safe. Steve I only have one Tamron lens which is a mediocre zoom (as most of those early ones were). Nothing to do with not being safe, I just don't use it. Shelf space is at a premium... Cheers, Kris.

05-04-2020, 02:58 AM - 1 Like	#11
BarneyL Pentaxian Join Date: Feb 2017 Posts: 899	If the list is open for additions, I'd like to submit the following: Compatible: - Auto Mamiya/Sekor 135mm F/2.8 (there are a few versions of this lens, I'm talking about the latest for TL/DTL cameras) Not compatible - Rollei HFT (Zeiss) Sonnar 85mm F/2.8 - Rollei HFT (Zeiss) Planar 50mm F/1.8 - Auto Mamiya/Sekor 55mm F/1.4 (supposedly Tomioka-made)

10-15-2020, 06:51 PM	#12
cigardoc New Member Join Date: Oct 2020 Photos: Albums Posts: 5	hey, long-time troller, first time poster, here. i have a spf and a new, to me, jupiter 37a. will this lens mount to this camera? thanks for all replies david

10-15-2020, 10:08 PM	#14
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007 Original Poster	Originally posted by cigardoc hey, long-time troller, first time poster, here. i have a spf and a new, to me, jupiter 37a. will this lens mount to this camera? thanks for all replies david Since the J-37a has a preset aperture mechanism, it has no aperture actuator pin to foul your SP F's aperture position coupler. From what I have seen in photos of the rear, there should be little risk of mirror box interference either. How you choose to meter and shoot will depend on how you decide to use your lens' preset aperture feature and whether shutter speed or a particular aperture setting are more important. Learning will be fun. Enjoy your lens! Steve

10-16-2020, 08:01 PM	#15
cigardoc New Member Join Date: Oct 2020 Photos: Albums Posts: 5	Originally posted by stevebrot Since the J-37a has a preset aperture mechanism, it has no aperture actuator pin to foul your SP F's aperture position coupler. From what I have seen in photos of the rear, there should be little risk of mirror box interference either. How you choose to meter and shoot will depend on how you decide to use your lens' preset aperture feature and whether shutter speed or a particular aperture setting are more important. Learning will be fun. Enjoy your lens! Steve thanks for your reply. i took a chance and gingerly screwed the lens on, took much longer than i anticipated, but it worked. i already shoot a nikon f2as, fe2 and f100, so it’s going to be a brand new thinking process, much more basic but, fortunately, i am acquainted with exposure, so it’s just a matter of establishing a workflow. again, thanks!