Super Takumar 50mm/f1.4 vs. Pentax-A 50mm/f2.0

I recently acquired a Pentax K10D digital SLR. Love it!

 

I have the 18-55m kit lens, but I also have several Pentax or Pentax-mount

lenses for my film cameras.

 

In particular, I have a Super-Takumar 50mm/f1.4 from my Spotmatic and a Pentax-

A 50mm/f2 from a Pentax P5.

 

Aside from the one-stop difference, and the fact that one is a KA mount, while

the S-T is an M42 screw-mount, are these lenses optically similar? I know that,

during the transition from the screw-mount to the K-mount eras, several former

screw-mount lenses were merely given a bayonet mount, but were otherwise

identical to the older lenses.

 

 

Super-Takumar 50mm/f1.4.

 

M42 screw-mount, requires adapter to use on K10D (I have one).

 

Stop-down metering only.

 

Not multi-coated.

 

This lens has long been highly regarded as one of Pentax' best ever lenses.

 

 

 

Pentax-A 50mm/f2.0.

 

Super-Multi-Coated (I think??).

 

KA mount, with electrical contacts, so only function lost is auto-focus.

 

No adapter required.

 

Physically a little smaller than the S-T.

 

I'm going to run some test shots with both lenses, but I was wondering if

anyone has any information they would like to share.

 

Thanks,

Paul Noble

Not being real familiar with the m42 Tak, I'm going to guess they aren't optically identical. Comparing the K-mount variants, the 50mm f/1.4, f/1.7, f/2, and f/2.8 variants all have different designs in terms of # of elements/groups. I can only assume that your question is which of the two you should use. Convenience & size vs. speed and <i>possible</i> optical superiority. Perhaps your own tests would best verify that last point to your satisfaction.

Is the screw mount 50mm or 55mm? I never owned a screwmount f/1.4 lens, but I have an f/1.8 Super-Tak and an f/2 Super-Tak and they are both 55mm.

 

Just curious...

I have used the SMC A 50/f2. Its an ok lens but nothing spectacular. The SMC A 50/f1.7 is a bit better as is the SMC M 50/f1.4.

I have the S-M-C 50mm f1.4 screw mount.. It's damn sharp! Loves taking pictures on my K10D with the Roxsen adapter.

 

I also have the SMC 50mm f1.7 K-mount.. It too is damn sharp!

Matthew, the screw mount Super Takumar is a 50mm. I also have the 55mm/f1.8. Back in the day, the Spotmatic was available with either the 55/1.8 or the 50/1.4, which cost about $50 more, IIRC. I was in high school, working as a busboy for about $1.10 per hour, so I bought the less expensive lens. I got the 50/1.4 from eBay a couple of years ago. It is not one of the radioactive ones that turns yellow with age.

 

As a former Spotmatic user (that's what I learned on), stop-down metering doesn't bother me.

 

BTW, my adapter is a third-party brand (don't remember the name) and the spring clip fell off, so I just leave it on the lens now. The fit is tight enough that the lack of a locking spring doesn't seem to pose a danger of the lens falling off.

 

Paul Noble

You will definetly have more raport with the K mount lens. I have the Super-Tak 1.4 which is really good (by all measures) but I find the adaptor is just too much hassle. And I have the Pentax adaptor.

I leave my third-party adapter on the lens all the time. As such, it acts very much like a k-mount lens, at least as far as mounting and removing it.

 

I guess I'll just have to experiment to find out which one I like best.

 

Paul Noble