[Kozlok]

If you want small, save up a bit and get a used 40XS. The thinnest lens you can mount on Pentax.

The 55/1.8 or 55/2 is hands-down the best lens for ~$50. I have the Takumar version, but the K-mount ones are also cheap.

[kypfer]

If you're up for a bit of handiwork and don't mind a fully manual aperture, the Prakticar 50mm f/2.4 is 7/8" thick when set to infinity and a lot easier to use than an Industar-50!


See here Pentacon Pancake on a Pentax! for my "adaption" of this under-rated lens

[Wasp]

The Pentax-m 50mm F1.7 seems to be the obvious choice here, Both cheap and thin and great IQ. I like focussing better than with the Pentax-a primes.

What he said.

You can't go wrong with an f/1.7. Cheaper and smaller than the f/1.4. Some say sharper as well. AFAIK as I know the A and M are identical internally, so it down to whether you like the more solid feel of the M or want the full program exposure that the A gives you.

[Dipsoid]

Don't want an ME; dial for shutter speed control > push buttons.

I think I'm on the hunt for an M 50 1.7.

Yeah, you want a MX then, I'd keep on the lookout for an MX anyway, I've seen them sold with a 50 for 125$ or so. I curse the late 70s-80s era industrial design, where everything started becoming plastic and push buttons became the norm. The ME Super would have been so much better with a shutter speed dial. It shouldn't be hard to find a 50 1.7 for cheap. Make sure you get an M version, the aperture ring is much better.

[WPRESTO]

Don't want an ME; dial for shutter speed control > push buttons.

I think I'm on the hunt for an M 50 1.7.

Check the offering by MightyMike in the for-sale thread I think he has both an "A" and an "M" version of the f1.7 posted.

[pres589]

Lots of good feedback and participation. Seems odd that I keep getting the "Get a DA 40 XS!" suggestion. I already own one, I can't use it on my film camera, I own an M 40 2.8, I want something f2 or faster. The Pentacon 50 looks pretty great but it doesn't meet the basic requirements I've listed.

I'll contact Mighty Mike when I get a moment.

[stevebrot]

Right now I'm using a Ricoh XR7. I may go looking for a mechanically control camera like a Cosina CS-3 or similar but that's down the road.

Your XR7 has full metered manual, it that is your pleasure. If full mechanical is your poison, Pentax KM would be my choice...a step down from the KX...basically a K-mount version of the Spotmatic F with modern batteries.


Steve

[pres589]

Wanting a camera with LED display for exposure instead of a needle. I'm being picky again.

[ramseybuckeye]

You may be lucky enough to find a Pentax-F 50mm F1.7 for that price, 1.2 inches long, sharp, fast autofucus.

[Not a Number]

The Pentax-m 50mm F1.7 seems to be the obvious choice here, Both cheap and thin and great IQ. I like focussing better than with the Pentax-a primes.

The M or A f/1.7 would be my choice. Small, inexpensive and great IQ. Which 50mm prime does the Pentax Auto Bellows M/A instruction manual recommend? Not the f/1.4 - indeed it advises you not to use them. The f/1.7 are the lenses of choice.

The aperture ring flaw on the "A" is not a problem if you leave it set in "A" mode.

[pres589]

I'm using a body that cannot control the aperture. Ergo, the A 50 1.7 isn't of interest, as the aperture ring seems problematic.

I realized that I own an F 50 1.7 at some point today and will try that. It's listed as the same length as the M 50 1.7 at 31mm. I don't know if the aperture ring on that lens is a troublesome as the A's or not. I would still prefer an M due to the better focusing ring but this might not be that bad and probably isn't any worse than that of the M 40 I own and am able to use.

[BigMackCam]

I'm using a body that cannot control the aperture. Ergo, the A 50 1.7 isn't of interest, as the aperture ring seems problematic.

I realized that I own an F 50 1.7 at some point today and will try that. It's listed as the same length as the M 50 1.7 at 31mm. I don't know if the aperture ring on that lens is a troublesome as the A's or not. I would still prefer an M due to the better focusing ring but this might not be that bad and probably isn't any worse than that of the M 40 I own and am able to use.

I don't know why, but for some reason I picked up that you preferred the A-series from your first post. I've re-read it, and have no idea where I got that notion from

As someone else already said, the M50/1.7 is an obvious choice - a really excellent lens in every way. But do bear in mind what I said about stopping down a little if you want decent frame-wide performance...

I think *everyone* should own a copy of the M50/1.7. The word "classic" gets over-used, but I think it's appropriate in this sense, when IQ, build quality and cost in the current market are viewed as a whole...

[Not a Number]

The aperture springs on the A f/1.7 are easy enough to fix in a manner that they won't fail again. Some of the lenses in the market place may have already been repaired. And not all of them break.

[cyberjunkie]

I quickly browsed through this thread, cause pancakes have been one of my interests, and unless I missed them, I didn't see two lenses that could interest the OP.
I extensively used the Pentax M 40mm when it was released, and after I collected a few other pancakes.
Apart the two late, plasticky Ricoh's (28mm and 50mm IIRC) that are rare and expensive, there are a few affordable lenses that have something more/different than the Pentax.
The two that come to my mind are both made by Cosina, and probably sold under various brands.
The two I have are a Revuenon 2.8/45mm, and a Porst 2.5/40mm.
Both are as good as the Pentax-M, and both are in PK mount.
I'd say they should perform more or less the same, maybe a touch sharper than the Pentax, which in turn should have better coating.
If you want either a little longer, or a little faster, have a look on Ebay.de.
Sorry, I don't sell mine.
In fact I'm looking for a Voigtlander/Cosina 2/40mm at the right price. It's not so common in PKA mount, and when one comes out it usually does not ship to where I live... so I'm always getting the same results from a couple of Japanese vendors who (IMHO) overprice the lens by at least 100 $/€.
I have been impressed by Porst and Revue lenses, especially Cosina or Tomioka made, and also (albeit to a lower degree) by two cheap 135mm's, made by Enna and Sun. Later offerings were quite inferior, but it's not a rule: I have a late Revuenon/Tomioka 1.4/55mm that has nice MC and the usual very good performance.

Speaking of adapted lenses, if anybody has attempted the conversion to PK of the highly regarded Konika Hexanon 1.8/40mm pancake, please let me know. I have one but I gave up, considering the short register and the pancake form factor. Recently I have seen online a successful Canon or Nikon conversion, so it should be doable..
On digital it should fringe, and be somewhat inferior to the Voigtlander and the Pentax Limited 43mm, but back in its time it was considered the best pancake.

Three other extremely small lenses, though not considered "pancakes", are the Meyer Trioplan 2.9/50mm, old silver Zeiss Tessar 2.8/50mm, and Ludwig Meritar 2.9/50mm.
Not super cheap in M42 mount though, especially the Trioplan.
I got away converting Trioplan and Tessar (both tiny preset lenses) in Altix mount to M39 > M42 > PK.
Infinity is spot on. The process is described in some older post of mine.
IIRC all/most of them are so petite that a 40.5mm hood/cap is way too large!
While the two triplets are bokeh monsters (the Trioplan even has soap bubble bokeh, albeit not as huge as the 100mm), the Tessar is believed to be even better than later versions, but the primitive coating calls for a proper hood, which sort of defeats the choice of such small form factor.

I'm sorry for the OP, it seems pancake fifties faster than f/2.8 can't be found for a cheap price
One word of caution: if you decide to go for an East Germany Tessar or triplet, I'd suggest to stay away from the more recent ones, like a Domiplan or late Tessar.
They were still single coated, and the build, precision of assembly and QC were nowhere near older examples from the same manufacturer. Even after such a long time, I found the "silver/alu" versions definitely better/sharper than zebra and black ones.


One example from a 50mm Trioplan more or less my age (60), though not the usual bokeh ball stuff this time
Shot wide open after sunset. The image sharpens up a lot stopping down.




EDIT:
checked the Internet, and found a few interesting info that I'm going to share with those who happen to have a soft spot for pancakes.
The f/2.5 version is primarily available as Cosina and Porst, but can be also found (not so easily, it's uncommon) as Vivitar VMC.
It really looks like the bastard twin of the Pentax-M, from a little distance they look the same!! Unsurprisingly it was made just a few years after the Pentax.
The 45mm looks a little different (minimally ), and is available as Chinon and Revuenon. Boh have a peculiar dark yellow lettering on the beauty ring. The Chinon brand reinforces my idea that it should be Cosina-made (Chinon didn't make lenses).
There is a review of both optics, quite positive. It appears that the inferior multicoating technology doesn't leave the two pancakes too far behind the Pentax. Sharpness is also quite good, if the lenses are stopped down a little.
At the time of its release the Hexanon tested great, and some magazines compared its performance with some "blue blood" glasses of much higher cost. In controlled lighting the sharpness is first class. Could even outperform the 40mm Limited, but flare is its enemy. Not a lens for late evening/night use with strong light sources within the frame. A short test published on the web shows crisp, very nice images should to shoulder wiith horrible ones, ruined by a disastrous amount of flare! Though the good ones show how the lens nicely matches the sensor of a modern Sony camera. I still like the idea of having it converted to PK...

[stevebrot]

And not all of them break.

With any luck, one of those people with a Pentax-A 50/1.7 having a trouble-free aperture ring will check in...

(...Bueller? ...Bueller? )


Steve

(...has one that technically works, but is cranky as can be...stays in "A" position...)