Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-16-2019, 08:06 PM - 2 Likes   #1
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 37,344
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.
11-16-2019, 08:27 PM   #2
Pentaxian
Aaron28's Avatar

Join Date: Jan 2015
Location: Huntsville, Al
Posts: 5,144
great stuff Steve!! helpful info.....have an ES that I would like to be in 'regular use'
11-16-2019, 10:15 PM   #3
Pentaxian




Join Date: Nov 2007
Location: Western Canada
Posts: 7,406
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
Site Supporter
Site Supporter




Join Date: Jun 2010
Location: Central Coast, CA
Posts: 737
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
Pentaxian
womble's Avatar

Join Date: Apr 2010
Location: Hertfordshire
Photos: Gallery
Posts: 3,179
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
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 37,344
Original Poster
QuoteOriginally posted by womble Quote
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
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 37,344
Original Poster
QuoteOriginally posted by pentaxus Quote
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
Site Supporter
Site Supporter




Join Date: Nov 2015
Photos: Albums
Posts: 2,111
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
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 37,344
Original Poster
QuoteOriginally posted by TwoUptons Quote
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
Pentaxian
womble's Avatar

Join Date: Apr 2010
Location: Hertfordshire
Photos: Gallery
Posts: 3,179
QuoteOriginally posted by stevebrot Quote
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
Site Supporter
Site Supporter




Join Date: Feb 2017
Posts: 451
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
New Member




Join Date: Oct 2020
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, 08:36 PM   #13
Pentaxian
g026r's Avatar

Join Date: Sep 2013
Location: Toronto
Photos: Gallery
Posts: 1,953
QuoteOriginally posted by cigardoc Quote
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.
10-15-2020, 10:08 PM   #14
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 37,344
Original Poster
QuoteOriginally posted by cigardoc Quote
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
New Member




Join Date: Oct 2020
Posts: 5
QuoteOriginally posted by stevebrot Quote
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 itís going to be a brand new thinking process, much more basic but, fortunately, i am acquainted with exposure, so itís just a matter of establishing a workflow.

again, thanks!
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
a/m, aperture, coupler, lens, lenses, mount, pin, position, spotmatic, switch
Thread Tools Search this Thread
Search this Thread:

Advanced Search


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 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 Pentax Film SLR Discussion 2 01-06-2014 04:59 PM
Older third party flashes and Pentax P3 compatibility CanadianPhotoLuddite Pentax Film SLR Discussion 6 04-23-2013 01:56 PM



All times are GMT -7. The time now is 04:54 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top