[Peter308]

Firstly, let me introduce myself. I am a keen photographer of some 30 years and shoot a mix of film and digital in 35mm and MF, using both SLR and rangefinders. To date I only briefly flirted with Pentax (an SFXn) but want to now experience an MX.

So regarding lens, if you were to choose only 3 primes for the MX to cover a range of Shooting situations, balancing quality, price and size, what would they be?

Thanks

[Wild Mark]

This would be my kit


SMC Pentax-M 24-35mm F3.5 (neat wide angle kit)

SMC Pentax-M 50mm F1.4 (normal with speed for indoor use when needed)

SMC Pentax-M 100mm 2.8 (lovely compact short tele with excellent IQ)

[Sandy Hancock]

Quality, price and size? You can't have everything

K28/2.0
A50/1.2
A*135/1.8

[Wild Mark]

Quality, price and size? You can't have everything

K28/2.0
A50/1.2
A*135/1.8

A wonderful contrarian option

[boriscleto]

SMC Pentax-M 28mm F/2
SMC Pentax-M 40mm F/2.8
SMC Pentax-M 120mm F/2.8

[pathdoc]

28/50/135. I have a Vivitar 28/2.8 I inherited from my late father in law, a Pentax A 50/2.0 likewise, and a M 135/3.5 I bought for myself. I have considered several times getting an M 50/1.4, but I have an FA 50/1.4 if I really need something that fast (and the focusing is good enough at a pinch) and a Rikenon 55/1.2 if I absolutely have to have the ultimate in speed.

(I also have the 40/2.8 Boriscleto mentioned above, but I find that more useful on my ME.)

Depending on my interests and whether I lived in a sunny climate, I might be tempted to make the fifty a macro. If not, then an investment in high-quality extension tubes with aperture coupling should be considered, if you don't have them already.

If you're having trouble finding a set of genuine coupled extension tubes, buy some really cheap, terrible secondhand extension tubes teleconverters in 1.4X, 2X and even 3X, and deglass them. This is not a difficult process, and can be done nondestructively; the optical elements unscrew from the back in most cases, though you may need a spanning wrench (or crib with a cheap set of compasses from a stationery store) to get things started.

[baro-nite]

Two lenses I own and consider a great match for the MX are the Pentax-M 28/2.8 (older version) and Pentax-M 50/1.7. Same vintage as the MX, and both are very compact, sharp when stopped down a bit, and easy and cheap to buy. I don't have any of the M-series telephoto lenses so I'll leave that to others to recommend.

[timw4mail]

Quality, price and size? You can't have everything

K28/2.0
A50/1.2
A*135/1.8

Why bother getting the more expensive A 50? a K50/1.2 would suffice.

My Three:

• K/M 28/3.5
• K/A 50/1.2
• K/M 135/2.8

Isn't this like a standard set of three primes? 28,50,135?

[twilhelm]

Yes, my first set of primes was a 28,50,135 and I still have and use them with my ME.

For size, weight and cost, the M series wins out with the 28 3.5, 50 1.7 and 135 3.5.

[Mistral]

My kit was:
K 18 f/3.5
M 50 f/1.4
M 100 f/2.8]

[pathdoc]

given the small size of the MX, you might find it a little unbalanced.

I'll second that. I have the Pentax-M 80-200 f/4.5 and find that quite awkward on the M bodies (ME, MX). (No, I don't have an MX winder, though if the OP gets one that may make handling a fair bit easier.)

OTOH the M 135/3.5 is one of the most compact primes (length and diameter-wise) of that focal length in my possession, doesn't weigh much either, and fits right into the middle of that focal range.

I know an alternative kit when zooms started getting half-decent optically was 28/50/80-200, but OP is looking for primes, and a 200mm prime lens next to a 50 might be just a little bit too much gap between the focal lengths. And I would worry that 100mm (as suggested by Mistral) wasn't nearly quite enough.

[twilhelm]

There’s a lot of agreement here on the primes, but possibly my favorite zoom for my ME is the 24-50. Perfect size and great image quality for film.

[stevebrot]

This is the kit I purchased in 1982 for my similarly-sized Ricoh XR-7:

• Pentax-M 50/1.7
• Tamron 28/2.5 (02B)
• Tamron 70-150/3.5 (20A)

The above were chosen for the combination of compactness and performance and I still own and use all three. The kit of all three plus PK adapter can be had for about $80 USD on today's market. My cost in 1982 was considerably more. The photo below was taken a few weeks ago with the Tamron zoom on my K-3.



Pentax K-3, Tamron 70-150/3.5 (20A)

Addendum: If all must be primes, I would slip in a Vivitar 135/2.8 to replace the zoom. Get the 5-element Komine-made version (serial #28xxxxxxxxxx) with 8 aperture blades. I know...Vivitar sounds soooo pedestrian, but it is pretty hard to build a bad 135mm. Performance is on a par with the M 135/3.5 and the extra 2/3 stop maximum aperture helps with focusing. Price would be about the same. Changed my mind. The Komine-made lens is rather rare in K-mount and my favorable impression is of the 5-element version...even rarer in K-mount.


Steve

[stevebrot]

If you want more tele range, the A 70-210mm is also a nice affordable option.

It is also a strong performer. It is a little heavy on the small body, but still well-balanced. I think I paid $30 USD for mine this last Spring.

BTW...I strongly agree with the recommendation of the M 50/1.7 over the M 50/1.4.


Steve

[monochrome]

M28/3.5
M50/1.4
M85/2

optional / substitute

M24~35//3.5
M100/2.8
M135/3.5
M150/3.5*

* less we’ll known ‘sleeper’ lens.