[mlag]

You are referencing prime lenses from a period when zoom lenses quality was not great. Thus many prime lenses with similar (100/105/120//135) mm FL were manufactured.

I own a number of the lenses in your list. You mention the 135/3.5 M as a lens to avoid. I could not disagree more. My copy i have owned from new, and still occasionally use it on digital. It probably represents the best value for money lens in your entire list.

+1
I think in those days it was also the affordable SLR price range for a first, modest prime Tele for the average, private users (no smartphones in those days!), while 200mm+ was more expensive/exotic/for professionals.
Beside that some have a reputation/purpose as macro or portrait lens...., so you would have a normal variant f3.5 and a close focus macro f2.8 and wide open aperture F2.x or F1.x variant of the same/similar focal length. in other words : marketing...
What OP is asking is if they live up to the expectations of being a nice macro, portrait, télé....which might be actually different for each of them!

[Gary H Perth]

I have quite a few of these. My favourites are the M 150mm and the A100mm non-macro. Sitting with these if I need is the K135/3.5. I get great results with all three on my K-1.

Somehow the M135/3.5 just does not excite me., does not seem quite sharp enough compared to the others.

I also have the SMC Takumar 150/4, just magic. From my M42 collection, this and the CZJ Sonnar electric would be supreme favourites on this range.

An alternative single purchase is the A 70-210 zoom, which is close to all these primes in image quality when the light is good and you can stop it down. And mostly is cheaper than almost any one of these primes.

[Papa_Joe]

Just for the sake of completeness.
The A 100 mm/f=4.0 is missing in the list.

By the way, for those who want to close the gap in their collection, there is an A* 135mm/f=1.8 on sale at our local shop in Ulm (Germany). Price is 1,349.00 EUR.

[Wasp]

Of the ones on the list, I have the following:

• M 100/2.8
• M 100/4 macro
• K 135/3.5
• K 135/2.5

They are all great - each in its own way - so there is no need to get any more of them. I think. Hang on, the A 135/1.8 would be great...

The wide variety probably points back to an era when a 135mm was the second lens that everyone bought.

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Last edited by Wasp; 03-07-2023 at 08:20 AM.

[jjjfff]

Thank you all for your comment. No one said: you have enough, don't buy anymore!

I've updated the table to show up and down votes in the comments for each lens. The lenses are reviewed on this site and not always in the same way as the small sample in this thread, with old second-hand lenses there's always a chance of unit-to-unit variation anyways, but this table helps me make more sense of the ecosystem as a whole.

I'll keep my eyes open for a K105 (though it has middling reviews and I think it's rare), maybe a M120 for travel and I'm curious about the 150s now...

J.

[Gene D]

Big fan of the K 135 f2.5...actually started using it to shoot some concerts (wide aperture, fast shutter, high ISO on my KP, spot metered, burst and auto white etc..) and while a bit challenging with manual focus accuracy, the keepers are great. There is something about how it renders the colors. Next one down for me is the K 85mm f1.8 which is amazing, so nothing in-between. Hard to imagine these nearly 50 year-old lenses producing this quality and adapting so well to the newer Pentax bodies. Great thread.

[GUB]

Thank you all for your comment. No one said: you have enough, don't buy anymore!

I've updated the table to show up and down votes in the comments for each lens. The lenses are reviewed on this site and not always in the same way as the small sample in this thread, with old second-hand lenses there's always a chance of unit-to-unit variation anyways, but this table helps me make more sense of the ecosystem as a whole.

I'll keep my eyes open for a K105 (though it has middling reviews and I think it's rare), maybe a M120 for travel and I'm curious about the 150s now...

J.

The Takumar Bayonet 135mm 2.5/2.8 really should have its own column - it is quite distinct from the K 135mm 2.5.
It will attract the most likes AND dislikes of all. Personally I rate it as the best "bang for buck" of all and it is up there with the sharpest 135.

[UncleVanya]

The Takumar Bayonet 135mm 2.5/2.8 really should have its own column - it is quite distinct from the K 135mm 2.5.
It will attract the most likes AND dislikes of all. Personally I rate it as the best "bang for buck" of all and it is up there with the sharpest 135.

Agreed. The k SMC 135 2.5 is very different optically from the Takumar Bayonet. I’ve seen tests where that Takumar f2.5 was pretty amazing but most people dislike it(many without trying it). Every test of the SMC f2.5 has shown excellent results as I recall.

[gofour3]

But I can't make sense of all the K, M and A lenses in the 100mm-150mm range (15 I think), did we need so many?

The main reason there are so may lenses in that focal range, is that each Pentax lens series also had a new range of camera bodies which the lenses were designed around.

Sure the K Series lenses were all that was really needed until auto-focus cameras came along, but having new lenses to accompany new cameras meant more sales for Pentax.


The bigger K Series lenses match perfectly with the bigger K Series film bodies.
The smaller M Series lenses match up perfectly with the smaller M Series film cameras.
The A Series lenses have the "A" aperture setting, which take advantage of the new programmed A Series film bodies.

I've got the K100/4 Macro, K105/2.8, K120/2.8, K135/2.5, K135/3.5, K150/4, M100/2.8, A100/2.8 Macro and the A*135/1.8. I can recommend all of them.


Phil.

[UncleVanya]

I have all the M series lenses on the list. M120 is my favorite of them. M150 is also very good. I do like 3D feeling of M135, but sharpness is not quite what I'd like. Macro is excellent when you need to get close, but in normal shooting distances not on the level of M120. M100/2.8 is the weakest of them due to lack of sharpness and I don't use it at all anymore.

Odd. My m100 was very good. I have it away years ago however so I can only judge by film results.

[wkraus]

In the 1970s, lens formulas were still being calculated with abacuses…

This is completely wrong. The first computers for calculating lens designs came into use in the 1950s. In the 1970s this was commonplace.

[wkraus]

Odd. My m100 was very good. I have it away years ago however so I can only judge by film results.

More to the point: one has to keep in mind that with lenses this old, and perhaps also due to the manufacturing processes at the time, there is quite some copy variation. My own M100, although quite beaten up after 44 years of use, is very fine and at infinity and larger f-stops clearly better that my A100 f/2.8 Macro which is a great lens too. My first M28 f/2.8 was a little weak but my present copy of the same lens is better.

The Takumar (Bayonet) is an f/2.8 lens in both of its incarnations, although the first one was marked f/2.5. Its four-element design was good enough to be reused in the A135 f/2.8 (but there may have been some tweaks, one never knows). As this was a budget offering, perhaps copy variation was even greater.

[iheiramo]

Odd. My m100 was very good. I have it away years ago however so I can only judge by film results.

There is always sample variation with these old lenses, especially in wide open performance, so I can only judge the lenses I own. M50/1.7 and M100/2.8 were the first vintage primes I bought and in the beginning I was very happy with it. Only after I started to collect M series and compare lenses against each other I became dissatisfied with it, as I had something better in my hand and ability to pixel peep RAW shots. And I believe that M120 is the hidden gem of the M series. Rare, yet cheap, lens that perform extremely well.

[jjjfff]

The Takumar (Bayonet) ..//.. four-element design was good enough to be reused in the A135 f/2.8 (but there may have been some tweaks, one never knows). As this was a budget offering, perhaps copy variation was even greater.

Ah, this makes sense

[jcdoss]

I have the M100f2.8, M100f4.0 Macro, A100f2.8 Macro, K105f2.8, M120f2.8, A*135f1.8, K135f2.5, M135f3.5, and M150f3.5. All of them are capable of very good sharpness and rendering of detail. I'd also recommend them all, and I agree with @iheiramo that the M120 is probably the best in the M series.